A Review of the Current Status of Peste des Petits Ruminants Epidemiology in Small Ruminants in Tanzania

Abstract

Peste des petits ruminants (PPR) is a highly contagious viral disease of sheep and goats with high mortality. The disease is of considerable economic importance in countries such as Tanzania, where small ruminant products are important for sustainable livelihoods. This review assesses current knowledge regarding the epidemiology of PPRV in Tanzania, highlighting the challenges with respect to control and suggesting possible interventions. Thirty-three articles were identified after literature searches using Google Scholar and PubMed. Studies revealed that PPRV is endemic in sheep and goats in Tanzania, although seropositivity has also been reported in cattle, camels, buffalo, Grant's gazelle, wildebeest and impala, but with no clinical manifestation. Three lineages (lineage II to IV) of PPRV have been identified in Tanzania, implying at least two separate introductions of the virus. Diagnosis of PPR in Tanzania is mostly by observation of clinical signs and lesions at post mortem. Risk factors in Tanzania include age, sex, species, and close contact of animals from different farms/localities. Although there is an efficacious vaccine available for PPR, poor disease surveillance, low vaccine coverage, and uncontrolled animal movements have been the bane of control efforts for PPR in Tanzania. There is need for collaborative efforts to develop interventions to control and eradicate the disease. The establishment of a national reference laboratory for PPR, conduct of surveillance, the development of high-quality DIVA vaccines, as well as execution of a carefully planned national vaccination campaign may be key to the control and subsequent eradication of PPR in Tanzania and achieving the global goal of eradicating PPR by 2030.

Transboundary Animal Diseases, an Overview of 17 Diseases with Potential for Global Spread and Serious Consequences

“…Peste des petits ruminants (PPR), is a highly contagious, devastating viral disease of domestic and wild ruminants, primarily affecting goats and sheep [490,491]. Peste des petits ruminants virus (PPRV) is a negative sense single stranded-RNA morbillivirus, of the family Paramyxoviridae, that is closely related to other members of the genus such as rinderpest, measles, and canine distemper [492]. Although only recognized as a completely distinct disease for approximately 40 years, phylogenetic morbillivirus data suggests PPRV has been in circulation as long as rinderpest virus [493].…”

“…In enzootic areas, morbidity and mortality vary between 10-100% [495]. First identified in Cote D'Ivoire in the 1940s, PPR has since been seen in North and Central Africa, the Middle East, and parts of East Africa, Asia, and Europe [492]. The affected countries are home to 68% of the world's small ruminant population [490].…”

“…Peste des petits ruminants virus is easily transmitted by direct contact with secretions and excretions from infected animals or contact with fomites [492]. The main entry route is respiratory [501].…”

“…The incubation period is generally 3-9 days [493]. Clinical signs include inappetence, emaciation, depression, fever, diarrhea, nasal and ocular discharge, pneumonia and erosive and necrotic stomatitis [492,504]. Fatal cases usually die between 5-12 days after disease onset [493].…”

“…Pregnant animals may abort and transient immunosuppression can make animals susceptible to an activation of latent or new infections [493]. Goats may be more susceptible to severe disease than sheep [492]. Pathognomonic histopathologic findings include multinucleated giant cells and cytoplasmic and/or nuclear eosinophilic inclusion bodies [502].…”