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.
Hand hygiene at risk moments is not “theatre”, but a cost-effective, proven method of suppressing infection. It is vital that we embed societal hygiene behaviours that have enduring value, so that we are prepared for public health issues we will face in the future, including epidemics and pandemics and tackling antibiotic resistance. It is regrettable that your article calls the fundamental value of hand and contact surface hygiene into question at this critical moment.
Sally F Bloomfield
Honorary professor, London School of Hygiene & Tropical Medicine; chair, International Scientific Forum on Home Hygiene
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