COVID-19 seroprevalence in military police force, Southern Brazil

Abstract

Background Limited data is available regarding the frequency of COVID-19 in populations that are highly exposed to SARS-CoV-2. In this cross-section study we evaluated COVID-19 seroprevalence in military police forces of 10 major cities in Rio Grande do Sul, South of Brazil. Methods Sampling was randomly performed in clusters, in respect to the number of professionals at service per city and military unit. Research subjects were evaluated on July 23, 2020 (first wave peak in Brazil). Clinical information was obtained, and venous blood was taken for ELISA testing (IgA, and IgG antibodies). Sample size consisted of 1,592 military workers (33.6% of study population). They were mostly man (81.2%) and young (median 34 years-old). Most had been asymptomatic (75.3%) during pandemic, and 27.5% reported close contact with COVID-19 cases (after a median time of 21 days). Antibodies were detected in 3.3% of the participants, mostly IgA (2.7%), and IgG (1.7%). After 3 weeks, 66.7% of IgA and IgG results turned negative, in addition to 78.3% and 100% of borderline IgA and IgG results, respectively. Conclusion The seroprevalence of COVID-19 amongst military police was at least 3.4 higher than the findings of other studies performed in the general population, in the same cities and dates. Most detectable antibodies were of IgA class, which implies recent exposure. Asymptomatic people were more prone to have negative antibody titters in the second run.

Epidemiological Indicators of SARS-CoV-2 (COVID-19) and Vaccination Effectiveness on the Report of Positive Cases in the Colombian Army

“…Opposite, the age range of the troops sets the personnel in a low-risk group to develop severe forms of the disease, explaining the lower fatality rate if compared to the one presented by the civil Colombian population. This was consistent with other military epidemiological surveillance studies conducted in countries of our region, such as Bolivia, Brazil, and the USA ( 13 – 15 ).…”

“…Although an exact attack rate of COVID-19 in the army health system could not be obtained, it, clearly, must be higher than the 8.55% reported for the confirmed cases ( 12 ). One must take into that active military personnel lives quartered in military forts or deploys in groups across the country, allowing rapid transmission of the virus in comparison with an incidence and prevalence of COVID-19 in studies with civil people ( 13 ). Opposite, the age range of the troops sets the personnel in a low-risk group to develop severe forms of the disease, explaining the lower fatality rate if compared to the one presented by the civil Colombian population.…”

Serosurveillance after a COVID‐19 vaccine campaign in a Swiss police cohort

“…14 , 15 Few seroprevalence studies focused on public safety personnel. 16 , 17 , 18 , 19 , 20 , 21 , 22 Garbarino et al 20 reported an overall seroprevalence of 4.8% in 10,535 police officers in Italy, with a higher seroprevalence in northern (9%) than in southern regions (1.6%).…”

Seroprevalence of SARS-CoV-2 Antibodies in Symptomatic Individuals Is Higher than in Persons Who Are at Increased Risk Exposure: The Results of the Single-Center, Prospective, Cross-Sectional Study

“…It is considered that these persons experience a potentially higher SARS-CoV-2 exposure risk due to the nature of their job than the general population [10,20,21]. Thus, according to the study of F-Y Lan et al (2020), employees with direct customer exposure were five times more likely to test positive for SARS-CoV-2 [18], while the seroprevalence of COVID-19 amongst police officers was at least 3.4 higher than in the general population [36]. Nevertheless, some recent data suggest that the seroprevalence of SARS-CoV-2 antibodies in persons from high-risk groups is similar [3] or only marginally higher [10,37] compared to that in the general population, depending on regional variation in COVID-19 incidence.…”