Optimising the benefits of anthelmintic treatment in children.

Optimal use of anthelmintics in children is of major public health importance because the parasites involved probably infect over 2 billion persons, and most are especially common and debilitating in children. Well targeted drug delivery, particularly via community chemotherapy, can substantially decrease aggregate morbidity and mortality and also improve growth rates, physical fitness and activity, cognitive and school performance, and social well-being. The drugs discussed here include the benzimidazoles (albendazole, levamisole and mebendazole), pyrantel, praziquantel, oxamniquine, ivermectin, diethylcarbamazine and some traditional medicines. The parasitic infections discussed are hookworm, ascariasis, trichuriasis, strongyloidiasis, schistosomiasis and lymphatic filariasis; onchocerciasis and loiasis are also mentioned briefly. Dosage regimens and effectiveness, including combination treatment, are discussed. Mechanisms by which parasites may cause or aggravate malnutrition and retard development are shown, along with examples of nutritional and functional improvement at various ages due to antiparasitic treatment. Improvement in appetite is likely to be the single most important mechanism through which a variety of physiological improvements occur. We recommend community treatment of girls and women of childbearing age in areas with widespread hookworm and anaemia, because effective treatment can reduce the incidence of low birthweight, mortality in infancy and pregnancy, and stunted growth and morbidity in children and adults. Treatment of moderate-to-severe anaemia improves appetite, growth and cognitive and school performance in children, and also improves work and social capacity and productivity in children and adults. Since treatment for helminth infections may also decrease both the probability of contracting HIV infection and the rate of viral replication in those infected with both types of organisms, large-scale treatment and control of helminths and treatment of individual cases when diagnosed are now truly urgent.