Hard surfaces and the risk of COVID-19
This week’s expert:
Dr Gary Grohmann, Virologist; Vaccine Manufacturing Expert; Former Director of Immunobiology and WHO ERL at the TGA, Office of Laboratories and Scientific Services
Drawn from Dr David Lim’s interview with Dr Gary Grohman on the Healthed Podcast, ‘Going Viral’.
– Recent reports of the SARS-CoV-2 remaining detectable on hard surfaces for up to 28 days are likely to be exaggerating the risk of transmission.
– Important to distinguish between a virus being detectable from it being infective. Similar issue occurred with the idea that money could be a source of transmission – since refuted.
– Infection is most commonly dose-related ie requires exposure to a high dose of the virus to contract infection.
– If hard surfaces were a significant source of infection, we would be seeing many more cases of COVID-19 where the source of infection could not be identified and that is not the case.
– While transmission is less likely in outdoor areas it is still possible courtesy of the fact it is transmitted via aerosol. Even with the easing of restrictions in most Australian states it is important to remember proven strategies to mitigate risk eg social distancing, hand washing and face masks continue to be necessary.
– Will still need to adhere to space restrictions at outdoor venues.
– Pandemic COVID-19 is likely to persist in the community courtesy of asymptomatic carriers.
– The Victorian experience has demonstrated the high risk of household contacts of an affected individual which is important when determining future containment of the virus.
– While current evidence suggests mutations of SARS-CoV-2 are relatively rare and evolve slowly, experience with past pandemics has shown mutations may be less virulent than the original. Analysis of the recent resurgence of cases of COVID-19 appears to support this in that the associated mortality rate with the latest wave in Europe is not nearly as high as that associated with the initial outbreak.