VETERINARY
MEDICINE : CETARTIODACTYLA
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Hippopotamidae
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Hippopotamus
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Hippopotamus
amphibius :
Bacillus anthracis
in Southern Africa is generally regarded to be sporadic in hippopotamiref.
An abnormally high mortality among hippos was observed in the Luangwa River
valley, Zambia, in 1987. It was estimated that between June and November
2004, > 4000 deaths were attributed to anthrax. The enzootic status of
the region was confirmed by a field study in 1989ref.
> 200 hippos in 2004 and 23 hippos in 2005 died of anthrax in the Queen
Elizabeth National Park in Uganda, and surrounding livestock at risk have
been vaccinated. As it is not unusual to find cattle being grazed within
National Park boundaries in Africa this is patently a wise thing to do.
In some cases mortality may be the result of the communal scavenging or
"cannibalism" of carcasses of anthrax-killed hippos by other hippos, an
hypothesis appears to be supported by the apparent absence, until quite
recently, of any contemporaneous reports of anthrax deaths among buffalo
or other common wildlife host species, first reported in 1996 (both of
which involved hippos consuming meat from scavenged impala carcasses and
one of which involved a communal feeding episode), then from Lake Malawi
and 2 instances from Tanzania of hippos consuming scavenged wildebeest
carcasses. Video footage from the Luangua Valley of a hippo eating the
gut contents and/or internal organs of a dead buffalo. Mortality in hippos
can be caused by various other infectious, non-infectious, and toxic agents.
There is only one strain of Bacillus anthracis found essentially
in only one species, and that is the one associated with wood bison in
northern Alberta and the Canadian North West Territories. The issue is
not so much species-dependence as behavior-dependence. In those Canadian
areas, there are very few other target species sharing the wood bison areas;
the caribou are elsewhere; wolves have disappeared for unknown reasons;
and only the occasional moose will be affected, as it prefers to feed in
flooded areas. In areas where there is scrub, blow flies and browsers are
involved (i.e. kudu or white tailed deer); grazing animals in open savannah
are rarely afflicted. With these hippos, there is contaminated water involved
as well as, apparently, feeding on infected carcasses. In Africa, contaminated
water, whether in river ponds or in artificial troughs, has long been seen
as a risk to wild and domestic ruminants drinking there. But, with the
activity, they may well be going elsewhere to drink. The outbreaks of anthrax
in hippos in most African ecosystems appear to be density-related. Excessive
densities may be relative (when resources are scarce, as in drought) or
absolute, following optimal climatic conditions when resources are abundant,
and reproductive success and recruitment are high. Excessive densities
frequently result in resource depletion, increased competition, and intra-specific
aggression and conflict. Hippos can be extremely aggressive, and fights
frequently leave the combatants with numerous lacerations, and may be fatal.
Hippo cannibalism has occasionally been reported from different parts of
Africa but is rare and appears to be triggered by stress-induced "displaced"
behavior, or possible nutritional deficiencies or needs. Hippos have a
well developed (partially fermenting) foregut, but they are not ruminants.
They also have a very well developed (fermenting) hindgut (similar to rhinos
and elephants), hardly the digestive anatomy that one would expect in an
evolved omnivore. With regards to anthrax infection of hippos, there are
multiple mechanisms and routes involved, namely:
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contamination of grazing, generally as a result of an infected animal carcass
leaking infected blood from its orifices onto the pasture.
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ingestion of contaminated water, particularly in small stagnant pools that
are drying up during dry periods. In this situation, the infection appears
to be related to stress, stagnation (no diluting or flushing of spores),
and relative overpopulation. Most outbreaks of anthrax in Africa occur
during the dry season or dry cycles.
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open wound lacerations resulting in per-cutaneous infections. This route
of infection may possibly even occur in larger expanses of water, where
there is a dilution factor, but is more likely to occur in smaller stagnant
pools that have become heavily contaminated.
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cannibalism with ingestion of tissues from an infected carcass.
Some 10 years ago, there was a severe anthrax epidemic among park hippos
in eastern Zambia. This followed an explosion in their population from
around 2,000 to over 6,000, with resulting overgrazing, long treks to find
food, and crowded rivers, clearly very stressful.
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anthrax is endemic in many areas of Africa and the world, and these endemic
areas are frequently associated with alkaline soils and alkaline surface
water frequently related to volcanic /calcite geological formations. The
Queen Elizabeth system fulfills most of these criteria.
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in the Bacillus anthracis life cycle, long dormant periods in the
environment in the resistant spore survival mode are interspersed with
short periods of exponential replication of the germinated bacilli within
suitable hosts during outbreaks. Interepidemic periods may be measured
in years or decades, and in remote areas of the developing world, the disease
may not have been previously recognised or documented.
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triggers for these outbreaks include local overabundance of hosts, poor
soil drainage and stressors generally associated with resource depletion
and intra- and inter-specific competition. Hippos have few natural enemies
except man, and there is a cyclical tendency for their population growth
to exceed the ecological carrying capacity of their nocturnal grazing range.
Dry seasons and dry cycles compound the problem. In the Queen Elizabeth
National Park system, Lake Edward and Lake George (linked by the Kazinga
channel) are major aquatic features stretching for many square miles, and
support a large hippo population. Census figures in 1958 reported a population
in excess of 15 000 for the system, with resultant severe overgrazing,
trampling and soil erosion. Between 1958 and 1966, more than 7000 hippos
were culled to address this overabundance issue. A 1969 census showed that
there were still 10 000 hippos in the system. Heavy poaching in the 1970s
reduced this population by half, but by the 1990s the population had recovered
again to over 7500. I unfortunately have no recent census figures.
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anthrax outbreaks may possibly be seen as a natural population-regulating
mechanism for some species (including hippos) under certain environmental
conditions and relative population density situations. Epidemic outbreaks
are relatively short-lived (generally measured in months) and in most species
(except buffalo and bison) there appears to be no gender predilection.
The male predilection seen in African buffalo and bison appears to be linked
to wallowing behaviour. Another observation is that sub-adult animals are
relatively under-represented in carcass counts.
Potential transmission modes include :
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contamination of grazing by the leaking of unclotted blood from body orifices
of terminal or dead individuals and from scavenged freshly dead carcasses.
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contamination of lake shallows and pools and cattle troughs by bathing
vultures that have recently fed on infected carcasses.
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percutaneous infection of fight wounds by spores in the environment or
spores in the oral cavity of the aggressor.
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mechanical transmission by large haematophagous biting flies (Pangonia
spp.) which target hippos.
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cannabalism with ingestion of tissues from infected carcasses.
Control of anthrax : from a purist's point of view, anthrax is an indigenous
multi-species disease, and in natural free-ranging systems it should be
considered an integral part of the ecology, and a periodic population regulator.
However, in a not-so-perfect world, because the disease affects livestock
and has zoonotic implications, control is attempted, based on 3 pillars
:
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vaccination of endangered wildlife species that are at risk -- as many
as possible -- where possible.
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public awareness campaigns stressing the danger of handling or utilising
carcasses of dead animals.
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reduction of contamination of the environment by burning or [2nd best]
burying carcasses. Alternately, making carcasses unattractive to scavengers
by spraying with formalin or covering with branches or sheets of plastic
until putrefaction, anaerobic conditions, acid pH and temperature destroy
the bacilli in the carcass (2- 4 days). About 10 years ago, the Canadians
discovered in the MacKenzie Bison Sanctuary that one could prevent carcass
scavenging long enough for decomposition to change the pH -- and thereby
kill the vegetative organisms -- by spraying carcasses with 5% formaldehyde.
This acid pH change takes only a few days (3 to 5 days), after which a
carcass can be left to rot and nature with minimal environmental contamination.
If the fresh carcass is not opened, minimal or no sporulation occurs. In
the case of hippopotami, their aquatic habits frequently result in the
carcasses of anthrax victims floating or surrounded by shallow water, making
them relatively inaccessible to winged or terrestrial scavengers. Their
thick hide is not easily penetrated (even by crocodiles) until putrefaction
is fairly advanced. Most bacilli in the carcases will therefore be destroyed
by their anaerobic and acidic environment together with the massive growth
of putrefactive organisms. Theoretically therefore, floating hippo carcasses
should not be a major source of contamination by spores, with the exception
of exudates from orifices (when present). Also, in the main bodies of water
of large lakes, the dilution factor for spores should be such as to pose
minimum risk. However, contamination of small pools and inlets will probably
require the removal, beaching and burning or burying of carcasses.
They are seeing large anthrax outbreaks these days in Africa which could
well be related to temporarily high local population densities. Stress
events will lower the LD50, causing individual grazing animals
which would otherwise be unaffected to die. Other factors then facilitate
disease spread. Bacillus anthracis will not survive in water in
its unsporulated state; the spores will, though subject to dilution, of
course. The very small proportion of deaths confirmed as anthrax, with
a presumption that all the rest are also anthrax; how to stop the ongoing
epidemic and whether hippos can be usefully darted with Sterne vaccine;
what part might biting flies be playing in the continuing problem; and,
as expected, other wildlife species may be involved. This epidemic has
lasted much longer than anyone would normally expect for anthrax, and the
reasons are unclear. Early on there were some 4 to 7 human deaths (accounts
vary) associated with persons eating these dead hippos.
Hippos' secretions all over their back, face and behind their ears
are neither blood nor precisely sweat, but a mixture of pigments (one red
and one orange, christened hipposudoric acid and norhipposudoric
acid) that function as both ultraviolet sunscreen and antibiotic for
Pseudomonas
aeruginosa and Klebsiella pneumoniae, as well as keeping the
animals cool. The hippos tend to produce more of the substance when they
are on dry land rather than swimming in rivers or lakes, bolstering the
idea that the secretions are akin to sweat. But other experts have suggested
that it functions as waterproofing; adults can remain submerged for > 5
minutes at a time. Such a dual function would be useful to the huge beasts,
which live in central Africa, largely in the Nile Valley. They spend a
lot of time in direct sunlight, and frequent fierce clashes with rival
hippos leave them scarred and potentially vulnerable to infection. In isolation,
the newly discovered compounds are very unstable, but hippos can retain
their blood-red hue for several hours before losing their lustre thanks
to the mucus secreted with the pigments may delay their discolourationref
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Ruminantia ("small ruminants" generally refers to either sheep or
goats), Pecora, Bovoidea
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Bovidae
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Antilocapridae
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Bovinae
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Bison
=> BSE
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Bos
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Bos
frontalis (gaur) are found in central and southern India, in
Nepal & Bhutan, and in SE Asiaref
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Bos
grunniens (domestic yak)
=> in 1991, rinderpest was diagnosed in yaks in the former Soviet Union,
near the border with Mongolia. At the peak of the epizootic, mortality
among affected yaks was 32-42% in adults and 65% in animals less than one
year old. However, if rinderpest is involved in the current yak die-off,
it may be assumed that the typical diarrhea would not remain unnoticed,
even if only dead animals were observed. Mortality in adult yaks could
be ascribed to numerous etiological agents, both non-infectious (metabolic,
toxic) and infectious ones. Among the possible infectious agents, various
bacteria (e.g. anthrax and pasteurella), viruses, protozoa and helminths
might be taken into considerations.
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Bos
indicus (zebu)
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Bos
primigenius (aurochs)
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Bos
primigenius indicus (dwarf zebu) : a type of Asiatic ox that
has a fleshy hump, floppy ears, a loose dewlap, and is highly resistant
to the effects of heat and insect attack
=> a male zoo animal born on 24 Jun 1985 in Basel, Switzerland died
on 7 Apr 2004 of BSE on probably feed with meat-and-bone meal
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Bos
taurus (cows, bovines, cattle) : cattle normally ingest 2-3
(up to 10) kg of soil per day
Taenia saginata
,Otobius
megnini
,
Hypoderma
bovis
,
Babesia
bovis
,
Babesia
divergens
,
Dermatophilus
congolensis
,
Bacillus anthracis
(bovine anthrax :
Epidemiology : contaminated muddy hay
in a 'champs maudit' (a field with a history of repeated anthrax
outbreaks) is not an unusual epidemiological history. Gravesites on the
banks of various rivers and even at the bottom of artificial water reservoirs
do not pose any serious epidemiological concern. A few years ago this happened
in Oklahoma, but similar reports go back decades to the 1920s in France.
