High rate of symptom-free COVID-19 infections among grocery store workers

Those in customer-facing roles are five times as positive as their peers

Grocery store employees are likely at increased risk of COVID-19 infection, with customer-facing employees being five times as positive as their counterparts in other positions, suggests the first of its kind, published in the journal Occupational & Environmental Medicine.

In addition, three out of four test subjects had no symptoms, suggesting these key workers could be an important reservoir of infection, the researchers say.

Published research focusing on essential / key workers has largely focused on healthcare workers. To fill this knowledge gap and find out how COVID-19 has affected the health and well-being of other key employees, the researchers examined 104 employees at a grocery store in Boston, Massachusetts.

Every employee was tested for SARS-CoV-2, the virus responsible for COVID-19 infection, as part of a mandatory testing policy across Boston this May.

Before doing this, however, they completed detailed questionnaires on the following topics: their lifestyle; Medical history; Employment history; Work pattern and role in business; Commuting to and from work; and the safeguards they could take against infection at work.

They were also asked to provide information about COVID-19, including all symptoms and exposure to people with confirmed SARS-CoV-2 for the past 14 days. Mental health information was extracted from two validated questionnaires for depression and anxiety: PHQ-9 and GAD-7.

Every fifth (21 out of 104) employee tested positive for SARS-CoV-2, which indicates a prevalence of 20% at this point in time. This was significantly higher than the prevalence of infection in the local community at that time: 0.9-1.3%.

Three out of four people who tested positive (76%) had no symptoms. And of the positive tests, most (91%) had a customer-facing role, compared to 59% of the negative tests.

Employees in customer-facing roles tested positive five times more often than their counterparts in other role types after considering potentially influential factors such as the prevalence of SARS-CoV-2 in their place of residence. Those in supervisory roles were six times more likely to do so.

Ninety-nine employees completed the mental health questionnaires: 24 employees reported at least mild anxiety. Only half (46%) of them said they could consistently practice social distancing at work, while most (76%) of those who weren’t afraid were able to do so.

Eight employees were classified as slightly depressed based on their questionnaire responses. They were less likely to consistently practice social distancing at work, and more likely to use public transit or shared trips to and from work than those who weren’t depressed.

Those who could commute on foot, by bike, or in their own car were 90% less likely to report depression symptoms.

This is a small observational study of workers in a shop in a city at one point in time that was based on subjective reports and, as such, cannot establish a reason, the researchers warn.

Still, they say, “This is the first study to demonstrate the significant asymptomatic infection rate, exposure risk and associated psychological stress of retail food workers during the pandemic.”

And they point out: “Once key workers are infected with SARS-CoV-2, they can become a significant source of transmission for the community they serve.”

They believe their findings support: “The policy recommendations that employers and government officials should take action to implement prevention strategies and administrative arrangements, such as: B. Methods to reduce human contact, repeated and routine SARS-CoV-2 employee testing to ensure the health and safety of essential workers. “

And they add, “Our significant mental health determination calls for action to be taken to provide comprehensive employee support services to help key workers manage the mental distress during the COVID-19 pandemic.”

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