Who Is at Risk for Strongyloidiasis?
We don’t know how many people on earth have strongyloidiasis, but the World Health Organization estimates the number at between 30 and 100 thousand. The parasite flourishes in tropical and subtropical regions where people lack toilets, but also extends into more temperate regions where sanitation is poor.
Because fresh feces can contain infective larvae, this parasite could potentially pass directly from person to person. Infection can also result if you accidentally swallow infective larvae, and researchers believe that the parasite might also pass from mother to baby in breast milk. Nonetheless, most infections result from contact with contaminated soil, and acquiring the parasite in a developed country is relatively uncommon.
Strongyloidiasis is usually not a life threatening infection. Even AIDS patients and donor organ recipients don’t experience life threatening autoinfection to the extent that one might expect. The important thing to remember is that anyone who has lived in or visited an endemic area could potentially have picked up this parasite, and could harbour it for many years without knowing. It’s prudent to consider testing for the parasite before treatment with corticosteroid drugs, or in other situations where the immune system isn’t functioning properly.
Schroeder L, and Banaei N. Strongyloides stercoralis Embryonated Ova in the Lung. (2013). New England Journal of Medicine 368:e15. Accessed March 21, 2013.
Roberts, LS and Janovy J Jr. Gerald D. Schmidt and Larry S. Roberts Foundations of Parasitology 8th ed. (2009). Boston:McGraw Hill. 414-417.
World Health Organization. Neglected Tropical Diseases: Strongyloidiasis. Accessed March 21, 2013.