Epidemiological survey of a clustering outbreak of influenza in Shenzhen City

Objective To anlayze the prevalenct features of influenza and control results for acumulating experence in control of outbreak of influenza in high risk population of Shenzhen City. Methods DNA of flu virus was determined by PCR and antibodies to influenza virus were detected by ELISA,The patients were diagnosed according to sdantart of GB15994-1995,and data ananlysis by SPSS10.0. Results 370 patients were infected with influenza virus in the period of 3～26 of July in Luohu Detaining Station,and the peak period was 10～11 of July,showed one apex distribution.Intection rate in the capture room was 21.38% higher than that of impounding room with infection rate 3.50%,and showed significant diffrence between two group(χ~2=130,P=0,n=1),and infection rate was 100%(39/39) in capturing section and 29.63%(8/27) in the impounding section(χ~2=38.24,P=0,n=1).The infection rate in the males was 17.50%(364/2 080) and that in the females was 1.88%(6/320),(χ~2=51.92,P=0,n=1),showing significant diference.Clinically symptoms of fever,headache,insobriety,tears,snuffle and cough were 100%,69.19%,54.32%,58.11%,32.70% and 19.46%,respectively.PCR positive rates were 42.67%,being 57.14% in peak period and 10.00% in stable period.and all the pathogen of 11 sample of flu were H3N2.The positive rate of IgM antibody was 2.41%,IgG antibody titer of double sera was 4 times or with an increasing rate of 91.67%.The highest titer was 1:1280 and with the highest increased times of 64.PCR did not show positve reaction with primers of H5N1 or SARS,and the patient sera did not reaction with SARS-IgM ,IgG and antigen.enterovirus. Conclusion Epidemic outbreak of influenza occurred in Shenzhen Detaining Station in July of 2004,and the pathegen is H3N2,and there is no mixed infection of the pathogen with H5N1,SARSCOV and enterovirus.The epidemic outbreak of influenza can be controlled by taking integrated control measures including isolating patients,treatment with drugs,improving ventilation and sterilization.