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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.
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<p><b>OBJECTIVE</b>To understand the epidemiological profiles of hand, foot and mouth disease (HFMD) and the major enteroviruses causing the epidemics of HFMD in Shanghai from 2010 to 2014.</p><p><b>METHOD</b>The city-wide surveillance data between 2010 and 2014 were used to analyze the epidemiologic characteristics of the HFMD outbreaks in Shanghai. The annual incidence of HFMD was estimated based on the 2010 Shanghai Census data.</p><p><b>RESULT</b>From 2010 to 2014, the reported HFMD cases were 41 080, 37 323, 51 172, 42 198, and 65 018, respectively; the severe cases (case-severity ratio) were 469 (1.14%), 456 (1.22%), 318 (0.62%), 104 (0.25%) and 248 (0.38%), respectively. Based on Shanghai census data by the end of 2010, the attack rates of HFMD in Shanghai were 0.16%-0.28% in the entire population. In terms of the proportion of HFMD cases and severe cases in the specific population, male accounted for 59.62%-61.48% and 62.26%-73.08%, migrant population accounted for 51.86%-62.40% and 72.01%-80.38%; children aged 1.0-1.9 years comprised the highest proportion, up to 22.70%-27.00% and 32.08%-36.40%. HFMD peaked from April to July, in parallel with the peak circulation of enterovirus (EV) 71, and a small peak usually occurred in autumn and winter. All the critically severe and fatal cases were caused by EV71. The detection rates of EV71 and Coxsackievirus A (CA) 16 were 73.08%-88.09% and 1.12%-2.90% in severe HFMD cases, 19.75%-48.74% and 2.02%-23.69% in uncomplicated inpatients, and 16.78%-40.08% and 8.36%-33.39% in mild community cases, respectively. The detection rates of CA6 and CA10 in the mild community cases in 2014 were 18.38% and 1.43%, respectively. In 2013 non-EV71 and non-CA16 enteroviruses comprised 74.86% in the community cases.</p><p><b>CONCLUSION</b>The annual HFMD outbreaks occurred in Shanghai during 2010-2014. Children under 5 years of age, migrant population and male were the major susceptible population. EV71 and CA16 were the predominant pathogens causing the epidemics of HFMD except in 2013, and CA6 was prevalent in the community cases in 2014. The major peak season of HFMD usually overlapped with the peak of EV71 circulation and the majority of severe HFMD cases were associated with EV71 infection.</p>