SBV case control kleine herk G (BO-20-009-015, BO-08-010-035)

During summer and fall 2011, farmers and veterinarians notified dairy cattle with clinical signs such as fever, decreased milk production and diarrhoea, especially in the eastern regions of the Netherlands and in Northwest Germany. A novel orthobunyavirus, provisionally named Schmallenberg virus (SBV), was identified as causative agent. Shortly after, an epizootic outbreak of congenital malformations in new-born lambs and calves started in North-western Europe. On December 15th 2011, brain tissue samples from malformed lambs in the Netherlands tested positive in a real-time quantitative reverse transcription PCR (RT-qPCR) provided by Friedrich Loeffler Institut (FLI). The impact of the The SBV epidemic on small ruminants is uncertain, knowledge on impact is necessary for animal helath policy makers to decide whether a control program is necessary. A risk factor study may provide tools for intervention and control. The objectives of this study were to identify and quantify flock-level risk factors for malformations in new-born lambs caused by SBV, as well as to describe the effects of SBV infection on mortality rates, and reproductive performance in sheep flocks in the Netherlands.