SARS-CoV-2 in Brazil

Coronavirus disease (COVID-19) pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a virus with zoonotic origins that was first detected in China in December 2019. Brazil confirmed the first cases on February 26, 2020, in a patient returning from Italy.

Epidemiological situation in Brazil. Official data

To track the number of cases and deaths in Brazil, check out our new COVID-19 Local Information Comparison (CLIC) tool done in collaboration with the Centre for Mathematical Modelling of Infectious Diseases, from the London School of Hygiene and Tropical Medicine. Official case and death counts can be found in the Painel Coronavirus. Now including measures for the effective reproductive number in real-time for all 5568 municipalities and Federal District in Brazil.

First SARS-CoV-2 genomes in Latin America. Read more

We conducted the genome sequencing and analysis of the first confirmed COVID-19 infections in Brazil. Rapid sequencing coupled with phylogenetic analyses in the context of travel history corroborate multiple independent importations from Italy and local spread during the initial stage of COVID-19 transmission in Brazil. The first cases were sequenced and analyzed in only 48 hours.

Routes of COVID-19 introduction in Brazil. Read more

Early in March 2020, as the number of imported SARS-CoV-2 cases was on the rise in Brazil, we use incidence and historical air travel data to estimate the most important routes of importation into the country.

Between February and March 2019, Brazil received 841,302 international passengers in a total of 84 cities across the country (Figure 1). São Paulo, the largest city in the country, was the final destination of nearly half (46.1%) of the passengers arriving in Brazil, followed by Rio de Janeiro (21%) and Belo Horizonte (4.1%). More than half of the international passengers started their journey in the USA (50.8%) followed by France (7.9%) and Italy (7.5%). The air-travel routes to airports in Brazil with most passengers were USA-São Paulo (23.3%), USA-Rio de Janeiro (9.8%) and Italy-São Paulo (3.4%).

Potential for COVID-19 importation to Brazil. Panel on the left shows the proportion (%) of passengers for the top-20 routes to Brazilian airports from countries that had reported COVID-19 cases by 5^th March 2020. Panel on the right side estimated proportion (%) of importations for the top-20 routes from countries that had reported local COVID-19 by 5^th March 2020.

Importantly, with the recent reduction in the number of flights leaving from Italy and 51% of flights to Brazil depart from airports in the USA, we should anticipate an increasing proportion of infected travelers arriving from the USA. At a time when the number of SARS-CoV-2 cases is steadily growing in Brazil, our findings highlight the high potential for the introduction of new cases in several cities of Brazil, especially in Sao Paulo and Rio de Janeiro metropolises. Rapid identification of locations where clusters of local transmission might first ignite is critical to better coordinate preparedness, readiness, and response actions. There is a critical need for epidemiological, human mobility, and genetic data to understand virus transmission dynamics across Brazil. Continued integration of these data streams should help guide the deployment of resources to mitigate COVID-19 transmission Brazil. Check out a youtube video from Dr. Chico Camargo explaining our findings (in Portuguese).

Epidemiological and clinical characteristics of the COVID-19 epidemic in Brazil. Read more

The first case of COVID-19 was detected in Brazil on 25 February 2020. We report and contextualize epidemiological, demographic and clinical findings for COVID-19 cases during the first 3 months of the epidemic. By 31 May 2020, 514,200 COVID-19 cases, including 29,314 deaths, had been reported in 75.3% (4,196 of 5,570) of municipalities across all five administrative regions of Brazil. The R₀ value for Brazil was estimated at 3.1 (95% Bayesian credible interval = 2.4–5.5), with a higher median but overlapping credible intervals compared with some other seriously affected countries. A positive association between higher per-capita income and COVID-19 diagnosis was identified. Furthermore, the severe acute respiratory infection cases with unknown aetiology were associated with lower per-capita income. Co-circulation of six respiratory viruses was detected but at very low levels. These findings provide a comprehensive description of the ongoing COVID-19 epidemic in Brazil and may help to guide subsequent measures to control virus transmission. Our study featured in Globo and Estadao.

