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 are currently working with colleagues in the state government forestry department veterinary services in India (Arun Zachariah) and SciGenom sequencing labs conducting RNAseq analysis of case and control animals to work out which genetic pathways of both host and virus are important in fatal infections.
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.