HUMAN ENTERIC INFECTION WITH ANCYLOSTOMA-CANINUM - HOOKWORMS REAPPRAISED IN THE LIGHT OF A NEW ZOONOSIS

Recent studies in northeastern Australia indicate that enteric infecti on with Ancylostoma caninum is a leading cause of human eosinophilic e nteritis. Much more frequent accompaniments of this infection are obsc ure abdominal pain with or without blood eosinophilia, while a large p art of the population is probably infected asymptomatically. These con clusions are based on extensive serological investigations in patients and control subjects, as well as 15 cases in which single, adult hook worms were identified in situ in patients. In no case has more than on e worm been identified, and none has been fully mature, so the infecti ons have never been patent. Aphthous ulcers of the terminal ileum, cae cum and colon have been seen in association with this infection and ha ve also been observed in almost 5% of patients who are colonoscoped in north Queensland. Serodiagnosis has relied on an IgG and IgE ELISA us ing excretory-secretory antigens from adult A. caninum, but Western bl ot using these antigens to identify IgG4 antibodies to a protein of mo lecular weight 68 kDa (Ac68) promises to be more specific and sensitiv e. However, identical antigens appear to be secreted by the anthropoph ilic hookworms as well. The clinical, public health and biological sig nificance of these findings are discussed in detail.