Epidemiological Characteristics and Trend in the Incidence of Human Brucellosis in Iran from 2009 to 2017

Background: The development of preventive measures and promotion of healthcare delivery systems for disease management is dependent on detecting the incidence rates of the diseases and important risk factors. The current study aimed to determine some epidemiological indices and trends of the human brucellosis incidence in Iran between 2009 and 2017. Study design: A descriptive cross-sectional study. Methods: In the current study, online data were gathered from all cases of brucellosis who were potentially or definitely diagnosed and registered in medical centers, hospitals, laboratories, and private clinics in all districts of Iran. Epidemiologic questionnaires were used to collect data on demographic and background characteristics, risk factors, high-risk behaviors, and lab test results, respectively, based on the national brucellosis control plan. Results: A total of 138,448 cases of brucellosis have been studied in Iran from 2009 to 2017. The highest (25.89) and the lowest (12.07) incidence rates were observed in 2014 and 2009, respectively. In this nine-year study, the highest incidences were reported in the Hamadan, Lorestan, Kurdistan, and Kermanshah provinces. The cumulative percentages of the disease were estimated for different variables at the following rates: by gender: 57.9% for males; by age groups: 36.2% and 16.7% for the 25-44 and16-24 years age groups, respectively; by occupation: 33.2% for housewives; and by residential area: 75.7% for rural residents. Conclusions: Based on the obtained results, although the incidence of human brucellosis in Iran has declined since 2015, the number of cases has remained high.