Trends in the Epidemiology of Brucellosis Cases in Iran during the Last Decade

Background: Brucellosis is one of the most important zoonotic diseases that impose a serious public health burden on some countries in the world. Annually, the WHO reports more than 500000 new cases of human brucellosis. The disease is endemic in most parts of Iran; especially, in areas where people live in close contact with infected animals. According to data from the Iranian Ministry of Health, the average incidence of brucellosis in Iran was 22 cases per 100000 population, with a decreasing trend of surveillance. 
Methods: This cross-sectional survey was carried out within 2011-2020 in all provinces of Iran and from patients with clinical symptoms. 
Results: During the last decade, a total of 173526 cases were reported from different provinces of Iran, with a higher frequency of occurrence in males (58.2%) living in rural areas (77%), as compared to those in urban areas (23%). Moreover, brucellosis was more common in the summer season (June) and most of the cases were via contact with infected livestock (91%) and consumption of unpasteurized dairy products (78% in rural areas and 76% in the urban areas). 
Conclusion: The failure to effectively control brucellosis may be attributed to lack of knowledge about the disease, consumption of unpasteurized dairy and raw meat, lack of proper and safe vaccines for prevention and eradication programs, lack of rapid detection systems, and ineffective methods of isolating infected animals. Therefore, education and advancement of people’s knowledge are key to the prevention and control of the disease.