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Peste des petits ruminants Author: Prof Moritz van Vuuren Adapted from: ROSSITER, P.B., 2004. Peste des Petits Ruminants. In: COETZER, J.A.W. & & TUSTIN, R.C. (eds). Infectious Diseases of Livestock Cape Town: Oxford University Press Southern Africa. Licensed under a Creative Commons Attribution license. Synonyms clinical disease caused by rinderpest virus in small Goat plague, Kata (a vernacular west-African name), ruminants was a relatively rare event, and will likely not pseudorinderpest, be seen again as a result of the eradication of and stomatitis-pneumo-enteritis complex. rinderpest. Introduction There is an incubation period of 3-4 days during which Peste des petits ruminants (PPR) is a disease of goats, the virus replicates in the draining lymph nodes of the sheep and closely related wild members of the family oro-pharynx before spreading via the blood and lymph Bovidae, and is clinically and pathologically similar to to other tissues and organs. The characteristic signs the now extinct rinderpest. In the areas where it occurs begin with fever and a serous nasal discharge that it is the most economically important virus disease that becomes mucopurulent. Other signs include a profuse affects small ruminants. The chronological sequence of catarrhal conjunctivitis with matted eyelids, necrotic new reports of PPR points to the fact that the virus has stomatitis, gastroenteritis, and bronchopneumonia. spread steadily eastwards from its origin in West Africa, and more recently southwards on the continent of Africa. Salient features of PPR Peste des petits ruminants virus causes an acute febrile illness in small ruminant species, mostly sheep and goats, with the highest pathogenicity in goats. It is an economically important disease and can cause Hyperaemia and congestion of the conjunctiva mortality rates of 50-80% in naïve populations. In areas where the disease is endemic, the most severely affected animals are those from 4 to 24 months-of-age. Antelope and other small wild ruminants species in captivity can also be severely affected. The virus is classified in the Morbillivirus genus of the Paramyxoviridae family. The virus is antigenically very similar to rinderpest virus and the clinical signs are similar to rinderpest in cattle, which made differential diagnosis difficult. However, Severe purulent nasal exudate Where does PPR occur? The disease occurs in Africa, the Middle East and the The renewed spread of PPR in Africa and the Middle Indian subcontinent. In Africa it is known to be present East has not only to do with biological factors, but is in a broad belt of sub-Saharan Africa between the also considered to be influenced by deteriorating Equator and Sahara desert including the Horn of standards in national veterinary services in many Africa. During the late 1980s, the disease spread to the countries. Changes in government priorities have lead Arabian Peninsula, throughout most of the Middle- to decreased funding and a restructuring which has Eastern countries, and eastwards. Outbreaks of PPR disrupted national veterinary services. are now known to be common in India, Nepal, Bangladesh, Pakistan, Afghanistan, and since July 2007 in Tibet (China). According to sero-surveys, PPR virus had already been circulating in Kenya and Uganda during the 1980's but has been officially declared to the OIE as endemic in Kenya since 16 May 2007, and in Uganda since 10 Aug 2007. The disease is now (2013) recognized as also being present in the Democratic Republic of Congo and northern Angola. Prevention and control The control of PPR is dependent on zoosanitary measures and vaccination. The former may variously include quarantine of infected premises, villages or areas; cleaning and disinfection of infected premises; movement control in general, including transhumance; and stamping out in the event of new introductions. Eradication of PPR in the endemic areas is not currently viewed as feasible as a result of the risk of reinfection from neighbouring regions, and would require serious regional coordination and collaboration. Vaccination represents the most important procedure for the control of PPR. As a result of the close antigenic relationships, attenuated rinderpest vaccines have been used to protect sheep and goats against PPR. Today attenuated PPR vaccines are available and are manufactured and marketed in African and Asia. Global distribution of PPR prior to its southern Recombinant poxvirus vaccine and chimeric rinderpest migration into Tanzania, DRC and Angola between virus vaccine were developed during the first decade of 2007 and 2012 this century, but their wide scale use has not yet materialized. What triggers an outbreak of PPR? Transmission of PPR requires close contact and the movement of live animals are the main means of spread. The virus is present in ocular, nasal, and oral secretions as well as faeces. Most infections occur through inhalation of aerosols from sneezing and coughing animals. Animals may be infectious during the incubation period. There is no known carrier state. There is controversy over whether fomites can play a role in transmission of PPR virus as it is a labile virus sensitive to environmental influences.