Evolution and spread of SARS-CoV-2 in Brazil. Read more

Brazil currently has one of the fastest growing SARS-CoV-2 epidemics in the world. Owing to limited available data, assessments of the impact of non-pharmaceutical interventions (NPIs) on virus spread remain challenging. Using a mobility-driven transmission model, we show that NPIs reduced the reproduction number from >3 to 1–1.6 in São Paulo and Rio de Janeiro. Sequencing of 427 new genomes and analysis of a geographically representative genomic dataset identified >100 international virus introductions in Brazil. We estimate that most (76%) of the Brazilian strains fell in three clades that were introduced from Europe between 22 February to 11 March 2020. During the early epidemic phase, we found that SARS-CoV-2 spread mostly locally and within-state borders. After this period, despite sharp decreases in air travel, we estimated multiple exportations from large urban centers that coincided with a 25% increase in average travelled distances in national flights. This study sheds new light on the epidemic transmission and evolutionary trajectories of SARS-CoV-2 lineages in Brazil, and provide evidence that current interventions remain insufficient to keep virus transmission under control in the country. Our study featured in Jornal Nacional, G1, and CNN Brasil.

Serial Interval Distribution of SARS-CoV-2 Infection in Brazil. Read more

Current assessments of SARS-CoV-2 transmission dynamics rely on accurate estimates of key epidemiological parameters, including the serial interval, which can be defined as the time between symptom onset of the source and the onset of symptoms of the recipient. Using 65 transmission pairs of SARS-CoV-2 cases reported to the Brazilian Ministry of Health we estimated the first serial interval estimates for SARS-CoV-2 from Latin America. We estimate the mean and standard deviation for the serial interval to be 2.97 and 3.29 days respectively. We also present a model for the serial interval probability distribution using only two parameters.

Three-quarters attack rate of SARS-CoV-2 in the Brazilian Amazon during a largely unmitigated epidemic. Read more

The herd immunity threshold is the proportion of a population that must be immune to an infectious disease, either by natural infection or vaccination such that, in the absence of additional preventative measures, new cases decline and the effective reproduction number falls below unity. This fundamental epidemiological parameter is still unknown for the recently-emerged COVID-19, and mathematical models have predicted very divergent results. Population studies using antibody testing to infer total cumulative infections can provide empirical evidence of the level of population immunity in severely affected areas. Here we show that the transmission of SARS-CoV-2 in Manaus, located in the Brazilian Amazon, increased quickly during March and April and declined more slowly from May to September. In June, one month following the epidemic peak, 44% of the population was seropositive for SARS-CoV-2, equating to a cumulative incidence of 52%, after correcting for the false-negative rate of the antibody test. The seroprevalence fell in July and August due to antibody waning. After correcting for this, we estimate a final epidemic size of 66%. Although non-pharmaceutical interventions, plus a change in population behavior, may have helped to limit SARS-CoV-2 transmission in Manaus, the unusually high infection rate suggests that herd immunity played a significant role in determining the size of the epidemic.

Local Transmission of SARS-CoV-2 Lineage B.1.1.7, Brazil, December 2020 Read more

In December 2020, research surveillance detected the B.1.1.7 lineage of severe acute respiratory syndrome coronavirus 2 in São Paulo, Brazil. Rapid genomic sequencing and phylogenetic analysis revealed 2 distinct introductions of the lineage. One patient reported no international travel. There may be more infections with this lineage in Brazil than reported. We report the phylogenetic context of novel severe acute respiratory syndrome coronavirus 2 B.1.1.7 genomes isolated from 2 patients in Brazil (Figure).

Resurgence of COVID-19 in Manaus, Brazil, despite high seroprevalence Read more

Our latest comment on the resurgence of COVID-19 in Manaus, Brazil, despite high seroprevalence is out now in The Lancet. After initially containing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), many European and Asian countries had a resurgence of COVID-19 consistent with a large proportion of the population remaining susceptible to the virus after the first epidemic wave. By contrast, in Manaus, Brazil, a study of blood donors indicated that 76% (95% CI 67–98) of the population had been infected with SARS-CoV-2 by October, 2020.

