郴州市某戒毒所一起流感暴发流行病学调查

Epidemiological survey of an influenza outbreak in a drug rehabilitation center in Chenzhou

目的通过对郴州市某戒毒所流感疫情特征和暴发原因的分析,有针对性地提出有效的预防和控制措施。方法采用流行病学调查方法,通过描述性研究和回顾性队列研究,探索暴发原因及流感疫苗保护效力。结果此次疫情共63例病例,其中可能病例55例,确诊病例8例,罹患率为13.46%(63/468)。首发病例发病时间为6月17日;6月22日—25日出现高峰,报告病例52例,占总病例数的82.5%(52/63)。对15例病例的咽拭子病毒核酸检测,其中8例为甲型H3N2流感病毒阳性。学员接种流感疫苗相对危险度(RR)为0.887(95%CI:0.56~1.43),流感疫苗保护率为11.3%。结论此次疫情为一起甲型H3N2流感暴发疫情,疫情初期未对病例进行及时有效的隔离,是导致疫情扩散的主要原因。

Objective To investigate the epidemic characteristics and causes of an influenza outbreak in a drugrehabilitation center in Chenzhou City so as to provide the reference for putting forward effective prevention and controlmeasures. Methods By using the epidemiological investigation method, including descriptive study and retrospective cohortstudy, the causes of the influenza outbreak and the protective efficacy of influenza vaccine were explored. Results A total of63 cases were founded, of which 55 cases were probable cases and 8 cases were confirmed cases. The attack rate was 13.46%（63/468）. The initial case＇s onset time was June 17. The peak time was June 22-25, and 52 cases were reported accounting for82.5% of the total cases（52/63）. The throat swabs of 15 cases were detected for viral nucleic acids, and 8 cases were positive ofinfluenza A（H3N2） virus. The relative risk（RR） was 0.887（95%CI： 0.56-1.43）, and the vaccine protection rate was 11.3%after influenza vaccination. Conclusion This outbreak is caused by influenza A（H3N2） virus, and the major cause leading tothe spread of disease is that at the beginning of the outbreak, the cases were not isolated timely and effectively.