STUDIES ON DRACUNCULIASIS IN THE INDIAN DESERT

Dracunculiasis (infection by the guinea worm, Dracunculus medinensis) has been a major rural waterborne problem in many areas of arid wester n Rajasthan. The presence of temporary ponds in endemic areas offers a peculiar habitat to cyclops, the vector of the disease. Cyclops can w ithstand drying of the ponds and regain viability when ponds refill du ring rains. Cyclops shows a diurnal cycle of migratory movements under natural as well as experimental conditions. The species of cyclops ac ting as intermediate host in endemic areas is Cyclops atter. This carn ivorous species is highly predatory on the infective first stage larva e of D. medinensis in experimental infection trials. Survival of infec tive guinea worm embryos in free-living form till ingested by vectors is favoured by an alkaline pH of the water. Measurements of water volu me in ponds, removal of soil from dry ponds to discard cyclops eggs an d recording the visit history of guinea worm patients are suggested as useful additions to an eradication programme against dracunculiasis. Literature concerning epidemiological, vector-biological, and parasito logical aspects of dracunculiasis as relevant to desert districts of R ajasthan is reviewed. (C) 1997 Academic Press Limited.