流感样病例定义对流感监测结果影响的比较分析

目的 比较不同临床症状的流感样病例流感检出情况的差异，探讨采用不同流感样病例定义对流感监测结果的影响。方法 根据2015年上海市2家国家级流感监测哨点医院的流感病原学监测数据和病例临床症状，计算不同临床症状（有咳嗽咽痛、仅咳嗽、仅咽痛）的流感样病例流感病毒检出情况，并通过多因素Logistic回归分析流感病毒检出情况的影响因素。结果 2 010例流感样病例中，有咳嗽咽痛者1 105例、仅有咳嗽者270例、仅有咽痛者635例，流感阳性率分别为36.2%、39.3%和15.9%，经分析，有咳嗽咽痛者、仅有咳嗽者的流感阳性检出率均高于仅有咽痛者（均有P<0.05）。对于发病3 d内采样的流感样病例，有咳嗽咽痛、仅有咳嗽者的流感阳性检出率均高于仅咽痛者（均有P<0.05）。多因素Logistic回归分析结果显示，流感病毒检出情况与病例体温（≥ 39℃）（OR=1.719，95%CI:1.389~2.127）、咳嗽（OR=3.046，95%CI:2.377~3.905）有关。结论 建议以"发热（体温≥ 38℃）伴咳嗽症状者"作为流感监测中的流感样病例定义。

The impacts of case definition of influenza-like illness on influenza surveillance

Objective To compare the detection situation of influenza-like illnesses with different symptoms and analyze the impact on the influenza surveillance by adopting different case definitions of influenza-like illness.Methods Data was collected from 2 national influenza surveillance sentinel hospitals in Shanghai,2015.We compared the positive rate of influenza virus among patients with different symptoms (with cough and sore throat,with cough only and with sore throat only),and utilized Logistic regression model to analyze the influencing factors of the detection rate of influenza virus.Results Among 2 010 influenza-like illnesses,1 105 patients were with cough and sore throat,270 patients were with cough,635 patients were with sore throat,and the positive rate of influenza was 36.2％,39.3％ and 15.9％ respectively.The patients with cough and sore throat or with cough only had a higher positive rate of influenza than patients with sore throat (all P ＜ 0.05).For patients with specimens collected within 3 days,patients with cough and sore throat,or with cough only had a higher positive rate than patients with sore throat only (all P ＜ 0.05).Logistic regression results showed that fever (body temperature≥39 ℃) (OR =1.719,95％ CI:1.389-2.127) and cough (OR =3.046,95％ CI:2.377-3.905) were associated with the detection of influenza virus.Conclusions We suggested that we can adopt the case definition of influenza-like illness'fever (body temperature ≥38 C) and cough'in the influenza surveillance system.