Atypical bovine morbillivirus infections in the Serengeti ecosystem

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Once the scourge of European, African and Asian livestock and wild ruminants, rinderpest virus is only the second virus in history after smallpox to be eradicated globally by vaccination. Rinderpest virus (RPV) is a morbillivirus, a close relative of measles virus (MV). Rinderpest was a devastating disease, threatening both food security and the health and wellbeing of many of the poorest livestock-dependent communities in the world. The eradication of rinderpest was arguably one of the most significant global successes in veterinary medicine. In recent years, we have developed highly sensitive and specific diagnostic tests with which we can measure morbillivirus-specific neutralising antibodies. Using these tests, we have identified sera from cattle in Northern Tanzania that display specific neutralising activity against novel cattle morbilliviruses, including canine distemper virus (CDV), peste des petits ruminants virus (PPRV) and a rinderpest-related bovine morbillivirus. The aim of this project is to characterise novel and atypical bovine morbilliviruses circulating in Northern Tanzania. We will build upon our preliminary screening of cattle sera, focussing on a set of ~5000 cattle sera from neighbouring areas of Serengeti and Ngorongoro districts. Collected between 2010 and 2016, these sera will provide a snapshot of the prevalence of morbillivirus-specific antibodies across the region and will enable us to locate target sites for future field studies. Informed by our findings, we will collect fresh sample material from herds in villages known to harbour antibody-positive animals, generating material for virus characterisation as well as allowing assessment of their clinical significance. The samples will be screened to identify the animals with morbillivirus-specific antibodies and the corresponding blood samples and swabs screened for viral gene sequences. These analyses will reveal the origin of the antibody reactivity, the nature of the infective agent and will permit the design of a more effective diagnostic test for the virus(es).This project will provide epidemiological and biological data to evaluate the potential threat posed by morbilliviruses in cattle. It will generate assay systems with which the viruses may be detected and inform strategies for subsequent monitoring and control. The knowledge generated by this project will counter the risk of a novel morbillivirus emerging in cattle, ensure that immunosurveillance for morbilliviruses is not undermined by misdiagnosis, while facilitating the design of future campaigns for control and eradication by vaccination.