Human Intestinal Infection with the Dog Hookworm, Ancylostoma caninum, in Western Australia.

Rare cases of aphthous ulceration and eosinophilic enteritis in humans caused by Ancylostoma caninum (A. caninum), a common intestinal nematode of dogs worldwide, have been reported over the past century in several regions of the world. The present report involves a case of aphthous ulceration of the colon caused by A. caninum in Western Australia. The identity of the worm recovered during routine colonoscopy of a 35-year-old immunocompetent male was confirmed via morphological analysis and sequencing of the mitochondrial cytochrome c oxidase subunit I gene and nuclear ribosomal internal transcriber spacer II region. A summary of this case and previous reports of human A. caninum intestinal infection is provided. Intestinal infection with A. caninum is likely an underdiagnosed zoonosis in tropical and temperate regions worldwide. Further epidemiological studies and increased clinical awareness of zoonotic hookworms in humans are warranted to clarify the prevalence and significance of A. caninum infection in human hosts.