The clinical significance of gastrointestinal helminths—a review

Abstract

Gastrointestinal helminths (nematodes, trematodes and cestodes) constitute some of the most common and important infective agents of mankind and are responsible for much morbidity and some mortality. Whereas many symptoms and signs are confined to the intestine and less often the associated digestive organs, systemic manifestations are also numerous; this applies especially to indigenous populations of developing 'Third World' countries. Using a clinical classification these organisms can be broadly separated into those involving the small-intestine and those which have a colo-rectal distribution; of the former, a minority has been causally related to intestinal malabsorption. Clearly, however, not all gastrointestinal helminths are associated with disease and it is important to be able to separate these two groups; when present at high concentration and especially in infants and children some of the least pathogenic are not, however, entirely asymptomatic. Maintenance of a high 'index of suspicion' is necessary and this applied especially to 'western' populations in whom rapid and extensive travel to areas of the world with substandard sanitation and contaminated food and water supplies is now common; first evidence of infection in them may result from serious clinical complications. Recent advances have focussed on treatment, and especially the introduction of the benzimidazole compounds (especially albendazole) for nematode, and praziquantel for cestode, infections. Treatment of strongyloidiasis remains, however, unsatisfactory. Mass elimination of gastrointestinal helminths in developing 'Third World' countries remains a major challenge.

Screening for intestinal parasites in recently arrived children from East Africa

“…The burden of intestinal parasitic disease remains one of the greatest health problems in the developing world, with over one billion people estimated to be infected 1 . While most infections remain asymptomatic, the clinical spectrum of disease is widespread, ranging from mild gastrointestinal symptoms to death from disseminated infection 1,2 .…”

<italic>Strongyloides stercoralis</italic> Hyperinfection Syndrome: How Often is it Missed?

“…A recent report of infection in a young woman at Nottingham strongly suggests that the parasite was acquired in a local recreational park [4]. Human infection is usually by penetration of intact skin by the filariform larvae which survive in moist soil contaminated with human faeces; this mode of transmission is exactly comparable with that of the hookworms Ankylostoma duodenale and Necator americanus [5,6]. Infection by the faecal-oral route is also possible.…”

“…Treatment is unsatisfactory at present and newer chemotherapeutic agents are required [6]. Thiabendazole (25 mg/kg b.d.…”

Anthelminthic agents: some recent developments and their clinical application

“…Following its introduction in 1983,7 it was rapidly shown to be active against the intestinal nematode infections.33'34 However, a far more important observation was that Onchocerca volvulus microfilariae are also highly susceptible to its action; when administered at a dose of 100-200 fig/kg it exerts a microfilaricidal action which lasts for [6][7][8][9][10][11][12] months.35-41. Annual re-treatment must be provided, however, until the adult worms are dead.…”