SARS-CoV-2 reinfection caused by the P.1 lineage in Araraquara city, Sao Paulo State, Brazil, Rev. Inst. Med. Trop. S. Paulo Read more

Reinfection by the severe acute respiratory syndrome coronavirus type 2 (SARS-COV-2) has been reported in many countries, suggesting that the virus may continue to circulate among humans despite the possibility of local herd immunity due to massive previous infections. The emergence of variants of concern (VOC) that are more transmissible than the previous circulating ones has raised particular concerns on the vaccines effectiveness and reinfection rates. The P.1 lineage was first identified in December 2020 in Manaus city and is now globally spread. We report the first case of reinfection of SARS-CoV-2 caused by the P.1 variant outside of Manaus. The potential of these new variants to escape naturally and vaccine- induced immunity highlights the need for a global vigilance.

Increasing frequency of SARS-CoV-2 lineages B.1.1.7, P.1 and P.2 and identification of a novel lineage harboring E484Q and N501T spike mutations in Minas Gerais, Southeast Brazil, Virological.org, Read more

We report preliminary results of an ongoing investigation of SARS-CoV-2 genomic diversity in the metropolitan region of Belo Horizonte (MRBH), Minas Gerais, Brazil. We sequenced and characterized 85 nearly complete SARS-CoV-2 genome sequences from randomized samples collected between 28 October 2020 and 15 March 2021. Phylogenetic analysis reveals co-circulation of two variants of concern (VOC), B.1.1.7 (n=3, 3.53%) and P.1 (n=30, 35.29%), and variant of interest (VOI) P.2 (n=41, 48.23%). These variants harbor E484K (P.1 and P.2) and N501Y (P.1 and B.1.1.7) mutations that are associated with increased transmissibility or immune escape. The N501Y mutation has also been associated with an increase in COVID-19 hospitalizations and deaths. Notably, we find that between 28 Feb and 15 Mar, 68% of cases were caused by the P.1 lineage in the MRBH. In addition, we report a cluster of two sequences characterized by a unique array of 18 mutations, including new non-synonymous changes in the same critical spike amino acid positions, E484Q and N501T. This lineage seems to have emerged independently from the nationally widespread B.1.1.28, as previously reported for P.1 and P.2, and adds up to the composition of a complex epidemiological scenario of the SARS-CoV-2 pandemic in Brazil.

Genomics and epidemiology of a novel SARS-CoV-2 lineage in Manaus, Brazil Read more

Cases of SARS-CoV-2 infection in Manaus, Brazil, resurged in late 2020, despite high levels of previous infection there. Through genome sequencing of viruses sampled in Manaus between November 2020 and January 2021, we identified the emergence and circulation of a novel SARS-CoV-2 variant of concern, lineage P.1, that acquired 17 mutations, including a trio in the spike protein (K417T, E484K and N501Y) associated with increased binding to the human ACE2 receptor. Molecular clock analysis shows that P.1 emergence occurred around early November 2020 and was preceded by a period of faster molecular evolution. Using a two-category dynamical model that integrates genomic and mortality data, we estimate that P.1 may be 1.4–2.2 times more transmissible and 25-61% more likely to evade protective immunity elicited by previous infection with non-P.1 lineages. Enhanced global genomic surveillance of variants of concern, which may exhibit increased transmissibility and/or immune evasion, is critical to accelerate pandemic responsiveness.

Respiratory viral shedding in healthcare workers reinfected with SARS-CoV-2, Brazil, 2020, Emerging Infections Diseases, Read more

We documented 4 cases of severe acute respiratory syndrome coronavirus 2 reinfection by non–variant of concern strains among healthcare workers in Campinas, Brazil. We isolated infectious particles from nasopharyngeal secretions during both infection episodes. Improved and continued protection measures are necessary to mitigate the risk for reinfection among healthcare workers

Higher risk of death from COVID-19 in low-income and non-White populations of São Paulo, Brazil, BMJ Global Health, Read more

Little evidence exists on the differential health effects of COVID-19 on disadvantaged population groups. Here we characterise the differential risk of hospitalisation and death in São Paulo state, Brazil, and show how vulnerability to COVID-19 is shaped by socioeconomic inequalities.

