The planning of a community health model project in an area in Egypt (El Qalyub) with concomitant occurrence of S. mansoni and S. haematobium.

In addition to knowing about the tolerance, efficacy, and safety of a new antischistosomal agent, public health authorities also have a critical need to know the degree to which population-based chemotherapeutic programmes can potentially reduce disease transmission and morbidity. Rational nationwide planning on a cost-effective basis is impossible without such information. Thus the Qalyub Project, a major collaborative research effort by the Egyptian Ministry of Health, the US Center for Disease Control and Tulane University, has undertaken to measure the impact of alternate control strategies in 8 study villages in a region where Schistosoma mansoni (over 50% prevalence) and S. haematobium (approximately 30%) are coendemic. Selected population chemotherapy with 2-cyclohexylcarbonyl-1,2,3,6,7,11b-hexahydro-4H-pyrazino[2,1-a] isoquinolin-4-one (praziquantel, EMBAY 8440, Biltricide) alone and in combination with snail control, is being evaluated in terms of cost and impact on transmission as measured by changes in precontrol levels of incidence (of new infections) and infection rates in natural and sentinel populations of the snail intermediate hosts. The methodology of such a community-based study requires meticulous and standardized collection of clinical, parasitologic, malacologic, and behavioral data over a period of years, and is described in detail in this paper. The outcome of the research in progress will have considerable significance for planning future schistosomiasis control effects in Egypt and elsewhere.