An interesting preprint on Medrxiv looked at this vexing question.
Harvey and others look at the longitudinal monitoring of SARS-CoV-2 RNA on high touch surfaces in a community setting.
They conducted longitudinal swab sampling of high touch non-porous surfaces in a Massachusetts town during a COVID-19 outbreak from April to June 2020.
29 of 348, which is 8.3% of surface samples were positive for SARS-CoV-2, including cross walk buttons, trashcan handles, and door handles of essential business entrances such as grocery stores, liquor stores, banks and gas stations.
However, the estimated risk of infection from touching a contaminated surface was low, less than 5 in 10,000 and this suggests that fomites play a minimal role in SARS-CoV-2 community transmission.
The weekly percentage of positive samples best predicted the variation in city level COVID-19 cases using a seven day lead time and they argue that the environmental surveillance of SARS-CoV-2 RNA on high touch surfaces could be a useful tool to provide early warning of COVID-19 case trends.
The London General Practice is reassured by this data, however, it still maintains that good hand washing and hand sensitisation is essential from person to person and no touch is essential in order to prevent person to person transmission.
However, with good hand sanitisation and hand washing, there should be a likely decrease in fomite findings on these hard surfaces.
Dr Paul Ettlinger
London General Practice