Clinical Signs, Epidemiology, Pathology and Diagnosis of an Emerging Teratogenic Vector Borne Viral Disease of Ruminants - Schmallenberg Virus as an Example

摘要

Vector borne viruses that have been associated with teratogenic defects in ruminants have mostly belong to the Orthobunyavinis genus. The most well known is Akabane virus as a result of the large epidemics of congenital arthrogryposis and hyrdanencephaly (AG/HE) that have occurred, mostly in Australia and Japan but to a lesser extent in some Middle Eastern countries1. Before the aetiological agent was recognised, a vector borne virus was suspected due to the geographical distribution of disease outbreaks and an association with favourable environmental conditions. However, there was some confusion about the linkage between a vector borne viral infection and the occurrence of disease due to the lack of disease in breeding females, the occurrence of disease in offspring during winter and spring months and the variety of defects that were observed. The recent emergence of Schmallenberg virus (SBV) presents another example of the issues that are faced when investigating disease outbreaks due to a similar novel agent. This presentation will focus on some of the important features of an incursion of a novel virus and the approaches to undertaking an effective investigation.