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Objective:To investigate the clinical characteristics of family clustering pediatric and adult cases with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infection in Shanghai City.Methods:A field investigation among the pediatric cases with Omicron variant infection and their household contacts from April 4 to April 30, 2022 in Children′s Hospital of Fudan University was conducted. The informations on case finding, clinical manifestations and SARS-CoV-2 vaccination status were collected. The epidemiological and clinical characteristics were compared between pediatric cases and adult cases. The independent sample t test or chi-square test was used for statistical analysis, and the relative risk ( RR) and 95% confidence interval (95% CI) were used to evaluate the protective effect of vaccination on the infection of Omicron variant. Results:There were 1 274 family members in 297 families including 370 children and 904 adults of whom 1 110(87.13%) were infected with Omicron variant, with 989(89.10%) symptomatic and 121(10.90%) asymptomatic. There were 355 children infected with Omicron variant, of whom 337(94.93%) were symptomatic, and the main manifestations were fever (96.74%(326/337)) and cough (40.36%(136/337)). Only one pediatric case with Rett syndrome developed critically severe pneumonia. A total of 194 pediatric cases had imaging examination, 64(32.99%) showed pulmonary inflammatory lesions. There were 755 adult cases infected with Omicron variant, of whom 652(86.26%) reported symptoms, and the main manifestations were fever (73.16%(477/652)) and cough (49.85%(325/652)). Among symptomatic cases, fever was more common in pediatric cases than in adult cases, while cough was more common in adult cases than in pediatric cases, and the differences were both statistically significant ( χ2=80.87 and 8.04, respectively, both P<0.01). The fever spike was higher in pediatric cases than in adult cases ((39.3±0.7) ℃ vs (38.6±0.6) ℃), and the difference was statistically significant ( t=9.85, P<0.001). The interval from the onset of symptoms to cycle threshold (Ct) value of the nucleic acid of Omicron variant≥35 was longer in pediatric cases than in adult cases ((13.0±3.1) d vs (10.9±3.6) d), and the difference had statistically significance ( t=2.97, P=0.004). Among 160 children aged 3 to 18 years, 54 (33.75%) received two-dose vaccination. Among the 904 adults, 388 (42.92%) received two-dose vaccination and 293 (32.41%) received a booster dose. In the adult cases, the risk of symptomatic infection was reduced by only 8% ( RR=0.92, 95% CI 0.86 to 0.98, P=0.014) following two-dose vaccination, and the risks of fever and cough following booster vaccination were reduced by 42%( RR=0.58, 95% CI 0.49 to 0.67, P=0.001) and 50% ( RR=0.50, 95% CI 0.34 to 0.78, P=0.001), respectively. Conclusions:Secondary attack rate and symptomatic rate of household infection are high in the context of the Omicron variant outbreak in Shanghai. Symptomatic infection is common in children and adults in household setting. Fever is the most common symptom and fever duration is short. Booster vaccination may provide certain protection against common symptoms caused by Omicron variant infection.
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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>
Subject(s)
Child , Female , Humans , Male , China , Epidemiology , Disease Outbreaks , Enterovirus A, Human , Hand, Foot and Mouth Disease , Epidemiology , Incidence , Prevalence , SeasonsABSTRACT
ObjectiveTo understand the clinical epidemiology of enterovirus 71 (EV71) in children with hand,foot,and mouth disease (HFMD) in Shanghai during 2010 to 2011.Methods The demographic,etiological and clinical data of children with HFMD were analyzed retrospectively.EV71 was tested in stool samples by one-step quantitative reverse transcription-polymerase chain reaction (RT-PCR).The date were analyzed by Chi-square test.ResultsEV71 was detected in 820 (54.45％) of 1506 inpatients in 2010 and in 924 (59.84％) of 1544 inpatients in 2011,respectively.The detection rates in severe cases and uncomplicated cases were 86.31％ and 46.67％ (x2 =247.146,P＜0.01) in 2010 and 88.78％ and 48.75％ (x2 =201.664,P＜0.01) in 2011,respectively.The detection rate of EV71 was the highest (60％- 67 ％) during May and June when HFMD peaked.Among 1744 EV71-infected HFMD inpatients,the male-to-female ratio was 1.78 ∶ 1 ; the proportion of cases was the lowest in infant ＜6 months of age (0.46％,8/1744),and the highest in children 1 years of age (34.92％,609/1744); children aged 1-3 years accounted for 76.78％ (1339/1744);and migrant children accounted for 72.76 ％ (1269/1744).The demographic characteristics in severe cases were similar to those in general EV71-infected children.Nine severe cases of pulmonary edema/hemorrhage were all infected with EV71.Conclusions EV71 was a major pathogen causing the outbreaks of HFMD and severe complications in Shanghai in 2010 and 2011.Most severe cases and all critically severe cases were associated with EV71 infection.