[Analysis on the epidemiological features of human brucellosis in northern and southern areas of China, 2015-2016].

Objective: To analyze the epidemiological characteristics of human brucellosis in northern and southern areas of China, and to develop national strategies for brucellosis prevention and control. Methods: Individual data on human brucellosis was collected from the National Notifiable Infectious Disease Reporting Information System to describe the situation of brucellosis in China during 2015-2016. Epidemiological features of the disease in northern and southern areas of China were analyzed. Results: A total of 104 125 cases were reported in mainland China during 2015-2016, with an average incidence rate as 3.81/100 000. The overall incidence rate from the northern provinces was 7.77/100 000 in 2016, a 18.6% decrease from 2015 (9.55/100 000), whereas the incidence rate in the southern provinces was 0.27/100 000 in 2016, with an increase of 28.6% than 0.21/100 000 in 2015. 90.0% of the newly infected counties mainly distributed in southern China. As for the locations of reporting cases, most of them were in the same counties in the northern areas (52.3%) while most cases in the southern areas (59.6%) were imported from other counties. The median age of the cases was 48 (IQR: 38-58) years, with male-to-female ratios as 2.7∶1 in the north and 2.2∶1 in the south. Majority of the cases were occupation-related, from both the northern (86.8%) and southern (62.7%) areas. Human brucellosis occurred every month throughout the year but with an obvious seasonal increase between March and July. Conclusions: Different epidemiological features of human brucellosis appeared in both northern and southern areas of China. The disease was seen endemic in the northern and dispersal in the southern provinces. Appropriate strategies for brucellosis prevention and control should be developed, according to the different epidemiological characteristics in the northern or southern areas.