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Published Date: 2012-09-26 08:25:13
Subject: PRO/AH/EDR> Schmallenberg virus - Europe (60): Austria, UK, Belgium
Archive Number: 20120926.1310236

SCHMALLENBERG VIRUS - EUROPE (60): AUSTRIA, UK (WALES), BELGIUM
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In this post:
[1], [2] Austria: 1st positive serology
[3] UK (Wales): 1st detected cases
[4] Belgium: 2011, wildlife, chronology

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[1] Austria: 1st positive serology
Date: Tue 25 Sep 2012
Source: Austrian Agency for Health and Food Safety (AGES) [in German, machine trans., edited]
http://www.ages.at/ages/gesundheit/tier/schmallenberg-virus/schmallenberg-infektion-erstmals-in-oesterreich-nachgewiesen/

1st identification of Schmallenberg infection in Austrian livestock
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The novel Schmallenberg virus (SBV), which has been spreading throughout Europe since the end of 2011, has now also reached Austria's livestock. In mid-September [2012], AGES detected, within the monitoring system set up since the beginning of 2012, SBV antibodies in cattle and sheep. For people, this virus represents no risk: people cannot become infected either by direct contact with animals or by food of animal origin.

Affected animals become immune after a brief illness, expressed mostly by mild clinical symptoms which are often overlooked by the keeper. Infection in pregnant animals can occasionally cause damage to embryos and problems during parturition. Experience gathered in Germany and the Netherlands shows that about 1 percent of cattle and about 4 percent of sheep flocks suffer SBV-associated abortions or birth of weak calves, lambs, and kids with deformities.

--
Communicated by:
Gert van der Hoek
Senior Moderator
FluTrackers

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[2] Austria: 1st positive serology
Date: Tue 25 Sep 2012
Source: Kleine Zeitung, Austrian Press Agency (APA) report [in German, machine trans., edited]
http://www.kleinezeitung.at/nachrichten/chronik/3125883/schmallenberg-virus-flaechendeckend-oesterreich.story

Schmallenberg virus throughout Austria
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During the 1st half of 2012, not a single case of SBV infection was been detected in Austria. According to information received by APA from an AGES expert, since the end of August/beginning of September [2012], "the virus has been spreading very rapidly throughout Austria." As of today, [25 Sep 2012], 89 percent of the samples -- including samples from suspected animals as well as those from the monitoring program -- have tested positive. So far, only infections have been detected, with no clinical disease which manifests itself in the animals with fever, diarrhea, and reduced milk yield.

The virus is transmitted by midges. So far, it has already been found in Belgium, Germany, France, Britain, the Netherlands, Luxembourg, Spain, Italy, Denmark, and Switzerland.

--
Communicated by:
Sabine Zentis
Castleview Pedigree English Longhorns
Gut Laach
52385 Nideggen
Germany
<cvlonghorns@aol.com>

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[3] UK (Wales): 1st detected cases
Date: Tue 25 Sep 2012
Source: Farmers Weekly Interactive [edited]
http://www.fwi.co.uk/Articles/25/09/2012/135383/Schmallenberg-virus-found-in-livestock-in-Wales.htm

Schmallenberg virus found in livestock in Wales
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Welsh farmers are being urged to be vigilant after the Schmallenberg virus [SBV] was detected in animals in the country for the 1st time.

The virus, which causes severe deformities in lambs and calves, was detected in 3 cows and one calf in Ceredigion.

The Farmers' Union of Wales (FUW) described the development as "very concerning".

The history of the 3 animals suggested they were infected by SBV while on the holding, up to a year ago.

FUW animal health and welfare committee chairman Catherine Nakielny said: "All farmers in Wales need to be on the lookout for any unusually high incidences of abortion or congenital abnormalities -- deformed lambs, swollen heads, and weak lambs. They should report anything unusual to their vet, especially given the recent developments."

The presence of SBV in Wales is not unexpected. The Animal Health Veterinary Laboratories Agency (AHVLA), the Welsh government, and the Wales Animal Health and Welfare Strategy Steering Group have kept SBV under close scrutiny since its arrival in Britain late in 2011.

As of July this year [2012], there were 275 UK farms reporting positive for Schmallenberg. Of these, 53 were in cattle, 219 in sheep, and 3 in both.

"There is a strong need to continue to monitor SBV in Wales and to this end livestock farmers should be vigilant and report suspicions to their private veterinary surgeon," said Dr Nakielny.

SBV is not currently a notifiable disease in the UK, but test samples taken from suspect animals are still being paid for by the government for the time being.

It remains possible that midges could continue to spread SBV in Britain through the autumn and into the winter, but the FUW hopes the poor weather that has blighted the industry over the summer has reduced the risks of transmission.

