Changes in clinical laboratory operations and biosafety measures to mitigate biohazard risks during the COVID-19 pandemic.

Many global health bodies have highlighted that the COVID-19 outbreak could be especially hazardous to health-care professionals, including laboratory workers. Various health agencies—international and national—have provided interim recommendations on biosafety measures for routine laboratories that operate at biosafety levels 1 and 2, to help minimise the risk of COVID-19 while working in clinical laboratories. Whether additional laboratory biosafety measures and changes in laboratory operations will substantially mitigate biohazard risks during the COVID-19 pandemic is unclear. To date, clinical laboratory-acquired severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has not been reported.

In 2003, laboratory-acquired severe acute respiratory syndrome coronavirus (SARS-CoV) infections were recorded in research laboratory settings in Singapore and Taiwan, but no cases were reported in routine clinical laboratories. The case from Singapore was a 27-year-old microbiologist who was working with a non-attenuated strain of West Nile virus in a biosafety level 3 laboratory at a university in which research on SARS-CoV was also done. No history of SARS-CoV exposure was reported and there was no relevant travel history. The case in Taiwan was a 44-year-old researcher who had been testing herbal remedies against SARS-CoV at a research laboratory. Although the individual was not in the contagious phase when they travelled, 90 contacts in Singapore and Taiwan were quarantined, none of whom was eventually found to be infected. With the case from Taiwan, SARS-CoV was most probably contracted while cleaning spilled waste liquid in the biosafety level 4 laboratory.

The International Federation of Clinical Chemistry and Laboratory Medicine Taskforce on COVID-19 did a global survey between April 16 and May 1, 2020, to better understand how biochemistry laboratories have mitigated biohazard risks during the COVID-19 pandemic.4, 5 1210 responses were analysed, 1067 of which were from hospital laboratories that handle moderate volumes of samples daily. During the survey period, 186 laboratories restricted tests on patients with clinically suspected COVID-19 and 171 laboratories restricted tests on patients with confirmed COVID-19. The most common restrictions were on tests of pleural fluid and respiratory samples followed by faecal tests, urine tests, and direct microscopy. 819 laboratories had increased the frequency of disinfection, most usually from once a day to four times a day. Use of pneumatic tube transport to deliver samples was reported to have diminished since the start of the COVID-19 pandemic, with hand deliveries increasing, and more layers of plastic bags were used to contain samples from patients with suspected or confirmed COVID-19. 992 laboratories denied requests for add-on testing for patients with clinically suspected COVID-19 and 814 laboratories denied requests for add-on testing for patients with confirmed COVID-19. 290 laboratories autoclaved blood samples of patients with clinically suspected COVID-19 and 276 laboratories autoclaved blood samples of patients with confirmed COVID-19.

Using a discrete event simulation, Lim and colleagues modelled the effect of different combinations of staff roster arrangements on workplace transmission of COVID-19 using a simulated index staff who had community-acquired infection over 3 weeks. The number of shifts per day, the number of staff per shift, total number of staff accessible to work in the laboratory, shift change frequency, team-splitting arrangements, and fixed work–rest days were all considered in the model. Lim and colleagues noted that a higher rate of SARS-CoV-2 transmission was associated with a smaller staff pool, a higher number of shifts per day, a larger staff number per shift, and longer consecutive days worked. Of note, use of personal protective equipment and physical distancing significantly reduced the transmission rate. Lim and colleagues proposed that laboratories should consider arranging staff into smaller teams and reducing the number of consecutive days worked.

Test and service restrictions could have adverse effects on health-care services—eg, by depriving clinicians of information important for patients' care. Large changes in laboratory operations can negatively affect staff morale, anxiety, and deployment. More data are needed to inform laboratory managers about whether these changes substantially mitigate biohazard risks in clinical laboratories during the COVID-19 outbreak, beyond the measures recommended in existing laboratory biosafety manuals, including those released by WHO.