[The ecological prerequisites for the spread of schistosomal dermatitis (cercariasis) in Moscow and the Moscow area]

Cases of schistosomiasis (cercarial dermatitis) were recorded in humans in Moscow in 1991. The authors analyze the ecologic conditions conducive to dissemination of cercariasis in 17 natural and artificial water bodies of Moscow and the Moscow region. They point out that high contamination of the water bodies with organic communal wastes and an abundant overgrowth of macrophytes favor the development of molluscs, intermediate hosts of Schistosoma, and promote the increase of the populations thereof. High number of Lymnaea ovata, L. auticularia, L. stagnalis, Planorbarius corneus, P. planorbis, Anisus sp. were found invaded with Trichobilharzia ocellata (up to 50%) and Bilharziella polonica (as much as 10%). A lot of ducks, end hosts of Schistosoma, were found at all the examined water bodies. in 30% of the examined water bodies the risk of human infection was found high. Recommendations on cercariasis prevention are given.