The diagnosis must be considered in any patient from an endemic region who is to be treated with immunosuppressive agents. Definite diagnosis requires demonstration of characteristic rhabditiform larvae because eggs hatch within the intestine. Diagnosis of uncomplicated infection can be difficult because repeated stool examinations often fail to demonstrate larvae, even after concentration. Yield may be further improved using duodenal fluid recovered by the string test. In Strongyloides hyperinfection, larvae may be readily recovered from sputum and other body fluids, as well as stool.
Treatment is with thiabendazole, but has frequent side effects.