Risk factors for human brucellosis in Iran: a case–control study

Abstract

BACKGROUND: Brucellosis is a zoonotic disease of worldwide distribution. Despite its control in many countries, it remains endemic in Iran. The aim of this study was to determine the risk factors for brucellosis acquisition in the central province of Iran. METHODS: A matched case-control study was conducted in the central part of Iran. A total of 300 subjects (150 cases and 150 controls) were enrolled in the investigation. Brucellosis cases were defined on the basis of epidemiologic, clinical, and laboratory criteria. Subjects were interviewed using a questionnaire to obtain risk factor information. We used odds ratios and conditional logistic regression models to explore the association between the disease and the variables studied. RESULT: Significant risk factors for infection were related to the existence of another case of brucellosis in the home (OR=7.55, p=0.0001) and consumption of unpasteurized dairy products (OR=3.7, p=0.014). Keeping cattle and cattle vaccination were also important risk factors. CONCLUSIONS: Pasteurization of dairy products and education regarding fresh cheese must be pursued for eradication of brucellosis. A major risk factor for acquiring brucellosis is the existence of another infected family member. Therefore screening family members of an index case of brucellosis may lead to the detection of additional cases.