Cystic echinococcosis as a neglected and emerging zoonotic threat in Africa: the Nigerian and South African picture

Source Agritrop Cirad (https://agritrop.cirad.fr/594656/)

International audience

إنجليزي. Cystic Echinococcosis (CE), caused by cestodes, is one of the most important parasitic zoonoses worldwide especially where there is a close relationship between humans, livestock and wildlife. Nigeria and South Africa asides being the top two economies in Africa share close demographic similarities, therefore necessitating an assessment of historical and epidemiological situations in both countries. A total of 49 and 31 available articles on CE were reviewed respectively for Nigeria and South Africa. The earliest recorded case was in 1961 in human, in Kano Northern Nigeria whereas as early as 1926, in present day KwaZulu-Natal Province of South Africa, the first report of the parasite was made in sheep. Also, the first documented account of wild carnivores as definitive host of E. granulosus in Africa was in South Africa. Most reports from both countries were abattoir studies based on post-mortem findings. A few human case series were described, and these were done in a more systematic approach in South Africa (unlike in Nigeria), with genotyping of circulating strains of Echinococcus reported to be E. granulosus (G1), E. canadensis (G6/7) and E. ortleppi (G5). Similarly, a conservative estimate of 137 human cases is expected yearly in South Africa. There is higher intermediate host infection (hydatid cysts) prevalence in Nigeria, highest being camels (70.9%). ELISA techniques revealed a prevalence of 12.5% in dogs in a study conducted 5 years ago and covering 3 states of Nigeria. In South Africa, the prevalence of CE infection in dogs was between 0.9-20%. Reports of sylvatic transmission of CE in South Africa was also documented. Most studies done in both countries were of small sample size and retrospective in nature, thus, lacking diagnostic measures that are sensitive enough. Recently, epidemiological data of CE in human, livestock and wildlife has not been adequately reported in both countries. The two countries as a matter of urgency need to put up individual national strategies and bilateral co-operations to evaluate, bridge the gaps in the epidemiology of the zoonosis and control its endemicity. Likewise, risk maps should be created for better surveillance, control and intervention priorities among susceptible populations.