Strongyloidiasis

Excerpt

Strongyloides stercoralis, commonly known as threadworm, is a soil-transmitted human parasite belonging to a group of nematodes called roundworms. Although prevalent almost worldwide, except only in the far north and south, the global burden of this parasitic infection is still underestimated because of the unavailability of precise data from endemic areas. S. stercoralis, therefore, becomes one of the most overlooked parasitic infections among the "neglected tropical diseases" (NTDs).

The helminth, S. stercoralis, mainly infects humans but also occurs naturally in domestic dogs, cats, and primates. The feature that makes it unique among other human nematodes is the ability to give rise to a progeny of free-living worms from rhabditiform larvae shed in human feces, which reproduce to form infective, skin-penetrating filariform larvae in the external environment. Humans infected with S. stercoralis present with varying degrees of clinical manifestations ranging from asymptomatic carriers to acute strongyloidiasis and disseminated infections.

Strongyloidiasis is the term used to indicate infection by Strongyloides stercoralis. It differs from other helminth infections by its ability to cause overwhelming hyperinfection in immunocompromised individuals. Strongyloides infection can last the host's lifetime due to its autoinfection life cycle and cause a wide spectrum of diseases ranging from asymptomatic eosinophilia to severe, life-threatening disseminated disease in immunocompromised patients.