Epidemiology of natural focus and vector borne infectious diseases in class B in Guizhou, 2008-2012

Objective To understand the epidemiological characteristics of natural focus and vector borne infectious diseases in class B in Guizhou province and provide evidence for the prevention and control of these diseases. Methods Descriptive epidemiological analysis was conducted on the incidence data of natural focus and vector borne infectious diseases in class B reported in Guizhou from 2008 to 2012. Results A total of 6034 cases of 9 natural focus and vector borne infectious diseases in class B were reported during this period. The average annual incidence was 3.25/lakh, the annual incidence was 5.36/lakh, 4.99/lakh, 2.66/lakh, 2.00/lakh and 1.22/lakh respectively, which showed a decline trend. A total of 1192 deaths were reported, the average annual death rate was 0.65/lakh. The first 3 prefectures reporting high incidences were Qiannan (9.27/lakh), Qiandongnan (5.30/lakh) and Qianxinan (4.59/lakh). The first 3 diseases with high case numbers were malaria (2714), Japanese encephalitis (1558) and rabies (1118), accounting for 89.33% of the total cases. Malaria mainly occurred in Qiannan, Qiandongnan and Qianxinan, Japanese encephalitis mainly affected children aged less than 10 years and mainly occurred during Jun-September with the peak in August. Rabies cases were mainly farmers, accounting for 61.81% of the total. During this period, three cases of human infection with highly pathogenic avian influenza virus were reported, all the cases had poultry contact histories. Conclusion The overall incidence of natural focus and vector borne infectious diseases in class B in Guizhou was in decline, but the incidence of brucellosis was in increase. The incidences of Japanese encephalitis and rabies still ranked third at national level. The diseases had obvious seasonality and population distribution. It is necessary to conduct targeted prevention and control of these diseases.