Reactive arthritis and other sequelae following sporadic Salmonella typhimurium infection in British Columbia,Canada: a case control study

OBJECTIVE: To describe sequelae occurring in the 3 months after sporadic Salmonella typhimurium (ST) infection in British Columbia (BC), Canada. METHODS: We compared the incidence of sequelae to similar symptoms in controls; identified risk factors for developing sequelae; identified the incidence of reactive arthritis (ReA) as diagnosed by a rheumatologist, and assessed primary care physician diagnosis of ReA. A questionnaire was administered by telephone to cases of ST occurring in BC between December 1, 1999, and November 30, 2000; and to controls obtained from the BC provincial client registry. Cases reporting symptoms were followed up by a rheumatologist. RESULTS: Thirty-five of 66 (53%) cases reported any symptom, 17 (26%) reported joint symptoms. The Mantel-Haenszel odds ratio (weighted by sex and pediatric/adult) of a salmonella case reporting "any symptom" compared to controls was 5.42; 95% confidence interval (CI) 2.18-16.27; and reporting joint symptoms was 4.40; 95% CI: 1.25-19.53. The sex distribution of cases reporting joint symptoms was not significantly different. No medication taken during the salmonella infection was significantly different between the cases who had joint symptoms and those who did not. Four cases (2 adults, 2 children) were considered by the rheumatologist to have symptoms consistent with ReA, 2 of these had been told by a physician that their symptoms were related to their ST infection. CONCLUSION: Cases were more than 4 times more likely to report joint symptoms than controls; and despite the loss of many cases to followup, 6% of all cases were considered to have ReA.