Prevalence and Clinical Profile of Severe Acute Respiratory Syndrome Coronavirus 2 Infection among Farmworkers, California, USA, June-November 2020

Emerg Infect Dis. 2021 May;27(5):1330-1342. doi: 10.3201/eid2705.204949. Epub 2021 Mar 3.


During the ongoing coronavirus disease (COVID-19) pandemic, farmworkers in the United States are considered essential personnel and continue in-person work. We conducted prospective surveillance for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and antibody prevalence among farmworkers in Salinas Valley, California, during June 15-November 30, 2020. We observed 22.1% (1,514/6,864) positivity for SARS-CoV-2 infection among farmworkers compared with 17.2% (1,255/7,305) among other adults from the same communities (risk ratio 1.29, 95% CI 1.20-1.37). In a nested study enrolling 1,115 farmworkers, prevalence of current infection was 27.7% among farmworkers reporting >1 COVID-19 symptom and 7.2% among farmworkers without symptoms (adjusted odds ratio 4.16, 95% CI 2.85-6.06). Prevalence of SARS-CoV-2 antibodies increased from 10.5% (95% CI 6.0%-18.4%) during July 16-August 31 to 21.2% (95% CI 16.6%-27.4%) during November 1-30. High SARS-CoV-2 infection prevalence among farmworkers underscores the need for vaccination and other preventive interventions.

Keywords: COVID-19; California; SARS; SARS-CoV-2; Salinas Valley; United States; coronavirus; coronavirus disease; essential workers; farmworkers; infection prevalence; respiratory infections; serosurvey; severe acute respiratory syndrome coronavirus 2; viruses; zoonoses.

MeSH terms

  • Adult
  • COVID-19*
  • California / epidemiology
  • Farmers
  • Humans
  • Prevalence
  • Prospective Studies
  • SARS-CoV-2*
  • United States