Ask Dr. Tessa: Co-workers & PPE


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Q: My co-workers and I are around each other all the time and we trust each other. When clients aren’t around, is it really necessary to continue wearing our masks around each other?

A: The novel 2019 coronavirus (called SARS-CoV-2) does not care about trust. It’s an incredibly infectious virus with a high affinity to bind to human cells and cause the infamous illness known as COVID-19.

The scientific community still has a lot to learn about SARS CoV-2, however two aspects of its spread  are fairly clear:

  1. Asymptomatic infected individuals (persons who are infected but will never develop symptoms) are contributing to the spread in our communities. This means that individuals can be infected with SARS-CoV-2, yet show no symptoms of the disease it causes—COVID-19. Asymptomatic infected individuals do not know they are infected, yet still shed the virus in respiratory droplets released from breathing and talking, potentially infecting others.
  2. Pre-symptomatic individuals (persons who are infected and will soon develop symptoms) can transmit/shed the virus before they develop clinical symptoms1. Early reports from China2 and Europe3 documented individuals who spread the virus to a large number of contacts before they developed symptoms.

No matter how well-intentioned and healthy our co-workers (and ourselves for that matter) may look, at any moment we may be transmitting virus. It’s so easy to become complacent in our mask-wearing behaviors. As the months have dragged on and the weather has become warmer, unless you have a close friend or family member who has become infected with COVID-19, it is hard to believe that a dangerous respiratory virus is really lurking. We are accustomed to thinking about winter as the season for flu and colds. But, as confirmed cases continue to climb right along with warmer temperatures, it is apparent that seasonality is not a major factor for community transmission of SARS-CoV-2. The risk is still incredibly high and we mustn’t let down our guard.  

We wear masks to protect our close contacts, not ourselves. Cloth masks function to capture the larger respiratory droplets released when we talk, breathe, sneeze, and cough. I like to think that by wearing a mask we are not only normalizing mask-wearing behavior, but giving our friends and colleagues a little “air hug” too.


  1. Ping Yu et al., “A Familial Cluster of Infection Associated With the 2019 Novel Coronavirus Indicating Possible Person-to-Person Transmission During the Incubation Period,” The Journal of  Infectious Diseases, 221, no. 11 (June 2020); 514–23
  2. J. Lu et al., “COVID-19 Outbreak Associated With Air Conditioning in Restaurant, Guangzhou, China, 2020,” Emerging Infectious Diseases, 26, no. 7 (July 2020)
  3. Michael Rettner, “UK 'Superspreader' May Have Passed Coronavirus to Nearly a Dozen People in 3 Countries,”(February 2020)


Please be sure to always work within your scope of practice as determined by your state and to adhere to all local and federal rules and regulations regarding COVID-19 protocols. To learn more about returning to your practice or to access free resources to assist you with reopening, access the ASCP Back-to-Practice Guide!


About the Author:

Dr. Tessa Crume is an Associate Professor in the Epidemiology Department at the Colorado School of Health at the University of Colorado Anschutz Medical Campus. Her research focuses on the development and utilization of public health surveillance systems to understand the burden of disease. She has been an academic researcher since 2011, before which she worked for a decade as an applied epidemiologist at the state and federal level, analyzing surveillance data and evaluating public health impact. Dr. Crume has taught the core epidemiology class at the Colorado School of Public Health for nine years.


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