Maré cohort-profile: a prospective cohort study based in a socially vulnerable community during the COVID-19 pandemic in Rio de Janeiro, Brazil

Abstract

Background: Socially vulnerable populations were vastly affected by the COVID-19 pandemic. The pandemic significantly impacted Brazil, pressuring its healthcare system for several months, with high mortality rates, even among the youngest population. Cohort studies combining disease surveillance are essential for understanding virus circulation in the community, surrogates of protection, vaccine effectiveness, and demand for health resources. Methods: Here, we present the protocol for a community-based prospective cohort study in the largest complex of favelas (slums) in Rio de Janeiro, Brazil (Complexo da Maré). The study participants are residents initially recruited during a massive vaccination campaign in the community. Five waves of data collection at approximately six-month intervals were planned. The first two waves have been completed at the time of writing this study protocol, and the third is underway. The protocol comprises interviews, blood sampling, and records linkage with secondary data to enrich the profiles of cohort participants and community information. We will describe COVID-19 seroprevalence, socio-demographic characteristics, and the burden of COVID-19, followed by estimating the association of socioeconomic factors and the burden of disease with seroprevalence. Discussion: The primary aims of the study are to assess COVID-19 clinical, epidemiological and genomic profiles and outcomes in residents from Maré, including vaccine effectiveness, surrogates of immune protection, virus transmission in households, and the overall burden of the pandemic.

Analysis of associations between the TLR3 SNPs rs3775291 and rs3775290 and COVID-19 in a cohort of professionals of Belém-PA, Brazil

“…These factors may be related to several elements that surround the host, such as those related to nutrition, body physiology, ethnic miscegenation, and others (Garg et al, 2020;Xie and Zhu, 2020;van der Made et al, 2022). They may also be associated with a predisposition to comorbidities, as in the cases of SNPs in other genes with higher frequency in this population associated with a worse prognosis of chronic conditions (such as the SNP rs7903146 of the TCF7L2 gene associated with a worse prognosis of type 2 Diabetes Mellitus [DM2] in population from Southern Brazilian Region), which may be more prevalent in this population and influence the worse clinical evolution of COVID-19 (Assmann et al, 2014;Bastos et al, 2021).…”

Prevalence, risk factors, and impact of long COVID in a socially vulnerable community in Brazil: a prospective cohort study

“…This was a community-based prospective cohort study in Complexo da Maré , Rio de Janeiro, Brazil, established in November 2021 during the Vacina Maré vaccination program. 17 It is also part of a global study to assess the long-term health consequences of COVID-19 in different populations, in collaboration with the International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC). 16 Ethical approval was obtained from the National Research Ethics Committee (IRB/CONEP) (CAEE: 49726921.6.0000.5248 and 44180821.1.0000.5249).…”

“…During the COVID-19 pandemic, this community became the focus of several initiatives jointly organised by academia (FIOCRUZ) and a local non-governmental organisation (Redes da Maré) with the support of the public and private sectors. 17 One of these initiatives was the Vacina Maré vaccination campaign in the Maré Cohort project. This cohort study aims to evaluate the impact of the COVID-19 pandemic on Maré residents, including assessments of clinical and epidemiological profiles, vaccine effectiveness, and long-term health impacts.…”

“… 4 , 13 , 14 To address this gap, we established a cohort of SARS-CoV-2 PCR-positive patients from Complexo da Maré , a complex of 16 slums in Rio de Janeiro, Brazil. 15 Our study had three primary objectives: First, to determine the prevalence of long COVID in the community. Second, to measure the impact of Long COVID in the quality of life and daily functioning of affected individuals.…”

A comparative NMR-based metabolomics study of lung parenchyma of severe COVID-19 patients

“…While most of the patients diagnosed with COVID-19 attended the disease at home, 13%-14% needed hospitalization in moderate care facilities, and between 5%-6% were admitted to intensive care units (Verity et al, 2020;Gosangi et al, 2022). Hospital mortality was between 30%-60% in case series reported in the first wave, increasing significantly for patients admitted to the ICU who required mechanical ventilation (Abate et al, 2020;Bastos et al, 2021;Estenssoro et al, 2021;Kurtz et al, 2021;Ranzani et al, 2021;Dongelmans et al, 2022). Uruguay was no exception, and towards the end of 2020 the average number of new cases increased exponentially to over 400 cases per day (GUIAD-COVID-19, 2022).…”