COVID-19 screening of health-care workers in a London maternity hospital

There have been increasing calls for universal screening of health-care workers for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).¹ We have been screening health-care workers at The Portland Hospital for Women and Children (London, UK) since March 17, 2020. By April 16, 2020, we had tested nasopharyngeal swabs taken from 266 staff members (>50% of the workforce) using SARS-CoV-2 RT-PCR, and 47 (18%) were found to be positive. Of these positive cases, 31 (66%) were symptomatic and 16 (34%) were asymptomatic (figure ). Overall, 28 (48%) staff members remained positive at 7 days after the initial test was taken, 16 (34%) at 10 days, and four (9%) at 14 days, with one health-care worker remaining positive until 26 days. Of 25 symptomatic staff members who initially tested negative and were retested, only one (4%) became positive after 7 days. Potential factors associated with SARS-CoV-2 positivity are summarised in the figure.

Figure.

SARS-CoV-2 test results of 266 health-care workers at a London maternity hospital

Test results by symptom status (A) and characteristics (B). The IMD quintile was derived from postcode data using the IMD Postcode search tool, where quintile 1 (least deprived) corresponds to an IDM score ≤8·49 and quintile 5 (most deprived) corresponds to an IDM score ≥34·18. IMD=index of multiple deprivation. SARS-CoV-2=severe acute respiratory syndrome coronavirus 2.

There are several potential benefits of universal staff testing.¹ Importantly, it would ameliorate current workforce depletion due to symptomatic staff self-isolating, because a substantial proportion do not have COVID-19.² For example, of 76 symptomatic health-care workers in our analysis, 45 (59%) tested negative for SARS-CoV-2. These health-care workers could, therefore, have returned to work (assuming they were not unwell) as soon as they received their result. Had these health-care workers not been tested, they would have been obliged to self-isolate for 7 days or more, and their household members for 14 days.

Regular testing also allows asymptomatic SARS-CoV-2-positive health-care workers to be identified and isolated early, thus reducing nosocomial transmission to potentially susceptible patients and other staff, and from the hospital to the community.3, 4 Reducing transmission is particularly relevant when personal protective equipment might be scarce. Health-care workers at our hospital are regularly reminded to self-isolate when symptomatic, and their body temperature is checked daily and they are assessed with structured questionnaires when swabbed. Our finding, however, that 16 (34%) of 47 health-care workers who tested positive for SARS-CoV-2 were asymptomatic, and that 45 (59%) of 76 symptomatic health-care workers tested negative for SARS-CoV-2, highlights a crucial need for the routine testing of all health-care workers, including those who do not have direct contact with patients.

During this pandemic, shortages of health-care staff have been a major challenge. Redeployment of health-care workers has depleted some specialties and has led to staff working in unfamiliar environments. Training and research have been suspended, and annual leave has been postponed. The UK Health Secretary's promise to reach a target of 100 000 tests per day by the end of April, 2020, was achieved. Therefore, universal testing of health-care workers is feasible, potentially ameliorating the current workforce depletion and reducing the risk of asymptomatic spread of SARS-CoV-2.