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Russia : places with any history of anthrax are permanently labelled as
'anthrax sites' :
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the Ural Federal region is approximately 1.8 million km2 in
area, with a human population of about 12.5 million. The region consists
of Kurgan, Sverdlovsk, Tumen, Chelyabinsk, Yamalo-Nenetskaya, and Hanti-Mansiyskaya
national districts. The entire region (north to south) has a history of
anthrax, and therefore the discovery of numerous anthrax sites (at least
2086) should not come as a surprise. At 4 of these sites, cases of animals
being infected with anthrax were recorded between 1991 and 2000. In reality,
the number of cattle gravesites is much higher, as there may be several
such gravesites at any one of these anthrax sites. However, it is hard
to say that there are positively identified anthrax spores in these gravesites
-- as there have never been such investigations into these sites. The Tobolski
gravesite, on the banks of the Irtish river, is peculiar, as it is the
result of activity at a nearby factory involved in the production of veterinary
prophylactic drugs, including vaccines against anthrax. Unfortunately despite
sealing off the toxic waste storage facility with concrete, which provides
isolation from the surrounding environment, the factory does not have any
resources for the radical disinfection of the waste.
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during the decade 1994-2004, none of the 515 anthrax sites in the Vologodskaya
oblast has shown disease activity.
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Ukraine : from 2000 through 2004, there were 26 bovine anthrax outbreak
with some 141 animals affected, 3 sheep/goat outbreaks reported (in these
species, un-reporting is the norm) with 13 deaths, 2 equine outbreaks with
7 deaths, and 5 pig outbreaks and only 5 deaths reported. The give-away
is that in the same period, there have been 15 human cases reported
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Georgia has a severe anthrax problem in its livestock. The diseaseis regularly
seen in a number of areas, and the government is struggling to develop
an efficient, and effective, veterinary control program. Human cases have
been regularly reported since 1995: 33 cases in 1996, 4 cases in 1997,
11 cases in 1998, 51 cases in 1999, 21 cases in 2000, and 26 cases in 2001.
This is not the 1st time urban cases in Tblisi have been only the tip of
a rural epidemiological anthrax iceberg. Gardabani district is regularly
blamed, but it suffers from being close to Tblisi, and, consequently, is
reported upon in the press. Some of the 2001 cases were in Abkhazia, Zugdidi
district.
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Europe
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Finland : outbreaks in 1988 and in 2004 (southern Finland)
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Italy. Basilicata : this mountainous area normally has 2 to 3 outbreaks
each summer. This series of outbreaks has been ascribed to the heavy rains
eroding historically contaminated cattle graves and thus depositing spores
in the pastures. In 2004 the 1st outbreak was noted in late July 2004 and
in retrospect was probably just the usual summer incident. But in late
August this epidemic started, and by 24 Sep 2004 totalled some 36 known
outbreaks; in this hilly area, there are certainly other cases not observed
or not reported. The total recorded cases are 54 cattle, 7 horses, 11 sheep,
and 4 red deer. Presumably there have been subsequent outbreaks in the
region. 2 veterinarians have developed cutaneous anthraxref.
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UK : 2 cows died of anthrax on a beef farm in Rhondda Cynon Taff in south
Wales on Apr 2006. It is the 1st case in Britain since 2002, when a cow
died at a farm in Wrexham, considered to be a sporadic incident on a farm
which had 3 anthrax cases in the previous 2 decades. There was also a case
in cattle in Clwyd in 1992 and pigs were confirmed
with the disease at a farm in Wrexham in 1989ref.
The pattern of UK anthrax outbreaks in the past 25 years is essentially
no longer from contaminated livestock feed --- the Wrexham pigs were a
notable exception --- but usually occur following an environmental disturbance,
such as trenching, bulldozing, or river dredging, disturbing buried spores
at cattle grave sites or occur in relation to mills & tanneries that
handled contaminated imported hair & hides. This is a common epidemiologic
pattern once an area is considered to be in a true sporadic state epidemiologically.
At one time the UK had some 425 outbreaks each year over the course of
decades thanks to contaminated feed. Once this was cleaned up, the rate
dropped precipitously to the present situation when years go by without
cases. It is now frankly a rare event subject to specific trigger events
and as time goes by, it will potentially become even rarer, as spores are
not immortal and can also lose their plasmids over time. Otherwise we would
be vaccinating cattle annually in Europe & North America. We don't.
And we have a situation where livestock veterinarians are ignorant of the
disease (not having seen much of it during their careers), which delays
recognition. This is further exaggerated in the UK where far too many farmers
are now too poor to regularly employ a veterinarian. This Welsh outbreak
is a good example as 5 cows had to die before it was diagnosed. I am mildly
puzzled at the timing. April is early for this disease in the UK for it
to be due to environmental exposure; theoretically dirty feed is available
year round. But without details one can only muse about possible sources.
And before anyone comes up with claims of Lazarus spores, my colleague
& good friend Peter Turnbull once investigated an outbreak in Dorset,
southern England, where some 5-6 steers were affected from a cow buried
some 60 plus years previously; Peter located the grave in the pasture and
showed the presence of viable spores in the surface soil
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Africa :
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Zambia : in this part of Africa it is not unusual to see a ratio of 10
human cases per bovine case
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Zimbabwe : just over 20 years ago it had 10 000 human cases when disease
control had been significantly weakened by their civil war. With the ongoing
lawlessness and fragile infrastructure, this may become a repeat of those
events. The first cases of anthrax at Morgenster in Masvingo were reported
in September 2003, and so far Bikita has the highest number, with 147 cases
having been reported in Ngorima, Mutikizizi, and Devure. In Gutu district,
a total of 82 cases, including 2 deaths, were reported, while in Chivi
51 cases and deaths were reported. It is highly probable that the true
incidence of human cases in rural areas is already a multiple of the reported
number. In normal circumstances this would have been controlled and prevented
from the start by proper livestock vaccination.
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Asia :
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India : anthrax is not frequent in western India but not unknown. It is
most common in the south and through the eastern states. The Indian National
Survey for 1989-94 had southern India and Tamil Nadu with the highest incidences
for the disease. A companion document for 1991-1996 had it occurring in
Tamil Nadu each year in cattle, buffalo, sheep, and goats in sometimes
spectacular numbers. In 1996 a paper described some 29 patients with anthrax
meningitis with an unfortunately high lethalityref.
A longer version can be found in the Indian Journal of Medical Microbiologyref,
1996, 14:63-67, with maps showing where cases have been seen in the state,
including a spot-map of human and animal cases in the North Arcot Ambedkar
district. In 2003 a paper described 27 patients seen at the Christian Medical
College & Hospital, Velloreref,
so I think we can unfortunately assume that the disease continues both
in humans and the rural livestock in Tamil Nadu, much as before
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USA : the last official update/newsletter was from 28 Jul 2005. The 16
Aug 2005 map has the following numbers of outbreaks in the following 11
South
Dakota counties: Brown (4), Day (1), Dewey (7), Hand (2), Hughes (2),
Hyde (2), Marshall (3), Potter (7), Spink (2), Sully (9), and Walworth
(1), which sum to 39 outbreaks. But the map, for some reason, is titled
"2004-2005 Anthrax Cases in South Dakota." It would seem that the cases
in northeast South Dakota may be epidemiologically linked to the cases
in southeast North Dakota, where the weight of the latter state's outbreaks
are. North
Dakota Department of Agriculture anthrax map. As of 16 Aug 2005, North
Dakota has had 86 cases (premises) in 13 counties. The cattle trails project
was to verify the traditional belief that anthrax was related to the cattle
trails of the 19th century. If your ranch/farm was in a county within some
10 km of a cattle trail going from the south to the north, there was a
significant risk, approx. 10 percent, of historical anthrax in that county.
This did not apply to the emigrant trails from east to west. This made
sense, as the south-to-north trails, including those from Texas to California,
involved longhorn cattle moving from an historic enzootic region of southern
Texas and Louisiana. The east-west trails involved less cattle and these
were largely British breeds, mainly Herefords, from breeding areas without
anthrax. The Red River trails were to get people, goods, and livestock
from St. Paul up into northwestern Minnesota and on to southern Manitoba
and Winnipeg.
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South America :
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Argentina : in 2006 there were 29 anthrax outbreaks affecting cattle with
a total of 9 human cutaneous anthrax cases, with 3 in the province of Buenos
Aires in
the partidos of Azul & Rauch. Provincia de Buenos Aires (from 1977
to 2006 there were 41 partidos (counties) affected in this province): Azul
(3), Benito Juarez (1), Coronel Pringles (1), Coronel Tejedor (1), Daireaux
(1), General Alvear (2), General Lamadrid (1), Lobos (1), Puan (2), Rauch
(2), Suipacha (1), Tandil (1). Provincia de Cordoba: Roque Saenz Pena (1),
Rosales (1). Provincia de La Pampa: Cohelo (3), Huacal (2), Santa Rosa
(1), Tornquist (4). Since 1997 the annual incidence has been steadily decreasing
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Peru : bovine anthrax is reported annually in and occurs in about 5 out
of 10 of the coastal departments. Lately, it has been reported in the following
departments: Ancash, Cajamarca, Huanuco, Ica, La Libertad, Lima, Moquegua,
and Tumbes.
While some sites will have viable spores in significant numbers, what determines
this state of affairs and its probability are totally unknown. Logically
it must depend on soil type -- anthrax persists in regions with alkaline
soils with high calcium content and is absent from acid soil regions --
but also presumably on whether necropsies were done on the affected carcasses
before burial, and strain genotype group. Decomposition in unopened carcasses
will rapidly kill the vegetative cells as the pH falls. Burning and
then burial of the ashes results in essentially zero risk.
Laboratory examinations : diagnosing anthrax
by necropsy is fraught with problems, even though some claim that the raspberry
jam appearance of the enlarged spleen is pathognemonic, as well the generalized
hemorrhagic edema of the carcass and viscera. This may be so, but the resulting
gross environmental contamination, the opportunity for massive sporulation,
and the significant risk to those examining the carcass make it inadvisable.
It is something a veterinarian should never do twice in his or her life,
preferably not even once. For many decades, a stained blood smear was an
adequate 1st screening if one suspected anthrax. As few vets these days
have stains and a microscope with them in the field -- assuming that their
microscopic skills are still adequate -- it reinforces the current urgent
need for cheap, robust, reliable carcass-side test kits to be available
in those parts of the world where this disease is enzootic. If you go to
the literature, there are more pathology papers based on human autopsies
than on necropsied animals with this disease. Possibly, this is because
veterinarians see more of this disease than physicians. And certainly,
there are no papers on animal autopsies.
Prevention :
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if possible, carcasses should be burnt. But this can present serious problems
when there is a lack of firewood and staff. Hippos and elephants are fuel-hungry
species. If all else fails, the best option is to stop scavengers opening
up carcasses for the first 3 or 4 days so that the carcass can ferment
and the pH drops to acid levels, thereby killing the vegetative cells.
Without oxygen they cannot sporulate. In this way the environmental contamination
is minimal, even if the carcass is later opened and the bones fed on and
dragged around. And even with sites that have spores, repeated sampling
over the years has shown some sites becoming 'apathogenic' from plasmid
loss. Examination of such sites is needed, if only to rule out those that
present no risk. Watery diarrhea is not a normal sign of clinical anthrax,
which is normally characterised by peracute death in cattle. Bloody exudates
from the various orifices post-mortem, though common in textbooks, in reality
is not a consistent feature of livestock anthrax. The US Navy test kit
depends on the PA titre in the bloody fluids, and this titre falls off
with time such that carcasses over 3 days old can be negative though culture-positive.
For fresh cases it is unbeatable.
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Carbosap vaccine (2 injections). Normally anthrax is rarely seen
in commercial herds in Africa because of the higher level of management
practiced and regular vaccinations. If animals are not in good condition
when vaccinated, any immunity developed is been minimal. Anthrax is not
a contagious disease. Post-outbreak herd quarantine is to stop animals
leaving the farm that are incubating the disease and before the vaccine
protection has kicked in. With Sterne it is frankly rare to see deaths
from anthrax > 8 days after vaccination; normal development of immunity
is faster. The most efficient way to control anthrax in cattle herds is
(1) to properly and quickly deal with the affected carcasses; (2) to treat
the survivors with a long-acting antibiotic (such as LA200, but use normal
penicillin with horses, as LA200 is painful); and (3) to wait 7-10 days
before vaccinating with Sterne or another recognised live vaccine.
