Schmallenberg Virus Infection among Red Deer, France, 2010–2012

Eve Laloy1, Emmanuel Bréard, Corinne Sailleau, Cyril Viarouge, Alexandra Desprat, Stéphan Zientara, François Klein, Jean Hars, and Sophie Rossi

Author affiliations: Ecole Nationale Vétérinaire d’Alfort, Maisons-Alfort, France (E. Laloy); French Agency for Food Environmental and Occupational Health and Safety, Maisons-Alfort (E. Breard, C. Sailleau, C. Viarouge, A. Desprat, S. Zientara); French Wildlife and Hunting Agency, Bar-le-Duc, France (F. Klein); French Wildlife and Hunting Agency, St Benoist, France (J. Hars, S. Rossi)

Abstract

Schmallenberg virus infection is emerging in European domestic and wild ruminants. We investigated the serologic status of 9 red deer populations to describe virus spread from September 2010 through March 2012 among wildlife in France. Deer in 7 populations exhibited seropositivity, with an average seroprevalence of 20%.

In summer and fall 2011, an unidentified disease was reported in dairy cattle in Germany and the Netherlands, causing decreased milk production, fever, and diarrhea (1,2). The virus associated with these clinical signs was identified as a new member of the genusOrthobunyavirus of the Simbu serogroup and named Schmallenberg virus (SBV) (2). This virus was later associated with abortions and congenital malformations in calves, lambs, and kids in several European countries (3). Serologic testing among wild cervids in Belgium revealed antibodies against Schmallenberg virus in roe deer (Capreolus capreolus) and red deer (Cervus elaphus) (4). Seroprevalence was already high (27% on average) in wild cervids in October 2011 in Belgium, suggesting that the virus began circulating months earlier (before August 2011). It has recently been shown that SBV had already circulated in Culicoides vectors in Belgium during August and September 2011 (5). Although SBV has been closely monitored among domestic ruminants in France, suggesting that clinical cases and antibodies appeared almost at the same time during 2011–2012 (6), little is known about the geographic spread of SBV in wildlife. To correct this lack of data, we conducted a serologic study using serum specimens collected from red deer in different regions in France.