Interacting Epidemics in Amazonian Brazil: Prior Dengue Infection Associated with Increased COVID-19 Risk in a Population-Based Cohort Study, Clinical Infectious Diseases, Read more

Serologically proven prior dengue infection is associated with increased subsequent risk of clinically apparent COVID-19 in Amazonians, implying that sequential dengue and COVID-19 epidemics may impose an extra burden of disease to affected communities in the tropical and subtropical world.

Multiplex qPCR discriminates variants of concern to enhance global surveillance of SARS-CoV-2, PLoS Biology, Read more

With the emergence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variants that may increase transmissibility and/or cause escape from immune responses, there is an urgent need for the targeted surveillance of circulating lineages. It was found that the B.1.1.7 (also 501Y.V1) variant, first detected in the United Kingdom, could be serendipitously detected by the Thermo Fisher TaqPath COVID-19 PCR assay because a key deletion in these viruses, spike Δ69–70, would cause a “spike gene target failure” (SGTF) result. However, a SGTF result is not definitive for B.1.1.7, and this assay cannot detect other variants of concern (VOC) that lack spike Δ69–70, such as B.1.351 (also 501Y.V2), detected in South Africa, and P.1 (also 501Y.V3), recently detected in Brazil. We identified a deletion in the ORF1a gene (ORF1a Δ3675–3677) in all 3 variants, which has not yet been widely detected in other SARS-CoV-2 lineages. Using ORF1a Δ3675–3677 as the primary target and spike Δ69–70 to differentiate, we designed and validated an open-source PCR assay to detect SARS-CoV-2 VOC. Our assay can be rapidly deployed in laboratories around the world to enhance surveillance for the local emergence and spread of B.1.1.7, B.1.351, and P.1.

Epidemic Spread of SARS-CoV-2 Lineage B.1.1.7 in Brazil, Viruses, Read more

The emergence of diverse lineages harboring mutations with functional significance and potentially enhanced transmissibility imposes an increased difficulty on the containment of the SARS-CoV-2 pandemic. In Brazil, six such lineages cocirculate, one originally from the UK (B.1.1.7), one original from South Africa (B.1.351), and four that emerged within different regions of the country, P.1 (Manaus), P.2 (Rio de Janeiro), N.9 (São Paulo), and N.10 (Maranhão). While reports on the spread of some of these lineages to other Brazilian regions exist, a single report on two cases of lineage B.1.1.7 in São Paulo has been published, and the extent of its geographic spread is currently unknown. Therefore, we conducted a genomic epidemiology study focused on characterizing the dissemination of this lineage in a national context.

Brazil needs a coordinated and cooperative approach to tackle COVID-19, Nature Medicine, Read more

After more than 14 months under siege, Brazilians continue to suffer as they see thousands of people dying every day, killed by the fast-moving respiratory pathogen SARS-CoV-2. Families are struggling to secure their livelihoods, quell hunger and, in some cases, adjust to the long-term toll of having survived infection with SARS-CoV-2. With the surge in cases, overcrowding of hospitals and high lethality, those on the front lines understand that Brazil is at war with COVID-19. The assault has been brutal¹. A quarter of all deaths from COVID-19 in Brazil were officially recorded in April 2021. Meanwhile, a SARS-CoV-2 variant of concern, lineage P.1 (B.1.1.28.1), continues to be detected in an ever-increasing share of infections, on the basis of the small number of genomes sequenced across the country. This Commentary discusses the many factors that explain why the toll of the pandemic on Brazil has been so extraordinary, including its close transport connectivity with world markets, the marked socioeconomic vulnerabilities of its many populations, and persistent inequities.

