Hydatid disease in the Turkana District of Kenya, VII: analysis of the infection pressure between definitive and intermediate hosts of Echinococcus granulosus, 1979-1988.

Abstract

The rate of acquisition of Echinococcus granulosus and other taeniids was examined in dogs treated with praziquantel(Droncit) in a pilot control scheme started in 1983 in north-western Turkana District of Kenya. An attempt was also made to assess the effect of drought on the prevalence of E. granulosus. The infection pressure to dogs with the cestodes was shown to be high, and the prevalence returned to pretreatment levels within 6 months. The unreliability of arecoline purging as compared to autopsy in prevalence studies of dog cestodes is shown mathematically; the arecoline purge may underestimate real prevalence 10-fold. It is proposed that the mass dog worming schedule in Turkana, using praziquantel, should take this into consideration, as well as the short prepatent period of E. granulosus, financial constraints and local slaughter practices. During the prolonged droughts (which occur approximately every 10 years) the programme must be adjusted to cater for the initial increase in infection intensity to dogs.