Human distribution of brucellosis' in Heilongjiang province, 1949-2009

Objective To analyze the epidemiological characteristics of brucellosis in Heilongjiang and explore the influence factors to the disease in different periods. Methods The descriptive epidemiological analysis was conducted on the incidence data of brucellosis in Heilongjiang from 1949 to 2009 to understand its population, age, gender, seasonal and geographic distributions in different periods. Results Three incidence peaks of brucellosis occurred from 1949 to 2009. The first one occurring in 1950s affected the whole province, the incidence in 1956 was highest (6.87/lakh). Most cases were farmers (about 81%). Two incidence peaks occurred in 2000s, 4040 cases were reported in 2005 with the incidence of 10.77/lakh and 4795 cases were reported in 2009 with the incidence of 12.59/lakh. The disease affected not only farmers but also other populations in urban area. Conclusion The incidence of brucellosis in previously existed epidemic area continued to increase and more areas were being affected by the disease in recent years. Sick sheep are the major infection source and more population might be affected, indicating that prevention and control of the disease should be strengthened.