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Original research
Association between SARS-CoV-2 infection, exposure risk and mental health among a cohort of essential retail workers in the USA
  1. Fan-Yun Lan1,2,
  2. Christian Suharlim3,
  3. Stefanos N Kales1,4,
  4. Justin Yang1,5
  1. 1 Environmental & Occupational Medicine & Epidemiology Program, Department of Environmental Health, Harvard University T H Chan School of Public Health, Boston, Massachusetts, USA
  2. 2 Department of Occupational and Environmental Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
  3. 3 Management Sciences for Health, Medford, Massachusetts, USA
  4. 4 Department of Occupational Medicine, Cambridge Health Alliance, Harvard Medical School, Cambridge, Massachusetts, USA
  5. 5 Department of General Internal Medicine, Boston University School of Medicine, Boston, Massachusetts, USA
  1. Correspondence to Dr Justin Yang, Environmental Health, Harvard University T H Chan School of Public Health, Boston, MA 02115, USA; justin.yang{at}


Objectives To investigate SARS-CoV-2 (the virus causing COVID-19) infection and exposure risks among grocery retail workers, and to investigate their mental health state during the pandemic.

Methods This cross-sectional study was conducted in May 2020 in a single grocery retail store in Massachusetts, USA. We assessed workers’ personal/occupational history and perception of COVID-19 by questionnaire. The health outcomes were measured by nasopharyngeal SARS-CoV-2 reverse transcriptase PCR (RT-PCR) results, General Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire-9 (PHQ-9).

Results Among 104 workers tested, 21 (20%) had positive viral assays. Seventy-six per cent positive cases were asymptomatic. Employees with direct customer exposure had an odds of 5.1 (95% CI 1.1 to 24.8) being tested positive for SARS-CoV-2 after adjustments. As to mental health, the prevalence of anxiety and depression (ie, GAD-7 score >4 or PHQ-9 score >4) was 24% and 8%, respectively. After adjusting for potential confounders, those able to practice social distancing consistently at work had odds of 0.3 (95% CI 0.1 to 0.9) and 0.2 (95% CI 0.03 to 0.99) screening positive for anxiety and depression, respectively. Workers commuting by foot, bike or private cars were less likely to screen positive for depression (OR 0.1, 95% CI 0.02 to 0.7).

Conclusions In this single store sample, we found a considerable asymptomatic SARS-CoV-2 infection rate among grocery workers. Employees with direct customer exposure were five times more likely to test positive for SARS-CoV-2. Those able to practice social distancing consistently at work had significantly lower risk of anxiety or depression.

  • occupational health practice
  • communicable diseases
  • health and safety
  • hygiene / occupational hygiene
  • public health

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  • Contributors JY designed the study and collected the data. F-YL conducted data analysis and drafted the manuscript. F-YL, CS, SNK and JY all contributed to the interpretation of the data, revising the manuscript and final approval. JY supervised the project.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests SNK has received COVID-19-related consulting fees from Open Health.

  • Patient consent for publication Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement De-identified data are available on reasonable request.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.