Posted Oct. 14, 2015
Following success in eradicating the cattle plague, world animal health advocates hope to use similar methods to eradicate a related “goat plague.”
Peste des petits ruminants, a viral disease devastating to sheep and goat populations, has spread at an alarming rate in the prior 15 years, according to information from the World Organisation for Animal Health (OIE). The disease is present in 70 countries of Africa, Asia, and the Middle East, together home to more than 80 percent of global sheep and goat populations.
Yet, Dr. Bernard Vallat, OIE director general, said in a column from the OIE that the disease could be wiped out in another 15 years, an “ambitious yet realistic target” of eradication by 2030.
The OIE is working with the Food and Agriculture Organization of the United Nations on the campaign, which will follow the model used to control and eradicate rinderpest, or cattle plague.
The OIE declared in 2011 that rinderpest had been eradicated, becoming the second disease behind smallpox to be eliminated through human intervention. Rinderpest could wipe out entire herds of cattle and buffalo, causing famines through millions of cattle deaths.
Dr. Vallat’s column notes that peste des petits ruminants can infect 90 percent of a sheep or goat flock and kill up to 70 percent of those infected. Economic losses induced by PPR “strike at the heart of vulnerable rural populations,” ruining production at national and regional levels.
Dr. Berhe Tekola, director of animal production and health for the FAO, said in September that, since the global campaign started in March, the FAO and OIE had overseen regional planning as countries began taking ownership of implementing the campaign. Governments will formulate vaccination strategies following the assessments in the first portion of the FAO and OIE campaign, he said. How the organizations will work with those governments in later stages of the campaigns remains to be seen.
Development of a thermostable PPR vaccine, as was done in the development of the rinderpest vaccine, was ongoing, he said. In the meantime, keeping existing vaccines refrigerated is of crucial importance.
The eradication campaign also includes bolstering veterinary systems, which Dr. Tekola notes has been a decades-long project of the FAO. The global strategy for eradicating PPR includes strengthening veterinary systems through an OIE program intended to create sustainable improvements to national veterinary services.
A joint report from the FAO and OIE, “Global control and eradication of peste des petits ruminants: Investing in veterinary systems, food security and poverty alleviation,” includes an estimate that a 15-year campaign could cost upward of $9 billion, and PPR eradication would prevent annual financial losses of about $1.8 billion.
“The investment will be recovered within the first five years after eradicating the disease,” the report states.
The report indicates efforts to control the disease are working, citing the lack of any new outbreaks in Somalia since vaccination campaigns started in the country in 2012. But it also indicates absence of similar efforts in neighboring countries threatens Somalia’s gains.
In addition, national PPR control programs have had inadequate resources and coordination, and they could benefit from a concerted, well-funded effort.
Both rinderpest and PPR have efficacious, safe, and inexpensive vaccines that provide years of immunity against the target viruses with a single inoculation. They also lack reservoir species outside the infected populations. And diagnostic tests, surveillance protocols, and control and eradication programs exist for both.
The founding of the world’s first veterinary school in 1761 in France and the OIE in 1924 both were related to efforts to fight rinderpest.
In 1956, Dr. Walter Plowright began field use of an attenuated live-virus rinderpest vaccine. Such vaccination made rinderpest eradication a practical objective, according to the World Food Prize Foundation, which awarded the British veterinarian the World Food Prize in 1999.
Peste des petits ruminants virus was identified in West Africa in the early 1940s. It was first thought to be a rinderpest virus variant adapted to small ruminants, according to the 2006 book “Rinderpest and Peste des Petits Ruminants.”