EOSINOPHILIC ENTERITIS IN NORTHEASTERN AUSTRALIA - PATHOLOGY, ASSOCIATION WITH ANCYLOSTOMA-CANINUM, AND IMPLICATIONS

While eosinophilic gastroenteritis is considered a rare condition, eos inophilic enteritis without gastric involvement is quite common in nor theastern Australia. We present 79 patients with biopsy-proven eosinop hilic enteritis, 70 seen since 1987. In 10 patients, eosinophilic ente ritis was associated with infection by single, sexually immature, adul t hookworms, most positively identified as the common dog hookworm Anc ylostoma caninum. An additional 22 patients (of 34 tested) had serolog ical evidence of A. caninum exposure. The essential pathology, i.e., e dema and eosinophilic infiltration of the gut wall, ascites, and regio nal lymphadenopathy, was identical to that seen in eosinophilic gastro enteritis. Additional, more specific features included pathological re actions centered on attached worms, mucosal alterations and ulcers con sidered to be hookworm bite sites, and submucosal and lymph node granu lomas with central eosinophil degranulation and degradation products. Since A. caninum has an almost worldwide distribution, it is probable that A. caninum-induced eosinophilic enteritis occurs outside Australi a. We show that the worm is easily overlooked in pathological specimen s and that care is required to preserve worms intact for specific para sitological identification. The clinical and pathological features wer e similar to those seen in another human enteric helminthic zoonosis, anisakiasis. The possibility that there are yet other undiscovered int estinal zoonoses remains.