Closing 'Anchor Businesses' Slowed Rise in New COVID-19 Cases

During the first few months of the COVID-19 pandemic, closure of anchor businesses — large employers located in small- to medium-sized communities — slowed the rate of increase in positive COVID-19 tests, suggests a study in the December Journal of Occupational and Environmental Medicine.

Decreased case rates were seen even after partial or short-term closures, according to the research by Megan McHugh, PhD, of Northwestern University Feinberg School of Medicine, Chicago, and colleagues.

The study focused on 153 anchor businesses — defined as manufacturing plants or distribution centers employing more than 1,000 workers — located in communities with between 10,000 and 500,000 residents. The anchor businesses were located in 110 counties in the US South.

Using publicly available data, the researchers identified 45 counties with an anchor business closure from March through May 2020. County-level rates of positive COVID-19 tests were compared for communities with and without an anchor business closure. In the southern states studied, Less than 10 percent of small- to medium-sized communities had an anchor business.

"Anchor closure was associated with a significant decrease in the increasing incidence trend of positive COVID-19 tests," the researchers write. After 40 days, the estimated incidence of positive COVID-19 tests was 1.0 per 100,000 population in counties with an anchor closure, compared to 17 per 100,000 in counties without an anchor closure.

The impact was similar for short-term anchor closures of 1 to 21 days, and even for partial closures. The impact of closures on rates of confirmed COVID-19 cases appeared similar to that of other measures, such as social distancing and wearing face masks.

"Temporary closure of anchor businesses is a strategy that governors, county officials, and business leaders could consider to slow the spread of COVID-19," Dr. McHugh and coauthors conclude. "Closure of anchor businesses must be adopted in combination with other strategies that have been shown to slow the spread of the virus (eg, social distancing measures), as closure will slow, but not completely contain, the spread of COVID-19."
About the Author
Dr. McHugh may be contacted for interviews at
ACOEM (, an international society of 4,000 occupational physicians and other health care professionals, provides leadership to promote optimal health and safety of workers, workplaces, and environments.
About the Journal of Occupational and Environmental Medicine
The Journal of Occupational and Environmental Medicine ( is the official journal of the American College of Occupational and Environmental Medicine. Edited to serve as a guide for physicians, nurses, and researchers, the clinically oriented research articles are an excellent source for new ideas, concepts, techniques, and procedures that can be readily applied in the industrial or commercial employment setting.


McHugh M, Tian Y, Maechling CR, Farley D, Holl JL. Closure of anchor businesses reduced COVID-19 transmission during the early months of the pandemic. J Occup Environ Med. 2021;(63)12:1019-1023.