Peste des petits ruminants (PPR)
PPR has been described as the most destructive viral disease in small ruminants with young animals (3 – 18 months) being most susceptible. It is the main constraint to small ruminant production especially amongst pastoral communities with production losses ranging from 50 – 90 % and mortality rates of 10 – 90%. When associated with other diseases such as Capripox, mortality can reach 100%.
In early 2000s, an animal disease consultancy of the FAO singled out PPR as one of the important animal diseases to be taken into consideration in poverty alleviation policies. The PPR vaccine has the ability to prevent infection, the disease and further shedding and it confers life-long immunity.
PPR is widespread in Western and Central Africa and appears to be spreading in Eastern Africa as well. The disease is also present in Middle East, the sub-Indian Continent and several Asian countries. Although good data is scarce in Africa, recent vaccination campaigns in Kenya (more than 10 million animals vaccinated), Northern Uganda and Somalia indicate that the situation is quite alarming. The disease was reported in Tanzania in December 2008 and is currently ravaging sheep and goats in Ethiopia. In recent years PPR has been spreading northward and has been diagnosed in Morocco with a high risk of spreading into southern Europe.
The socio-economic importance of PPR is a result of heavy losses at production level and market effects along the value chain. It is estimated that 10% of the total impact of the disease is on trade and public expenditure and 90% on herd productivity.
- In Nigeria, an outbreak that occurred in 1979 killed 10-20% of the national small ruminant flock that was estimated at US$ 75 million.
- A cost benefit analysis conducted in Niger in 1993 to assess the benefit of vaccination against PPR concluded that an investment of US$ 2 million on vaccination would generate US$ 24 million in return for a five year vaccination program.
- In Ethiopia FAO estimates that losses associated with PPR reached an average of US$ 375 per flock per year, with an average of 143 small ruminants per flock (an average loss of more than US$ 2 per animal).
- In the 2008 outbreak in Kenya, the cost of vaccines used is estimated at € 4.8 million out of a total vaccination campaign cost of €12 million.
The important direct economic losses caused by PPR are often further aggravated by the sanitary measures imposed by authorities in controlling animal movement and trade restriction on their by-products. Because of the high negative economic impact in countries affected by PPR, this disease is one of the priorities of the FAO Emergency Preventive System (EMPRES) programme.
A number of African laboratories in Botswana, Cameroon, Niger, Mali, Senegal, Nigeria, Morocco, Chad, Kenya and Ethiopia, and some in the Middle East have obtained the seed stock for the vaccine from the OIE Reference Laboratory at CIRAD-EMVT (Elevage et Médecine Vétérinaire Tropicale) and are producing the vaccine.