Seroprevalence of SARS-CoV-2 infection among blue-collar workers in United Arab Emirates

Background: This is one of the first studies exploring immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among blue-collar workers in Abu Dhabi. Aims: This study estimated the seroprevalence of SARS-CoV-2 infection among workers living in a closed setting using qualitative analysis of the total SARS CoV-2 antibody immune response. Methods: We conducted this monocentric, prospective, observational study in a labour compound for a cohort of workers between 28 March and 6 July 2020. We tested for SARS-CoV-2 (nasopharyngeal) (RT-PCR) and anti-SARS-CoV-2 T-Ab. Results: Out of a total of 1600 workers, 1206 (75.0%) participated in the study – all were males, median age 35 years (19–63 years). We found 51% of the participants to be positive for SARS-CoV-2; the 49.0% who tested negative were considered as contacts. Anti-SARS-CoV-2 T-Ab was detected among 864 participants, showing an overall point prevalence of 71.6%. A relatively higher response was found among cases (89.0%) than among contacts (53.2%). Conclusion: This study highlights the need to prioritize public health interventions in closed settings where disease transmission is higher due to greater overall exposure. A high seroprevalence of anti-SARS-CoV-2 T-Ab was found among the residents. A serial quantitative study applying time series and regression models is recommended to further evaluate the sustainability of the immune response among this and similar population groups.