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Sterne vaccine : the common experience is that you will get deaths
up to 8 days post-vaccination because it is only at that point that protection
has been fully developed. And because of that 8-day risk window, ranchers
are encouraged to 1st treat their stock with long-acting antibiotics to
treat any apparently healthy animals that are incubating an infection.
LA200 gives a 3-day cover but cannot be used with lactating dairy cows.
Benzathine Penicillin with Penicillin G Procaine gives a 48-hour cover
and can be used with dairy cows. Because the latter is shorter acting,
it may not be as efficacious and may need to be given twice or in larger
doses than specified on the bottle. Anyway, if there have been deaths in
a dairy herd, animals' temperatures should be checked morning and afternoon
when they come in for milking until the vaccination has taken effect; any
animal with a temperature or seeming to be ill (dairymen know their animals)
should be taken out of the line and treated. There is no risk to humans
from the vaccine when they drink the milk from healthy vaccinated cows.
If you use the antibiotics after the vaccine, it can stop the vaccine from
developing a full immunity by killing circulating live vaccine organisms.
So the best course of action is to 1st treat with antibiotics, wait 7-10
days, and then vaccinate. If you use antibiotics simultaneously with vaccine,
you will have to revaccinate the animals 2 weeks later to get any long
term protection. Once a herd has had anthrax, you should revaccinate each
following spring for at least 3 years because of any pasture contamination.
This also applies to ranchers who may not have had any anthrax deaths but
whose neighbors have. You cannot count on the latter remembering to revaccinate
next year, and when they are reminded by cows dying, it may be too late
for you to protect your animals. I have seen this happen more than a few
times.
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simultaneous treatment with antibiotics and Sterne only results in killing
the live vaccine and any incubating infections without any medium-term
benefits. The report of human cases from consuming "preserved meat" follows
from the need of farm managers -- usually poor relatives of the farm owner
-- having to prove that any missing animals had died and had not been sold
or given away. Thus animals dying are skinned; the meat is stripped from
the carcass and sun-dried; and the head, hide and dried meat are available
to the owner when he or she later visits the farm. This handling maximises
the number of spores in these products)
, Brucella
melitensis biovar Abortus
(bovine brucellosis : it is endemic in Korea; 110 outbreaks have
been reported during 2002. Brucella abortus had not been isolated
from any premises in Great Britain since October 1993 until its confirmation
on 4 premises in Scotland during early 2003. An additional, unrelated case
was identified later (2 Dec 2003) in a Scottish beef herd when post-import
blood testing was undertaken on a heifer imported from the Republic of
Ireland. All the infected and contact cattle at risk of infection were
slaughtered. Reportedly, all 4 outbreaks were caused by the importation
of infected cattle. In March 2004, a whole breeding beef herd was slaughtered
in Cornwall on the strength of a Brucella abortus biovar 1 isolate
from an
aborting cow. 3 other cows aborted with culture-positive vaginal swabs
or fetal stomach contents. A specialist epidemiological team was set up
to look into the source of the infection. The results of the said investigation
were published by DEFRA on 20 Jul 2004 (press release 287/04). The conclusion
was that the infection had, most likely, been introduced into the herd
in Cornwall between Spring 2002 and Spring 2003 and that it was an isolated
incident. The origin of infection was never identified, for which 2 reasons
were offered:
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the animal which introduced the infection may no longer be alive;
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although the disease reached and became established in the herd in Cornwall,
it may not have persisted elsewhere.
According to article 2.3.1.2. of OIE's terrestrial animal health code,
a Country or zone shall satisfy the following requirements to qualify free
from bovine brucellosis:
-
1) bovine brucellosis or any suspicion thereof is notifiable;
-
2) the entire cattle population is under official veterinary control and
it has been ascertained that the rate of brucellosis infection does not
exceed 0.2% of the cattle herds in the country or zone under consideration;
-
3) the serological tests for bovine brucellosis are periodically conducted
in each herd, with or without the ring test;
-
4) no animal has been vaccinated against bovine brucellosis for at least
the past 3 years;
-
5) all reactors are slaughtered;
-
6) animals introduced into a free country or zone shall only come from
herds officially free from bovine brucellosis or from herds free from bovine
brucellosis. This condition may be waived for animals which have not been
vaccinated and which, prior to entry into the herd, were isolated and were
subjected to the serological tests for bovine brucellosis with negative
results on 2 occasions, with an interval of 30 days between each test.
These tests are not considered valid in female animals which have calved
during the past 14 days. In a country where all herds of cattle have qualified
as officially free from bovine brucellosis and where no reactor has been
found for the past 5 years, the system for further control may be decided
by the country concerned)
..., Burkholderia
pseudomallei
,
Escherichia coli O157:H7
Prevention : vaccine administered in 3
doses at 3-wk interval. Both the Bioniche Life Sciences Inc. manufactured
vaccine and the vaccine produced by the Alberta Research Council - Biologics
fermentation facility demonstrated significant effectiveness and the most
effective commercial-vaccine formulation resulted in a 99.56% or 2.35 log
reduction in the amount of bacteria shed in manure, and a 70% reduction
in the number of animals shedding after a single, orally-administered challenge
with 1x109 or one billion E. coli O157:H7 bacteria 2 weeks following
the last vaccination
Coxiella burnetii
,
Leptospira
interrogans serovar hardjo
,
Anaplasma
phagocytophilum
,
Chlamydiophila
psittaci
(Buss disease / sporadic bovine encephalomyelitis : encephalomyelitis
with pleuritis affecting cattle in the United States, Japan, and parts
of Europe; characteristics include fever, labored breathing, cough, diarrhea,
and neurological signs such as a staggering gait; sometimes there is drooling
or a nasal discharge),
bovine papular
stomatitis virus
,
Crimean-Congo
hemorrhagic fever virus
,
Rift Valley fever
virus
(adult cattle are known to be less susceptible than young animals; less
susceptible than sheep),
Wesselsbron virus
(WSL)
(Wesselsbron disease : a viral disease of sheep and cattle in southern
Africa, resembling Rift Valley fever but caused by a flavivirus. It causes
death in newborn lambs and abortion in cows and ewes; human infection results
in mild febrile illness), rabies
virus
(vaccinations should especially be done in animals being prepared for show,
primarily because of the much closer, more frequent contact with people),
foot-and-mouth
disease virus (FMDV)
(foot-and-mouth disease (FMD) / aftosa / aphthous fever / hoof-and-mouth
disease / contagious or epizootic aphthae / tabak (in Pakistan) : an
acute extremely contagious disease caused by a picornavirus, affecting
wild and domestic animals, particularly ruminants and pigs, and occasionally
humans
=> epizootic aphta
/ aphthous fever / foot-and-mouth disease (FMD) / illness No.5
: acute fever, followed by the eruption of vesicles on the lips, buccal
cavity, pharynx, legs, and feet; sometimes the skin of the udder or teats
is involved. Infected animals secrete numerous virus particles before clinical
signs appear; infected cattle become weak and yield less milk. Though it
is true that animals can survive FMD, production drops dramatically. Certain
strains of the O serotype may be even more infective and invasive than
Asia 1 serotype, affecting several susceptible species. Pancreatic lesions
related to FMD were seen in the past in Italian cattle (Barboni & Manocchio
(1962). Archo vet. ital., 13 (6), 477-489) and Israeli mountain gazelles
(Perl et al (1988). Rev. sci. tech, OIE, 8(3), 765-9). Pancarditis,
causing sudden asymptomatic death, is one of the possible manifestations
of FMD. Speculatively, one might ask if the hepatic lesions (with various
potential etiologies, infectious as well as non-infectious) may have merely
been a red herring. FMD in free-roaming Gazella gazelle has been
described in Israel in 1985, with extremely high morbidity and mortality
rates. Similarly, cases have been reported from Israel in 2006 and EAU
in 2007.
Epidemiology :
-
Europe
-
Great Britain : > 8 millions
animals (around 1 in 8 were cows) were slaughtered in 2001 in a desperate
effort to control the most serious British epidemic of FMD disease in over
30 years, caused by serotype O. Inactivated vaccine, which had proven to
be successful for the eradication of the disease, was ruled out because
the blood of dosed and infected animals is indistinguishable (their immune
responses are similar) and symptoms can take days to develop : during this
delay a healthy-looking animal can spread the FMD virus, so under current
European and American laws vaccinated animals cannot be bought or sold
due to inability to distinguish vaccinated animals from infected one. The
European Commission in 1990-1, after undertaking a cost benefit analysis,
implemented a policy of non-vaccination to increase export opportunities
and to ensure high animal health standards : this outbreak containment
policy requires an export ban on all livestock and animal products from
any affected country, along with movement restrictions and the slaughter
and burning of all cloven-hoofed animals that are either infected, on infected
premises, or in contact with infected animals. Until now the European Union
has remained free of FMD since an outbreak in Greece in 1996. At the time,
authorities were criticised for their lack of preparedness. Several years
on, the government has taken important steps to avert a future outbreak,
summarized in a report
(alternative
URL) by the Royal Society
: first, the government has taken steps to prevent the disease entering
the country by clamping down on imported meat and animal feed that might
harbour the virus. Second, it has made moves to stop a small outbreak escalating
into a full-scale epidemic by, for example, making faster diagnoses and
introducing measures to freeze movement of infected animals immediately.
But on the down side, the panel concludes that the government is not fully
prepared to thwart the disease by vaccinating animals. Vaccination was
not used in the 2001 British epidemic, partly because it is difficult to
tell animals that have been vaccinated from those that have been infected,
as both produce a similar immune response. Tests to distinguish vaccinated
and infected animals have now become available and vaccination is considered
a first line of defence, but the tests have not yet been validated and
so are not ready to use. The country also lacks the infrastructure to ensure
that vaccines and tests could be deployed on a massive scale, and there
is no clear commitment to use it widely. The report urges the government
to re-visit its emergency plans every few years to ensure that these remain
adequate as farming practices change. The government has already taken
steps to identify remaining shortfalls in its foot-and-mouth strategy.
Exercise
Hornbeam, for example, simulated days 7 and 8 of a disease outbreak
in June 2004. There is an urgent need for a vaccine that can prevent the
disease from taking root in animals in the first place rather than simply
protecting them from the symptoms of the disease
-
South America : during 2003, FMD was officially reported from 3 countries:
Argentina, Bolivia, and Paraguay. Serotype C has been reported in the Brazilian
state of Amazonas, in the North of Brazil in 2004 after last detection
in 1995 : the Argentine vaccine is bivalent, O and A, tetravalent in serotype,
and contains, besides O, the antigens A-24, A-2000, and A-2004, but it
does not contain type C. The Reference Lab at the Institute for Animal
Health, Pirbright does not show any isolates of Type C after 1996. During
this period, most of the outbreaks in South America were either Type A,
Type O, or a mixture of both types.
-
Asia : 2 FMD serotypes are, reportedly, evolving now in eastern Asia/the
far east: type Asia 1 in Russia's Amur region (Khabarovsk province); type
A in eastern Mongolia's Dornod province. They are > 1000 miles apart; both
share borders with the People's Republic of China
-
between 1990 and 1996, there were 29 reports of type C virus, almost all
from Asia. Nepal led the list with 14 isolates, Philippines was next with
8 isolates, and one came from the Soviet Union (1991). The data obviously
indicate that Type C has been absent from the world scene for several years
now. It is very important to figure out exactly how it came back and to
ensure that it is contained on the island in the Amazon. FMD is endemic
in Cambodia : according to Cambodia's detailed monthly reports to the OIE,
FMD was recorded there during each month of 2003 (20 outbreaks), affecting
3023 cows, 528 buffalo, and 351 pigs in 8 provinces (The cattle population
of Cambodia is approximately 2.9 million; buffalo, 0.6 million; and pigs
2.1 million) and the last FMD virus typing of samples from Cambodia was
carried out at the World Reference Laboratory (Pirbright, UK) in 2000 (serotype
O was identified). FMD is endemic in Pakistan, reportedly caused, during
2003, by 3 serotypes: A, Asia1, and O. FMD has been spreading in Zambia
since February 2004.
-
Russia's concern about the FMD situation in China is understandable in
view of the outbreak in dairy cattle, caused by FMD virus serotype O of
the pan-Asian group, detected in Amur, 15 km from the Chinese border, in
April 2004. China's last OIE-reported outbreak of FMD occurred in May 1999.
It was caused by FMD serotype O (most probably of the pan-Asian group).
