Intestinal geohelminthiasis in the developing world.

ABSTRACT

Intestinal parasitic helminths such as roundworms (Ascaris lumbricoides), hookworms (Ancylostoma doudenale and Necator americanus) and whipworm (Trichuris trichiura) are common in the developing world. Strongyloides stercoralis, though not so common, also contributes to health problems. The prevalence of intestinal worm infestation in India varies from 5% to 76%, which is similar to that in other developing countries. These parasitic infestations are acquired by ingestion, inhalation or penetration of the skin by the infective forms. Ascaris causes many intestinal and respiratory symptoms and plays an important role in precipitating protein-energy malnutrition in undernourished children. Hookworms cause anaemia and hypoproteinaemia. In areas where hookworm infestation is endemic, 90% of pregnant mothers are anaemic. Trichuriasis as a causative agent of human disease has only recently gained attention. Heavy infestation with T. trichiura can result in severe colitis and significant blood loss. This in turn can lead to impaired cognitive functions which are reversible on treatment. Though not as widely prevalent as the other geohelminths in India, Strongyloides stercoralis infestation can be fatal in debilitated and immunosuppressed children. So far, the impact of these parasites on the health of children has been underestimated and concentrated efforts to minimize the worm load and its consequences have not been given due importance in our health policies. This article reviews the pathophysiology, clinical impact and control options of the most commonly prevalent geohelminths in the developing world.