Neutralisation of SARS-CoV-2 lineage P.1 by antibodies elicited through natural SARS-CoV-2 infection or vaccination with an inactivated SARS-CoV-2 vaccine: an immunological study, Lancet Microbe, Read more

Mutations accrued by SARS-CoV-2 lineage P.1—first detected in Brazil in early January, 2021—include amino acid changes in the receptor-binding domain of the viral spike protein that also are reported in other variants of concern, including B.1.1.7 and B.1.351. We aimed to investigate whether isolates of wild-type P.1 lineage SARS-CoV-2 can escape from neutralising antibodies generated by a polyclonal immune response. We did an immunological study to assess the neutralising effects of antibodies on lineage P.1 and lineage B isolates of SARS-CoV-2, using plasma samples from patients previously infected with or vaccinated against SARS-CoV-2. We found that SARS-CoV-2 lineage P.1 might escape neutralisation by antibodies generated in response to polyclonal stimulation against previously circulating variants of SARS-CoV-2. Continuous genomic surveillance of SARS-CoV-2 combined with antibody neutralisation assays could help to guide national immunisation programmes.

Altered demographic profile of hospitalizations during the second COVID-19 wave in Amazonas, Brazil, The Lancet Regional Health, Read more

Recent months have seen the emergence of SARS-CoV-2 variants with altered epidemiological properties, including increased transmissibility and the ability to partially evade protection immunity from prior infection. These variants have frequently been associated with resurgence of transmission and COVID-19 mortality in settings where they have established. Detailed investigations into the epidemiology of variants of concern (VOC) are crucial to sustained, long-term control of SARS-CoV-2. Despite this, epidemiological studies remain scarce, particularly with regards to clinical outcomes and profiles of disease severity associated with VOC transmission.

Understanding the Potential Impact of Different Drug Properties on SARS-CoV-2 Transmission and Disease Burden: A Modeling Analysis, Clinical Infectious Diseases, Read more

The public health impact of the COVID-19 pandemic has motivated a rapid search for potential therapeutics, with some key successes. However, the potential impact of different treatments, and consequently research and procurement priorities, have not been clear. Using a mathematical model of SARS-CoV-2 transmission, COVID-19 disease and clinical care, we explore the public-health impact of different potential therapeutics, under a range of scenarios varying healthcare capacity, epidemic trajectories; and drug efficacy in the absence of supportive care. The impact of drugs like dexamethasone (delivered to the most critically-ill in hospital and whose therapeutic benefit is expected to depend on the availability of supportive care such as oxygen and mechanical ventilation) is likely to be limited in settings where healthcare capacity is lowest or where uncontrolled epidemics result in hospitals being overwhelmed. As such, it may avert 22% of deaths in high-income countries but only 8% in low-income countries (assuming R=1.35). Therapeutics for different patient populations (those not in hospital, early in the course of infection) and types of benefit (reducing disease severity or infectiousness, preventing hospitalisation) could have much greater benefits, particularly in resource-poor settings facing large epidemics. Advances in the treatment of COVID-19 to date have been focussed on hospitalised-patients and predicated on an assumption of adequate access to supportive care. Therapeutics delivered earlier in the course of infection that reduce the need for healthcare or reduce infectiousness could have significant impact, and research into their efficacy and means of delivery should be a priority.

Tracking the emergence of disparities in the subnational spread of COVID-19 in Brazil using an online application for real-time data visualisation: a longitudinal analysis, The Lancet Regional Health- Americas, Read more

Brazil is one of the countries worst affected by the COVID-19 pandemic with over 20 million cases and 557,000 deaths reported by August 2021. Comparison of real-time local COVID-19 data between areas is essential for understanding transmission, measuring the effects of interventions, and predicting the course of the epidemic, but are often challenging due to different population sizes and structures. We describe the development of a new app for the real-time visualisation of COVID-19 data in Brazil at the municipality level. In the CLIC-Brazil app, daily updates of case and death data are downloaded, age standardised and used to estimate the effective reproduction number (Rt). We show how such platforms can perform real-time regression analyses to identify factors associated with the rate of initial spread and early reproduction number. We also use survival methods to predict the likelihood of occurrence of a new peak of COVID-19 incidence.

