Healthcare workers acquired COVID-19 disease from patients? An investigation by phylogenomics

Wong, R.C.W.; Lee, M.K.P.; Siu, G.K.H.; Lee, L.K.; Leung, J.S.L.; Leung, E.C.M.; Ho, Y.I.I.; Lai, R.W.M.

The increasing number of coronavirus disease 2019 (COVID-19) cases in the community has posed a significant epidemic pressure on healthcare settings. When healthcare workers (HCWs) acquire COVID-19, contact tracing and epidemiological investigation might not be adequate for determining the source of transmission. Here, we report a phylogenetic investigation involving two infected HCWs and nine patients to determine whether patient-to-HCW transmission had occurred in a hospital without a previous COVID-19 outbreak. This is the first study to apply phylogenomics to investigate suspected nosocomial transmission in a region with low prevalence of COVID-19. Our results do not support the occurrence of direct patient-to-HCW transmission.