Surveillance for hemorrhagic fever with renal syndrome in China, 2013

Objective To understand the epidemiological characteristics of hemorrhagic fever with renal syndrome (HFRS) in China in 2013. Methods Descriptive epidemiological analysis was conducted on the surveillance data of HFRS in China in 2013, which were collected from national disease reporting information system and national HFRS surveillance network. Results A total of 12 810 HFRS cases, including 109 deaths, were reported in 2013, a decline of 3.74% compared with 2012. The incidence was 0.95/100 000 and the case fatality 0.85%. The disease mainly occurred in northeastern China and Shandong, Shaanxi, Hebei, Zhejiang, Jiangxi and Hunan provinces, the HFRS cases in these areas accounted for 82% of the national total. More cases were reported in spring and during autumn-winter, and the incidence peak was in November. The cases number in males was 2.70 times higher than that in females. Most cases were young and middle-aged farmers. A total of 1 165 cases were reported in 40 HFRS surveillance areas in 2013, accounting for 9.09% of national total. The incidence in the surveillance areas slightly increased, which was inconsistent with national one. Both the rat density and the hantavirus carriage rate of rats slightly increased in the surveillance areas in 2013 than in 2012, especially in spring, and obvious fluctuations was observed in some surveillance areas. Apodemus agrarius was predominant in the wild and Rattus norvegicus was predominant in residential areas, followed by Mus musculus. Apodemus agrarius and Rattus norvegicus were still the major host animals of HFRS in China. HNTV or SEOV were still major pathogens causing HFRS. In recent years, HFRS focus, where Eothenomys miletus was predominant, was found in Luxi, Yunnan province. Conclusion The overall incidence of HFRS was in slight decline in China in 2013, but the incidence in national HFRS surveillance areas was in slight increase, and the rat density and the hantavirus carriage rates in rats were still high and unstable in some surveillance areas, suggesting the possibility of HFRS outbreaks in these areas. Therefore, it is still necessary to strengthen HFRS prevention and control by means of vaccination, deratization, environmental management and health education.