Introduction
The role of nosocomial transmission of SARS-CoV-2 has been highlighted by recent evidence suggesting that 20% of SARS-CoV-2 infections among UK hospital patients and up to 89% of infections among HCWs may have originated in hospital.2,3 Since the introduction of ‘lockdown’ in the UK, community transmission rates of SARS-CoV-2 have generally declined.4 Conversely, concerns have been raised that hospitals could become independent ‘hubs’ for ongoing SARS-CoV-2 transmission between patients and HCWs, which would effectively prolong the epidemic.3 In this context, evolution of the epidemic curves of a hospital’s symptomatic and asymptomatic workforce have not been well described.
We recently initiated a comprehensive HCW screening programme for SARS-CoV-2 in a large teaching hospital in Cambridge, UK. Over a three-week period from 6th to 24th April 2020, 3% (31/1,032) HCWs in the asymptomatic screening arm , 15.4% (26/169) HCWs in the symptomatic screening arm and 7.7% (4/52) contacts in the symptomatic household contact screening arm tested positive for SARS-CoV-2.Our data from the asymptomatic screening arm were consistent with another study since published.5 Over the subsequent four weeks from 25th April to 24th May 2020, we performed a further 3,388 additional tests. Here, we present these longitudinal data, in the context of the hospital patient population and wider local community.