Human Coronavirus 229E Remains Infectious on Common Touch Surface Materials

Warnes, Sarah L.; Little, Zoë R.; Keevil, C. William

Analysis of coronavirus genomic RNA from viruses exposed to copper and copper alloys revealed a nonspecific fragmentation of the entire genome that can also be observed at the gene level by the reduction in copy number of a small fragment of nsp4 proteins, and the extent of damage increased with contact time. We have observed that the reduction in the capsid integrity of norovirus allows access of copper ions to the genome inactivating the virus. For coronavirus, the envelope and nucleoprotein are likewise compromised, and the process occurs more rapidly than with nonenveloped norovirus, which has a resistant capsid, to allow copper ion and/or ROS to destroy the genome. Interestingly, there was a 10-min delay in inactivation of simulated wet-droplet contamination which may reflect the time taken to breach the envelope and disrupt the nucleoprotein which allows access of copper ions to the coronavirus genome. Further studies may determine if the use of synergistic cleaning agents to weaken the envelope could reduce this delay. Sagripanti et al. (45) also reported increased sensitivity to solutions of copper ions of enveloped viruses compared to nonenveloped phages.