Exploring the relationship between job characteristics and infection: Application of a COVID-19 job exposure matrix to SARS-CoV-2 infection data in the United Kingdom

Gender and sex differences in occupation-specific infectious diseases: a systematic review

Occupational infectious disease risks between men and women have often been attributed to the gendered distribution of the labour force, with limited comparative research on occupation-specific infectious disease risks. The objective of this study was to compare infectious disease risks within the same occupations by gender. A systematic review of peer-reviewed studies published between 2016 and 2021 was undertaken. To be included, studies were required to report infectious disease risks for men, women or non-binary people within the same occupation. The included studies were appraised for methodological quality. A post hoc power calculation was also conducted. 63 studies were included in the systematic review. Among high-quality studies with statistical power (9/63), there was evidence of a higher hepatitis risk for men than for women among patient-facing healthcare workers (HCWs) and a higher parasitic infection risk for men than for women among farmers (one study each). The rest of the high-quality studies (7/63) reported no difference between men and women, including for COVID-19 risk among patient-facing HCWs and physicians, hepatitis risk among swine workers, influenza risk among poultry workers, tuberculosis risk among livestock workers and toxoplasmosis risk among abattoir workers. The findings suggest that occupational infectious disease risks are similarly experienced for men and women within the same occupation with a few exceptions showing a higher risk for men. Future studies examining gender/sex differences in occupational infectious diseases need to ensure adequate sampling by gender.

Precarious employment and the workplace transmission of COVID-19: evidence from workers' compensation claims in Ontario, Canada

OBJECTIVE

To examine the association between precarious employment and risk of work-related COVID-19 infection in Ontario, Canada.

METHODS

We combined data from an administrative census of workers' compensation claims with corresponding labour force statistics to estimate rates of work-related COVID-19 infection between April 2020 and April 2022. Precarious employment was imputed using a job exposure matrix capturing temporary employment, low wages, irregular hours, involuntary part-time employment and a multidimensional indicator of 'low', 'medium', 'high' and 'very high' overall exposure to precarious employment. We used negative binomial regression models to quantify associations between precarious employment and accepted compensation claims for COVID-19.

RESULTS

We observed a monotonic association between precarious employment and work-related COVID-19 claims. Workers with 'very high' exposure to precarious employment presented a nearly fivefold claim risk in models controlling for age, sex and pandemic wave (rate ratio (RR): 4.90, 95% CI 4.07 to 5.89). Further controlling for occupational exposures (public facing work, working in close proximity to others, indoor work) somewhat attenuated observed associations. After accounting for these factors, workers with 'very high' exposure to precarious employment were still nearly four times as likely to file a successful claim for COVID-19 (RR: 3.78, 95% CI 3.28 to 4.36).

CONCLUSIONS

During the first 2 years of the pandemic, precariously employed workers were more likely to acquire a work-related COVID-19 infection resulting in a successful lost-time compensation claim. Strategies aiming to promote an equitable and sustained recovery from the pandemic should consider and address the notable risks associated with precarious employment.

Potential contribution of vaccination uptake to occupational differences in risk of SARS-CoV-2: analysis of the ONS COVID-19 Infection Survey

OBJECTIVES

To assess variation in vaccination uptake across occupational groups as a potential explanation for variation in risk of SARS-CoV-2 infection.

DESIGN

We analysed data from the UK Office of National Statistics COVID-19 Infection Survey linked to vaccination data from the National Immunisation Management System in England from 1 December 2020 to 11 May 2022. We analysed vaccination uptake and SARS-CoV-2 infection risk by occupational group and assessed whether adjustment for vaccination reduced the variation in risk between occupational groups.

RESULTS

Estimated rates of triple vaccination were high across all occupational groups (80% or above), but were lowest for food processing (80%), personal care (82%), hospitality (83%), manual occupations (84%) and retail (85%). High rates were observed for individuals working in health (95% for office based, 92% for those in patient-facing roles) and education (91%) and office-based workers not included in other categories (90%). The impact of adjusting for vaccination when estimating relative risks of infection was generally modest (ratio of hazard ratios across all occupational groups reduced from 1.37 to 1.32), but was consistent with the hypothesis that low vaccination rates contribute to elevated risk in some groups.

CONCLUSIONS

Variation in vaccination coverage might account for a modest proportion of occupational differences in infection risk. Vaccination rates were uniformly very high in this cohort, which may suggest that the participants are not representative of the general population. Accordingly, these results should be considered tentative pending the accumulation of additional evidence.

Potential Work-related Exposure to SARS-CoV-2 by Standard Occupational Grouping Based on Pre-lockdown Working Conditions in France

This study aims to ascertain occupations potentially at greatest risk of exposure to SARS-CoV-2 based on pre-lockdown working conditions in France. We combined two French population-based surveys documenting workplace exposures to infectious agents, face-to-face contact with the public, and working with colleagues just before the pandemic. Then, for each 87-level standard French occupational grouping, we estimated the number and percentage of the French working population reporting these occupational exposure factors, by gender, using survey weights. As much as 40% (11 million) of all workers reported at least two exposure factors. Most of the workers concerned were in the healthcare sector. However, army/police officers, firefighters, hairdressers, teachers, cultural/sports professionals, and some manual workers were also exposed. Women were overrepresented in certain occupations with potentially higher risks of exposure such as home caregivers, childminders, and hairdressers. Our gender-stratified matrix can be used to assign prelockdown work-related exposures to cohorts implemented during the pandemic.

