Prevalence of Current and Past SARS-CoV-2 Infections among Police Employees in Poland, June-July 2020

J Clin Med. 2020 Oct 11;9(10):3245. doi: 10.3390/jcm9103245.

Abstract

Background: Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We aimed to determine the prevalence of current and past SARS-CoV-2 infections among police employees.

Methods: This cross-sectional survey was undertaken among 5082 police employees from Mazowieckie Province, Poland. RT-PCR testing for current SARS-CoV-2 infection and serological tests (ELISA) for the presence of anti-SARS-CoV-2 IgM+IgA and IgG antibodies were performed.

Results: All RT-PCR tests were negative. The anti-SARS-CoV-2 IgM+IgA index was positive (>8) in 8.9% of participants, including 11.2% women and 7.7% men (p < 0.001). Equivocal IgM+IgA index (6-8) was found in 9.8% of participants, including 11.9% women and 8.7% men (p < 0.001). The IgG index was positive (>6) in 4.3% and equivocal (4-6) in 13.2% of participants. A higher odds of positive IgM+IgA index was found in women vs. men (OR: 1.742) and police officers vs. civilian employees (OR: 1.411). Participants aged ≥60 years had a higher odds of positive IgG index vs. those aged 20-29 years (OR: 3.309). Daily vaping also increased the odds of positive IgG index (OR: 2.058).

Conclusions: The majority of Polish police employees are seronegative for SARS-CoV-2 infection. Vaping and older age (≥60 years) were associated with a higher risk of SARS-CoV-2 infection.

Keywords: COVID-19; RT-PCR; SARS-CoV-2; epidemiology; police; serology.