Medically reviewed by Susan Kerrigan, MD and Marianne Madsen
“Place the mask over your face and breathe normally.” If these words sound familiar it’s because you hear them during the safety briefing every time you board a plane (remember those days??). As it turns out, research shows that self-imposed measures such as handwashing, social distancing, and mask wearing are crucial in controlling the ongoing epidemic, even without a vaccine or additional treatments.
For many countries around the world, the focus of public health officers in the context of COVID-19 epidemic has shifted from containment to mitigation and delay. The study (the first of its kind) that was published recently in the journal PLoS Medicine studied the efficacy of government-imposed lockdowns and has created a new model to look at the spread of the disease and prevention efforts that could help to stop it.
The contact rate data was based on contact rates from the Netherlands but can be applied to any Western country. The efficacy of the model is entirely dependent on the alacrity with which the public adopt these practices. They claim that “A large epidemic can be prevented if the efficacy of these measures exceeds 50%.” In addition they assert that if the public is slow but does eventually change behavior, it can reduce the number of cases but not delay a peak in cases.
The study also found that a three-month government-imposed intervention would delay the peak by–at most–seven months. However, if these measures were combined with government shutdown/physical distancing measures as well as disease awareness and personal steps, the height of the peak could be radically reduced.
The authors of the study assert that “the effect of combinations of self-imposed measures is additive… In practical terms, it means that SARS-CoV-2 will not cause a large outbreak in a country where 90% of the population adopts handwashing and social distancing that are 25% efficacious.” This may be a rather audacious claim but one that is really promising if people choose to adopt these three simple measures: Hand washing, social distancing, and mask wearing.
Handwashing will not provide 100% efficacy for those who practice it because infectious individuals may transmit the virus to others without direct physical contact. Self-imposed social distancing–which entails maintaining distance to others and avoiding congregate settings–reduces contact rates but cannot completely eliminate contact and also will not reach 100% efficacy in controlling the disease. Regarding mask wearing, people often lack awareness of how to wear a mask, and the study thus assumed that this measure lowers only the infectivity of disease-aware infectious individuals. However, combining these self-imposed measures with government-imposed reduced contact is proposed to be the best method of curbing the virus.
Another key factor worth sharing includes the importance of raising awareness about these self-imposed measures. When such measures are adopted early, it provides essential time for increasing capacity of healthcare systems and can significantly mitigate the epidemic. Authors assert that “while information on the rising number of COVID-19 diagnoses reported by the media may fuel anxiety in the population, wide and intensive promotion of self-imposed measures with proven efficacy by governments or public health institutions may be a key ingredient to tackle COVID-19.”
There are some limits to the model in that it doesn’t take into effect demographics, nor does it account for the imperfect isolation of people who are sick with COVID-19, meaning they can infect others who care for them in a health care setting or at home. The model also doesn’t account for the possibility of reinfection.
American public health officers are echoing the sentiments of this study. “If we all wore face coverings for the next four, six, eight, twelve weeks, across the nation, this virus transmission would stop,” the CDC’s Dr. Robert Redfield said. Admiral Brett Giroir, a member of the White House coronavirus task force, said at a briefing from the US Health and Human Services Department that masks and physical distancing could quickly stop the spread of the pandemic. “If we have that degree of compliance with these simple measures, our models say that’s really as good as shutting it down.” Giroir added: “these simple facts can really shut down the outbreak without completely shutting down your local area.”
In trying times such as these, we would like to do whatever we can to contribute to the solution, so it is mildly comforting to know that the self-imposed measures which we adopt and encourage those around us to adopt are backed by evidence that proves that they do in fact make a difference in tackling COVID-19.
References
- Impact of self-imposed prevention measures and short-term government-imposed social distancing on mitigating and delaying a COVID-19 epidemic: A modelling study
- WHO: Coronavirus disease (COVID-19) advice for the public: When and how to use masks
- The timing of one-shot interventions for epidemic control
- CNN: Three simple acts can stop Covid-19 outbreaks, study finds