Dynamics of SARS-CoV-2 seroprevalence during the first year of the COVID-19 pandemic in the Northeast region of Brazil.

In this household-based seroepidemiological survey, we analyzed the dynamics of SARS-CoV-2 seroprevalence during the first year of the COVID-19 pandemic in Sergipe State, Northeast Brazil, the poorest region of the country. A total of 16,547 individuals were tested using a rapid IgM-IgG antibody test and fluorescence immunoassay (FIA). Seroprevalence rates were presented according to age, sex, and geographic region. A comparative analysis was performed between the results obtained in July 2020 (peak of the first wave), August - November 2020 (end of the first wave), and February - March 2021 (beginning of the second wave). Seroprevalence rates in the three phases were estimated at 9.3% (95% CI 8.5-10.1), 12.0% (95% CI 11.2-12.9) and 15.4% (95% CI 14.5-16.4). At the end of the first wave, there was a rise in seroprevalence in the countryside (p < 0.001). At the beginning of the second wave, we found an increase in seroprevalence among women (p < 0.001), adults aged 20 to 59 years (p < 0.001), and the elderly (p < 0.001). In this phase, we found an increase in estimates both in metropolitan areas and in the countryside (p < 0.001). This study showed an increase in SARS-CoV-2 seroprevalence over the first year of the pandemic, with approximately one in six people having anti-SARS-CoV-2 antibodies at the beginning of the second wave of COVID-19. Furthermore, our results suggest a rapid spread of COVID-19 from metropolitan areas to the countryside during the first months of the pandemic.

Prevalence of SARS-CoV-2 infection among urban cleaning and solid waste management workers during transmission of the Omicron variant in Brazil.

This study estimated the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in urban cleaning and solid waste management workers during the transmission of the Omicron variant in one of the poorest regions of Brazil (the state of Sergipe). Nasopharyngeal swabs were collected from 494 workers, and the presence of SARS-CoV-2 RNA was tested by quantitative reverse-transcriptase polymerase chain reaction. Data on socio-demographic characteristics, comorbidities, vaccination status, mask use, and use of public transport to commute to the workplace were collected. The prevalence with a 95% confidence interval (CI) was calculated from the proportion of SARS-CoV-2 positive cases among the total number of individuals tested. The prevalence ratio (PR) with a 95% CI was the measure of association used to evaluate the relationship between SARS-CoV-2 infection and the exposure variables. The prevalence of SARS-CoV-2 infection was 22.5% (95% CI, 19.0 to 26.4). Individuals under the age of 40 had a higher prevalence of infection (PR, 1.53; 95% CI, 1.03 to 2.30) as well as those who did not believe in the protective effect of vaccines (PR, 1.78; 95% CI, 1.05 to 2.89). Our results indicate the need for better guidance on preventive measures against coronavirus disease 2019 among urban cleaning and solid waste management workers.

Oxidative stress and inflammatory markers in patients with COVID-19: Potential role of RAGE, HMGB1, GFAP and COX-2 in disease severity.

BACKGROUND: SARS-CoV-2 infection can lead to the abnormal induction of cytokines and a dysregulated hyperinflammatory state that is implicated in disease severity and risk of death. There are several molecules present in blood associated with immune cellular response, inflammation, and oxidative stress that could be used as severity markers in respiratory viral infections such as COVID-19. However, there is a lack of clinical studies evaluating the role of oxidative stress-related molecules including glial fibrillary acidic protein (GFAP), the receptor for advanced glycation end products (RAGE), high mobility group box-1 protein (HMGB1) and cyclo-oxygenase-2 (COX-2) in COVID-19 pathogenesis. AIM: To evaluate the role of oxidative stress-related molecules in COVID-19. METHOD: An observational study with 93 Brazilian participants from September 2020 to April 2021, comprising 23 patients with COVID-19 admitted to intensive care unit (ICU), 19 outpatients with COVID-19 with mild to moderate symptoms, 17 individuals reporting a COVID-19 history, and 34 healthy controls. Blood samples were taken from all participants and western blot assay was used to determine the RAGE, HMGB1, GFAP, and COX-2 immunocontent. RESULTS: We found that GFAP levels were higher in patients with severe or critical COVID-19 compared to outpatients (p = 0.030) and controls (p < 0.001). A significant increase in immunocontents of RAGE (p < 0.001) and HMGB1 (p < 0.001) were also found among patients admitted to the ICU compared to healthy controls, as well as an overexpression of the inducible COX-2 (p < 0.001). In addition, we found a moderate to strong correlation between RAGE, GFAP and HMGB1 proteins. CONCLUSION: SARS-CoV-2 infection induces the upregulation of GFAP, RAGE, HMGB1, and COX-2 in patients with the most severe forms of COVID-19.

Seroprevalence of SARS-CoV-2 antibodies in the poorest region of Brazil: results from a population-based study.

Population-based seroprevalence studies on coronavirus disease 2019 (COVID-19) in low- and middle-income countries are lacking. We investigated the seroprevalence of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) antibodies in Sergipe state, Northeast Brazil, using rapid IgM-IgG antibody test and fluorescence immunoassay. The seroprevalence was 9.3% (95% CI 8.5-10.1), 10.2% (95% CI 9.2-11.3) for women and 7.9% (IC 95% 6.8-9.1) for men (P = 0.004). We found a decline in the prevalence of SARS-CoV-2 antibodies according to age, but the differences were not statistically significant: 0-19 years (9.9%; 95% CI 7.8-12.5), 20-59 years (9.3%; 95% CI 8.4-10.3) and ≥60 years (9.0%; 95% CI 7.5-10.8) (P = 0.517). The metropolitan area had a higher seroprevalence (11.7%, 95% CI 10.3-13.2) than outside municipalities (8.0%, 95% CI 7.2-8.9) (P < 0.001). These findings highlight the importance of serosurveillance to estimate the real impact of the COVID-19 outbreak and thereby provide data to better understand the spread of the virus, as well as providing information to guide stay-at-home measures and other policies. In addition, these results may be useful as basic data to follow the progress of COVID-19 outbreak as social restriction initiatives start to be relaxed in Brazil.