SARS-CoV-2 rapid antigen screening of asymptomatic employees: a pilot project

Rapid antigen screening can be effective in identifying infectious individuals in occupational settings to reduce transmission and outbreaks. We report results from a pilot project at the Greater Toronto Airports Authority (GTAA) and describe the operationalization. Toronto Pearson is a large international airport encompassing over 400 employers and, pre-pandemic, with approximately 50,000 employees.

An employee screening program was piloted between March 8 and May 28, 2021, to implement rapid antigen testing for asymptomatic employees. Recruitment targeted enrolment of 400 employees and yielded participation of 717 from 58 companies. Employees were recommended to book three times per week for nasal swabs on site, and were tested on the Abbot Panbio^TM rapid antigen test. No action was taken from a negative result, and if positive, the employee was told to isolate at home and obtain a confirmatory polymerase chain reaction test.

A total of 5117 tests were performed on 717 individuals over 12 weeks; 5091 tests were negative (99.5%), and 22 individuals tested positive (3.1% positivity rate). One hundred twenty-four (17%) completed the post-participation survey. All respondents reported that testing did not change their behaviour at work with respect to public health recommendations, and only 1 (1%) reported behaviour change outside of work (socializing with family) as a result of the program.

This pilot program identified 22 (3.1%) potentially infectious employees. Onsite testing was feasible and highly accepted by this group of employees who completed the survey. Education resulted in reasonable uptake and no substantial change in behaviour, although the survey response rate may limit generalizability. Home-based testing may facilitate larger recruitment.