Totally, 8 outbreaks were officially reported: 5 outbreaks from Tibet,
2 from Hainan, and one from Fujian. The disease was reported as absent
during 2000-2002ref.
During 2003, 4 China's monthly reports are available on OIE's Handistatus
database and cover only the period September - December, and stated that
the disease was absent. In 2004, monthly reports cover the period January
- August 2004, also stating absence of the disease. No later reports are
available. An OIE experts mission visited China during 10-19 May 2004.
According to the Mission's 20-page report (which was available on OIE's
web-site until very recently), 6 Reference Laboratories for the following
List A diseases were visited and reviewed: classical swine fever (CSF),
rinderpest, avian influenza (AI), contagious bovine pleuropneumonia (CBPP),
Newcastle disease (ND) and bovine spongiform encephalopathy (BSE). Hopefully,
FMD will be covered in future visits. In 2004 Russia suffered an outbreak
of FMD, serotype O, in dairy cattle in the Amur region, 15 km from the
Chinese border. Subsequently (in September 2004), Russia restricted imports
from China. The 2 official reports of Russia to the OIE on the 2004 outbreak
mentioned a total number of 141 dairy cows (12 months old) exposed to the
virus, which was identified as serotype O of the pan-Asian group. 87 of
them were clinically affected; 890 animals -- including in-contact animals
-- were destroyed. The current media-derived data concerning 2004's outbreak
are somewhat different, particularly in regard to the alleged involvement
of pigs. Clarifications will help. As to the current outbreak, caused by
a different serotype (Asia 1), here also there are discrepancies between
official and unofficial data, particularly regarding the numbers of affected
animals. The 2 affected bovines mentioned in the official notification
might reflect the number of sampled animals tested in the laboratory. It
will be helpful to obtain the number of exposed and clinically affected
animals, and to exclude -- or otherwise -- the possibility that pigs are
involved as well. The event in Busse, Svobodnenskiy, Amur region (Amurskaya
oblast) (20 km from the closest village in the Russian territory and 300
m from the border with the People's Republic of China) started on 6 Jun
2005 and involved 2 cases. The Asia 1 epizootic in Russia's far east seems
to continue its pace; a look at the map will reveal that this is not necessarily
a spread within Russian territory, but more probably repeated introductions
from neighboring China. Busse, where the 1st outbreak was reported in June
2005, is situated on the Amur river, which separates Russia from China.
The 3 villages in the Khabarovsk region, found infected in August 2005,
are situated on the Ussuri river, also separating Russia from China. This
area is more than 1000 km distant (southeast) from Busse. The new outbreak,
reported on 26 Aug 2005 in the Primorskiy region, also borders China, about
700 km south of the foci in Khabarovsk. According to an analysis by the
FAO (June 2005, following the Amur outbreak), countries bordering China
to the south and east could be considered at risk of Asia 1 on a geographical
basis. Indeed, outbreaks have been recorded in Mongolia and Myanmar. Unless
drastic and efficient control activities are immediately applied in China,
additional introductions of the virus to other countries might be expected
along her borders. The further spread, observed since June 2005, prescribes
the need for increased alertness in the region, including consideration
of the need to apply mass vaccinations against serotype Asia 1.
-
Pakistan : FMD is endemic; the efficient way to help the farmers reduce
their losses is a preventive, not a curative one. Pakistan's last available
annual report to the OIE, for 2003, does not include data on vaccinations.
In 2002, 13 690 bovines and 28 765 buffalo were reportedly vaccinated;
the national herd included 22.8 million bovines and 24 million buffalo.
During 2004, 8 samples were sent from Pakistan to the OIE/FAO World Reference
Laboratory for Foot and Mouth Disease at Pirbright, UK. 2 of them were
found positive for FMDV (serotype Asia 1). During 2003, 81 samples were
sent, of which 29 were found positive for FMDV serotype O, 8 serotype A
and 4 serotype Asia 1. In 2 samples, mixed infections, including serotypes
O and A, were demonstrated
-
China : according to China's reports to the OIE, not a single outbreak
of FMD was recorded there between May 1999 and the end of 2004. Since 13
May 2005 to 13 July 2006, China has sent the OIE 14 official notifications
on FMD in bovines, caused by FMD virus serotype Asia 1, in the following
9 provinces (in chronological order of their 1st recordings): Jiangsu,
Beijing, Hebei, Xinjiang, Gansu, Qinghai, Shandong, Ningxia and Jiangxi.
During 2005, the Chinese veterinary services sent the OIE 6 reports on
FMD, serotype Asia 1, causing 10 outbreaks in 4 (out of China's 22) provinces,
1 out of China's 5 autonomous regions and 1 out of China's 4 major municipalities.
The affected provinces were (in brackets, number of outbreaks): Shandong
(2), Gansu (1), Qinghai (1), Hebei (2), Xinjiang Uygur Autonomous Region
(2), Beijing municipality (1), and Jiangsu (1). They spread over distances
of about 4000 km, from the far eastern parts of China (Jiangsu, Shandong,
Hebei and Beijing) to the centre (Gansu), midwest (Qinghai) and the far
north west (Xinjiang autonomous region), as follows:
No / report date / infected species / location (province)
-
1. 13 May 2005 / bov / Jiangsu province (east)
-
2. 13 May 2005 / bov / Shandong province (east)
-
3. 26 May 2005 / bov / Xinjiang (autonomous region, north-west)
-
4. 26 May 2005 / bov / Hebei province (east)
-
5. 26 May 2005 / bov / Beijing municipality (east)
-
6. 20 Jun 2005 / bov / Xinjiang (autonomous region, north-west)
-
7. 27 Jun 2005 / bov / Hebei (east)
-
8. 20 Jul 2005 / bov / Qinghai (mid-west)
-
9. 20 Jul 2005 / bov / Gansu (centre/mid-west)
This situation puts the countries bordering China at risk, especially on
the north and north western borders (Kazakhstan, the Russian Federation,
and Mongolia). Taipingzen and Wangjiaxiang areas, both within the city
boundary of Wangyuan, Sichuan province, had a suspected outbreak of FMD
since 15 Apr 2005. > 200 pigs were destroyed by burning. The epidemic then
spread further between 15 and 20 Apr 2005 to involve Taiping, Wanjiaxiang,
Hualoufen, Chinhuazen, and Tchanfenxiang. In May and June 2004 a similar
outbreak had occurred : that outbreak lasted for about 1 month and resulted
in destruction of 100 to 200 pigs. Other outbreaks were recorded in Jiangsu
province, Wuxi city, Huishan district, and Shandong province, Tai'an city,
Daiyue district (in the eastern part of the country). Couple these reports
to the November 2004 unconfirmed report of FMD in Xinjiang, located in
the extreme north west of China, as well as to the Mongolian reports, and
a very confusing picture emerges for those of us outside China. China was
suspected by outside observers to be the origin of many FMD epidemics,
such as the 1997 outbreaks in Taiwan, which were the 1st to strike
the island in 68 years. There are rumors about an outbreak of FMD in a
village in Yanqing district, Beijing. China has been sending annual reports
to the OIE on its animal disease situation at least since 1996. The last
official reporting to the OIE on FMD in (mainland; excluding Hong Kong)
PRC related to 8 outbreaks in May 1999, affecting 68 bovines and 1212 porcines
in Fujian, Hainan and Tibet, caused by FMD serotype O. This might have
been a part of the worldwide panzootic caused by the PanAsia FMD O strain
or Middle-East/Southern Asia (ME-SA) topotype. Previously, FMD had been
reported in mainland PRC in 1998 and 1997, namely 2 outbreaks in July 1998
(Yunnan; no virus type mentioned), and 3 in July 1997 (Yunnan). During
1997, unspecified number of outbreaks were reported also from the Hong-Kong
area, and the Chinese mentioned FMD virus serotypes A, O and Asia 1. According
to OIE annual reports of the years 2000-2002, PRC reported no FMD cases.
A report for January 2003 mentioned 3 clinically diagnosed FMD outbreaks
in swine in Hong-Kong. Since September 2003, China began to duly provide
monthly reports. According to the available monthly reports Sep 2003 -
Nov 2004, FMD was absent. No further such reports are available, but an
annual report for 2004 might be expected during next week's General Session
of the OIE in Paris. Indeed, the sending of an "Immediate notification
report" on 13 May 2005 may hopefully herald China's desirable improved
transparency. The current FMD outbreaks in China have reportedly been caused
by virus type Asia 1. According to the monthly report of the FAO World
Reference Laboratory for Foot and Mouth Disease at Pirbright, 8 samples
from cattle in Hong Kong have been received there during March 2005, all
positive for FMDV serotype Asia 1. This serotype is restricted to the Asian
continent; during the early 1960's it spread to the Middle East, where
it seems to have become endemic since. It seriously affected cattle, sheep,
and goats. (In central and Eastern Asia, pigs are known to be seriously
affected). Several ME countries routinely vaccinate against 3 FMD
serotypes, namely O, A and Asia 1. The virus has never penetrated Europe;
the European Commission for FMD (EUFMD) has been engaged for decades with
studies and activities to prevent such spread. Clear official Chinese data
on the current disease situation in various species, with special attention
to porcines, and further data on the characteristics of the current causative
virus, will help. Formal and informal border trade with China has resulted
in the introduction of both the Cathay (pig-adapted) and Pan Asia strains
of FMD into the northern provinces of Viet Nam in the recent past. Despite
the lack of definitive evidence, the outbreak in April 2005 of goatpox
in the border provinces points to the introduction by border trade of another
contagious disease from the northern neighbour. While routine country reporting
suggests that Type O FMD virus is probably endemic in Viet Nam, the country
has not reported Asia 1 virus for some years and does not use or hold Asia
1 vaccine. Given that the disease is in pigs in China, and the reports
from the feed companies would suggest a much more widespread phenomenon
than thus far acknowledged, there is a high probability of introduction
into Viet Nam via the border trade. Gene sequence and dendrogram analysis
might then give an initial indication about the protection likely to be
conferred by Asia 1 vaccine strains currently in use or available in Southeast
Asia. The most helpful action for the other countries in the region would
be for the field strain to be submitted to the World Reference Laboratory
for FMD in the UK, so that a proper antigenic characterisation can be carried
out and vaccine recommendations updated. It would appear that the animal
health situation in Hong Kong SAR might be a very useful indicator of the
animal health status of the rest of PR China, as the 'spill-over' and detection
of Asia 1 virus in Hong Kong in March 2005 was a prelude to the reporting
from Beijing of an epidemic of FMD type Asia 1. As FMD does not spontaneously
generate, the occurrence of an outbreak on the east coast in May 2005 implies
that there was a sequence of previous source outbreaks up to 2 months ago.
FMD submitted between 1996 and 2001 to the OIE Sub-Commission for FMD in
South-East Asia (SEA). Of the 10 countries in SEA, FMD is endemic in 7
(Cambodia, Laos, Malaysia, Myanmar, the Philippines, Thailand and Vietnam)
and 3 are free of the disease (Brunei, Indonesia and Singapore). Part of
the Philippines is also recognised internationally as being free of FMD.
From 1996 to 2001, serotype O viruses caused outbreaks in all 7 of the
endemically infected countries. On the mainland, 3 different type O lineages
have been recorded, namely: the SEA topotype, the pig-adapted or Cathay
topotype and the pan-Asian topotype. Prior to 1999, one group of SEA topotype
viruses occurred in the eastern part of the region and another group in
the western part. However, in 1999, the pan-Asian lineage was introduced
to the region and has become widespread. The Cathay topotype was reported
from Vietnam in 1997 and is the only FMD virus currently endemic in the
Philippines. Type Asia 1 has never been reported from the Philippines but
was reported from all countries on the mainland except Vietnam between
1996 and 2001. Type A virus has not been reported from east of the Mekong
River in the past 6 years and seems to be mainly confined to Thailand with
occasional spillover into Malaysia. The distribution and movement of FMD
viruses in the region is a reflection of the trade-driven movement of livestock.
There is great disparity across the region in the strength and resources
of the animal health services and this has a direct impact on FMD control.
Regulatory environments are not well developed and enforcement of regulations
can be ineffectual. The management of animal movement is quite variable
across the region and much market-driven transboundary movement of livestock
is unregulated. Formal quarantine approaches are generally not supported
by traders or are not available. Vaccination is not used widely as a control
tool because of the expense. However, it is applied by the Veterinary Services
in Malaysia to control incursions of the disease and there is a mass vaccination
programme for large ruminants in Thailand where the Government produces
and distributes vaccine. Vaccination is also used by the commercial pig
sector, particularly in the Philippines and Thailandref.
