Qom Cholera Outbreak in 2011: Influential and Determinant Factors

Cholera outbreaks are a worldwide health challenge. It poses major threats to public''s health. This study was designed to assess the magnitude of and factors responsible for an outbreak in a Qom during an outbreak in 2011. In a case-control study inclusion criteria was to be staying in Qom province 5 days before clinical symptoms. Accordingly, 100 cases from 136 total cases were entered into study. As controls two persons for each case were entered into analyses. The controls and cases were pair-matched. Frequency tables and logistic regression were used to analyze variables. Eighty percent of cases were of 21-60 years old and 73% were laborers and housekeepers. Female, rural residents, Iranians and outpatient comprised 51, 13, 91 and 90% of cholera cases respectively. From vegetable specimens, collected during epidemic, 43% were infected by Non Agglutinating Group (NAG) bacteria and there was only one Ogawa positive specimen. Consumption of non-disinfected vegetables, salads and history of any travelling had 5.04 (95%CI= 2.6-9.7), 0.1 (CI= 0.07-0.31) and 0.15 (CI= 0.01-0.9) Odds Ratios (OR) respectively. Against expectations, type of salad had a different effect on epidemic. Consumption of lemon-juice salad (called as Shirazi salad) had a protective effect (OR= 6.3 (CI= 3.6-13)) against cholera. Consumption of non-disinfected vegetables poses a high risk for cholera outbreak and, consequently, much more attempts are needed to solve this problem. Consumption of lemon-juice salad has a protective effect on cholera and can be used as a preventive device.