À especial atenção dos M.V. exercerndo na área da Sanidade Animal e na Produção Aninal (ruminantes)
Schmallenberg virus – Europe (07): update, Germany OIE Schmallenberg virus more difficult to discover in cattle
——————————————————–
It is more difficult to prove the presence of the Schmallenberg virus[SBV] in calves than it is in lambs; on the other hand, the number of reports on congenitally malformed calves is on the increase.
That the virus is difficult to prove in calves is due to the longer gestation period of cattle compared with sheep. “In cattle, the time gap between SBV infection and parturition is significantly longer than in sheep. This decreases the chance of the virus remaining in the
(malformed) foetus until parturition,” said Wim van der Poel of the Central Veterinary Institute (CVI). The same is seen in the related Akabane virus in Asia and Australia. This virus is also more difficult to prove in calves than in lambs.
The calves are born infected or with antibodies. Once a test for antibody is available, it will become possible to say with certainty whether they have had been infected by SBV. Until then, the calves are examined for SBV in the same manner as lambs.
The Dutch Food and Wares Authority (nVWA) gets more and more reports of deformed calves. During the last 10 days, 22 cattle farms with deformed calves have been added to the list. Currently, 86 cattle farms have sent deformed calves to the Animal Health Service (GD). The SBV has not yet been demonstrated in even one of the calves examined in the Netherlands. [According to the data as of noon, 18 Jan 2012, the number of holdings reporting the occurrence of congenital malformations is: cattle 101, sheep 129, goats 11. See
http://www.vwa.nl/txmpub/files/?p_file_id=2201855. – Mod.AS]
The German Veterinary Institute (Friedrich-Loeffler-Institute/FLI), has detected, at the beginning of January 2012, SBV in a stillborn calf. This remains the 1st and only case of the virus shown in calves.
The health service in the German state North Rhine-Westphalia expected in the coming months 15 to 20 per cent of the calves to be born as SBV infected. No forecasts for Dutch calves are yet available. “Assuming that most cattle have been infected during the autumn, I expect a peak of deformed calves in February 2012,” said van der Poel.
[byline: Emmy Koeleman]
—
communicated by:
Sabine Zentis
Castleview Pedigree English Longhorns
Gut Laach
52385 Nideggen
Germany
cvlonghorns@aol.com
[2]
Date: Tue 17 Jan 2012
Source: The Scientist [edited]
http://the-scientist.com/2012/01/17/new-herd-virus-haunts-europe/
New herd virus haunts Europe
—————————-
In November 2011, farmers from Schmallenberg, Germany, noticed that
some of their dairy cows were feverish and not producing much milk.
Not 2 months later, the virus — named the Schmallenberg virus, after
the 25 000-person town — has been observed on around 90 farms [the
number has increased significantly. – Mod.AS] in Germany and the
neighboring countries of Belgium and the Netherlands, affecting adult
cows, and also causing stillbirths and birth defects in calves, lambs,
and newborn goats.
“We are taking this very, very seriously,” Thomas Mettenleiter, head
of the Friedrich-Loeffler-Institute, a German animal health research
center, told ScienceNOW. “Now, in some herds, 20 per cent to 50 per
cent of lambs show such malformations,” including fluid sacs in the
brain and scoliosis, Mettenleiter added. “And most of these animals
are born dead.”
[byline: Hannah Waters]
—
communicated by:
ProMED-mail
promed@promedmail.org
[3]
Date: Fri 13 Jan 2012
Source: ScienceNow (Science magazine) [summ., edited]
http://news.sciencemag.org/sciencenow/2012/01/new-animal-virus-takes-northern-.html.
New animal virus takes Northern Europe by surprise
————————————————–
The virus appears to be transmitted by midges (Culicoides spp.), and
infections likely occurred in summer and autumn of last year [2011],
but fetuses that were exposed to the virus in the womb are only now
being born. The 1st cases of lambs with congenital malformations such
as hydranencephaly — where parts of the brain are replaced by sacs
filled with fluid — and scoliosis (a curved spine) appeared before
Christmas. “Now, in some herds 20 per cent to 50 per cent of lambs
show such malformations,” Mettenleiter [FLI, Riems, Germany] says.
“And most of these animals are born dead.”
Scientists are bracing for many more cases to appear, especially in
cattle, because bovine fetuses infected in summer 2011 would be
expected to be born in February and March 2012.
Virologists have made some headway since they first announced the
detection of the SBV in November 2011. They have been able to isolate
the virus and to culture it in insect and hamster cells. Evidence that
it’s responsible for the observed symptoms has become stronger with
its [demonstration in] brain tissue of affected lambs. “The
characteristic malformations, together with the frequent virus
detection in brains of malformed animals, clearly support a causal
link,” FLI’s Martin Beer says. In a 1st animal experiment, scientists
at FLI also infected 3 cows with the virus and showed that the virus
replicated in them; one developed fever and diarrhea.
