Children are unlikely to have been the primary source of household SARS-CoV-2 infections

Zhu, Yanshan; Bloxham, Conor J; Hulme, Katina D; Sinclair, Jane E; Tong, Zhen Wei Marcus; Steele, Lauren E; Noye, Ellesandra C; Lu, Jiahai; Chew, Keng Yih; Pickering, Janessa; Gilks, Charles; Bowen, Asha C; Short, Kirsty R

BACKGROUND: Since its identification on the 7th of January 2020, SARS-CoV-2 has spread to more than 180 countries worldwide, causing >11,000 deaths. At present, viral disease and transmission amongst children is incompletely understood. Specifically, there is concern that children could be an important source of SARS-CoV-2 in household transmission clusters. METHODS: We performed an observational study analysing literature published between December 2019 and March 2020 of the clinical features of SARS-CoV-2 in children and descriptions of household transmission clusters of SARS-CoV-2. In these studies the index case of each cluster defined as the individual in the household cluster who first developed symptoms. FINDINGS: Drawing on studies from China, Singapore, South Korea, Japan, and Iran a broad range of clinical symptoms were observed in children. These ranged from asymptomatic to severe disease. Of the 31 household transmission clusters that were identified, 9.7% (3/31) were identified as having a paediatric index case. This is in contrast other zoonotic infections (namely H5N1 influenza virus) where 54% (30/56) of transmission clusters identified children as the index case. INTERPRETATION: Whilst SARS-CoV-2 can cause mild disease in children, the data available to date suggests that children have not played a substantive role in the intra-household transmission of SARS-CoV-2.