Experimental Canine Cholera IV. The Chronic Carrier State for Vibrio cho/erae

Studies during the present pandemic of cholera due to Vibrio cholerae, var. el tor, have indicated that the chronic carrier state in man may be sig-nificant in the persistence of vibrios in the envi-ronment. Although Kulesha in 1911 described one chronic carrier with organisms in the gall bladder [I], the first documentation of this condi-tion in recent times was in convalescent patients in the Philippines [2]. In one such patient, stools as well as duodenal aspirates continued to yield positive cultures for V. cholerae for 6 years [3]. Reports from other endemic areas [4, 5] have also documented the occurrence of the per-sistent carrier of V. cholerae, and have indicated that between 5 % and 21 % of patients with chol-era may continue to excrete vibrios for many weeks following recovery. Indirect evidence strongly suggests that these human carriers har-bor the vibrios in the gallbladder. Prior to these recent observations on the car-rier state in humans, vibrio infections of the gall bladder had been studied in experimental ani-mals. Schobl [6] showed that guinea pigs became carriers for several weeks following direct inocu-lation of vibrios into the gall bladder. Nikonov [1] also injected the intact gall bladders of guinea pigs and rabbits, and found that although the ani-mals did not become ill, they continued to pass Received for publication August 5, 1968