RESUMEN
The efficacy of a single dose of albendazole 400 mg, levamisole 2.5 mg/kg, mebendazole 500 mg, mebendazole 200 mg and pyrantel pamoate 10 mg/kg was evaluated in relation to the intensity of infection of Ascaris lumbricoides, Necator americanus and Trichuris trichiura. The study group comprised 667 3 to 12 year old children from poorer segments of the community. All 5 treatments produced high egg reduction rates ranging from 95.9% to 99.7% and substantial cure rates for Ascaris infection; the differences observed in the 5 treatment groups were not significant (p greater than 0.05). Although all treatment groups were effective against Necator, the number of patients was too small to draw useful conclusions. In Trichuris infections, although higher cure rates were obtained in light compared to heavy infections, the results were uniformly poor in all treatment groups. The few side effects encountered were mild and did not require any intervention.