Though it is primarily an airborne pathogen, we still need an integrated approach to hygiene, says Sally F Bloomfield
While Covid-19 is primarily an airborne pathogen (Hygiene theatre: how excessive cleaning gives us a false sense of security, 12 July), transmission via hands in combination with surfaces recently and frequently touched by other people remains a secondary but real danger, as the World Health Organization, the NHS and the Centers for Disease Control acknowledge. The need for an integrated approach (social distancing, ventilation, face coverings, hands and hand-contact surfaces) for controlling Covid-19 was reiterated in a 6 July government review. While “hygiene theatre”, particularly spraying of surfaces in public spaces, is largely irrelevant, bracketing this alongside – and thus dismissing – contact surface hygiene is a serious error.
Prof Emanuel Goldman concluded “I believe that fomites that have not been in contact with an infected carrier for many hours do not pose a measurable risk”, but this does not take account of indoor situations, such as hospitality venues, and particularly the domestic environment, where several or many people are in close proximity for significant periods. Data from the Diamond Princess cruise ship outbreak showed that the contributions of airborne and surface transmission to infected cases were 70% and 30% respectively. If correct, this proportion translates into case numbers across communities which are far from trivial.
