Strongyloidiasis

An intestinal parasitic infection in humans caused by two species of the parasitic nematode Strongyloides. The nematode or round worms are also called thread worms.

The fact of being infested with Strongyloides which enters the skin and then travels to the lungs and the intestines.

An infection caused by the roundworm Strongyloides stercorals. Strongyloidiasis occurs when human skin is penetrated by larvae of this roundworm that exists in contaminated soil. The larvae migrate through the bloodstream to the lungs and are transported through the bronchial tree to the throat, where they are swallowed and move down into the small intestine. They mature into females in the small intestine, where the females live in the lining of the intestinal walls and produce eggs, which yield larvae. These larvae are either eliminated in the stool or remain in the body and penetrate the mucosal lining of the intestines or the skin of the area surrounding the anus. These larvae then follow the route from the lungs to the small intestines where they mature into adults and begin their life cycle again. This ongoing cycle causes persistent infection and reinfection in the human host.

An infestation of the small intestine with the parasitic nematode worm Strongyloides stercoralis, common in humid tropical regions. Larvae, present in soil contaminated with human feces, penetrate the skin of a human host and may produce an itching rash. They migrate to the lungs, where they cause tissue destruction and bleeding, and then via the windpipe and gullet to the intestine. Adult worms burrow into the intestinal wall and may cause ulceration, diarrhea, abdominal pain, nausea, anemia, and weakness. Treatment involves use of the drugs thiabendazole and dithiazanine.

This infestation 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. Larvae penetrate intact skin, especially the feet (as with hookworm infection). Their eggs mature and hatch in the lower gastrointestinal tract and 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 the Second World War.

Infestation of the intestines by the parasitic worm Strongyloides stercoralis is referred to as strongyloidiasis. This prevalent disease is common in tropical regions and is contracted by walking barefoot on soil contaminated with feces in affected areas. The larvae of the parasite penetrate the skin of the soles, migrate through the lungs and throat, and eventually settle in the small intestine, where they mature into adults and generate new larvae. While a majority of these larvae are expelled through feces, some enter the skin around the anal area to initiate a new life cycle. An individual can remain infested for over four decades.

The entry of larvae into the skin results in itching and the formation of red welts. Within the lungs, these larvae might induce conditions like asthma or pneumonia. When the intestines experience a substantial infestation, symptoms like abdominal swelling and diarrhea can manifest. In some instances, individuals infected with compromised immunity might succumb to complications such as septicemia or meningitis.