Soil-transmitted nematode infections and mebendazole treatment in Mafia Island schoolchildren.

In August 2000, a cross-sectional study was performed to assess the prevalence and intensity of soil-transmitted nematode infections in schoolchildren on Mafia Island. Hookworm infection was widespread (72.5% prevalence) whereas Trichuris trichiura was less prevalent (39.7%) and Ascaris lumbricoides was present at a low prevalence (4.2%), mainly in urban areas. In a subsample of the study population, both Necator americanus and Ancylostoma duodenale were found, although N. americanus was more prevalent. This survey was followed by a parasitological evaluation of mebendazole treatment using a single, 500-mg dose. The data on outcome were used for comparison with those from recent studies of similar treatment regimens in the neighbouring island of Pemba, Zanzibar, where periodic chemotherapy with mebendazole to schoolchildren has been implemented as part of a helminth-control programme since 1994. A higher efficacy of mebendazole against hookworm infection was found in Mafia Island (where a cure 'rate' of 31.3% and an egg-reduction 'rate' of 78.1% were recorded) when compared with that observed in Pemba Island, possibly indicating that hookworms may be developing mebendazole resistance on Pemba Island as a result of intense exposure to the drug there.

A comparative trial of a single-dose ivermectin versus three days of albendazole for treatment of Strongyloides stercoralis and other soil-transmitted helminth infections in children.

A randomized trial carried out in rural Zanzibar comparing a single dose of 200 micrograms/kg of ivermectin and 400 mg/day for three days of albendazole for treatment of strongyloidiasis and other intestinal nematodes is described. In 301 children with Strongyloides stercoralis infection, treatment with ivermectin or albendazole resulted in cure rates of 83% and 45%, respectively. While both drugs were very effective against Ascaris lumbricoides, Trichuris trichiura was cured only in 11% (ivermectin) and 43% (albendazole) of the subjects, although the mean eggload was reduced by 59% and 92%, respectively. Ivermectin was ineffective against hookworms, while albendazole resulted in a cure rate of 98%. No severe side effects were recorded and mild side effects were of transient nature for both treatments. Therefore, ivermectin provides a safe and a highly effective single dose treatment for S. stercoralis and A. lumbricoides, while it is not an alternative for the treatment of T. trichiura and hookworm infections.