Strongyloides Stercoralis

Strongyloides stercoralis is the scientific name of a human parasitic roundworm causing the disease of strongyloidiasis. Its common name is pinworm in the UK and threadworm in the US. In the UK, however, the term threadworm refers to nematodes of the genus Enterobius.

The Strongyloides stercoralis nematode can parasitize humans. The adult parasitic stage lives in tunnels in the mucosa of the small intestine. The genus Strongyloides contains 53 species and S. stercoralis is the type species. S. stercoralis has been reported in other mammals, including cats and dogs. However, it seems that the species in dogs is typically not S. stercoralis, but the related species S. canis. Nonhuman primates are more commonly infected with S. fuelleborni and S. cebus, although S. stercoralis has been reported in captive primates. Other species of Strongyloides, naturally parasitic in humans, but with restricted distributions, are S. fuelleborni in central Africa and S. kellyi in Papua New Guinea.