The international pledge to eradicate a devastating livestock disease affecting mostly sheep and goats has taken on new urgency in the wake of a mass die-off of a rare Mongolian antelope.
Some 900 Saiga antelopes (Saiga tatarica mongolica) – almost 10 percent of the sub-species’ population – have been found dead in Mongolia’s western Khovd province. Samples taken from carcasses indicated the animals were positive for Peste des Petits Ruminants (PPR), a highly fatal viral disease with plague-like impact on domestic sheep and goat herds, killing up to 90 percent of infected animals.
The Food and Agriculture Organization of the United Nations (FAO) and the World Organisation for Animal Health (OIE) are leading a multinational effort to eradicate PPR, which can have devastating food-security and economic impacts, by 2030. Eighty percent of the world’s estimated 2.1 billion small ruminants live in affected regions and constitute an important asset for a third of poor rural households. PPR, first identified in Côte d’Ivoire in the 1940s, is now threatening over 75 countries.
While wildlife have long been considered potentially vulnerable, relatively few actual cases of PPR infection have been documented in free ranging wild goat-like species and never in free-ranging antelope.
The dead are highly suggestive of a spillover event from domestic animals with whom they share common grazing areas, especially in winter when foraging ranges are fewer. Efforts are ongoing to investigate the situation on the ground, geared in particular to investigating possible other causes, such as the bacterial infection (Pasteurella multocida) that is now suspected to have been the cause of death of hundreds of thousands of Saiga in Kazakhstan in 2015.
Saiga in Mongolia are not truly migratory but are certainly nomadic with an extensive range of about 130 000 square kilometers with seasonal movements in autumn for breeding and early spring for calving. The species, was once widely spread across the Eurasian steppes, is classified as critically endangered by the International Union for Conservation of Nature.
Mongolia reported its first-ever outbreak of PPR in September 2016, when sheep and goat deaths were linked to an extension of PPR cases occurring in China.
The domestic small ruminant population in Mongolia is currently 45 million and plays an essential economic and social role in a country where more than one third of the population derives its livelihoods directly from livestock. Mongolia exports live animals, meat, milk and is the world’s top producer of high-quality cashmere wool.
At that time, FAO and OIE immediately mobilized their Crisis Management Center for Animal Health (CMC-AH) to Ulaanbaatar to help local veterinary services assess the epidemiological situation and propose immediate and medium-term actions aimed at controlling the spread of the disease. More than 11 million domestic small ruminants – crucial for food security and nutrition – were vaccinated in the effort.
The Saiga deaths, which highlight the extreme vulnerability of animals that have not been exposed to PPR as well as the challenge of protecting wildlife, are an “unprecedented and worrisome development,” said OIE Director-General, Dr Monique Eloit.
“More field investigations will have to be carried out to know the extent of the recent outbreak. If PPR is confirmed to be the main cause, the Saiga death toll is likely to reach into the thousands in the next three months”, said Bouna Diop, Secretary of the joint FAO-OIE PPR Eradication Programme. “For this reason, preparations to face even more extensive disease spread should be made and we must try to separate contact between domestic ruminants and these prized and endangered wildlife,” he added.
Heightened surveillance and vaccination of domestic animals should be considered as the main tool currently available to safeguard this endangered species.
“In parallel, critical communication efforts must be made to let Mongolian herders know the risks of the PPR virus spilling over from Saiga to livestock”, added Richard Kock Professor of Emerging Diseases from the Royal Veterinary College, London. “We have learned that these events require a particularly high level of international cooperation and the inclusion of the FAO and OIE world reference laboratories network to ensure full understanding of the epidemiology.”