Dataset Information

High anti-SARS-CoV-2 antibody seroconversion rates before the second wave in Manaus, Brazil, and the protective effect of social behaviour measures: results from the prospective DETECTCoV-19 cohort.

ABSTRACT:

Background

The city of Manaus, Brazil, has seen two collapses of the health system due to the COVID-19 pandemic. We report anti-SARS-CoV-2 nucleocapsid IgG antibody seroconversion rates and associated risk factors in Manaus residents before the second wave of the epidemic in Brazil.

Methods

A convenience sample of adult (aged ≥18 years) residents of Manaus was recruited through online and university website advertising into the DETECTCoV-19 study cohort. The current analysis of seroconversion included a subgroup of DETECTCoV-19 participants who had at least two serum sample collections separated by at least 4 weeks between Aug 19 and Oct 2, 2020 (visit 1), and Oct 19 and Nov 27, 2020 (visit 2). Those who reported (or had no data on) having a COVID-19 diagnosis before visit 1, and who were positive for anti-SARS-CoV-2 nucleocapsid IgG antibodies at visit 1 were excluded. Using an in-house ELISA, the reactivity index (RI; calculated as the optical density ratio of the sample to the negative control) for serum anti-SARS-CoV-2 nucleocapsid IgG antibodies was measured at both visits. We calculated the incidence of seroconversion (defined as RI values ≤1·5 at visit 1 and ≥1·5 at visit 2, and a ratio >2 between the visit 2 and visit 1 RI values) during the study period, as well as incidence rate ratios (IRRs) through cluster-corrected and adjusted Poisson regression models to analyse associations between seroconversion and variables related to sociodemographic characteristics, health access, comorbidities, COVID-19 exposure, protective behaviours, and symptoms.

Findings

2496 DETECTCoV-19 cohort participants returned for a follow-up visit between Oct 19 and Nov 27, 2020, of whom 204 reported having COVID-19 before the first visit and 24 had no data regarding previous disease status. 559 participants were seropositive for anti-SARS-CoV-2 nucleocapsid IgG antibodies at baseline. Of the remaining 1709 participants who were seronegative at baseline, 71 did not meet the criteria for seroconversion and were excluded from the analyses. Among the remaining 1638 participants who were seronegative at baseline, 214 showed seroconversion at visit 2. The seroconversion incidence was 13·06% (95% CI 11·52-14·79) overall and 6·78% (5·61-8·10) for symptomatic seroconversion, over a median follow-up period of 57 days (IQR 54-61). 48·1% of seroconversion events were estimated to be asymptomatic. The sample had higher proportions of affluent and higher-educated people than those reported for the Manaus city population. In the fully adjusted and corrected model, risk factors for seroconversion before visit 2 were having a COVID-19 case in the household (IRR 1·49 [95% CI 1·21-1·83]), not wearing a mask during contact with a person with COVID-19 (1·25 [1·09-1·45]), relaxation of physical distancing (1·31 [1·05-1·64]), and having flu-like symptoms (1·79 [1·23-2·59]) or a COVID-19 diagnosis (3·57 [2·27-5·63]) between the first and second visits, whereas working remotely was associated with lower incidence (0·74 [0·56-0·97]).

Interpretation

An intense infection transmission period preceded the second wave of COVID-19 in Manaus. Several modifiable behaviours increased the risk of seroconversion, including non-compliance with non-pharmaceutical interventions measures such as not wearing a mask during contact, relaxation of protective measures, and non-remote working. Increased testing in high-transmission areas is needed to provide timely information about ongoing transmission and aid appropriate implementation of transmission mitigation measures.

Funding

Ministry of Education, Brazil; Fundação de Amparo à Pesquisa do Estado do Amazonas; Pan American Health Organization (PAHO)/WHO.

SUBMITTER: Lalwani P

PROVIDER: S-EPMC8525986 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic spread rapidly and this scenario is concerning in South America, mainly in Brazil that presented more than 21 million coronavirus disease 2019 cases and 590 000 deaths. The recent emergence of novel lineages carrying several mutations in the spike protein has raised additional public health concerns worldwide. The present study describes the temporal spreading and evolution of SARS-CoV2 in the beginning of the second pandemic wave in Brazil, highlighting the fast dissemination of the two major concerning variants (P.1 and P.2). A total of 2507 SARS-CoV-2 whole-genome sequences (WGSs) with available information from the country (Brazil) and sampling date (July 2020-February 2021), were obtained and the frequencies of the lineages were evaluated in the period of the growing second pandemic wave. The results demonstrated the increasing prevalence of P.1 and P.2 lineages in the period evaluated. P.2 lineage was first detected in the middle of 2020, but a high increase occurred only in the last trimester of this same year and the spreading to all Brazilian regions. P.1 lineage emerged even later, first in the North region in December 2020 and really fast dissemination to all other Brazilian regions in January and February 2021. All SARS-CoV-2 WGSs of P.1 and P.2 were further separately evaluated with a Bayesian approach. The rates of nucleotide and amino acid substitutions were statistically higher in P.1 than P.2 (p < 0.01). The phylodynamic analysis demonstrated that P.2 gradually spread in all the country from September 2020 to January 2021, while P.1 disseminated even faster from December 2020 to February 2021. Skyline plots of both lineages demonstrated a slight rise in the spreading for P.2 and exponential growth for P.1. In conclusion, these data demonstrated that the P.1 (recently renamed as Gamma) and P.2 lineages have predominated in the second pandemic wave due to the very high spreading across all geographic regions in Brazil at the end of 2020 and beginning of 2021.

Project description:Arthropod-borne viruses (arboviruses) represent a threat to global public health, especially in the tropical and subtropical regions of the world. More than 150 arboviruses can infect humans; they cause mainly febrile illness, although hemorrhagic complications and diseases affecting the central nervous system (SNC) can also be observed. Arboviruses represent a threat to Brazil and, therefore, a permanent surveillance of these viruses is required to timely reduce the risk of epidemic outbreaks. The Brazilian Amazon region is where the highest number of arboviruses has been detected in the world. Besides, malaria is also endemic in the Amazon region, with a significant predominance of Plasmodium vivax. It is often difficult to differentiate between malaria and arboviral diseases, as they share similar clinical features and laboratory findings, mainly undifferentiated fever. This study aimed to estimate possible viral etiology in patients with febrile syndrome negative for Plasmodium infection, in the Brazilian Amazon. We initially analyzed serum samples of 124 participants with a DNA microarray platform designed for the detection of arboviruses and viruses transmitted by small mammals, but no virus was detected. Then, the serum samples of 76 participants were analyzed with a deep New Generation Sequencing, which showed evidence of the presence of only one arbovirus, the Zika virus in only one pool of 9 serum samples. This result is in contrast with our hypothesis, showing that arboviruses are not frequent in suspected malaria cases in Manaus, Brazil. Other viruses instead of arboviruses were found in this study. Primate erythrovirus 1 was the virus most frequently found virus in the suspected malaria patients, followed by Enterobacteria phage lambda. Besides, we detected, in a lower frequency, the Pegivirus C. In addition to the exogenous viruses, we also detected human endogenous retrovirus in all pools. Due to the high number of viruses that are important in the differential diagnosis of malaria, cost-effective and simple high throughput methods are required, helping molecular surveillance of misdiagnosed viral infections. Further studies with more robust sample sizes in other areas in the Amazon are needed.