This review summarises current knowledge of the ill-effects of soil-transmitted
helminthiasis and takes a detailed look at studies that have been published over the past decade describing the effect of mass anthelminthic use on the health of endemic communities. Mass
chemotherapy appears to give maximal returns in terms of improved health in areas where hookworm is a major problem and
albendazole is used regularly, along with
iron supplements; in children it improves physical growth and
iron stores, and in pregnant women it reduces the prevalence of
iron-deficiency anaemia. In areas where
ascariasis is common, the directly attributable benefits of
chemotherapy may be minimal, but it can facilitate the entry of other health care programmes in children, because deworming for
ascariasis is often much desired and appreciated by the community. In areas with
Vitamin A deficiency and endemic
ascariasis,
Vitamin A supplementation can be combined with deworming: anthelminthics do not impair
Vitamin A absorption but the worms may interfere with
Vitamin A uptake by reducing fat absorption. Where
trichuriasis is a major problem, single dose
chemotherapy may take some time to reduce prevalence, but reduction of heavy
infections will reduce the incidence of Trichuris
Dysentery Syndrome, probably benefit the learning abilities of affected schoolchildren, and may reduce anaemia and
stunting. In general, children should be treated as early as possible, and in areas of very high prevalence, thrice-yearly mass
chemotherapy probably improves health better than twice-yearly treatment.