Strongyloidiasis was first described in French troops stationed in modern day Vietnam during the late 19th century who were suffering from severe, persistent diarrhea. It is a parasitic disease caused by nematodes, or roundworms, in the genus Strongyloides that enter the body through exposed skin, such as bare feet. Strongyloides is most common in tropical or subtropical climates.

Most people who are infected with Strongyloides do not know they are infected and have no symptoms. Others may develop a severe form and, if untreated, become critically ill and potentially die.

Image: Left: Adult free-living female S. stercoralis. Notice the row of eggs within the female's body. Right: Filariform (L3) larva of S. stercoralis in an unstained wet mount. Credit: DPDx.