Peste des petits ruminants
Peste des Petits Ruminants (PPR) is an OIE-listed disease of sheep and goats, caused by PPRV, a Morbillivirus, from the Paramyxoviridae family. Because of its high economic impact, PPR is considered one of the major livestock diseases. There is now a global effort to eradicate PPR.
Since its first description in the Ivory Coast in 1942 PPR has expanded to cover large regions of Africa, the Middle East and Asia. Southern Africa is still free of the disease, but it appears to be spreading in that direction. It is circulating endemically in Turkey, in close vicinity to Europe. There have been outbreaks in Georgia and Mongolia in 2016/2017, where the disease had never been reported before.
PPR affects sheep, goats, and a large number of species within the order Artiodactyla, both wild and captive, with a mortality rate of 50-80% in a susceptible population. The recent outbreak in Mongolia resulted in thousands of deaths in endangered Saïga antelopes, highlighting the threat of PPR to endangered wild species. The disease spreads mainly by direct contact with discharges from infected animals. Extensive systems with communal resources and seasonal migration facilitate disease transmission. No carrier or reservoir has yet been identified.
Clinical diagnosis can be difficult in areas where multiple diseases circulate. Immunocapture enzyme-linked immunosorbent assay (ICE-ELISA), and nucleic acid amplification are the most currently used diagnostic tests for PPRV identification. Serological tests are also routinely used, including the competitive ELISA and virus neutralisation.
PPR can be controlled through mass vaccination campaigns. Current live attenuated vaccines for PPR provide a good immunity which may last for at least 3 years but cannot be distinguished serologically from infected animals. A cold chain is required for transport and storage of PPR vaccine.
The PPR situation in countries bordering the EU emphasises the importance of implementing and maintaining appropriate control measures with regard to illegal imports and animal movements to mitigate risks. Equally the tools necessary to control and eradicate any incursion into the EU must be available.