Associations between an international COVID-19 job exposure matrix and SARS-CoV-2 infection among 2 million workers in Denmark

OBJECTIVES

This study investigates the associations between the Danish version of a job exposure matrix for COVID-19 (COVID-19-JEM) and Danish register-based SARS-CoV-2 infection information across three waves of the pandemic. The COVID-19-JEM consists of four dimensions on transmission: two on mitigation measures, and two on precarious work characteristics.

METHODS

The study comprised 2 021 309 persons from the Danish working population between 26 February 2020 and 15 December 2021. Logistic regression models were applied to assess the associations between the JEM dimensions and overall score and SARS-CoV-2 infection across three infection waves, with peaks in March-April 2020, December-January 2021, and February-March 2022. Sex, age, household income, country of birth, wave, residential region and during wave 3 vaccination status were accounted for.

RESULTS

Higher risk scores within the transmission and mitigation dimensions and the overall JEM score resulted in higher odds ratios (OR) of a SARS-CoV-2 infection. OR attenuated across the three waves with ranges of 1.08-5.09 in wave 1, 1.06-1.60 in wave 2, and 1.05-1.45 in those not (fully) vaccinated in wave 3. In wave 3, no associations were found for those fully vaccinated. In all waves, the two precarious work dimensions showed weaker or inversed associations.

CONCLUSIONS

The COVID-19-JEM is a promising tool for assessing occupational exposure to SARS-CoV-2 and other airborne infectious agents that mainly spread between people who are in close contact with each other. However, its usefulness depends on applied restrictions and the vaccination status in the population of interest.

Occupational risks associated with severe COVID-19 disease and SARS-CoV-2 infection - a Swedish national case-control study conducted from October 2020 to December 2021

OBJECTIVE

This study aimed to investigate whether workplace factors and occupations are associated with SARS-CoV-2 infection or severe COVID-19 in the later waves of the pandemic.

METHODS

We studied 552 562 cases with a positive test for SARS-CoV-2 in the Swedish registry of communicable diseases, and 5985 cases with severe COVID-19 based on hospital admissions from October 2020 to December 2021. Four population controls were assigned the index dates of their corresponding cases. We linked job histories to job-exposure matrices to assess the odds for different transmission dimensions and different occupations. We used adjusted conditional logistic analyses to estimate odds ratios (OR) for severe COVID-19 and SARS-CoV-2 with 95% confidence intervals (CI).

RESULTS

The highest OR for severe COVID-19 were for: regular contact with infected patients, (OR 1.37, 95% CI 1.23-1.54), close physical proximity (OR 1.47, 95% CI 1.34-1.61), and high exposure to diseases or infections (OR 1.72, 95% CI 1.52-1.96). Mostly working outside had lower OR (OR 0.77, 95% CI 0.57-1.06). The odds for SARS-CoV-2 when mostly working outside were similar (OR 0.83, 95% CI 0.80-0.86). The occupation with the highest OR for severe COVID-19 (compared with low-exposure occupations) was certified specialist physician (OR 2.05, 95% CI 1.31-3.21) among women and bus and tram drivers (OR 2.04, 95% CI 1.49-2.79) among men.

CONCLUSIONS

Contact with infected patients, close proximity and crowded workplaces increase the risks for severe COVID-19 and SARS-CoV-2 infection. Outdoor work is associated with decreased odds for SARS-CoV-2 infection and severe COVID-19.

Occupational risk of SARS-CoV-2 infection: a nationwide register-based study of the Danish workforce during the COVID-19 pandemic, 2020-2021

OBJECTIVE

Most earlier studies on occupational risk of COVID-19 covering the entire workforce are based on relatively rare outcomes such as hospital admission and mortality. This study examines the incidence of SARS-CoV-2 infection by occupational group based on real-time PCR (RT-PCR) tests.

METHODS

The cohort includes 2.4 million Danish employees, 20-69 years of age. All data were retrieved from public registries. The incidence rate ratios (IRRs) of first-occurring positive RT-PCR test from week 8 of 2020 to week 50 of 2021 were computed by Poisson regression for each four-digit Danish Version of the International Standard Classification of Occupations job code with more than 100 male and 100 female employees (n=205). Occupational groups with low risk of workplace infection according to a job exposure matrix constituted the reference group. Risk estimates were adjusted by demographic, social and health characteristics including household size, completed COVID-19 vaccination, pandemic wave and occupation-specific frequency of testing.

RESULTS

IRRs of SARS-CoV-2 infection were elevated in seven healthcare occupations and 42 occupations in other sectors, mainly social work activities, residential care, education, defence and security, accommodation and transportation. No IRRs exceeded 2.0. The relative risk in healthcare, residential care and defence/security declined across pandemic waves. Decreased IRRs were observed in 12 occupations.

DISCUSSION

We observed a modestly increased risk of SARS-CoV-2 infection among employees in numerous occupations, indicating a large potential for preventive actions. Cautious interpretation of observed risk in specific occupations is needed because of methodological issues inherent in analyses of RT-PCR test results and because of multiple statistical tests.