The Schmallenberg livestock virus, which caused birth defects in thousands of sheep and cattle in Europe this year, has been detected in 16 countries to date, the European Food Safety Authority reported.
In addition to 14 European Union countries, Switzerland has found the virus in domestic ruminants and Norway detected Schmallenberg in biting midges trapped as part of a surveillance program, the EFSA wrote in a report on its website.
The number of farms in Europe with laboratory-confirmed cases was 5,955 as of Oct. 30, from a total of 10,124 holdings with suspected cases, according to the Parma, Italy-based EFSA. New cases peaked in March for sheep and in May for cattle.
“SBV is continuing to spread in new areas of Europe, and it is likely that new SBV cases will be observed in southern and eastern regions of Europe in 2013,” the EFSA wrote.
The virus was first detected last year and has been confirmed in 3,562 cattle herds, including 2,018 in France and 820 in Germany, as well as 2,278 sheep flocks, about half of them in France, the report showed. Other cases were in goats, horses and bison.
The virus, named after the German town near where it was first identified, is believed to be transmitted by insects and after infecting pregnant sheep or cows causes stillbirths and deformed, nonviable young that die after delivery.
The number of sheep flocks with confirmed cases peaked in the week through March 5, with “very few” cases after May 13, according to the EFSA.
“This decrease is due to the end of the lambing season in affected countries,” the EFSA wrote. “It is likely that new cases in sheep will be reported in spring 2013.”
Reports of infected cattle herds peaked in the week through May 13, while reporting of new cases continued throughout the summer, according to the regulator. Many new cases from August to October were in adult animals in Switzerland as well as the U.K., based on the report.