Mo Y, Eyre DW, Lumley SF, et al. - Researchers sought to determine the drivers of hospital-acquired SARS-CoV2 infection the knowledge of which is critical for preventing and controlling the spread of SARS-CoV-2 in hospitals.

• Four teaching hospitals in Oxfordshire, United Kingdom, provided data from January to October 2020.

• Using statistical models, researchers examined how infectious SARS-CoV-2 individuals (classified as community- or hospital-acquired) are associated with infection risk posed to the susceptible individuals.

• For susceptible patients, an additional 8 infections per 1,000 susceptible patients was observed in correlation with 1 day in the same ward with another patient with hospital-acquired SARS-CoV-2, while there was substantially reduced infection risks of 2 per 1,000 susceptible patients in correlation with exposure to an infectious patient with community-acquired COVID-19 or to an infectious HCW.

• As for HCW infections, an additional 1 infection per 1,000 susceptible HCWs per day was recorded in correlation with exposure to both an infectious patient with hospital-acquired SARS-CoV-2 or to an infectious HCW, while less than half this risk was noted in correlation with exposure to an infectious patient with community-acquired SARS-CoV-2.

• Overall, risk of onward transmission to patients and HCWs in hospital is high in correlation with newly infected COVID-19 patients.

• Implementation of enhanced strategies, such as regular screening and prompt testing, may avert and detect early hospital-onset SARS-CoV-2 infection among hospitalized patients.

• It is important to implement measures to ensure infected staff are not at work, including regular staff screening and adequate sick pay arrangements.