China's reported concern about its reputation in the lead-up to the 2008
Olympics is not baseless. Protecting participants from infectious diseases
during the games is one of the responsibilities of the host country. Similar
responsibility relates to participating animals, namely horses. For example,
the participation of horses from the USA in the equestrian sport events
during the Barcelona Olympic games in 1992 became possible only after completed
eradication of African Horse Sickness in Spain. According to the terrestrial
animal health code, China should forward to the OIE weekly reports on FMD
following its 1st report of 13 May 2005, until eradication of the disease
or its becoming endemic. Although neither humans nor horses are susceptible
to FMD, lack of transparency in reporting FMD leads to doubts about the
reporting of human and other animal diseases. Another outbreak infected
40 head of cattle in Weili county, in central Xinjiang region, northwest
China, and was reported on 22 Jun 2005 : to stop the spread of the disease,
authorities culled 261 cows, including the 40 infected ones and those raised
near them. Since the beginning of 2005, FMD (serotype Asia 1) was officially
reported from 5 (out of China's 22) provinces (Shandong, Gansu, Qinghai,
Hebei and Jiangxi), in 2 out of China's 5 autonomous regions (Xinjiang
Uygur and Ningxia) and in one out of China's 4 major municipalities (Beijing).
In view of the multiple recurring outbreaks in neighbouring countries --
adjacent to their frontiers with China -- it may be assumed that the disease
is rather endemic in larger if not all parts of China; in other words,
"an ordinary epidemic", if the first part only of Liaoning's veterinary
authorities' statement in the above press item may be cited. An official
report on the current event, which -- based upon the above described details
-- is highly suspected to be an FMD outbreak, is anticipated. Culling infected
animals in an endemic country is not justifiable; mass vaccinations, combined
with animal movement control backed by assiduous animal identification,
should be the preferred policy in this situationref.
Periodically, repeatedly vaccinating all of China's susceptible livestock
(large and small ruminants, pigs) is a gigantic undertaking. In this respect,
it is interesting to note that Chinese scientists are engaged in efforts
to develop synthetic peptide vaccine which, if combined with transgenic
crops, could be used in feed for mass immunizationref.
Should this (utopian?) scenario -- an oral (through feed or drinking water)
FMD vaccination developed, tested and proven effective -- be realised,
then controlling the disease in China, as well as in other endemic areas,
might become feasible. For instance, for the so-far unachievable mass vaccination
of the extensive small ruminant populations of the Middle East and North
Africa
-
Cambodia : in 2000, when serotype O was identified. An outbreak in pigs
occurred in 2005
-
Peninsular Malaysia reported 39 outbreaks in 1996, 39 in 1997, 10 in 1998,
9 in 1999, 3 in 2000, 189 in 2001, 39 in 2002 (incomplete outbreak number
but some 5760 individuals were affected), 21 in 2003, 37 in 2004, and only
1 in 2005
-
Kyrgyzstan (officially, Kyrgyz Republic; 2005 est. pop. 5 146 000; c. 76
600 sq mi or 198 400 sq km), borders China in the southeast, Kazakhstan
in the north, Uzbekistan in the west, and Tajikistan in the southwestref.
The 2005 numbers of FMD-susceptible species, according to FAO statistics,
are the following: cattle 1 034 890, sheep 2 965 220, goats 808 397, pigs
82 659. FMD outbreaks were due to Asia 1 in January 2004, FMDV O in 2006
and A in 2007ref.
However, according to Kyrgyzstan's official reports to the OIE (their last
available report covered 2004), no outbreaks were officially recorded after
Feb 2001, when 2 outbreaks were reported in Naryn and one in Issyk-Koul.
They were reportedly caused by FMD virus serotype Oref
-
Tajikistan : last reported, in large and small ruminants, in 2003. In May
2007, FMD has been reported from several parts of Tajikistan's northern
neighbour, Kyrgyzstanref
-
Recent serotyping of samples sent from Southeast Asian countries to Pirbright
reveals the presence of serotypes O (Viet Nam, Myanmar, Hong Kong and Thailand),
A (Thailand) and Asia 1 (Hong Kong). The spread of serotype Asia 1 throughout
China has been recently reported, with one penetration into Russia (Amur).
-
Turkey : since 21 Jan 2006 outbreak due to virus type A was reported in
the village of Nadirli (Babaeski, province of Kirklareli), in Thrace region.
According to the OIE, the last reported outbreak was in 2001; FMD serotypes
A and O are endemic in Turkey, excluding Thrace, which has been free for
years. An FMD outbreak occurred in Georgia in 2002. An extensive
outbreak of FMD occurred in the region in 1996 affecting Bulgaria, Albania
and several parts of the former Yugoslaviaref
-
The Middle East is one of the heaviest FMD-infected regions on globe, with
seroytypes O and A as the predominant virus types, with FMDV Asia 1 occasionally
present. Exceptional incursions of African serotypes (FMDV SAT1, SAT2)
have been recorded in the past as well (e.g. Libya, 1993). Although Israel
exercises a severe policy to prevent the introduction of FMD, particularly
to protect its record-yielding dairy cattle (national production means
in 2006 exceeding 11 000 kg milk/cow, with about 100 000 cows in lactation),
outbreaks of FMD have been recorded during 15 out of the 24 years between
1982 and 2005. This included only one outbreak in a dairy farm. Since the
early 1970's, the most prevalent serotype recorded in Israel has been FMDV-0,
found in cattle, sheep, goats, gazelles, pigs and wild boars. FMDV
serotype A22 has not been seen in Israel since its last recording in 1981.
FMDV serotype Asia 1 has been last recorded during 1984 and 1989, infecting
beef (2 herds) and dairy (1 herd) cattle. Serotype SAT-1 was last recorded
in 1962. A remarkable feature of FMD in Israel is its seasonality (in large
and small ruminants). First (primary) cases during the season usually appear
in December - February, and if spreading, the peak of the epizootic will
be seen in April-June (70-75 percent of all annual totals). Since 1974,
not a single case has been recorded in November. The reasons for that puzzling
phenomenon have not been clarified so far. About 70 percent of primary
outbreaks of FMD in Israel are seen in areas adjacent to the northern frontiers,
bordering Lebanon and Syria. The current outbreak is -- geographically,
chronologically, and apparently also virologically (serotype O) -- not
exceptional. The Israeli FMD vaccination scheme includes annual vaccination
of all cattle over the age of 3 months during October to December, applying
a trivalent oil-emulsion vaccine (01, A22, Asial). During 2006, the following
strains were included in the vaccine: O1 Geshur 85; O1 Manisa; O1 3039;
A22 Iraq 87; A Iran 96; Asia 1 Shamir. Booster vaccination is carried out
in cattle younger than 18 months, 8 to 12 weeks after their initial vaccination.
Calves born after the general vaccination period are vaccinated when 3
months old within a secondary scheme. The timing of the mass vaccinations
has been planned in an attempt to confer maximal immunity level at the
commencement of the "FMD season", namely January-April. Vaccination also
involves the entire national sheep and goat population with a monovalent
FMDV-0 oil-emulsion vaccine, though without the booster vaccinations in
cattle. Livestock owners are obliged, by law, to pay for the vaccination
which is carried out by personnel of the State Veterinary Service. During
2005, about 480 000 vaccinations (including revaccinations) have been carried
out in cattle and 760 000 in small ruminants (mainly sheep). Data for 2006
have not yet been published, but may be expected to have been of similar
magnitude
-
Africa :
-
Zambia : according to current OIE's epidemiological statistics, FMD types
SAT1, SAT2, and SAT3 have been officially reported from northern province
in each of the months Feb-Jun 2004. FMD type SAT1 was reported during July
in the central province and in Sep 2004 in an unspecified arearef.
Final data for 2004 and an update for the 1st semester of 2005, from all
member countries including Zambia, might be expected during the current
General Session of the OIE in Paris (22-27 May 2005). Dipping cattle has
no impact upon the control of FMD; however, it is an important measure
for the control of corridor disease.
-
Botswana : according to 2003 report, following the 2002/2003 FMD outbreaks,
358 088 head of cattle were vaccinated -- all within the "vaccination zone".
The vaccine is produced by the Botswana Vaccine Institute, which is OIE's
Regional Reference Laboratory for FMD, Africa. A National Animal Health
Status Report for 2004, submitted by Botswana for the 16th Conference of
the OIE Regional Commission for Africa in Khartoum (Sudan), 7-10 Feb 2005,
included the following FMD-related data pertaining to the recent epidemiological
situation: "FMDV in Botswana is restricted to the northern part of the
country where the 3 South African Territory serotypes (SAT I, II and III)
are maintained within the African Buffalo (Syncerus caffer) populations.
Before the 2002/2003 outbreaks, Botswana had been free from FMD for over
21 years. FMD control in Botswana is based on vaccination of cattle and
movement control of cloven-hoofed animals and animal products. To that
end, a system of zoning using disease control cordon fences has been employed.
The 2002/2003 FMD outbreaks were successfully controlled through stamping
out. Currently The World Animal Health Organisation (OIE) recognizes Botswana
as having zonal freedom from FMD without vaccination".ref
-
Tanzania : FMD seems to have become widespread in recent years. Though
also endemic in Uganda, it seems that the situation there this year is
deteriorating. Uganda's most recent FMD data on OIE's Handistatus data-base
relate to 2004. The serotypes recorded were O, SAT 1, SAT 2 and SAT 3.
The 2004 report included the following statement: "Control of FMD outbreaks
through strict livestock movement control and ring vaccination. 245 000
doses of vaccines were provided to control the outbreaks. Private companies
procured additional vaccine"
-
New Zealand : a letter claimed a release on Waiheke Island (39 farmers)
on 9 May and threatening a further release unless the government responded
to demands for taxation changes, and paid a large sum of money. The New
Zealand police are investigating the attempted extortion and are treating
the letter as a hoaxref1,
ref2.
All stock will be checked every 48 hours for 14 days -- the longest possible
incubation period for FMD before clinical symptoms appear. Pigs are by
far the greatest risk of spread, but there are few pigs on Waiheke Island.
Cattle and sheep are a much lower risk -- there are some 2500 cattle and
18 000 sheep on the island. FMD is an unwanted organism under the Biosecurity
Act of 1993. Anyone convicted of spreading it faces a penalty of up to
5 years' imprisonment or a fine up to $100 000 [USD 73 000]. Under the
Crimes Act anyone convicted of threatening to commit a crime that would
cause major damage to the economy can be sentenced to 7 years in jail.
Section 298A stipulates that anyone causing disease or sickness to animals
can be sentenced to up to 10 years in jail. A 2nd letter, received 16 May
2005 by Wellington's Dominion Post newspaper, has stated that the claims
made last week are a hoax and that no FMDV was released in New Zealand.
As a result of this additional information and the surveillance results
thus far, MAF now intends to remove the legal restrictions covering the
movement of animals and risk goods off Waiheke Island by 5 p.m. on Tue
17 May 2005. MAF will, however, continue with a low level of monitoring
of livestock on the island until 23 May 2005
Lab escapes :
-
early to mid-1960s outbreak of FMD a few miles from the Animal Virus Research
Institute at Pirbright, UK, in a ?dairy herd, when the former was doing
experiments on birds possibly transmitting virus and the infected animals
were in a loose box (stable) one side of an open courtyard, and target
animals on the opposite side
-
the other was from an offshore Danish FMD research institute that affected
a herd some kilometers away in Norway, about the same time. Present institutional
construction has dealt with any such risks today.
The introduction of FMD (and other disease agents) into disease-free countries
through untreated animal products, such as meat and offal from infected
countries, being fed to pigs as "swill" or catering waste -- is a notorious,
long-known phenomenon. This route has been also suspected to be the one
by which FMD was introduced into the UK in 1967 and 2001. One of the main
recommendations of all 3 official inquiries into the last UK FMD outbreak
was: "Stringent checks on pig swill operators to ensure food was being
boiled for an hour to kill off disease". The EU has consequently tightened
its own control upon such practices, including new regulations.
FMDV crosses the placenta and causes death in fetal lambsref
Laboratory examinations : the tissue of
choice is epithelium. Ideally, at least 1 g of epithelial tissue should
be collected from an unruptured or recently ruptured vesicle. Where epithelial
tissue is not available from ruminant animals, for example in advanced
or convalescent cases, or where infection is suspected in the absence of
clinical signs, samples of OP fluid can be collected by means of a probang
(sputum) cupref.
