Failure of pyrantel in treatment of human hookworm infections (Ancylostoma duodenale) in the Kimberley region of north west Australia.

A survey of 108 individuals from a coastal Aboriginal community in north Western Australia revealed that two species of gastrointestinal protozoan parasites (Giardia duodenalis--39.8%, Entamoeba coli--40.7%) and five gastrointestinal helminths (Hymenolepis nana--54.6%, Hookworm [Ancylostoma duodenale]--30.6%, Enterobius vermicularis--6.5%, Trichuris trichiura--2.8%, Strongyloides stercoralis 1.9%) were present. A total of 29 individuals infected with hookworm were offered treatment with either pyrantel pamoate at a single dose rate of 10 mg/kg body weight or albendazole (single 400 mg dose). Seven days after treatment stool samples were examined. Pyrantel had no significant effect against hookworm. In contrast, albendazole cleared hookworm infections completely and reduced the prevalence of Giardia. The former result suggests that locally A. duodenale is resistant to pyrantel and despite its relatively low cost and wide availability, should not be considered a drug of choice at this dose rate in the treatment of hookworm infections (A. duodenale) in endemic regions.