There is no known risk to human health from SBV, but the advice for pregnant women remains to be cautious around farm animals and to follow strict hygiene procedures, the union has stressed.

[Byline: Philip Case]

--
Communicated by:
Gert van der Hoek
Senior Moderator
FluTrackers

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[4] Belgium: 2011, wildlife, chronology
Date: Tue 25 Sep 2012
Source: Source: Emerging Infectious Diseases journal [summ., edited]
http://wwwnc.cdc.gov/eid/article/18/12/12-1067_article.htm

[Ref: Linden A, Desmecht D, Volpe R, et al: Epizootic spread of Schmallenberg virus among wild cervids, Belgium, fall 2011. Emerg Infect Dis [Internet]. 2012 Dec (ahead of print, cited 25 Sep 2012)]
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Abstract
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Schmallenberg virus was detected in cattle and sheep in northwestern Europe in 2011. To determine whether wild ruminants are also susceptible, we measured antibody seroprevalence in cervids (roe deer and red deer) in Belgium in 2010 and 2011. Findings indicated rapid spread among these deer since virus emergence 250 km [155 mi] away.

Conclusions
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SBV infects wild cervid populations, and infected insect vectors were homogeneously distributed over southern Belgium in the fall of 2011. Emergence probably took place in 2011. However, because seroprevalence was already 20 percent in red deer and 34 percent in roe deer during October [2011] and because our results show that the proportion of the infected population increased exponentially during October-December, we suggest that the virus began circulating months earlier than the currently believed August/September. We recently showed that among the fetuses of pregnant cows that were infected after the establishment of the 1st placentome, 28 percent were infected and that an arthrogryposis/hydranencephaly syndrome follows if transplacental virus transmission occurs before fetuses are immunocompetent. For this study, no feedback from forest rangers, no macroscopic observations, and no PCR results suggested transplacental contamination. However, aborted fetuses and stillborn and distorted nonviable newborn fawns are almost impossible to collect in the wild (quickly eaten by scavengers), and the absence of SBV-specific genetic material or morphologic alterations at necropsy are not evidence of noninfection. Therefore, no objective facts confirm or refute transplacental transfer.

Because the virus can infect the fetus only after the 1st placentome has developed and because roe deer embryos remain in diapause until January, it is unlikely that SBV has contaminated many roe deer fetuses. Because 90 percent of roe deer were already SBV positive in mid-December [2011] and because circulating antibodies prevent transplacental passage of the closest phylogenetic relatives of the virus, we suggest that roe deer fetuses were probably not infected. On the contrary, red deer mate in September, and the 1st functional placentome is established by the end of October; thus, 80 percent of pregnant red deer were exposed to the emerging virus when placental transfer was possible. Furthermore, 35 percent of pregnant red deer were infected in November and December [2011], that is, after establishment of the 1st placentome and before the fetus was immunocompetent. By extrapolating the rate of transplacental infection among cattle, we determined that 28 percent of these pregnancies resulted in contamination of the fetus, that is, 10 percent, of expected pregnancies. Because unrestricted replication of Simbu-like viruses occurs in the central nervous system of immunologically incompetent ruminant fetuses, which can lead to a typical arthrogryposis/hydranencephaly syndrome, a 10 percent loss among fawns can be expected in 2012.

In the same geographic area, 5 years apart, 2 arboviruses have emerged: bluetongue virus serotype 8 (BTV-8) during the summer of 2006 and SBV during the summer of 2011. For each virus, _Culicoides_ spp. midges function as vectors and infect sheep, goats, cattle, and red deer. Although most (more than 50 percent) red deer seroconverted against BTV-8, only a few (less than 3 percent) roe deer sampled in the same places and at the same time were BTV-8-positive, which sharply contrasts with the SBV seroconversion rates reported here. This finding invalidates the assumption that less exposure of roe deer to infected midge bites explains the almost complete absence of seroconversion against BTV-8 in this species. The emergence of SBV thus reveals the existence of roe deer-specific anti-BTV-8 host factors, posing a fascinating question.

--
Communicated by:
Sabine Zentis
Castleview Pedigree English Longhorns
Gut Laach
52385 Nideggen
Germany
<cvlonghorns@aol.com>

[The spread of SBV into and within Austria could be expected in view of SBV circulation in 2 adjacent countries, Germany and Switzerland; see the updated SBV maps of Germany (25 Sep 2012, at http://tinyurl.com/cemgo58) and of Switzerland (19 Sep 2012, at http://tinyurl.com/cobubev). Results of SBV monitoring in the other eastern neighbours of Germany, namely Poland and the Czech Republic, are anticipated with interest. - Mod.AS]

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