Cattle, worms and zooprophylaxis

Epidemiological studies in North Cameroon indicate that a high population density of cattle in relation to man protects from severe onchocerciasis. In the following, we present a mathematical model which allows to study the effects of zoophily of the vectors, of concomitant immunity in the human population and of cross-protective immunity caused by the infective larvae of a bovine parasite, Onchocerca ochengi, inoculated into man by Simulium damnosum s.l. Besides this influence on onchocerciasis, cattle also play a major role in the epidemiology of malaria (zooprophylaxis through vector dilution) and schistosomiasis (protection by crossreactive concomitant immunity). © PRINCEPS Editions, Paris, 1994.