Examining the Relationship Between Workplace Industry and COVID-19 Infection: A Cross-sectional Study of Canada's Largest Rapid Antigen Screening Program.

OBJECTIVES: To control virus spread while keeping the economy open, this study aimed to identify individuals at increased risk of COVID-19 transmission in the workplace using rapid antigen screening data. METHODS: Among adult participants in a large Canadian rapid antigen screening program (January 2021-March 2022), we examined screening, personal, and workplace characteristics and conducted logistic regressions, adjusted for COVID-19 wave, screening frequency and location, role, age group, and geography. RESULTS: Among 145,814 participants across 2707 worksites, 6209 screened positive at least once. Workers in natural resources (odds ratio [OR] = 2.1 [1.73-2.55]), utilities (OR = 1.67 [1.38-2.03]), construction (OR = 1.35 [1.06-1.71]), and transportation/warehousing (OR = 1.32 [1.12-1.56]) had increased odds of screening positive; workers in education/health (OR = 0.62 [0.52-0.73]), leisure/hospitality (OR = 0.71 [0.56-0.90]), and finance (OR = 0.84 [0.71-0.99]) had lesser odds of screening positive, compared with professional/business services. CONCLUSIONS: Certain industries involving in-person work in close quarters are associated with elevated COVID-19 transmission. Continued reliance on rapid screening in these sectors is warranted.

Large-scale implementation of rapid antigen testing system for COVID-19 in workplaces.

The transmission of coronavirus disease 2019 (COVID-19) in workplaces has been a persistent issue throughout the pandemic. In response, a not-for-profit initiative emerged to mitigate COVID-19 workplace transmission in Canada. We report the process for establishing a workplace frequent rapid antigen test (RAT) program. The screening program identified 473 asymptomatic individuals who tested positive on the RAT and confirmed positive by a nasopharyngeal polymerase chain reaction (PCR) diagnostic test. One in 4300 RATs was presumptive positive but later tested PCR negative, and thus, false positives did not meaningfully disrupt workplace operations. Most employers rated the program highly and felt strongly that the program contributed to workplace and community safety. The findings describe a sustained and scalable implementation plan for establishing a frequent workplace testing program. High-frequency testing programs offer the potential to break chains of transmission and act as an extra layer of protection in a comprehensive public health response.