Bovine malignant catarrhal fever

Species of virus

Bovine malignant catarrhal fever (BMCF) is a fatal lymphoproliferative disease caused by a group of ruminant gamma herpes viruses including Alcelaphine gammaherpesvirus 1 (AlHV 1) and Ovine gammaherpesvirus 2 (OvHV 2) These viruses cause unapparent infection in their reservoir hosts (sheep with OvHV 2 and wildebeest with AlHV 1), but are usually fatal in cattle and other ungulates such as deer, antelope, and buffalo. BMCF is an important disease where reservoir and susceptible animals mix. There is a particular problem with Bali cattle in Indonesia, bison in the US and in pastoralist herds in Eastern and Southern Africa. Disease outbreaks in cattle are usually sporadic although infection of up to 40% of a herd has been reported. The reasons for this are unknown. Some species appear to be particularly susceptible, for example Père David's deer, Bali cattle In contrast, post infection cattle will usually survive a week or more.

Diagnosis of BMCF depends on a combination of history and symptoms, histopathology or of viral DNA by PCR. The characteristic histologic lesions of MCF are lymphocytic arteritis with necrosis of the blood vessel wall and the presence of large T lymphocytes mixed with other cells. The world organisation for animal health

Bison bison are found by Nelson et al 2010 to suffer widespread mucosal necrosis but rarely occlusive thrombosis, and they judge thrombosis to be hardly able to explain the incidences of necrosis. This discovery undoubtedly puts scientists on the right track for developing a vaccine – starting with the correct cell culture for each stage of the virus lifecycle – but ARS researchers are also looking into alternative methods to develop a vaccine. Researchers are experimenting with the MCF virus that infects topi (an African antelope) because it will grow in cell culture and does not infect cattle. Researchers hope that inserting genes from the sheep MCF virus into the topi MCF virus will ultimately be an effective MCF vaccine for cattle and bison. While there is much ground left to cover, scientists are getting closer and closer to developing a vaccine.