甲型H1N1流感密切接触者感染危险因素的病例对照研究

目的 了解甲型H1N1流感密切接触者感染甲型H1N1流感病毒的危险因素.方法 选择2009年5月16日～9月15日在北京发现的7 099名甲型H1N1流感密切接触者作为研究对象,根据流行病学调查资料,将其中感染甲型H1N1流感病毒者纳入病例组,未感染者纳入对照组,开展病例对照研究,通过单因素和多因素非条件Logistic回归分析探寻甲型H1N1流感密切接触者感染流感的危险因素.结果 多因素分析结果显示:与＞50岁的甲型H1N1流感密切接触者相比较,20～ 50岁(OR=3.57,95％ CI:1.63～7.81)和＜20岁(OR=8.29,95％ CI:3.76 ～ 18.29)的密切接触者更有可能出现甲型H1N1流感病毒感染；与原发病例关系为家庭成员的密切接触者(OR=4.87,95％ CI:3.32 ～7.13)、暴露于症状期原发病例的密切接触者(OR=1.87,95％ CI:1.25～2.82)以及与原发病例暴露时间＞12h的密切接触者(OR=1.81,95％ CI:1.24～2.63)更易出现甲型H1N1流感病毒感染.结论 密切接触者年龄低、与原发病例关系密切、暴露于症状期的原发病例、长时间暴露于原发病例是甲型H1N1流感密切接触者发生感染的危险因素.

A case-control study on risk factors for 2009 H1N1 influenza infection among close contacts

Objective To determine risk factors for 2009 H1N1 influenza infection among close contacts.Methods The 7 099 close contacts of 2009 H1N1 influenza traced in Beijing between May 16 and September 15,2009 were involved in this study.The close contacts infected with 2009 H1N1 influenza were included in case group,and those not infected in control group.A case-control study was conducted,univariate and multivariate unconditional Logistic regression were employed for analysis.Results In comparison with close contacts aged 50 years,those of 20-50 years（OR=3.57,95% CI：1.63-7.81）and 20 years（OR= 8.29,95%CI：3.76-18.29） were more likely to develop infection.Moreover,close contacts who were household members of index cases（OR=4.87,95%CI：3.32-7.13）,exposed to index cases in symptomatic phase（OR=1.87,95%CI： 1.25-2.82）,and with exposure duration 12 h（OR=1.81,95%CI：1.24-2.63） were at higher risk of infection as well.Conclusions Younger age,close relationship with index case,exposure to index case in symptomatic phase and long exposure to index case were risk factors for 2009 H1N1 influenza infection among close contacts.