Participatory Epidemiology of Coenurus cerebralis Infections in Goats and Sheep kept by Pastoralists in Ngorongoro District, Tanzania

Abstract

Livestock diseases are among the most important causes of poverty in Ngorongoro district since such diseases deteriorate the livelihoods of local people. Participatory Epidemiology (PE) study was conducted in ten pastoralist villages in Ngorongoro district to determine morbidity, case fatality rates and their impact on livelihoods of the livestock keepers. PE tools that were used included simple ranking, proportional piling, seasonal calendars, timelines and probing. Goats were perceived as the most abundant among livestock species kept followed by sheep and cattle in that order. However, cattle with an average score of 51.6 were perceived as the most important for their livelihood.The importance of other animals in descending order was goats, sheep, donkeys, poultry and pigs being the least that scored 22.9, 16.7, 6.2 and 2.6 respectively. For goats the mean flock morbidity and case fatality rates for major diseases were 58.7% and 35% respectively while in sheep it was 61.5% and 24.5%. For the goats the overall score for morbidity rates for nervous signs/gid (ormilo in Maasai), pest des petites ruminants, pox, contagious Caprine pleuropneumonia and other diseases were 12%, 13.6%, 7.5%, 19.3%, and 7.3% while their respective mean score for case fatality rates were 100%, 48.5%, 33.3%, 34% and 38.3% respectively For sheep diseases, the overall score for morbidity for gid (ormiloin Massai tribe) pest des petites ruminants, pox, mange and other diseases were 12.5%, 12.4%  8.7%, 20.1%, and 7.8% while the respective mean scores for case fatality rates were 100%, 48.3%, 26.4%, 5.4% and 33.3% respectively. The clinical signs of gid (omilo in Massai tribe) included unidirectional cycling, frequent abnormal noise, staggering, head tilting, difficult to chew and swallow and eventual death. Large cysts (up to 6cm in diameter) that were confirmed parasitologically to be Coenuruscerebralis were found mainly embedded between the different parts of brain lobes under the meninges. The present study confirms the debatable aetiology of CNS syndrome (Omillo in Massai tribe) for small ruminants in Ngorongoro district to be Coenurouscerebralis and validates development of strategies to control the disease that at present its case fatality rate issalarming and is a major threat to livestock health and Maasai pastoral community livelihood.