These
tests may occasionally give false positives, mainly in older animals
with a history of regular repeated vaccinations. A negative result for
antibody to NS proteins cannot be taken as definitive proof that an individual
animal has not been exposed to FMD virus. This must be taken into account
if NS protein antibody tests are used for assessment of risks for animals
involved in international trade. Anyway an ELISA test looking for antibodies
recognizing strain-independent infection-specific linear B-cell epitopes
located in the nonstructural (NS) proteins has been recently developed
to differentiate between infected and vaccinated cattle. However, an issue
not yet solved is the identification of "carrier" animals, which can be
produced by vaccination and consecutive infection. These animals without
FMDV symptoms are a continuous threat for nonvaccinated animal populations.
A sensitive method for detection of these animals is highly important for
FMDV diagnosis; the author say that detailed analyses of carrier animals
and their antibody repertoire will be the subjects of further studies.
Prognosis : left alone, adult animals
recover within weeks.
Prevention : the animal vaccineref
takes 7 days to be effective, hence IFN-a
has to be used in the meanwhile.
Generally meat from FMD infected animals -- with thorough cooking --
is considered safe for consumption. But transporting the animal to the
processing plant may spread the disease, which is why most infected animals
are not transported to a processing plant. Routine vaccination against
FMD is done on a regular basis in Egypt using locally manufactured oily
dead virus vaccine against FMD serotype O1. Vaccination by bivalent strains
of FMD (A and O) will be undertaken. Some countries in the Middle East
have been applying annual vaccinations with a trivalent vaccine, including
the serotypes O1, A22 and Asia 1. It is not clear whether these vaccines
will protect against the Egyptian strain. The genotyping of the Egyptian
FMD A virus, and its relationship to vaccine strains currently in use within
the region, such as <A22 Iraq 87> and <A Iran 96>, are urgently required.
Samples from Egypt were tested by the World FMD Reference laboratory WRL
at Pirbright. The results were included in the February 2006 report: the
strains, EGY 1/2006 Cattle 09.02.06 and EGY 2/2006 Cattle 09.02.06, were
found to be serotype Aref.
No additional data on the said strains, with special reference to their
genotyping, could be found on the WRL's website. Their relations to other
FMD A genotypes -- particularly potential vaccine strains -- are of importance.
Such data, and provision of seed material of the candidate vaccine strains,
are needed urgently for the selection and production of efficient vaccines
to prevent further spread in Egypt and elsewhere. In the past, the Middle
East witnessed major FMD pandemics which spread throughout the entire region
and, in several occasions, reached southeastern Europe
Web resources : The OIE/FAO-designated
World
Reference Laboratory for FMD (WRLFMD)
..., Vesicular
stomatitis virus (VSV)
-
milk
-
Mycobacterium bovis
: 15.8% of cattle in Devon, UK has been hit by an outbreak of bovine
tuberculosis (BTB), with 537 new outbreaks in 2003. The 3 English culling
trials, prior to 1998, at Thornbury, Steeple Leaze and Hartland
Point and the large Irish trial in East Offaly achieved badger
culling targets, which are seen as the main carrier of the disease, > 80%
and produced a profound and sustained reduction in bovine TB in associated
cattle herds. Eradication of bovine TB reduces disease and death from tuberculosis
among farmers and people in contact with infected cattle, or who drink
unpasteurized milk. Bovine TB had spread to deer, yellow-necked mouse,
wood mouse, shrew, polecat, muntjac and stoatref.
-
pearl disease : bovine tuberculosis of the peritoneum and mesentery
in which the tubercles are calcified and pearllike
A 1-million-pound [USD 1.8 million] field trial of a vaccine to combat
tuberculosis in badgers has been launched by the government in June 2006.
The trials in Gloucestershire could lead to > 100 000 badgers being
vaccinated nationwide. Badgers can carry bovine tuberculosis which they
catch from cattle and other badgers before spreading it to herds. In 2005
24,000 cows infected with TB were put down and the cost of compensating
farmers and testing for the disease was 92 million GBP [USD 168 million].
The Randomised Badger Culling Trials demonstrated that if you do not achieve
culling targets > 60% (and sometimes these were < 20%), you will only
make matters worse -- because of so called 'perturbation'. Incomplete badger
culling can actually exacerbate the problem by the perturbation or fringe
effect whereby inefficient culling disturbs and disperses infected badgers
over a wider area. Prior to 1998 the During the subsequent 8 years of the
Randomised Badger Culling Trials saw a significant increase in the numbers
of TB-reactor cattle slaughtered from 5000 cattle slaughtered as reactors
in 1998 to over 25 500 slaughtered in 2005. Bovine TB was practically eradicated
in the UK by 1986 by proactive badger culling along with tuberculin testing
of cattle when only 84 herd breakdowns were recorded in that year. But
in 1982 doubts had been raised about the welfare aspects of the gassing
method used and culling was modified first to a clean ring trapping policy
and then to limited on-farm reactive culling. And from 1997, except for
the RBCTs, culling was abandoned altogether. Since then the incidence in
cattle has taken off and is now increasing 18-20 percent year on year and,
as the UK Government acknowledges in their report of 2004, if the present
policy of inaction continues there is no way but up! In enzootically infected
areas at least a quarter of badgers carry the disease (26% in 1998, when
figures were last available). Highly susceptible cattle simply act as sentinels
for the disease in badgers. Thus killing more and more cattle will not
and cannot solve the problem. Much of the problem associated with bovine
TB in UK and Ireland is because the badger -- a species without natural
predators and protected by law since 1973 -- is now a classic example of
a population out of control through lack of management. The population
has probably increased 10-20 fold in the last decade and, apart from being
a potential reservoir of a serious zoonotic disease, the animal has now
become a major agricultural pest across the country from a) the damage
that it does by digging and, b) from its predation on ground nesting birds,
hedgehogs, and newborn lambs. Furthermore it is probable that the substantial
increase in numbers of badgers over the last decade will have contributed
in
part to the perturbation problem in high-density areas. The badger is not
an endangered species and no longer merits its protected status. Culling,
when done efficiently, i.e. when delineated areas are free of badgers for
at least 12 months, has an immediate disease control benefit. In the UK
there is a stark dichotomy between the demands for culling by the farming
community, including wildlife veterinarians, and the extreme reluctance
on the part of the government
-
Mycobacterium
avium subsp. paratuberculosis
(Johne's disease / chronic dysentery of
cattle / paratuberculosis : a usually fatal form of chronic distal
enteritis or proctitis
,
affecting chiefly cattle but also ruminants (including Oryctolagus
cuniculus, Ovis
aries, Lama
pacos and Capra hircus)
and other animals. It remotely resembles a tuberculous infection, and is
marked by lymphangitis
or mesenteric lymphadenitis
,
intermittent or persistent diarrhea, progressive emaciation, anemia, and
extreme weakness. MAP can live undetected in cattle for years. Infected
cows secrete the bacteria into their milk and on to their pastures)
-
cowpox virus

-
pseudocowpox virus / paravaccinia
virus / milker's nodule virus (MNV)

-
Russian
Spring-Summer encephalitis virus (RRSEV)

-
the 2002 NAHM's Dairy Survey indicated that 87.2% of dairy farms in the
United States feed waste milk to their neonatal calves. Although cost-effective,
this practice can lead to increased calf morbidity and mortality due to
ingestion of pathogenic agents. In an effort to reduce the risk of infection,
dairy producers are implementing on-farm pasteurization of the waste milk
as a control procedure before feeding the milk to calves. In the present
study, the efficacy of a commercial high-temperature, short-time (HTST)
on-farm pasteurizer unit to destroy MAP, Salmonella enterica spp.,
and Mycoplasma spp. in raw milk was evaluated. Replicate experiments
were run for 3 isolates of M. paratuberculosis, 3 serovars of Salmonella
(derby, dublin, typhimurium); and 4 species of Mycoplasma (bovis,
californicum, canadense, serogroup 7) at 2 different levels of experimental
inoculation. In addition, HTST pasteurization experiments were performed
on colostrum experimentally inoculated with MAP. After culture of the pasteurized
milk samples, no viable MAP, Salmonella, or Mycoplasma were
recovered, regardless of species, strain, or isolate. Pasteurization of
colostrum was also effective in the destruction of MAP but resulted in
an average 25% reduction in colostral immunoglobulin. These results suggest
that HTST pasteurization is effective in generating a safer product to
feed to young calvesref.
-
CNS :
-
PrPSc
=> bovine spongiform encephalopathy
(BSE) / mad-cow disease is a TSE
.
The first clinical case occurred to cow 142 from Pitsham Farm in Sussex
on December 22, 1984 but the existence of a new disease was first confirmed
microscopically in November 1986. It was not, however, until June 1987
that the Consultant Pathology Unit at the Central Veterinary Laboratory,
Weybridge, UK, confirmed this as a case of BSE. However, the BSE inquiry
("Lord Phillips Report", October 2000) further remarked that Epidemiological
evidence given to the Inquiry suggests that it is likely that the first
cases of BSE probably originated early in the 1970s - possibly a single
cow or other animal that developed the disease as a consequence of a gene
mutation
-
infection is acquired by some animals between age
3 and 5 by eating ruminant-derived processed animal proteins (PAPs)
including meat and bone meal (MBM) : 2.5-6 years of incubation =>
circling.
At least 3 oral challenge trials are being performed in various countriesref1,
ref2
:
-
in DEFRA's research project SE1736 (1998-2004), groups
of calves were challenged orally with either 100g or 1g of BSE infected
bovine CNS of known infectious titre. Tissues and fluids were also produced
from age matched controls kept under similar husbandry conditions. In the
100g challenge group, a wide range of tissue and fluid samples were collected
at 3 month intervals from 30 months post-challenge. In the 1g challenge
group, a wide range of tissues and fluids were collected at approximately
6 month intervals from 36 months post-challenge. The tissues and fluids
from these animals have been collected following strict protocols and are
archived under ISO9001 conditions. The TSE
archive of the Veterinary Laboratories Agency (VLA) represents a valuable
resource of bovine BSE materials, which is used within the UK program and
may be supplied to those engaged elsewhere in BSE research, particularly,
but not exclusively, for the development of diagnostic tests. As this is
a limited and valuable long term resource, the approval of requests, and
release of material, is through an independent archive advisory group (IAAG)
made up of scientists with TSE research experience. IAAG consists of 6
researchers from the UK, France and Germany and provides an external review
to ensure all requests are dealt with fairly. Officials from Defra, the
Food Standards Agency and the European Commission oversee the group
-
another trial is led by a special BSE infection unit
of the Institute of Novel and Emerging Infective Agents (INNT) at the Federal
Research Centre for Virus Diseases of Animals (BFAV) on the Island of Riems
(a tiny island in the Baltic sea). In this study, begun in early 2003,
56 calves were orally challenged (100g brain stem homogenate each, 1st
group (28 animals) in Jan 2003, 2nd group (28 animals brought to the Island
of Riems after 6 weeks and quarantined for further 4 weeks) in May 2003).
Another 18 calves serve as controls. Blood (serum, plasma etc.), CSF, and
urine samples regularly (2 to 4 samples per month) are collected, and selected
animals are serially killed and autopsied. From each animal, a panel of
more than 120 tissue and bodily fluid samples are taken and preserved in
a number of ways (frozen, snap-frozen, formalin-fixed etc.). All samples
are taken under BSE-sterile conditions. Samples considered to be important
in terms of BSE pathogenesis, and consumer safety, are used in a bioassay
experiment utilizing bovine PrPC over-expressing transgenic
mice, which are lacking a species barrier for cattle BSE infectivity. British
scientists have supported this infection trial in providing > 5 kg brain
tissue from BSE cattle. The study aims to research the course of infection
from the start of the infection until the outbreak of the disease. During
the 1st year of this trial, 9 out of the 56 challenged calves have been
sacrificed and 38 000 specimens collectedref.
As of May 2004, > 60 000 samples have been collected from the animals of
the German BSE pathogenesis study, and > 200 000 samples will have been
taken by the end of the experiment in the year 2007ref.
> 4000 samples have already been distributed to German TSE research groups
and commercial test developers. This experiment is a German initiative
within the framework of the German TSE
research platform. The distribution of the samples is regulated by
the TSE-platform's advisory board, which is composed of elected members
-- German TSE researchers -- as well as the heads of the German CJD and
BSE archives.
