EPICOVID19 protocol: repeated serological surveys on SARS-CoV-2 antibodies in Brazil

Hallal, Pedro Curi; Barros, Fernando C.; Silveira, Mariângela Freitas da; Barros, Aluísio J D; Dellagostin, Odir A.; Pellanda, Lúcia Campos; Struchiner, Cláudio J.; Burattini, Marcelo Nascimento; Hartwig, Fernando Pires; Menezes, Ana Maria Baptista; Horta, Bernardo Lessa; Victora, Cesar G

doi:10.1590/1413-81232020259.25532020

Cited by 16 publications

(12 citation statements)

References 6 publications

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“…Using data from the most recent wave of the EPICOVID19 study, a nationwide household-based survey including 133 cities from all states of Brazil, 7 we estimate the proportion of people with and without antibodies for SARS-CoV-2 who were asymptomatic. We investigated which symptoms were most frequently reported, how many symptoms were reported by each subject, and the associations between symptoms and sociodemographic characteristics.…”

Section: Introductionmentioning

confidence: 99%

High prevalence of symptoms among Brazilian subjects with antibodies against SARS-CoV-2: a nationwide household survey

Menezes

Victora

Hartwig

et al. 2020

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Since the beginning of the pandemic of COVID-19, there has been a widespread assumption that most infected persons are asymptomatic. A frequently-cited early study from China suggested that 86% of all infections were undocumented, which was used as indirect evidence that patients were asymptomatic. Using data from the most recent wave of the EPICOVID19 study, a nationwide household-based survey including 133 cities from all states of Brazil, we estimated the proportion of people with and without antibodies for SARS-CoV-2 who were asymptomatic, which symptoms were most frequently reported, the number of symptoms reported and the association between symptomatology and socio-demographic characteristics. We were able to test 33,205 subjects using a rapid antibody test that was previously validated. Information on symptoms was collected before participants received the test result. Out of 849 (2.7%) participants who tested positive for SARS-CoV-2 antibodies, only 12.1% (95%CI 10.1-14.5) reported no symptoms since the start of the pandemic, compared to 42.2% (95%CI 41.7-42.8) among those who tested negative. The largest difference between the two groups was observed for changes in smell or taste (56.5% versus 9.1%, a 6.2-fold difference). Symptoms change in smell or taste, fever and myalgia were most likely to predict positive test results as suggested by recursive partitioning tree analysis. Among individuals without any of these three symptoms (74.2% of the sample), only 0.8% tested positive, compared to 18.3% of those with both fever and changes in smell or taste. Most subjects with antibodies against SARS-CoV-2 in Brazil are symptomatic, even though most present only mild symptoms.

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Section: Introductionmentioning

confidence: 99%

High prevalence of symptoms among Brazilian subjects with antibodies against SARS-CoV-2: a nationwide household survey

Menezes

Victora

Hartwig

et al. 2020

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“…Another seroprevalence study conducted in Brazil in 90 cities (comprising 54 million individuals) finds that the official number of cases is underestimated by a factor of 7. These cities combined had (until May 2020) ∼ 105, 000 official cases and ∼ 8, 000 deaths, suggesting a corrected case fatality rate of ∼ 1.10% [55,56]. Finally, another seroprevalence study conducted in New York City finds a corrected case fatality rate for the first wave of the COVID-19 pandemic of 0.97% [57].…”

Section: Discussionmentioning

confidence: 99%

Uncovering the Universality of COVID-19 Fatality Rates

Leão

Lima

2021

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An important and elusive characteristic of the COVID-19 pandemic is the fatality rate which allows us to understand the severity of this disease, health care needs, and the impact on large populations. To address this and other questions we present a probabilistic model to study the evolution of the COVID-19 pandemic and to correct the case fatality rates. Our model employs probabilities to estimate the time evolution of infections, recoveries, and deaths. This model discriminates asymptomatic, mild/moderate, and severe cases and allows for the estimation of undiagnosed individuals. Furthermore, we compare the model curves to official data for medium-sized cities, world metropolises, and medium-sized countries, spanning a range of populations from a few million to several million individuals. Using the undiagnosed estimates we correct the case fatality rates and find that it ranges from 0.33% ± 0.02% to 1.14% ± 0.07%. Since we applied the method to cities and countries with different characteristics, the corrected case fatality rates indicate a universality that is independent of location and other social/demographic conditions. Our results agree with sample tests and seroprevalence studies, considerably changing our understanding of the COVID-19 fatality rates. Other applications include the estimate for severe cases, ICU needs, and undiagnosed cases.

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“…Os testes rápidos positivos e 20% dos negativos foram avaliados por um segundo observador. A metodologia detalhada do estudo Epicovid-19 Brasil foi publicada previamente 12 .…”

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Doenças crônicas não transmissíveis e covid-19: resultados do estudo Epicovid-19 Brasil

et al. 2021

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OBJETIVO Descrever a prevalência de doenças crônicas e fatores socioeconômicos e demográficos associados, avaliar os padrões de distanciamento social e a prevalência de anticorpos contra SARS-CoV-2 e sintomas de covid-19 em portadores e não portadores de doenças crônicas. MÉTODOS Foram avaliados dados de 77.075 mil indivíduos de 20 a 59 anos de três etapas do inquérito sorológico de abrangência nacional Epicovid-19 Brasil, realizadas entre maio e junho de 2021. A presença de anticorpos contra SARS-CoV-2 foi avaliada por teste rápido. Foram investigadas as prevalências autorreferidas de hipertensão, diabetes, asma, câncer, doença renal crônica e doença cardíaca. A prevalência de uso de máscara, de adesão a medidas de isolamento e de anticorpos foi avaliada separadamente entre portadores e não portadores de doenças crônicas. A prevalência de sintomas foi avaliada entre doentes crônicos e não doentes portadores de anticorpos. RESULTADOS A prevalência do pelo menos uma doença crônica foi de 43%, maior na região Sudeste, entre indivíduos brancos e indígenas, mulheres, menos escolarizados e em menor posição socioeconômica. O uso de máscara ao sair do domicílio não diferiu entre doentes crônicos e não doentes (98%). A proporção de participantes que referiram adesão ao isolamento foi maior entre doentes crônicos (15,9%) que entre não doentes (24,9%). A prevalência de anticorpos contra SARS-CoV-2 foi semelhante entre doentes crônicos e não doentes (2,4% e 2,3%). A prevalência de tosse, dispneia, palpitações e mialgia foi significativamente maior entre doentes crônicos, mas a proporção de sintomáticos não diferiu entre os grupos. CONCLUSÃO A prevalência de doenças crônicas no país é alta e a pandemia de covid-19 atinge de forma semelhante doentes e não doentes. Doentes crônicos apresentam formas mais graves de covid-19 e maior prevalência de sintomas. A maior adesão às medidas de distanciamento social entre doentes crônicos não se reflete em menor incidência de covid-19 nesse grupo.

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EPICOVID19 protocol: repeated serological surveys on SARS-CoV-2 antibodies in Brazil

Cited by 16 publications

References 6 publications

High prevalence of symptoms among Brazilian subjects with antibodies against SARS-CoV-2: a nationwide household survey

High prevalence of symptoms among Brazilian subjects with antibodies against SARS-CoV-2: a nationwide household survey

Uncovering the Universality of COVID-19 Fatality Rates

Doenças crônicas não transmissíveis e covid-19: resultados do estudo Epicovid-19 Brasil

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