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

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

We showed that of the 31 recorded SARS-CoV-2 household transmission clusters there were only three incidences of children being identified as the index case in the family. This observation is supported by previous evidence from China, where a study of 66 family transmission clusters showed that children were never the first in the family to be diagnosed with COVID-19. 62 Similarly, a separate study of 419 household SARS-CoV-2 transmission clusters in China did not detect a single cluster where the index case was under the age of 15, and only three where the index case was under the age of 18. 63 Early observations from Wuhan also suggested that children were most likely to be diagnosed with SARS-CoV-2 following an exposure history to a household infection, indicating that even in epidemic areas children were more likely to be contact, rather than index cases. 64, 65 The reasons for these observations remain unclear. These data may reflect an overall lower incidence of infection in children. 2 Alternatively, these data may reflect altered viral shedding (either in titre or duration) in children or an alternate, less efficient route of virus transmission from infected children to adults. 24, 66 It is also possible that children simply have fewer interactions outside . CC-BY-NC-ND 4.0 International license It is made available under a author/funder, who has granted medRxiv a license to display the preprint in perpetuity.