-
tallow-based calf milk-replacer (CMR) associated
with the allowable levels of impurities in tallowref.
Interestingly, EU's Scientific Steering Committee has not classified cattle
tallow derivatives as "not infectious"
Feeding of ruminant derived protein to ruminant
animals has been forbidden in UK in July 1988 (in Canada in 1997): PAPs
are better detected with immunoassays than with PCR.
-
transplacental transmission may occur
-
10-fold concentrated urinary proteins from scrapie-infected mice with lymphocytic
nephritis induced scrapie upon inoculation into 50% of noninfected indicator
mice. Prionuria was found in presymptomatic scrapie-infected and in sick
mice, whereas neither prionuria nor urinary PrPSc was detectable in prion-infected
wild-type or PrPC-overexpressing mice, or in nephritic mice inoculated
with noninfectious brain. Thus, urine may provide a vector for horizontal
prion transmission, and inflammation of excretory organs may influence
prion spread The research may explain how animals such as sheep, elk and
deer transmit prion diseases. In the USA, a chronic
wasting disease is spreading like wildfire among elk and deer. About
20% of the wild deer in some parts of Colorado are infected, and yet these
animals are herbivores. Nobody understands what controls the spread : dust
mites have been suggested as one method of transmission. Animals may be
eating urine-contaminated grass. An explanation that involves urine has
difficulties however : the concentration of prions found in the mouse urine
in the experiment was 10,000 times lower than in the lymphatic organs,
and a million times less than in the brains, the original site of infection.
The risk of getting sick by touching or ingesting infected urine is minuscule.
Quite apart from the low concentration of prions in urine, it would take
a higher dose of the proteins to cause infection this way than through
injection into the brain. As yet, there are no data on the risk that might
be attached to contact with urine from vCJD patients. On the other hand,
nobody wants human prions in the hospital laundryref
Surveys conducted by USDA place the number of
downer cattle (those that have trouble walking to the slaughterhouse under
their own power) at between 150 000 and 200 000 animals annually. Downer
cows does not mean diseased cows. It means the animal cannot get up, because
of a torn tendon, perhaps from a rough trailer ride, or a broken bone from
a slippery floor. There are reasons that animals can fall, and can be injured.
It does not mean they have a neurological disease. Other reasons for "downer
cattle" include having a large calf, which can injure the obturator nerve
as the calf squeezes through the birth canal. Though neurological disease
is not a factor in the ratio of the size of the calf vs that of the birthing
canal, a downer cow is the result. This is not brain-related neurological
disease any more than if a severed spinal cord on an athlete resulted from
a throw from his polo pony. Whatever the reason the animal is down, this
status now means this animal will not be allowed into the human food chain.
Those downers will still be used for pet food and other products, including
tallow and cosmetic ingredients [There certainly is nothing more than speculation
at the moment as to what the downed animals may go for. However, these
cows are not likely to be used for pet food. The final rules are not yet
complete, but many of the pet food manufacturers do not want downer animals,
because they want to be assured of the safety of the pet food, and because
some indigent people consume pet food.]. Affected animals will no longer
be going to slaughterhouses but instead most likely most of them will be
euthanized and sent to rendering plants, whose products fall within
2 major categories :
-
proteins
-
meat meal is seldom produced as per definition
anymore, but when used was in pet food as applicable.
-
meat and bone meal (MBM) can generally be
made from raw material of all livestock species. Obviously with the current
feed rule, if the product contains raw materials originating from ruminants,
it cannot be fed to cattle or other ruminants. MBM could be made from pure
bovine, porcine tissues, etc. and traded as such. This may include blood
meal, spray-dried animal blood, poultry meal, poultry byproduct meal, poultry
hatchery byproducts, and blood protein. MBM is allowed to be in pet food.
However, the pet food industry does not want downer animals in its products,
and is actively working to institute a similar ban.
-
fats : tallow, lard, gelatin, greases (yellow
and white), fatty acids, glycerine, etc. can be used in the human food
chain. So the key for use of rendered products in the human food chain
(lard, tallow, gelatin) must be inspection by the Food Safety nspection
Service (FSIS). They are products that have scientifically been shown not
to harbor prions.
-
fish meal and bakery byproduct meals
(those damaged packages of Twinkies, potato chips, corn chips, and other
similar products that are crushed and recooked to make a pleasant grain-based
product that may be fed to some pets). Their uses include livestock and
poultry feeds; pet foods; industrial uses such as lubricants, paints, ipsticks,
gums, glues, etc. None of the bakery by-products goes into the human food
chain. Blood meal has not been shown to process the prion agent. However,
it is used by gardeners.
Rendered products are not found in baby food products, aside from possibly
fats (lards), which are inspected for safety and cleanliness by the FSIS.
Specified
risk materials / specified bovine offals (SBO) whose use in the human
food supply and advanced meat recovery (AMR) (an industrial technology
developed a decade ago that uses hydraulic pressure to force extra pounds
muscle tissue from the bone of cow carcasses, without incorporating bone
material when operated properly, producing filler for processed foods like
hamburger, hot dogs, and pizza toppings. Consumer groups initially complained
that bone was getting into the advanced meat recovery product and argued
that the product should not be labeled as beef. Then, in 1997, federal
agriculture officials announced that they had found spinal cord tissue
in some of the meat) is prohibited by USDA include skull, brain, trigeminal
ganglia, eyes, vertebral column, spinal cord, and dorsal root ganglia (DRT)
of cattle over 30 months of age, and tonsils and small intestine of cattle
of all ages. The 1997 ruminant-to-ruminant feeding ban was changed in Dec
2003 to a mammalian-to-ruminant feeding ban, which means that no
mammalian tissue can be processed and fed to ruminant animals (cattle,
goats, and sheep). The use of these animals as feed for birds, specifically
commercial poultry (chickens and turkeys) has caused some concern. Poultry
litter is often fed back to cattle, and the concern is that any prion may
pass through the litter and be transmitted to the ruminant animal. There
is little concern that birds are susceptible to prion agents : although
genetically modified chickens have been made to produce the disease under
experimental conditions, it is not found naturally. Likewise, the issue
of fish being susceptible to prion disease has not been proven in the natural
setting, and is again of little concern. One must understand that feed
manufactures and renderers are not the same. Renderers produce a starting
material that is delivered to the feed manufactures. Feed manufactures
include a variety of livestock feed manufacturers as well as pet food manufacturers.
Meat and bone meal is still an acceptable product to be fed to companion
animals. To ensure that portions of the brain are not dislocated into the
tissues of the carcass as a consequence of humanely stunning cattle during
the slaughter process, FSIS is issuing a regulation to ban the practice
of air-injection stunning. USDA will prohibit use of mechanically separated
meat in human food. In June 2006 cattle tissue may have contaminated 2
feed ingredients given to dairy cows -- Pro-Lak and Pro-Amino II -- made
by H.J. Baker between August 2005 and June 2006. The 3rd of the recalled
ingredients, Pro-Pak with Porcine Meat and Bone, was mislabeled. It is
used in poultry feedref.
The methodology by which the Geographical
BSE Risk (GBR) of countries is assessed was developed by the Scientific
Steering Committee (SSC) of the EU as a qualitative indicator for the likelihood
of BSE being present in the relevant countries, basically trying to answer
2
questions:
-
is there a risk that the BSE-agent was imported into
the country under consideration ("external challenge")?
-
if the BSE-agent was introduced into a country, would
it have been recycled and amplified ("unstable" situation) or was the BSE/cattle
system of that country able to eliminate the agent ("stable" situation)?
The GBR of 66 countries has already been evaluated
by the SSC and its successor, EFSA's GBR working
group. Currently, the 4 categories ("levels"), pertaining to the "Presence
of one or more cattle clinically or pre-clinically infected with BSE agent
in geographical region/country", include the following countries:
-
level I (highly unlikely) : Argentina, Australia,
Botswana, Brazil, Chile, El Salvador, Iceland, Namibia, New Caledonia,
New Zealand, Nicaragua, Panama, Paraguay, Singapore, Swaziland, Uruguay,
Vanuatu
-
level II (unlikely but not excluded) : Colombia,
Costa Rica, India, Kenya, Mauritius, Nigeria, Norway, Pakistan, Sweden
-
level III (likely but not confirmed or confirmed,
at a lower level) : Albania, Andorra, Austria, Belarus, Belgium, Bulgaria,
Canada, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Ireland (Eire), Israel, Italy, Japan, Latvia,
Lithuania, Luxembourg, Macedonia (FYR), Malta, Mexico, Netherlands, Poland,
Romania, San Marino, Slovak Republic, Slovenia, South Africa, Spain, Switzerland,
Turkey, USA
-
level 4 (confirmed, at a higher level) : Portugal,
UK
OIE defines a minimal risk country as having had < 2 cases per million
cattle over the age of 24 months.
The reclassifications of Canada and the USA,
from GBR category II ("unlikely but not excluded") to category III ("presence
of BSE likely but not confirmed, or confirmed at a lower level"), were
inevitable since the detection of their 1st BSE cases. Norway's reclassification
from "highly unlikely" to "unlikely but not excluded" means its exporters
will have to remove more of the "significant risk material (SRM)" before
shipping beef into the EU. GBR re-assessments of Botswana, Costa Rica,
El Salvador, Nicaragua, Namibia, Panama and Swaziland, presently classified
in level I, are expected before the end of 2004.
These 23 countries reported > 184 000 indigenous
cases since 1987 to 7 Dec 2004 :
-
UK is classified in the highest (GBR IV) EU risk
category group. > 95% of BSE cases were detected before 2000 : incidence
peak occurred in 1992 (37 000, 700 new cases per week) and is currently
declining by some 40% year-on-year : 184 138 cows have died from BSE since
1987 (1443 (270.56 per million bovines aged over 24 months) in 2000, 1202
(232.76 per million bovines aged over 24 months) in 2001, 1144 in 2002
(445 clinical cases and 594 cases detected by tests; 228.24 per million
bovines aged over 24 months), 611 (122.44 per million bovines aged over
24 months) in 2003, 343 (67.796 per million bovines aged over 24 months)
in 2004, 151 in 2005. There are estimated to have been 4 million BSE infected
cows compared with 184 131 officially reported cases
-
Portugal is classified in the highest (GBR IV) EU
risk category group : 949 cases since 1987 (186.95 indigenous cases per
million bovines aged over 24 months; 110 cases (137.88 per million bovines
aged over 24 months) in 2001; 86 (107.80 per million bovines aged over
24 months) in 2002; 133 (137.19 per million bovines aged over 24 months)
in 2003; 91 in 2004 (93.870 per million bovines aged over 24 months); 13
at 22 Apr 2005)
-
Ireland : 1470 cases since 1987 (38.17 per million
bovines aged over 24 months in 2000 (annual incidence rate in cases detected
by the active surveillance programme = 17.93; annual incidence rate in
BSE clinical cases = 35.356, 246 (61.80 per million bovines aged over 24
months; annual incidence rate in cases detected by the active surveillance
programme = 29.90; annual incidence rate in BSE clinical cases = 30.90)
in 2001; 333 (88.39 per million bovines aged over 24 months) in 2002; 183
(57.81 per million bovines aged over 24 months) in 2003, 117 (43.327 per
million bovines aged over 24 months) in 2004, 23 at 22 Apr 2005). According
to official Irish statistics, the percentage of cases diagnosed in animals
less than 6 years of age has declined from 40% in 2000 to 16% in 2001,
2% in 2002, and 0% in 2003.
