Risk Factors for Malformations and Impact on Reproductive Performance and Mortality Rates of Schmallenberg Virus in Sheep Flocks in the Netherlands

摘要: In Northwestern Europe, an epizootic outbreak of congenital malformations in newborn lambs due to infection with Schmallenberg virus (SBV) started at the end 2011. The objectives this study were describe clinical symptoms SBV infection, effect on mortality rates, and reproductive performance sheep, as well identify quantify flock level risk factors for infections resulting lambs. A case-control design was used, 93 case flocks that had notified malformed 84 control no such Overall animal seroprevalence estimated 82.0% (95% CI: 74.3–87.8), not significantly different from prevalence being 76.4% 67.2–83.6). percentages stillborn or died before weaning, repeat breeders, abnormal suckling behaviour higher compared flocks. However, rates seemed be limited. Multivariable analysis showed sheep early start mating season, i.e. August 2011 (OR = 33.1; 95% 10.0–109.8) 8.2; 2.7–24.6) increased odds caused by a season October Other flock-level purchase silage 5.0; 1.7–15.0) one more dogs 3.3; 1.3–8.3). Delaying until could potential preventive measure naive animals reduce induced losses. As duration immunity after is expected last several years, future are mainly offspring mated seronegative animals.