By Carol A. Kemper, MD, FACP
Clinical Associate Professor of Medicine, Stanford University, Division of Infectious Diseases, Santa Clara Valley Medical Center
Dr. Kemper reports no financial relationships relevant to this field of study.
SOURCES: Thompson D. Hygiene theater is a huge waste of time. The Atlantic, July 27, 2020.
Goldman E. Exaggerated risk of transmission of COVID-19 by fomites. Lancet Infect Dis 2020;20:892-893.
I received an email from clinic administrators in which they asked whether disinfection of the chairs in the waiting room every 30 minutes during the COVID-19 pandemic was sufficient. Two fabric paintings, gifted by a patient, were removed from the walls, and the magazines in the waiting room were confiscated, lest the SARS-CoV-2 virus jump off and infect visitors. The New York subway system is spraying seats, walls, and poles with disinfectant. Yet, people are still riding the subway and standing next to each other.
In an immediate notice on May 22, the CDC sought to assuage people’s fears by attempting to clarify that although surface contamination resulting in COVID-19 may be possible, most people acquire infection through person-to-person spread.1 Sadly, this statement did not go far enough, and my friend is still washing her store-bought fruits and vegetables with soap and water. My sister lets her groceries sit in the garage for two days before unpacking them. My neighbor is wearing gloves to get the mail. It reminds me of those televised scenes of the Chinese government spraying disinfectant throughout the city streets during H1N1 crisis in 2009.
This “hygiene theater” is completely misguided, mistakenly making some people feel safer while obscuring the real risk for infection: contact with other people. Such activities also waste time, energy, and valuable resources. The real risk is friends, family, and co-workers, not the mail.
The press has made much about the risk of COVID-19 viral particles surviving for days on surfaces and objects. However, none of the relevant studies are based in realistic scenarios of viral surface contamination or on the common understanding of respiratory infections. The longest survival of SARS-CoV-2 on surfaces required a large laboratory inoculation of 107 viral particles, and viable virus was found out to six days. Another study applied 106 viral particles to surfaces, and retrieved viable virus four days later. Aerosols spiked with a large inoculum of 105 to 107 of SARS-CoV-2 particles found viable virus on surfaces two days later. This would be like 100 people sneezing on that surface, immediately followed by one licking the surface.
In a study of surfaces contaminated by an actual patient, no viable virus could be found. Similar studies of common community coronavirus found the virus survived less than one to three hours after drying on various surfaces, including surgical gloves and aluminum. People’s fears have been exaggerated by bad science and worse public policy.
Theoretically, high-touch surfaces may pose a risk. Realistically, fomites carrying small amounts of virus that have not been in contact with their owner for more than one or two hours do not. Ask how many cases of COVID-19 have been traced to fomites as the cause for infection. As the columnist states, “the extreme infrequency of evidence may indeed be evidence of extreme infrequency.”
- Centers for Disease Control and Prevention. CDC updates COVID-19 transmission webpage to clarify information about types of spread. Media Statement. May 22, 2020.