家庭聚集性新型冠状病毒奥密克戎变异株感染儿童和成人患者的临床特征

Clinical characteristics of family clustering pediatric and adult cases with severe acute respiratory syndrome coronavirus 2 Omicron variant infection

目的了解上海市家庭聚集性新型冠状病毒奥密克戎变异株感染儿童和成人患者的临床特征。方法收集2022年4月4日至30日复旦大学附属儿科医院收治的奥密克戎变异株感染儿童及其家庭内密切接触者的临床资料,包括年龄、性别、临床症状、新型冠状病毒疫苗接种情况等。比较儿童与成人病例的流行病学和临床特征。统计学分析采用独立样本t检验或χ2检验,并采用相对危险度(RR)和95%可信区间(95%CI)评估接种疫苗对奥密克戎变异株感染的保护作用。结果297个家庭中有1274名家庭成员,其中儿童370名,成人904名。1110例(87.13%)感染奥密克戎变异株,其中症状感染989例(89.10%),无症状感染121例(10.90%)。355例儿童感染奥密克戎变异株,其中症状感染337例(94.93%),主要表现为发热[96.74%(326/337)]和咳嗽[40.36%(136/337)]。仅1例患有雷特综合征的患儿进展为危重型。194例患儿接受影像学检查,64例(32.99%)提示肺部炎症病变。755例成人感染奥密克戎变异株,其中症状感染者652例(86.36%),主要表现为发热[73.16%(477/652)]和咳嗽[49.85%(325/652)]。症状感染病例中,儿童患者的发热发生率高于成人,而咳嗽发生率低于成人,差异均有统计学意义(χ2=80.87、8.04,均P<0.01)。儿童病例的热峰高于成人[(39.3±0.7)℃比(38.6±0.6)℃],差异有统计学意义(t=9.85,P<0.001)。儿童患者发病至呼吸道核酸循环阈值≥35的时间间隔长于成人[(13.0±3.1)d比(10.9±3.6)d],差异有统计学意义(t=2.97,P=0.004)。160名3~18岁儿童中,54名(33.75%)接种2剂疫苗。904名成人中,388名(42.92%)接种2剂疫苗,293名(32.41%)接种加强针。相对于未接种+接种1剂疫苗的成人患者,接种2剂次后症状感染的风险仅降低8%(RR=0.92,95%CI 0.86~0.98,P=0.014),接种加强针后发热和咳嗽发生风险分别降低42%(RR=0.58,95%CI 0.49~0.67,P=0.001)和50%(RR=0.50,95%CI 0.34~0.78,P=0.001)。结论上海地区奥密克戎变异株流行高峰时期,家庭续发率和症状感染率高,家庭聚集性儿童和成人病例以症状感染为主,发热最为常见,热程持续时间短。成人接种加强针可以对奥密克戎株感染引起的常见症状提供一定保护作用。

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 1274 family members in 297 families including 370 children and 904 adults of whom 1110(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.