A collaborative study involving scientists from The Pirbright Institute, has revealed that African buffalo and Grant’s gazelle are unlikely to sustain circulation of peste des petits ruminants virus (PPRV), improving prospects for disease eradication.
Also known as goat plague, PPR is highly contagious and infects small ruminants such as sheep and goats, causing up to 90 percent mortality. The disease is prevalent across large parts of Africa, the Middle East, India and China and is estimated to cost between US$1.4 billion and US$2.1 billion globally each year.
Wild animals can also be infected by PPRV, but their role in disease circulation has been difficult to establish. In the first large-scale randomised survey of its kind, scientists found that nearly 20 percent of 132 animals sampled in Greater Serengeti and Amboseli ecosystems of Kenya and Tanzania had previously been infected with PPRV. This included African buffalo, wildebeest, topi, kongoni, Grant’s gazelle, impala, Thomson’s gazelle, warthog and gerenuk.
The team also looked specifically at herds of African buffalo and Grant’s gazelle to understand how frequently they had been infected. Their findings, published in Viruses, reveal that swab samples from both species were negative for PPRV and only low levels of antibodies against the virus were detected in smaller number of animals, indicating they had previously been exposed to PPRV. This suggests that sporadic spill over from infected sheep and goats is the most likely source of disease rather than circulation within the wild populations.
This could mean that if PPR is eliminated in sheep and goat populations that interface with wildlife through livestock vaccination, the risk of African buffalo and Grant’s gazelle maintaining the disease and then reintroducing infection to livestock would be low. If this is the same for other susceptible species across other major ecosystems, the disease would be less likely to remerge from wild populations once the disease is eliminated from livestock.
Professor Satya Parida, former Pirbright group leader who jointly led the research, said: “This fills an important knowledge gap for the Global Strategy for the Control and Eradication of PPR, and gives us hope that PPR could join the ranks of rinderpest and smallpox as the only viral diseases to have been successfully eradicated.”
The study was carried out in collaboration with the Royal Veterinary College, the Food and Agriculture Organization of the United Nations (FAO), CIRAD (France), Southern African Centre for Infectious Disease Surveillance (SACIDS), Kenya Wildlife Service and Tanzania Wildlife Research Institute. This research was funded by Biotechnology and Biological Sciences Research Council (BBSRC), part of UK Research and Innovation (UKRI).