Clinical characteristics of COVID-19 in family clusters: a systematic review

Background Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread around the world and reports of children during early epidemic period showed features of family clusters. The aim of this study is to assess clinical profiles of COVID-19 in family clusters with children. Methods We performed a systematic literature review of English database (PubMed, Web of Science) and Chinese database ("www.cnki. net", "www.cqvip.com" and "www.Wanfangdata.com.cn") to identify papers on family clusters of COVID-19 with children and their family members. Results Eighteen studies involving 34 children and 98 adults from 28 families were included. Fever, cough and ground-grass opacity change of chest computed tomography (CT) were the dominant features, whereas proportion of asymptomatic infections for children was higher than adults with statistical significance (32.4% and 13.3%, respectively, P < 0.05). Median time of longer incubation period (10 days) and shorter duration of pharyngeal swab nucleic acid test positive period (11 days) were seen in children than adults (7 and 17 days, respectively) with statistical significance (P < 0.05). There were statistically significant differences in lymphopenia, increased C-reactive protein and abnormal chest CT between children and adult patients (P < 0.05). Twenty-seven families reported adults as first case of COVID-19 in family clusters. Conclusions The same virus strain can cause milder disease in children compared with their caregivers. Children of COVID-19 were infected by adults in family during the early epidemic period. Asymptomatic patients can transmit the virus.