Surface sampling for SARS-CoV-2 in workplace outbreak settings in the UK, 2021-22

ABSTRACT Aims To utilise environmental surface sampling to evaluate areas of SARS-CoV-2 contamination within workplaces to identify trends and improve local COVID-control measures. Methods and Results Surface sampling was undertaken at 12 workplaces that experienced a cluster of COVID-19 cases in the workforce between March 2021 and March 2022. 7.4% (61/829) of samples collected were positive for SARS-CoV-2 RNA by qPCR with only 1.8% (15/829) of samples identified with crossing threshold (Ct) values below 35.0. No sample returned whole genome sequence inferring RNA detected was degraded. Conclusions Few workplace surface samples were positive for SARS-CoV-2 RNA and positive samples typically contained low levels of nucleic acid. Although these data may infer a low probability of fomite transmission or other forms of transmission within the workplace, Ct values may have been lower at the time of contamination. Workplace environmental sampling identified lapses in COVID-control measures within individual sites and showed trends through the pandemic. Significance and Impact of the Study Prior to this study, few published reports investigated SARS-CoV-2 RNA contamination within workplaces experiencing cases of COVID-19. This report provides extensive data on environmental sampling identifying trends across workplaces and through the pandemic.