Discussion In our study. elevated anti-ov antibody as well as the con tion of raw fish correlated with increased risk for cholangiocarci have A few points should be considered. First, all fishes do not may ov metacercariae in their flesh. Second, individual cases possibly differ with respect to susceptibility to the infection. Third, it is unclear as to how precisely the duration and intensity of the ov infection was estimated in cases with elevated anti-ov antibody. Finally, the reported history of treatment with prazi- quantel should be considered because this drug is effective after only a single administration: however, statistical adjustment for use of this drug did not affect the increased risk due elevated anti-ov antibody. It may be difficult to measure exactly the mag- nitude of the effect of ov infection and eating raw fish. However t if the prevalence of infection, as indicated by an elevated antibody level, is assumed to be 6% (8/127) among the study population, 1 then 60% of cholangiocarcinomas may be preventable by elimi r nating the infection. Thus, avoiding the consumption of raw and