March 30, 2020

Since the novel coronavirus SARS-CoV-2 was identified in December 2019, it has been transmitted around the globe. Currently, the World Health Organization reports 634,835 confirmed cases and 29,891 deaths worldwide.

The epidemiology of COVID-19 — the disease caused by SARS-CoV-2 — has become clearer as case numbers rise and researchers refine their estimates of the severity and transmissibility of the virus. Given the current lack of vaccines and effective antiviral drugs, non-pharmaceutical interventions (NPIs) are the most effective tools society has to slow the spread of the virus.

A new article in The Journal of Infectious Diseases — “Public health measures to slow community spread of COVID-19” — shares the NPIs that are likely to be most effective given the current understanding of how COVID-19 functions.

Dr. Allison Aiello

Dr. Allison Aiello

The study co-authors are Allison Aiello, PhD, professor of epidemiology at the UNC Gillings School of Global Public Health and fellow at the Carolina Population Center; and Benjamin Cowling, PhD, a professor in the World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control at the University of Hong Kong’s School of Public Health.

“An estimated 80% of COVID-19 cases are mild,” they write. “This is not a glass half full statistic, as 20% of infections result in clinically severe cases that have the potential to overwhelm already overburdened health facilities.”

There is a light in the darkness, however: These infectious disease experts report that basic protective measures can help enormously. They recommend:

  • Practicing good hand handwashing techniques or — only when needed — using alcohol-based hand sanitizer.
  • Wearing a standard face mask (not an N95 mask) when ill, caring for an ill person or interacting in highly crowded settings where widespread community transmission is known to be occurring.
  • Flattening the curve through social distancing, which includes closing schools and workplaces and cancelling mass gatherings.
  • Isolating people with confirmed COVID-19 cases and quarantining individuals who have been exposed. (It is proving difficult, however, to track community transmission of COVID-19 due to a large number of mild or asymptomatic cases. Therefore, public health messaging should encourage all individuals to self-isolate whenever possible.)

“Given the evolving picture of the COVID-19 pandemic, the application of layered, multi-faceted NPIs will need to be initiated quickly to curb widespread transmission,” the authors write. “When NPIs are reactive to widespread transmission, instead of proactive to the potential for transmission, they often fail to reduce rates of illness. The types of proactive measures we describe here were successful in mitigating the 1918/19 influenza pandemic and may be just as valuable almost a century later.”

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