FLI researchers have already sequenced the genome of the new pathogen.
Comparisons indicate it is a member of a group called the
orthobunyaviruses. These viruses consist of 3 segments called S
(short), M (middle), and L (long) and are mainly transmitted by
mosquitoes and midges. Although the viruses are best known from Asia,
some have been circulating in Europe for decades. Initially,
scientists said the virus most closely resembled the Akabane virus, a
pathogen that has been found in cattle, buffalo, sheep, camels, dogs,
and other species, leading them to call it an “Akabane-like virus.”
Now they say that at least the S segment of Schmallenberg’s genome is
most closely related to sequences of a different orthobunyavirus
called Shamonda virus. Both Akabane and Shamonda virus belong to the
so-called Simbu serogroup and are known to infect ruminants and to be
transmitted by midges. But there are few orthobunyavirus sequences
available with which to compare the new virus, so scientists are
starting to sequence more members of the family. “Orthobunyaviruses
have been neglected for a long time, and we just don’t know a lot
about them,” says Jonas Schmidt-Chanasit of the Bernhard Nocht
Institute for Tropical Medicine in Hamburg, Germany.
A host of questions remains unanswered. Which vector species is
transmitting the disease? Can animals infect each other directly? And
of course, where did the virus come from? “The problem with
orthobunyaviruses is that their segmented genome makes the emergence
of new combinations very easy, just like with influenza viruses,”
Schmidt-Chanasit says. He points to a recent outbreak of a new
orthobunyavirus in Peru. The pathogen, named Iquitos virus, turned out
to have combined S and L segments of a known virus called Oropouche
and the M segment of a new virus.
Whether the SBV could sicken humans is unknown. At least 30
orthobunyaviruses have been associated with human disease; the
Oropouche virus, also a member of the Simbu serogroup, causes a
febrile disease often associated with headaches, dizziness, skin rash,
and malaise, whereas the Iquitos virus can cause diarrhea, vomiting,
and nausea. But these viruses seem to be dependent on midges to infect
humans and are not known to be directly transmitted from infected farm
animals. Midges are less likely to bite humans than mosquitoes, and
there have been no reports of unusual human illnesses from farmers
whose livestock is infected.
A risk assessment by the European Centre for Disease Prevention and
Control in Stockholm, issued just before Christmas 2011, concluded
that “it is unlikely that this new orthobunyavirus can cause disease
in humans, but it cannot be excluded at this stage.” But the experts
recommended closely monitoring the health of farmers and vets.
In order not to lose time and to answer the most pressing questions
fast, FLI has decided not to file for any patents on
Schmallenberg-related discoveries. “Our resources are limited,”
Mettenleiter says, “and we are happy to share our knowledge and
materials with anyone interested in it for noncommercial or commercial
reasons.” The German and Dutch institutes have divided up the work:
the Dutch researchers will concentrate on sheep, Van der Poel says,
while their German colleagues focus on cattle.
[byline: Kai Kupferschmidt]
—
communicated by:
ProMED-mail promed@promedmail.org
[According to German press (Westfalen Blat, 17 Jan 2012), the FLI has
already collected blood samples from cattle and sheep, which will be
serologically tested as soon as the test becomes available. This will
allow a better evaluation of SBV incidence and of the expected losses
due to the possible occurrence of malformed calves.
On Wed 18 Jan 2012, the German CVO submitted an official notification
to the OIE on the ‘Emerging disease’ Schmallenberg virus. Doing so,
Germany joined the earlier similar notifications from the Netherlands
and Belgium.
According to the notification, the event started on 27 Dec 2011, the
morbidity is 2.88 per cent and the mortality 2.52 per cent; there is
“no zoonotic impact”. The causal agent is ‘Schmallenberg virus’. The
total number of outbreaks is 13, all in sheep, located in the German
states (Landern) Lower Saxony, North Rhine Westphalia, and Hessen. The
reported “susceptible population” counts 2460, number of “cases” 71,
“deaths” 62 ,”destroyed” 6. The notification, including a map, is
available at
http://web.oie.int/wahis/public.php?page=single_report&pop=1&reportid=11514.
The size of the susceptible population with respect to a teratogenic
virus is a complex issue. In fact, the actual susceptible population
is composed of pregnant ewes during the 1st semester of their
pregnancy. If this segment of the population had been considered for
the calculation, the morbidity/mortality rates would have become
significantly higher than the given 2.88 and 2.52 per cent.
Following the notifications from 3 members on SBV, the OIE may
consider adding this disease to its list. – Mod.AS
A HealthMap/ProMED-mail map can be accessed at:
http://healthmap.org/r/1r1l, http://healthmap.org/r/1zJl.]