A letter published in the Journal of Infection by several paediatricians and doctors from hospitals within the North West Anglia Trust has revealed that nine babies were born between April 27 and May 21 who tested positive for COVID-19 within the first 24 hours. Of these nine infants, eight mothers tested negative.
The trust delivered 481 babies during this time period, with 418 screened with maternal consent.
Only one infant was symptomatic, and required oxygen for two hours and respiratory support for 22 hours.
This is the first description of a universal screening programme for term and near-term newborns - and finding eight infants who returned positive results while mothers tested negative has never been described before.
The letter details four potential explanations for why these findings occurred.
The possibility that all positive tests were contaminated is unlikely as all samples were taken on different days by different staff members who were all wearing appropriate PPE. The suggestion that all eight positive tests were falsely positive is also not likely, with the letter saying that all eight are thought to be "valid results".
The potential for the mothers' results to be false negatives was possible, as was the notion that the asymptomatic mothers could have been previously positive but were no longer shedding enough of the virus to be detected by the test.
Much more testing is required before any conclusions can be drawn, but the study conducted by medical professionals at local trust hospitals suggests that "universal swabbing of all newborns is easy and could add substantially to our understanding".