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Spain : 532 cases since 1987 ((0.59 per million bovines
aged over 24 months), 82 in 2001 (24.23 per million bovines aged over 24
months), 127 in 2002 (37.95 per million bovines aged over 24 months); 167
in 2003 (46.31 per million bovines aged over 24 months), 137 in 2004 (38.945
per million bovines aged over 24 months), 12 at 22 Apr 2005). It
is the only European country not showing, in 2003, a decline in the number
of diagnosed cases
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Switzerland : 456 cases since November 1990 ((40.6
per million bovines aged over 24 months); 42 (49.1 per million bovines
aged over 24 months) in 2001; 24 (27.93 per million bovines aged over 24
months) in 2002; 21 (24.86 per million bovines aged over 24 months) in
2003; 3 (including a case in a zoo zebu) in 2004 (3.750 per million bovines
aged over 24 months); 0 at 22 Apr 2005). Switzerland reported in November
1990 the first BSE case on the European mainland which could not be attributed
to an animal imported from Great Britain. According to the official Swiss
data, the infection was presumably due to feed constituents that had been
inadequately heated; material which originated from Britain was most probably
given new origin labelling and then imported via an indirect route, as
according to the Swiss foreign trade statistics, only very small quantities
of meat-and-bone meal were imported directly from Great Britain. Switzerland
was the first country to introduce active monitoring of BSE, in 1999; the
Swiss prionic BSE test is used for the systematic testing of groups of
cows at risk. The annual BSE incidence rate (number of indigenous cases
per million bovines aged over 24 months) during the years 1999-2003 was
58.7, 40.6, 49.1, 27.93, and 24.86, respectively
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Belgium : 127 cases since 1987 (5.53 per million
bovines aged over 24 months in 2000; 46 (28.22 per million bovines aged
over 24 months) in 2001, 38 (25.75 per million bovines aged over 24 months)
in 2002, 15 (10.54 per million bovines aged over 24 months) in 2003, 11
(7.882 per million bovines aged over 24 months) in 2004, 1 at 22 Apr 2005)
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France : 946 cases since 1991 (14.73 per million
bovines aged over 24 months in 2000 (annual incidence rate in animals euthanised
or found dead = 5.45; annual incidence rate in BSE clinical cases = 9.27;);
274 in 2001 (19.70 per million bovines aged over 24 months); 239 in 2002
(20.96 per million bovines aged over 24 months); 137 in 2003 (12.01 per
million bovines aged over 24 months), 54 in 2004 (4.736 per million bovines
aged over 24 months), 31 in 2005, 6 in 2006ref.
> 301 200 cattle in France may have been infected with BSE since the disease
first appeared in the 1980s to June 2000, based on the amount of meat and
bone meal (MBM) from the United Kingdom used in France during the 1980s
(46 000 tons between 1986 and 1990), and the fact that most cattle are
infected with the disease between the ages of 6 to 12 months. There is
uncertainty about estimates of the number of cases in the early 1980s,
but the level of animals infected climbed between 1987 and 1990 and dropped
from then until 1992. Furthermore, 47 300 animals at an advanced stage
of the disease entered into the food chain before 1996, and 1500 between
July 1996 and June 2000. According to previous official figures there were
just 103 confirmed cases of the disease between 1991 and 2000, during which
period the government relied on farmers and veterinarians to report animals
with BSE. Since 2000, when controls were tightened, a further 820 cases
have been confirmed, according to figures published last month, bringing
the total to 923 over the past 13 years. The
majority of beef cattle in France are slaughtered before 24 months of age.
The infected animals would have been killed before the disease could have
shown itself, because of BSE's long incubation period. In 1989, France
banned the use of meat and bone meal in cattle feed. The law was modified
only in June 1996 (almost 7 years after Britain) and 2000 to ban it from
being fed to all ruminant feeds. Just 4 years ago, as France ignored a
European Union ruling that British beef was safe again, infected cattle
were still entering the food chain. The discovery of an apparent link between
BSE and its human equivalent, vCJD, was made in 1996 and led to a worldwide
ban on British beef. The ban was lifted by the EU 1999 but illegally maintained
by France until 2002. Yet it was not until 2001 that France introduced
compulsory tests for BSE in cows, older than 24 months, sent for slaughterref.
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Slovakia : 20 cases (5 in 2001 (18.34 per million
bovines aged over 24 months), 6 in 2002 (18.73 per million bovines aged
over 24 months); 2 in 2003 (6.74 per million bovines aged over 24 months);
7 in 2004 (24.635 per million bovines aged over 24 months); 0 at 22 Apr
2005)
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Czech Republic : 15 cases since 1987 (2 in 2001 (2.85
per million bovines aged over 24 months), 2 in 2002 (2.50 per million bovines
aged over 24 months), 4 in 2003 (5.78 per million bovines aged over 24
months), 7 in 2004 (10.234 per million bovines aged over 24 months), 3
at 22 Apr 2005)
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Slovenia : 5 cases since 1987 (1 in 2001 (4.34 per
million bovines aged over 24 months), 1 in 2002 (4.44 per million bovines
aged over 24 months), 1 in 2003 (4.39 per million bovines aged over 24
months); 2 (including an animal born in Germany) in 2004 (4.585 per million
bovines aged over 24 months); 0 at 22 Apr 2005)
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Germany : 362 cases since 2000 (1.07 per million
bovines aged over 24 months in 2000; 125 in 2001 (19.97 per million bovines
aged over 24 months); 106 in 2002 (17.02 per million bovines aged over
24 months); 54 in 2003 (8.71 per million bovines aged over 24 months),
64 in 2004, 15 at 22 Apr 2005; the number of BSE-positive cases detected
in Germany since 2001, according to their respective years of birth, is
as follows: 2 in 1992; 3 in 1993; 13 in 1994; 80 in 1995; 123 in 1996;
29 in 1997; 18 in 1998; 13 in 1999; 0 in 2000). The 1st case of BSE in
native cattle is reported from Germany in 2000. However, according to EU's
Geographical BSE-Risk (GBR) opinion, exported German cattle could have
been contaminated since 1988
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Greece : 1 only case since 1987 in 2001 (3.3 per
million bovines aged over 24 months)
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Liechtenstein : 2 cases between 1987 and 2000
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Luxembourg : 2 cases since 1987 (1 in 2002) (14.54
per million bovines aged over 24 months)
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Austria : 2 case since 1987 in December 2001 (in
Lower Austria federal province) and in 2005. In the latter case an 11 year
old cow from a small farm with 8 cattle and 2 pigs located in Riezlern,
Bregenz district, Vorarlberg federal province, in the western part of the
country, near the German border. The farm is not a member of a breeding
association; there was never any purchase of animals. No live animals have
ever been sold; all cattle to be slaughtered were taken directly to the
slaughterhouse. The affected cow had ear tag number AT 138 752 583. It
was born on 31 Mar 1994 at the farm and was found dead on 26 May 2005.
The most recently born offspring of the affected cow (calf AT 583 539 672,
born on 24 Jan 2005) was slaughtered on 26 Apr 2005. 2 offspring of the
affected cow were still on the farm when the farm was quarantined (cow
AT 777 654 242, born in 2002, and female calf AT 079 944 747, born in 2003,
on pasture). Feed: concentrated feed, whole meal, beet. Since 2002, controls
of feeding stuff providers are carried out every year in spring on the
occasion of farm audits. The feeding ban was met completely. Before 1995,
concentrated feed was imported from Germany. The affected cow was well-fed
and delivered about 9 litres of milk per day. During the period prior to
its death it showed movement disorders, with no improvement after hoof
trimming. The head was held in a low position but there were no disturbances
in excretion or behaviour. The owner ascribed the movement disorders to
the age of the cow and did not consult a veterinarian. The Austrian Federal
Ministry of Health and Women was informed of the suspicion of BSE by the
German Federal Ministry of Consumer Protection, Food and Agriculture on
17 Jun 2005. The affected cow had been delivered to a rendering plant in
Germany. Samples for BSE testing were taken in Germany. Due to the fact
that the 1st rapid test was positive, the sample was sent to the German
National Reference Laboratory in the isle of Riems on 16 Jun 2005. A rapid
test made at Bavarian Department for Health and Food Safety (Bayerisches
Landesamt fuer Gesundheit und Lebensmittelsicherheit, Dienststelle Oberschleissheim),
Oberschleissheim, Germany, on 15 Jun 2005 was positive (twice). Immunohistochemistry
made at Friedrich-Loeffler Institute, Riems, Germany, on 21 Jun 2005 resulted
positive. All 7 animals were slaughtered and cremated. Agriculture Minister
Josef Proell said it was a standard safety procedure in Austria for cattle
older than 24 months that die of unknown causes to be tested for BSE. As
this cow died unexpectedly in late May after showing suspicious signs including
tiredness, it was tested. Feeding animal meal to farm animals has been
banned in Austria since 1991. If one carefully reads the Opinion of EU's
Scientific Steering Committee on the GBR (Geographic Risk of BSE) in Austria,
adopted on 16 May 2002, the occurrence of a 2nd case, particularly in a
cow born prior to 2001, should not be overly surprising. According to the
opinion, Austria was exposed to a very high external challenge from 1980-2000
due to import of large numbers of live cattle (about 190,000) and large
amounts of MBM (meat and bone meat; 45 000 tons according to the country
or 95,000 tons according to Eurostat and other export statistics) from
BSE-risk countries. While significant fractions of these imports most likely
did not enter the Austrian BSE/cattle system it was very likely that the
BSE agent was imported into the country. Taken account of the information
available on the origin and use made of the imported cattle and MBM it
was concluded that the external challenge from cattle imports was high
for 1986 to 1995 and very high for the period 1996-2000. On the other hand,
MBM imports were posing a very high external challenge throughout the period
1980 to 2000. Though feed controls have been implemented since 1990, cross-contamination
still appeared until 2001, there are at present still 2 EU member-countries
with only one recorded BSE case: Greece and Finland. Luxembourg, like Austria,
has had 2 cases
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Denmark : 16 Danish-born BSE cases since 1987. 13
of the cases were diagnosed in Denmark (2000-1 (1.14 per million bovines
aged over 24 months); 2001-6 (6.77 per million bovines aged over 24 months);
2002-3 (3.35 per million bovines aged over 24 months); 2003-2 (2.39 per
million bovines aged over 24 months), 2004-1 (1.296 per million bovines
aged over 24 months), 2005-Apr-22-0). 2 were diagnosed in Portugal and
1 was found in Italy. In 1992, there was one case in a cow imported from
Scotland.
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Swedenref
: a 12 year old domestic cow at a farm in Vastmanlandref
in central Sweden showed signs of the illness on Mar 2, 2006 and tested
positive on Mar 3ref.
Sweden has not recorded any case, and is the only EU country of which the
GBR rating is II, namely that "It is unlikely that domestic cattle are
(clinically or pre-clinically) infected with the BSE-agent, but it cannot
be excluded". All other EU countries have been rated as GBR III, namely
"BSE has been confirmed, or it is likely but not confirmed that one or
several domestic cattle are (pre-clinically or clinically) infected with
the BSE-agent". The 12-year-old beef cow of mixed Charolais breed was born
on a farm of 50 cattle in Sweden. She was in late pregnancy, had shown
difficulties in rising for approximately 2 weeks, did not respond to treatment,
and was euthanized and sent to destruction to a rendering plant. Brain
stem sampling was done in accordance with the EU legislation for BSE testing.
The sample was positive in the rapid/screening test (Biorad TeSeE ELISA)
with an OD value of 2,42 in the 1st testing, 2,76 and 2,88 in the 2nd testing
of the same preparation and of 3,22 in the 3rd testing from a new brain
homogenate (cut-off value for all the runs was 0,22). The confirmatory
testing, conducted at SVA (National Veterinary Institute of Sweden), were
Western immunoblotting (TeSeE Western Blot, Biorad) and immunohistochemistry
employing F89/160.1.5 antibodies; both tests were positive. In the immunohistochemistry,
11 pieces of brain stem were analyzed; all of them showed diffuse granular
positive immunostaining of the grey matter, including the BSE target brain
areas. All TSE testing, including all the screening testing for Sweden,
is conducted at SVA and is quality-certified. The current BSE-surveillance
in Sweden involves testing of all fallen stock and all emergency slaughtered
cattle above 24 months of age as well as a yearly random sample of 10,000
cattle above 30 months of age at normal slaughter. Between 2001 and 2005,
> 170,000 cattle were tested; out of these, 46,700 were normal slaughter
and 125,000 were fallen stock and emergency slaughter. All tested negativeref.
An epidemiological investigation on the possible source of infection is
currently underway. Sweden has followed the European Union's legislation
on feed banning. Since January 2001, there is a total ban on the use of
mammalian protein in feed to food animals in order to avoid any possible
cross contamination of the cattle feed at the feed mills.
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Finland : 1 case since 1987 in 2001 (2.39 per million
bovines aged over 24 months)
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Italy : 125 cases since 1987 (48 in 2001 (14.1 per
million bovines aged over 24 months); 38 in 2002 (10.60 per million bovines
aged over 24 months); 29 in 2003 (9.86 per million bovines aged over 24
months); 8 in 2004 (2.348 per million bovines aged over 24 months), 3 at
22 Apr 2005; 67