Control trial of soil-transmitted helminthic infections with pyrantel pamoate.

Pyrantel pamoate at dosage of 10 mg per kilogramme body weight was given to each villager at 4-6 weeks intervals for three times. The infection rates of hookworms among those who received and did not received the drug decreased from 60.5% pre-treatment to 19.6% after the third treatment and then increased to 32.4% one year after the third treatment. Infection rates of A. lumbricoides and Strongyloides spp. among the villagers who received and did not received the drug decreased from 27.5% pre-treatment to 2.2% after the third treatment and then increased to 20.1% one year later for the former, while the latter decreased from 6.5% pre-treatment to 2.3% after the third treatment and 0.4% one year later. The infection rate of T. trichiura was found to increase as pyrantel pamoate had no effect on this nematode. The authors suggested that to obtain more satisfactory results the anthelmintic drug used must likewise be effective against T. trichiura particularly in areas where this nematode is a public health problem. It was also suggested that the duration of treatment should be prolonged.