September 16, 2020

Editorial from Marschall S. Runge, M.D., Ph.D.: Masking proves critical to safe return to college campuses

We can protect ourselves and loved ones against COVID-19 infection, no matter how worrisome the setting; we are all in this together, and working together toward our common mission will get us closer to eradicating COVID-19 and building healthier communities

Marschall S. Runge, M.D., Ph.D.

Widely publicized efforts to control the rate of COVID-19 infection among returning higher ed students have met with variable success. In some cases, colleges and universities have cancelled or postponed on-campus activities; in other instances, the rate of infection has been modest and on-campus classes continue.

Across the spectrum, these varied results have led to many conversations, some quite heated, about the pros and cons of on-campus learning.

Unfortunately, as in so many circumstances, there is uncertainty which can lead to strongly held beliefs, passionate debate and in some cases real polarization. But the main point is getting lost. We do know one thing: 

Wearing a mask, whether you are in the classroom or in the community, provides protection.

Even for the most medically and scientifically sophisticated reader, keeping a scorecard on what works and does not work for COVID-19 prevention and treatment is very difficult because our understanding of SARS CoV-2 and COVID-19 continues to evolve and is context- and community-specific.

The use of masks during the course of the pandemic is a good case in point. Over the past six months, we have moved from a public health stance of “don’t wear a mask because masks are in short supply and an essential worker may need it” to studies quantifying the reduction in spread when everyone wears a mask. 

The good news: 

For anyone who is truly concerned about COVID-19 infection in themselves or their loved ones, this is often preventable. Put aside the tangentially-related epidemiologic and laboratory studies or the so-called “real world experiences” and hold onto one reality: masks work.

Early on at Michigan Medicine, we mandated masking (medical ear-loop masks in almost all settings), hand hygiene and social distancing. For patients with symptoms (many infections are asymptomatic, of course) we developed protocols for testing and isolation.

But that’s all. And no surveillance testing was available at the time.

What happened?

We have had low rates of infection (see below) and strong evidence that many of these infections occurred in the community, not in the hospital.

The CDC recently conducted studies of front-line health care workers. At Michigan Medicine, about 3,000 health care workers in the EDs and ICUs were tested after the peak of our COVID-19 experience, which included two weeks of more than 200 COVID-19 positive patients in the hospital at a time.

The prevalence of COVID-19 positivity in this group — by serology testing for anti-COVID-19 antibodies — was 1.7%, less than half the of the prevalence in our local community, and far less than the 7% rate for all health care workers in our region. Additional voluntary testing of health care workers has shown the serologic positivity rate has remained at about 2%. Isolation and testing of symptomatic patients, strict use of PPE and universal masking were the foundation of this result.

Our experience is not unique. These experiences have been seen across the country in analogous surveys, but they have not made the medical literature yet. The media have reported on a number of tragic infections among health care workers, but of the hundreds of thousands who treated COVID-19 positive patients, the prevalence of patient-to-provider transmission is really low.

This is consistent with a number of “real-world” observations.

In January, a man flew from Wuhan, China to his final destination of Toronto, Canada. He had a dry cough, wore a mask on the flights, and tested positive for COVID-19 the day after he travelled. The 25 passengers on the plane closest to the infected man all tested negative for COVID-19. In a Missouri salon, two hair stylists had close contact with 140 clients in May while infected with COVID-19. Most likely because everyone wore a mask, none of the clients tested positive for the virus.

There is also societal benefit, as has also been reported. A research study tracked COVID-19 transmission rates in 15 states and the District of Columbia before and after state leadership mandated masks. After mask mandates, the daily rate of COVID-19 transmission slowed, more markedly over time. Five days after the mandate started, daily transmission rates slowed by 0.9 percentage points, and at three weeks, rates slowed by 2 percentage points. 

The messages of most importance are:

  • We can protect ourselves and loved ones against COVID-19 infection, no matter how worrisome the setting; and
  • We are all in this together, and working together toward our common mission will get us closer to eradicating COVID-19 and building healthier communities.

Learn even more about the use of face coverings and why they are so important in these FAQs.