Seroprevalence Of SARS-COV-2 infection in asymptomatic indigenous from the largest Brazilian periurban area

Abstract

This study assessed the seroprevalence of SARS-CoV-2 in 496 asymptomatic individuals from Mato Grosso do Sul, located in Dourados, the largest periurban indigenous area in Brazil, from January 25 to February 4, 2021. The volunteers participated before receiving their first dose of the CoronaVac inactivated vaccine. For screening, blood samples were collected and analyzed using SARS-CoV-2 rapid tests and the enzyme-linked immunosorbent assay (ELISA). We observed varying trends in total anti-SARS-CoV-2 antibodies across different variables. Seropositivity among the participants tested was 63.70% (316/496) using the rapid test and 52.82% (262/496) were positive using the ELISA method. The majority of participants identified with the Guarani-Kaiowá ethnic group, with 66.15% (217/328), and other ethnic groups with 58.84% (193/328). The median age of the subjects was 30.5 years, with 79.57% (261/328) being femaleThis research showed the elevated seroprevalence of SARS-CoV-2 antibodies in asymptomatic Brazilians. The findings indicate a high seropositivity rate among the asymptomatic indigenous population of Midwest Brazil. This underscores the overlooked status of these communities and underscores the need for targeted national initiatives that emphasize the protection of vulnerable ethnic groups in the fight against COVID-19.

Genetic predisposition to milder forms of COVID-19 may provide some resilience to head and neck cancers

“…For example, prolonged immunosuppression in inflammatory bowel disease also increases the risk of developing HNC ( 29 , 30 ). In the case of asymptomatic disease, which is expected to be common in adult COVID-19 controls according to recent epidemiological evaluations ( 31 , 32 ), the state of immunosuppression may be present at the time of infection and is due to various genetic or environmental causes. Indeed, the epidemiology of the first two waves of COVID-19, which occurred before the advent of anti-SARS-CoV-2 vaccination, seems to reflect a mix of asymptomatic cases of SARS-CoV-2 with cases of non-exposure rather than true innate resistance to SARS-CoV-2 infection or pre-existing B- or T-cell immunity.…”