CROSS-SECTIONAL PATTERNS OF HEPATOBILIARY ABNORMALITIES AND POSSIBLE PRECURSOR CONDITIONS OF CHOLANGIOCARCINOMA ASSOCIATED WITH OPISTHORCHIS-VIVERRINI INFECTION IN HUMANS

The liver fluke, Opisthorchis viverrini, is both highly prevalent and closely associated with cholangiocarcinoma in northeast Thailand. This study measured associations between intensity of liver fluke infectio n and nonmalignant hepatobiliary disease diagnosed by ultrasonography among 1,807 largely asymptomatic adult residents drawn from endemic co mmunities. Abnormalities significantly associated with intensity of in fection included gallbladder enlargement in all dimensions, presence o f sludge, irregular gallbladder wall, liver enlargement, and enhanced portal vein radicle echoes. While gallbladder enlargement was not sex- specific, the prevalence odds of the other abnormalities were 2-3 time s higher among males compared with females. Those recently treated wit h the anthelmintic praziquantel had higher odds of these abnormalities compared with others with the same infection status who were untreate d. The low prevalence of gallstones suggests that this impairment of g allbladder structure and function does not frequently stimulate gallst one formation. However, gallbladder disturbances, together with chroni c inflammation and fibrosis of the bile ducts. which are visualized as enhanced portal vein radicle echoes, may contribute to the strikingly enhanced susceptibility to cholangiocarcinoma among people, especiall y males, with heavy liver fluke infection.