Objective To determine species composition and distribution patterns and seasonal dynamics of fly populations in Haidian district, providing data for the formulation of scientific prevention and control measures. Methods The cage trap method was employed to monitor densities and population distributions of flies at five monitoring sites at Haidian district. Results The average density of flies was 22.52/cage in Haidian district in 2008, the dominant species being Sarcophagidae. Significant seasonal fluctuations of the fly populations were observed, the highest density, 59.60/cage in late July. Most flies were captured at the monitoring sites in Taizhouwu Dock Trade Market with a density of 59.19/cage. Conclusion Urban areas should be the key areas for prevention and control of flies for the successful proceeding of 2008 Olympic Games.

【Abstract】 Objective To investigate the situation of the natural infection of Hantaviruses (HV) in rodents and provide the guidance for the control and prevention of hemorrhagic fever with renal syndrome (HFRS) in Haidian district, Beijing. Methods Rodents were captured by night trap, and lung tissue samples were taken out and stored in liquid Nitrogen. HV was detected by indirect immuno?fluorescence assay (IFA). Results There were 225 rodents captured in different habitats of Haidian district,  which belonged to 3 species and 2 Genera. Rattus norvegicus was the dominant species in the habitats investigated. The total natural infection rates of HV in rodents ranged from 4.60% to 20.00%, and the average was 6.22%. Different species had different natural infection rates. The rate of infection among R.norvegicus and Mus musculus was 6.96% and 6.06% respectively, while Apodemus agrarius was not infected. Conclusion The rodents were infected by HV in Haidian district commonly, and its main host was Rattu Genera.