Strongyloides Health Dictionary

This infection is caused by nematode worms of the genus Strongyloides spp. – the great majority being from S. stercoralis. This helminth is present throughout most tropical and subtropical countries; a single case report has been made in England – about an individual who had not been exposed to such an environment. Larvae usually penetrate intact skin, especially the feet (as with hookworm infection). Unlike hookworm infection, eggs mature and hatch in the lower gastrointestinal tract; thus larvae can immediately re-enter the circulation in the colo-rectum or perianal region, setting up an auto-infection cycle. Therefore, infection can continue for the remaining lifespan of the individual. Severe malnutrition may be a predisposing factor to infection, as was the case in prisoners of war in south-east Asia during World War II.

Whilst an infected patient is frequently asymptomatic, heavy infection can cause jejunal mucosal abnormalities, and an absorptive defect, with weight loss. During the migratory phase an itchy linear rash (larva currens) may be present on the lower abdomen, buttocks, and groins; this gives rise to recurrent transient itching. In an immunosuppressed individual, the ‘hyperinfection syndrome’ may ensue; migratory larvae invade all organs and tissues, including the lungs and brain. Associated with this widespread infection, the patient may develop an Enterobacteriacae spp. SEPTICAEMIA; this, together with S. stercoralis larvae, produces a MENINGOENCEPHALITIS. There is no evidence that this syndrome is more common in patients with HIV infection.

Diagnosis consists of visualisation of S. stercoralis (larvae or adults) in a jejunal biopsy-section or aspirate. Larvae may also be demonstrable in a faecal sample, especially following culture. Eosinophilia may be present in peripheral blood, during the invasive stage of infection. Chemotherapy consists of albendazole. The formerly used benzimidazole compound, thiabendazole, is now rarely prescribed in an uncomplicated infection due to unpleasant side-effects; even so, in the ‘hyperinfection syndrome’ it probably remains the more e?ective of the two compounds.... strongyloidiasis

A cutaneous eruption resulting from exposure of the skin the infective filariform larva of non-human hookworms, Ancylostoma braziliense, A. caninum and some Strongyloides spp (especially S. procyormis of the raccoon and S. myopotami of the nutria).... cutaneous larva migrans

A rash rather like that of cutaneous larva migrans resulting from penetration of the filariform larva of Strongyloides stercoralis in the skin around the anus and buttocks, as part of autoinfection.... larva currens

An extension of cuticle around the mouth of nematodes; there may be three, one dorsal and two subventral as in Ascaroidea or two as in Spiruroidea or absent as in Strongyloides and Filarioidea.... lip

A muscular structure of three parts proximal bulb, narrow isthmus and distal body or corpus as in freeliving rhabditoids, parasitic oxyuroids, and free-living and non-infective stages of Strongyloides spp.... rhabditiform

A condition seen in very young children in Papua New Guinea infected with a Strongyloides fu?lleborni-like species of intestinal nematode.... swollen belly syndrome

The drug of choice for adults infected with the intestinal parasite Strongyloides stercoralis (see STRONGYLOIDIASIS). Its side-effects, including ANOREXIA, nausea, vomiting, diarrhoea, abdominal pain, itching and drowsiness, are more troublesome in elderly patients.... thiabendazole