Track Omicron’s spread with molecular data, Science, Read more

On 26 November, the newly emerged variant Omicron was designated a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant of concern (VOC) (1). Rapid polymerase chain reaction (PCR) test results could improve estimates of the prevalence of Omicron around the world. The widely used Thermo Fisher TaqPath COVID-19 PCR assay was valuable in tracking the spread of the Alpha (B.1.1.7) VOC (2) because a deletion of amino acids 69 and 70 in Alpha’s spike gene (Δ69–70) yields a distinct absent S-gene (S^–) despite positive test results. The Delta VOC lacks this deletion and is therefore S-gene positive (S⁺) on TaqPath PCR tests (3). The Omicron VOC shares the spike Δ69–70 deletion with Alpha, which has dropped to negligible levels worldwide. Therefore, the frequency of S^– results can be used as a rapid proxy for the frequency of Omicron cases, provided initial detection of local circulation had been confirmed by sequencing.

Global disparities in SARS-CoV-2 genomic surveillance, Preprint, Read more

Genomic sequencing provides critical information to track the evolution and spread of SARS-CoV-2, optimize molecular tests, treatments and vaccines, and guide public health responses. To investigate the spatiotemporal heterogeneity in the global SARS-CoV-2 genomic surveillance, we estimated the impact of sequencing intensity and turnaround times (TAT) on variant detection in 167 countries. Most countries submit genomes >21 days after sample collection, and 77% of low and middle income countries sequenced <0.5% of their cases. We found that sequencing at least 0.5% of the cases, with a TAT <21 days, could be a benchmark for SARS-CoV-2 genomic surveillance efforts. Socioeconomic inequalities substantially impact our ability to quickly detect SARS-CoV-2 variants, and undermine the global pandemic preparedness.

Epidemiology of COVID-19 after Emergence of SARS-CoV-2 Gamma Variant, Brazilian Amazon, 2020–2021, Emerging Infectious Diseases – Dispatch, Read more

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Gamma variant has been hypothesized to cause more severe illness than previous variants, especially in children. Successive SARS-CoV-2 IgG serosurveys in the Brazilian Amazon showed that age-specific attack rates and proportions of symptomatic SARS-CoV-2 infections were similar before and after Gamma variant emergence.

Reinfection by the SARS-CoV-2 Gamma variant in blood donors in Manaus, Brazil, BMC Infectious Diseases, Read more

The city of Manaus, north Brazil, was stricken by a second epidemic wave of SARS-CoV-2 despite high seroprevalence estimates, coinciding with the emergence of the Gamma (P.1) variant. Reinfections were postulated as a partial explanation for the second surge. However, accurate calculation of reinfection rates is difficult when stringent criteria as two time-separated RT-PCR tests and/or genome sequencing are required.

To estimate the proportion of reinfections caused by the Gamma variant during the second wave in Manaus and the protection conferred by previous infection, we analyzed a cohort of repeat blood donors to identify anti-SARS-CoV-2 antibody boosting as a means to infer reinfection. Reinfection due to Gamma is common and may play a significant role in epidemics where Gamma is prevalent, highlighting the continued threat variants of concern pose even to settings previously hit by substantial epidemics.

SARS-CoV-2 antibody dynamics in blood donors and COVID-19 epidemiology in eight Brazilian state capitals, Preprint, Read more

There are large differences in the shape and size of regional SARS-CoV-2 epidemics in Brazil. Here we tested monthly blood donation samples for IgG antibodies from March 2020 to March 2021 in eight of Brazil’s most populous cities. There was large variation in the inferred attack rate adjusted for seroreversion across cities, and seroprevalence was consistently smaller in women and donors older than 55 years. The age-specific infection fatality rate differed between cities and consistently increased with age. The infection hospitalisation rate (IHR) increased significantly during the gamma-dominated second wave in Manaus, suggesting increased morbidity of the Gamma VOC compared to previous variants circulating in Manaus. The higher disease penetrance associated with the health system’s collapse increased the overall IFR by a minimum factor of 2.91 (95% CrI 2.43–3.53). These results demonstrate large heterogeneity in epidemic spread and highlight the utility of blood donor serosurveillance to monitor SARS-CoV-2 epidemics.

