What are elephant herpesviruses?
Elephant endotheliotropic herpesviruses (EEHVs) are associated with a fatal haemorrhagic fever syndrome in juvenile Asian elephants, killing a large percentage of calves born in both captive and wild populations each year. However, most adult animals have what’s assumed to be a latent EEHV infection, shedding the virus intermittently throughout their lives.
It isn’t clear why some animals develop fatal disease and others have this inapparent lifelong infection, but there are several current theories. These focus on the timing of an animal’s first infection in relation to waning maternal immunity, differences in the genetic susceptibility of individual elephants to the virus, or a co-infection (though it’s not clear with what).
Our research and its impact
Our work on EEHV has demonstrated that some potential risk factors for virus shedding (such as pregnancy) aren’t in fact linked consistently with virus detection. We’ve also established cell culture methods for elephant cell lines and pedigree analysis of cases in European and North American institutes, all paving the way for genetic risk factor analysis.
We’ve collaborated extensively with our clinical associate Twycross Zoo on this project, with their veterinary staff giving us access to clinical samples from Asian elephants. Other zoos such as ZSL, Chester Zoo, Dublin Zoo and Zurich Zoo have also provided access to clinical material for this work. Much of the current work on this project is being co-ordinated through Copenhagen Zoo, which is working on European-level studies of EEHV epidemiology.