We've seen massive outbreaks at certain workplaces. Are you aware of common mistakes made by the employers that led to those outbreaks? Are those investigation reports (CDC, CDPH, OSHA) usually available to the public?

Workplace outbreaks of COVID-19 are mostly preventable by following recommended practices intended to reduce exposure. Failure to follow these practices has resulted in numerous workplace outbreaks of varying sizes.

Examples of
mistakes resulting in outbreaks include:

Travel and large meetings – Early in the pandemic, at a time when many other companies were restricting travel and large meetings, one company held a leadership meeting which resulted in more than 100 people becoming infected and spreading the infection in at least 6 states and 3 countries. Some attendees had flown in from parts of Europe with significant epidemics.1

Insufficient availability of PPE
– A number of outbreaks reported in hospitals and skilled nursing facilities have been associated with a lack of available PPE, especially respirators.2-5 

Ignoring physical distancing
– As of June, more than 25,000 cases of COVID-19 were reported among workers in meat-packing plants.6 At one plant, a worker reported that at “least two employees were infected, and 90 percent of the staff was still working ‘less than a meter away’ from one another”.7

More than 15,000
prison staff members have tested positive for COVID-19, although it is unclear how many of these cases were due to workplace exposure.8 Prison staff have reported inadequate PPE and confusion about how and when to social distance.9,10

Bars and restaurants
were a source of an infection cluster in Hong Kong affecting staff and customers, presumably due to a lack of distancing.11,12  

Sick workers continuing to work -
In a community where hospitals were seeing large numbers of patients connected to a meat packing plant, public health officials were concerned that “many employees must be working when sick and spreading infection to others”.13

Lack of protections for workers in congregate living settings/dormitories
– In some settings, workers live and work together in dormitories or onboard ships. 

Farmworkers “often live in crowded housing, sharing space with other families. Many are transported to job sites in packed vans”, increasing the risk of an outbreak.14

In an outbreak involving hundreds of
sailors on the USS Theodore Roosevelt in April, higher odds of infection were associated with self-report of not wearing a face covering, not avoiding common areas and not observing social distancing.15

While not yet implicated in published reports, a number of additional mistakes could also lead to outbreaks including:

Not requiring customers to wear masks – Would expose workers, especially in grocery stores and big box stores.

Workers in quarantine or isolation returning to work before medically appropriate (including symptomatic workers with a negative RT-PCR test).

Many reports of outbreaks appear in the lay media. Some state public health departments, such as Oregon, provide details of workplaces where outbreaks have occurred, but not the causes of the outbreaks.16 CDC has published information on some of the outbreaks in skilled nursing facilities, prisons, and a naval vessel in Morbidity and Mortality Weekly Report (MMWR).5,15,17 Most outbreak investigations are not published.


  1. Stockman F, Barker K. How a Premier U.S. Drug Company Became a Virus ‘Super Spreader’. New York Times, April 12,2020.
  1. Bernstein L, Boburg S, Sacchetti M, Brown E. Covid-19 hits doctors, nurses and EMTs, threatening health system. The Washington Post, March 17, 2020. https://www.washingtonpost.com/health/covid-19-hits-doctors-nurses-emts-threatening-health-system/2020/03/17/f21147e8-67aa-11ea-b313-df458622c2cc_story.html 
  1. Cha AE. More than 9,000 U.S. health-care workers have been infected with the coronavirus. The Washington Post, April 14, 2020.
  1. Moench M. Bay Area hospital reports a major coronavirus outbreak. San Francisco Chronicle, June 13, 2020. https://www.sfchronicle.com/health/article/Bay-Area-hospital-reports-a-major-coronavirus-15336968.php
  1. CDC. Characteristics of Health Care Personnel with COVID-19 — United States, February 12–April 9, 2020. MMWR 69(15);477–481, April 17, 2020. https://www.cdc.gov/mmwr/volumes/69/wr/mm6915e6.htm
  1. Parshina-Kottas Y, et al. Take a Look at How Covid-19 Is Changing Meatpacking Plants. New York Times, June 8, 2020 
  1. Corkery M, Yaffe-Bellany D, Kravitz D. As Meatpacking Plants Reopen, Data About Worker Illness Remains Elusive. New York Times, May 25, 2020. https://www.nytimes.com/2020/05/25/business/coronavirus-meatpacking-plants-cases.html 
  1. The Marshall Project. A State-by-State Look at Coronavirus in Prisons. July 23, 2020.
  1. Sugie N. California needs to protect its prison staff and inmates during COVID-19 pandemic. Cal Matters, May 30, 2020.
  1. Sears D, Ahalt C, Augustine D, Williams B. Occupational Health: A Key to the Control of COVID-19 in Correctional Facilities. Ann Int Med, July 27, 2020
  1. Adam D, et al. Coronavirus 2 (SARS-CoV-2) infections in Hong Kong. Research Square May 21, 2020. https://assets.researchsquare.com/files/rs-29548/v1_stamped.pdf
  1. Courage HM. How superspreading is fueling the pandemic — and how we can stop it. Vox, July 2, 2020. https://www.vox.com/21296067/coronavirus-covid-symptoms-superspreaders-superspreading-contagious-bars-restaurants 
  1. Grabell M. What Happened When Health Officials Wanted to Close a Meatpacking Plant, but the Governor Said No. Pro Publica, May 7, 2020. 
  1. Chabria A. This county knew coronavirus could ravage its farmworkers. Why didn’t officials stop it? Los Angeles Times, July 25, 2020.
  1. CDC. SARS-CoV-2 Infections and Serologic Responses from a Sample of U.S. Navy Service Members — USS Theodore Roosevelt, April 2020. MMWR 69(23);714–721, June 9, 2020.
  1. Oregon Health Authority. COVID-19 Weekly Report - Oregon’s Weekly Surveillance Summary Novel Coronavirus (COVID-19), July 22, 2020. 
  1. CDC. Update: COVID-19 Among Workers in Meat and Poultry Processing Facilities — United States, April–May 2020. MMWR 69(27);887-892, July 7, 2020. 

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The Forum does not necessarily represent an official ACOEM position. The Forum is intended for health professionals and is not intended to provide medical or legal advice, including illness prevention, diagnosis or treatment, or regulatory compliance. Such advice should be obtained directly from a physician and/or attorney. Questions are answered with the best available data or recommendations at the time.