Measuring the effects of COVID-19-related disruption on dengue transmission in southeast Asia and Latin America: a statistical modelling study, The Lancet Infectious Diseases, Read more

The COVID-19 pandemic has resulted in unprecedented disruption to society, which indirectly affects infectious disease dynamics. We aimed to assess the effects of COVID-19-related disruption on dengue, a major expanding acute public health threat, in southeast Asia and Latin America. We assembled data on monthly dengue incidence from WHO weekly reports, climatic data from ERA5, and population variables from WorldPop for 23 countries between January, 2014 and December, 2019 and fit a Bayesian regression model to explain and predict seasonal and multi-year dengue cycles. We compared model predictions with reported dengue data January to December, 2020, and assessed if deviations from projected incidence since March, 2020 are associated with specific public health and social measures (from the Oxford Coronavirus Government Response Tracer database) or human movement behaviours (as measured by Google mobility reports). We found a consistent, prolonged decline in dengue incidence across many dengue-endemic regions that began in March, 2020 (2·28 million cases in 2020 vs 4·08 million cases in 2019; a 44·1% decrease). We found a strong association between COVID-19-related disruption (as measured independently by public health and social measures and human movement behaviours) and reduced dengue risk, even after taking into account other drivers of dengue cycles including climatic and host immunity (relative risk 0·01–0·17, p<0·01). Measures related to the closure of schools and reduced time spent in non-residential areas had the strongest evidence of association with reduced dengue risk, but high collinearity between covariates made specific attribution challenging. Overall, we estimate that 0·72 million (95% CI 0·12–1·47) fewer dengue cases occurred in 2020 potentially attributable to COVID-19-related disruption.

SARS-CoV-2 hospital-associated transmission dynamics in São Paulo, Brazil: a retrospective genomic surveillance study: Preprint, Read more

Brazil reported its first SARS-CoV-2 case on 26 February 2020 in an international traveler returning to São Paulo, Brazil. By 10 June 2020, 3,898 healthcare workers (HCW) and patients at the Hospital das Clínicas (HC) in São Paulo, the largest hospital complex in Latin America, had tested positive for SARS-CoV-2 RNA. We aimed to provide insight into the transmission of SARS-CoV-2 in healthcare workers and patients, and within and between HC institutes during the early phase of the epidemic in Brazil. We analyzed epidemiological data from SARS-CoV-2 RT-PCR confirmed cases between 13 March to 10 June 2020. A total of 340 SARS-CoV-2 genomes were generated from healthcare workers and patients from two HC institutes not receiving COVID-19 patients (institutes A and C) and one institute receiving exclusively COVID-19 patients (institute B). Within- and between-institute transmission clusters were identified and within-cluster transmission dynamics was assessed using logistic regression analysis and a suite of phylogenetic genetic analyses.

Spatial and temporal fluctuations in COVID-19 fatality rates in Brazilian hospitals, Nature Medicine, Read more

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Gamma variant of concern has spread rapidly across Brazil since late 2020, causing substantial infection and death waves. Here we used individual-level patient records after hospitalization with suspected or confirmed coronavirus disease 2019 (COVID-19) between 20 January 2020 and 26 July 2021 to document temporary, sweeping shocks in hospital fatality rates that followed the spread of Gamma across 14 state capitals, during which typically more than half of hospitalized patients aged 70 years and older died. We show that such extensive shocks in COVID-19 in-hospital fatality rates also existed before the detection of Gamma. Using a Bayesian fatality rate model, we found that the geographic and temporal fluctuations in Brazil’s COVID-19 in-hospital fatality rates were primarily associated with geographic inequities and shortages in healthcare capacity. We estimate that approximately half of the COVID-19 deaths in hospitals in the 14 cities could have been avoided without pre-pandemic geographic inequities and without pandemic healthcare pressure. Our results suggest that investments in healthcare resources, healthcare optimization and pandemic preparedness are critical to minimize population-wide mortality and morbidity caused by highly transmissible and deadly pathogens such as SARS-CoV-2, especially in low- and middle-income countries.