Evaluation of two years of mass chemotherapy against ascariasis in Hamadan, Islamic Republic of Iran.

OBJECTIVE To evaluate the mass treatment of ascariasis in rural areas of Hamadan Province, Islamic Republic of Iran. METHODS A control programme in rural areas of Hamadan Province, which began in November 1997, involved giving all persons a single dose of 400 mg albendazole at intervals of three months. The efficacy of the treatment was evaluated by the formalin-ether concentration technique for stool examination and by the Stoll quantitative method. FINDINGS The average rate of infection with Ascaris before treatment was 53.3%, ranging from 40% in Hamadan district to 75% in Toysercan. Two areas, Malayer and Nahavand, were excluded from the programme because the infection rates were only 13% and 4%, respectively. After two years of mass treatment the infection rate had decreased to 6%. The proportion of positive cases excreting only unfertilized eggs increased to 32%. No side-effects of mass treatment were observed. CONCLUSION Systematic mass treatment giving high coverage proved to be very effective in the control of ascariasis, notwithstanding a lack of other preventive measures.