Effective diagnostic tests and anthelmintic treatment for Strongyloides stercoralis make community control feasible

Abstract

Strongyloides stercoralis is endemic in tropical and subtropical countries, and is prevalent particularly in economically impoverished people. Although an estimated 30 to 100 million people world-wide suffer from S. stercoralis infection and it is a life-long disease, it remains a neglected tropical disease. Faecal testing for S. stercoralis is very insensitive. The prevalence of S. stercoralis in Indigenous Australians (up to 60%) is much higher than previously thought, and its prevalence in Papua New Guinea is likely to be much higher than currently believed. When S. stercoralis and the HTLV-1 virus coexist in the one person, both diseases progress more quickly than when either infection is on its own. When people become infected with S. stercoralis, they develop acute strongyloidiasis which may be life threatening. At any time during the course of the disease, if the immune system is suppressed, most often by corticosteroid drugs, infected people may develop hyperinfective strongyloidiasis and they will die unless the underlying S. stercoralis infection is effectively treated. The use of serology for diagnosis, together with ivermectin treatment, has revealed that it is possible to eradicate S. stercoralis from the patient, and serology can also define the effectiveness of treatment. The reservoir of infection is humans; the free-living stages are short-lived. Mass treatment may be effective at eliminating S. stercoralis from a community. Safe water and effective sanitation alone do not lead to elimination of S. stercoralis. Up-to-date knowledge of S. stercoralis has been revealed through the workshops of the National Strongyloides Working Group in Australia and is summarized here. Much of this information is now available on the world wide web, and the addresses of relevant web sites are given.