Asymptomatic health-care worker screening during the COVID-19 pandemic

Mass testing of asymptomatic health-care workers (HCWs) has been suggested to reduce nosocomial transmission of COVID-19.¹ This level of testing might not be necessary in hospitals with protocols for personal protective equipment,² despite recommendations by Thomas Treibel and colleagues.³ The 1600-bed Tan Tock Seng Hospital, Singapore, is colocated with the 330-bed National Centre for Infectious Diseases, Singapore, which, together, manage most patients with COVID-19 in Singapore. At this hospital, HCWs use fit-tested N95 respirators, eye protection, gloves, and gowns in areas where patients with COVID-19 are treated and wear surgical masks across the campus. A robust HCW sickness-surveillance system ensures that symptomatic staff are referred promptly for medical review.⁴

Since the first COVID-19 case,⁵ the weekly number of new patients with COVID-19 admitted to Tan Tock Seng Hospital and National Centre for Infectious Diseases increased to 765 in epidemiological week 19 (ie, week ending May 9, 2020) and declined to 33 in epidemiological week 35 (ie, week ending Aug 29, 2020; appendix p 1). Only ten (0·08%) of 12 663 total HCWs were confirmed with COVID-19. Of the 141 work contacts of HCWs with confirmed COVID-19, 29 people were quarantined, 13 people were furloughed, and 99 people were placed under surveillance. Apart from one HCW, who was infected by another during social gatherings, five other symptomatic contacts were screened and found negative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Five close patient contacts of HCWs who were confirmed to have COVID-19 also screened negative. No in-hospital clusters resulted from the HCWs with COVID-19. During this period, 35 acute respiratory illness clusters in HCWs were identified, but SARS-CoV-2 was not detected. One-time screening of 1378 asymptomatic housekeeping, facilities, information-technology, and security staff identified one (0·07%) person with COVID-19 infection. Since May 6, 2020, all HCWs with acute respiratory illness have been tested for SARS-CoV-2, further reducing the risk of nosocomial transmission. In hospitals that have staff who are well trained and supplied with personal protective equipment, have comprehensive sickness-surveillance systems, and have a universal mask policy, testing of asymptomatic HCWs would not be indicated.