Strongyloidiasis in Oceania

Strongyloidiasis is a potentially fatal disease caused by species of Strongyloides (Nematoda). In Oceania, two species infect humans: S. stercoralis and S. kellyi. S. stercoralis is widespread throughout Oceania and causes serious disease in any age group. S. kellyi is localised to Papua New Guinea and causes serious disease in infants. Infective larvae enter the body through the skin and migrate through the tissues. Adult females live in the mucosa of the proximal small intestine. The life cycle of S. stercoralis includes autoinfection, unusual in parasitic worms, whereby some of the offspring of the parasitic adults become infective in the lower intestine and complete the life cycle in the same person. This ensures that the infection persists, and the population of the worms can increase out of control, usually when the person is immunodefi cient or immunosuppressed. The worms can be eliminated by oral ivermectin, and the person is probably cured if their serology is negative 6 months after treatment. This chapter contains details of the life cycles, transmission, clinical manifestations, diagnostic tests and how to interpret them, most effective treatment options, how to ensure that treatment has been effective and what to consider when developing effective prevention and control strategies