Investigations on the control of bilharziasis vectors in Israel.

In spite of the arrival in Israel over the past decade of large numbers of immigrants infected with bilharziasis and although during that period there have been two sporadic outbreaks of the disease, there seems little immediate danger of bilharziasis spreading in the country. However, hydrographical, agricultural and economic conditions are subject to rapid changes in Israel and the present favourable situation may not be lasting. In anticipation, therefore, of possible outbreaks, laboratory experiments have been conducted to evaluate the efficacy in the control of Bulinus ova and adult snails and schistosome cercariae of a number of known molluscides and other substances. Although similar studies have been made in several other countries, it was felt advisable to repeat them under local hydrological conditions, particularly in view of the high carbonate content of the local waters. While most of the substances tested exert some molluscicidal action, only copper sulfate, sodium pentachlorophenate and common salt were found to be of practical value.