Risk factors for SARS-CoV-2 infection at a UK electricity-generating company: a test-negative design case-control...

Area of Science:

• Occupational Health
• Epidemiology
• Infectious Disease Surveillance

Background:

• Understanding workplace transmission dynamics of SARS-CoV-2 is crucial for public health interventions.
• The electricity-generating sector presents unique occupational settings with potential for varied exposure risks.

Purpose of the Study:

• To identify specific workplace risk factors associated with SARS-CoV-2 infection among employees in a UK electricity-generating company.
• To analyze the influence of job category, site characteristics, testing reasons, and other variables on infection risk.

Main Methods:

• A test-negative design case-control study was employed, analyzing COVID-19 test data from company employees.
• Odds ratios (OR) for infection were estimated by job category, site, test reason, sex, vaccination status, vulnerability, site outage, and site COVID-19 risk rating.
• Adjustments were made for age, test date, and test type to control for confounding factors.

Main Results:

• Out of 80,077 initial tests, 70,646 were included. Symptomatic testing (OR=94.99) and close contact testing (OR=16.73) showed significantly higher positivity rates compared to routine testing.
• While most job categories showed similar risk, specific sites exhibited notably lower (three sites) or higher (one site) infection risks.
• Women were less likely to test positive than men (OR=0.71).

Conclusions:

• Job category was not a significant predictor of SARS-CoV-2 infection risk.
• Increased risk was observed during site outages and for symptomatic individuals. Vulnerable individuals had slightly lower risk.
• Vaccination status did not demonstrate a clear effect on testing positive, and site COVID-19 risk ratings did not correlate with positivity trends.