Progress towards the control of bilharziasis in Iran

Abstract

Enough information collected on the problem of bilharziasis by an assisted Bilharziasis Project in Iran, has enabled the authors to start control programmes in the whole endemic area. Interruption of transmission has been achieved in most areas by molluscicides and elimination of the snail habitats. Bayluscide, the molluscicide of choice, was used to treat 197 habitats up to the end of 1967; Bulinus has been disappearing in 42 habitats after one application and more after repeated operations; 127 habitats were also treated in 1968. Engineering methods were used to eliminate habitats by drainage and filling. 47 small and large habitats were completely, and 27 were partially eliminated. Of 156 villages with a prevalence of 10% or more, mass chemotherapy (by treating all patients in villages) was undertaken in 132, and only 24 remained untreated at the end of 1968. Niridazole (Ambilhar) was given in daily doses of 30 mg. per kg. for 4 days; the result was evaluated by follow-up examination 3 and 6 months later. Of 7,317 infected persons detected, 6,488 have completed their treatments. The result of follow-up has shown that only 3% and 2·1% of treated subjects were still passing viable eggs 3 and 6 months respectively after treatment. Estimation of the cases not detected during urine examination, patients not treated during the operations and patients who remained positive after treatment, indicates that after 1 year the number of infected persons in each village was reduced by 80%. Although the general result is encouraging and shows the possibility of bilharziasis control in Iran, the increase of infection due to the extension of water resources, which has already started in the endemic area, may jeopardize this success.