Chronic typhoid infection and the risk of biliary tract cancer and stones in Shanghai, China

Previous studies have shown a positive association between chronic typhoid carriage and biliary cancers. We compared serum Salmonella enterica serovar Typhi antibody titers between biliary tract cancer cases, biliary stone cases without evidence of cancer, and healthy subjects in a large population-based case-control study in Shanghai, China. Participants included 627 newly diagnosed primary biliary tract cancer patients; 1,037 biliary stone cases (774 gallbladder and 263 bile-duct) and 959 healthy subjects without a history of cancer, randomly selected from the Shanghai Resident Registry. Overall only 6/2,293 (0.26%) were Typhi positive. The prevalence of Typhi was 1/457 (0.22%), 4/977 (0.41%), and 1/859 (0.12%) among cancer cases, biliary-stone cases, and population controls, respectively. We did not find an association between Typhi and biliary cancer in Shanghai, due to the very low prevalence of chronic carriers in this population. The low seroprevalence of S. Typhi in Shanghai is unlikely to explain the high incidence of biliary cancers in this population.