Typhoid carriers among patients with gallstones are at increased risk for carcinoma of the gallbladder

OBJECTIVE: The aim of this study was to identify risk factors for carcinoma of the gallbladder (CaGB) among patients with gallstones (GS) with special reference to role of chronic Salmonella typhi carrier state. METHODS: A prospective case-control study was conducted in a tertiary care center in India. Cases were defined as consecutive patients with CaGB and GS, whereas controls were patients with GS alone. All were assessed clinically and their demographic data, diet, and smoking history recorded. Patients were detected to be typhoid carriers on the basis of Vi serology by enzyme linked immunosorbent assay. Cases (n = 37) and controls (n = 80) were compared by univariate and logistic regression analysis. RESULTS: The mean age of the cases and the controls were 53.4 +/- 11 yr and 43.5 +/- 14 yr, respectively. Among the cases, six (16%) patients were detected to be typhoid carriers, in contrast to two (2.5%) among controls (p = 0.01). Compared to controls, cases were more often older (p = 0.0002), of a lower socioeconomic status (p = 0.0005), and smokers (p = 0.0002). Stepwise logistic regression analysis identified typhoid carrier state (OR = 14; CI 2-92), age > or =47 yr (OR = 5; CI 2-14) and smoking (OR = 11; CI 2-71) as the three independent risk factors for development of CaGB among patients with GS. CONCLUSION: Chronic typhoid carrier state was the most important risk factor among patients with CaGB and gallstones.