Also known as sheep and goat plague, Peste des Petits Ruminants (PPR) is a highly contagious viral disease that has a disproportionate effect on the poorest farmers in the world, with 330 million farmers in Africa and Asia directly relying on sheep and goats. It has been estimated that the disease is causing between $1.45 billion to $2.1 billion in losses each year.
Over 70 countries are now affected by PPR and it threatens to spread into many more. Find out where the latest reported outbreaks are with this map.
The virus that causes PPR is classified as belonging to the Morbillivirus genus in the family Paramyxoviridae. Early reports of PPR suggested that there were four lineages restricted to certain geographic areas, including lineage I in western and central Africa, and lineage IV circulating in India and the Middle East. However, in recent years this distinct distribution has broken down with lineages appearing in new areas, for example lineage IV is now found in northern and central Africa1. 1Peste des petits ruminants virus, Tunisia, 2012–2013, Emerging Infectious Diseases , 20 ( 12 ) pp. 2184 – 2186, Sghaier, S., Cosseddu, G.M., Hassen, S.B., Hammami, S., Ammar, H.H., Petrini, A., Monaco, F., 2014.
Infected animals shed the virus into various secretions and excretions and so the virus can pass to susceptible animals in a variety of ways including inhalation. This means that PPR is transmitted when animals come into close contact with each other. Animals being allowed to roam freely and the movement of animals can contribute to the spread of the disease.
Vaccination is effective and central to the control and eradication of PPR. Current research indicates that there is a strong level of cross-protection between the different lineages, which is expected because the lineages are all within the same serotype and have little antigenic divergence. This means that PPR vaccines can be expected to give protection regardless of the lineage that the vaccine strain is derived from. As with other livestock diseases, such as foot-and-mouth disease (FMD), a high quality vaccine should always be selected and used.
PPR is caused by a virus and there is no specific treatment for it. Focus must be on prevention, particularly vaccination.
Quarantine, movement restrictions, and cleaning and disinfection may be used in the event of outbreaks. With 80% of the world’s sheep and goats coming from those regions impacted the most by PPR, this growing threat means that millions of small ruminants are now considered at risk. There is a global strategy for the eradication of PPR, developed in conjunction with OIE and FAO, which involves vaccination and is targeting PPR-freedom by 2030.