ABSTRACT OBJECTIVE To estimate the prevalence of SARS-CoV-2 antibodies and the adherence to measures of social distancing in children and adolescents studied in three national surveys conducted in Brazil between May–June 2020. METHODS Three national serological surveys were conducted in 133 sentinel cities located in all 27 Federative Units. Multistage probability sampling was used to select 250 individuals per city. The total sample size in age ranges 0–9 and 10–19 years old are of 4,263 and 8,024 individuals, respectively. Information on children or adolescents was gathered with a data collection app, and a rapid point-of-case test for SARS-CoV-2 was conducted on a finger prick blood sample. RESULTS The adjusted prevalence of antibodies was 2.9% (2.2–3.6) among children 0–9 years, 2.2% (1.8–2.6) among adolescents 10-19 years, and 3.0% (2.7–3.3) among adults 20+years. Prevalence of antibodies was higher among poor children and adolescents compared to those of rich families. Adherence to social distancing measures was seen in 72.4% (71.9–73.8) of families with children, 60.8% (59.6–61.9) for adolescents, and 57.4% (56.9–57.8) for adults. For not leaving the house except for essential matters the proportions were 81.7% (80.5–82.9), 70.6% (69.6–61.9), and 65.1% (64.7–65.5), respectively. Among children and adolescents, social distancing was strongly associated with socioeconomic status, being much higher in the better-off families. CONCLUSIONS The prevalence of antibodies against SARS-CoV-2 showed comparable levels among children, adolescents, and adults. Adherence to social distancing measures was more prevalent in children, followed by adolescents. There were important socioeconomic differences in the adherence to social distancing among children and adolescents.

ABSTRACT OBJECTIVE To estimate the prevalence of SARS-CoV-2 antibodies and the adherence to measures of social distancing in children and adolescents studied in three national surveys conducted in Brazil between May–June 2020. METHODS Three national serological surveys were conducted in 133 sentinel cities located in all 27 Federative Units. Multistage probability sampling was used to select 250 individuals per city. The total sample size in age ranges 0–9 and 10–19 years old are of 4,263 and 8,024 individuals, respectively. Information on children or adolescents was gathered with a data collection app, and a rapid point-of-case test for SARS-CoV-2 was conducted on a finger prick blood sample. RESULTS The adjusted prevalence of antibodies was 2.9% (2.2–3.6) among children 0–9 years, 2.2% (1.8–2.6) among adolescents 10-19 years, and 3.0% (2.7–3.3) among adults 20+years. Prevalence of antibodies was higher among poor children and adolescents compared to those of rich families. Adherence to social distancing measures was seen in 72.4% (71.9–73.8) of families with children, 60.8% (59.6–61.9) for adolescents, and 57.4% (56.9–57.8) for adults. For not leaving the house except for essential matters the proportions were 81.7% (80.5–82.9), 70.6% (69.6–61.9), and 65.1% (64.7–65.5), respectively. Among children and adolescents, social distancing was strongly associated with socioeconomic status, being much higher in the better-off families. CONCLUSIONS The prevalence of antibodies against SARS-CoV-2 showed comparable levels among children, adolescents, and adults. Adherence to social distancing measures was more prevalent in children, followed by adolescents. There were important socioeconomic differences in the adherence to social distancing among children and adolescents.

ABSTRACT OBJECTIVE To describe the evolution of seropositivity in the State of Rio Grande do Sul, Brazil, through 10 consecutive surveys conducted between April 2020 and April 2021. METHODS Nine cities covering all regions of the State were studied, 500 households in each city. One resident in each household was randomly selected for testing. In survey rounds 1–8 we used the rapid WONDFO SARS-CoV-2 Antibody Test (Wondfo Biotech Co., Guangzhou, China). In rounds 9–10, we used a direct ELISA test that identifies IgG to the viral S protein (S-UFRJ). In terms of social distancing, individuals were asked three questions, from which we generated an exposure score using principal components analysis. RESULTS Antibody prevalence in early April 2020 was 0.07%, increasing to 10.0% in February 2021, and to 18.2% in April 2021. In round 10, self-reported whites showed the lowest seroprevalence (17.3%), while indigenous individuals presented the highest (44.4%). Seropositivity increased by 40% when comparing the most with the least exposed. CONCLUSIONS The proportion of the population already infected by SARS-Cov-2 in the state is still far from any perspective of herd immunity and the infection affects population groups in very different levels.

RESUMO OBJETIVO Avaliar prevalência de relato de sintomas característicos de covid-19 entre indivíduos com e sem anticorpos e identificar aqueles com maior capacidade de predição da presença de anticorpos contra o SARS-CoV-2. MÉTODOS O presente estudo usa dados coletados nas fases de 5 a 8 do Epicovid-19-RS. A presença de anticorpos contra o SARS-CoV-2 foi avaliada por um teste rápido. Avaliou-se também a ocorrência dos sintomas tosse, febre, palpitações, dor de garganta, dificuldade para respirar, alterações no paladar e olfato, vômito, diarreia, dor no corpo, tremedeira e dor de cabeça, desde março de 2020. Então, calculou-se a capacidade de predição dos sintomas avaliados em relação a presença de anticorpos. RESULTADOS Nas fases de 5 a 8, 18 mil indivíduos foram entrevistados e 181 apresentaram anticorpos contra covid-19. A proporção de indivíduos assintomáticos foi de 19,9% entre participantes com anticorpos e 49,7% entre aqueles sem anticorpos. Todos os sintomas foram relatados com maior frequência por indivíduos com presença de anticorpos. A divisão da prevalência de sintomas entre indivíduos com anticorpos pela prevalência entre indivíduos sem anticorpos evidenciou as seguintes razões de prevalência: para alterações de olfato ou paladar (9,1), febre (4,2), tremedeira (3,9), dificuldade respiratória (3,2) e tosse (2,8 vezes). Anosmia e febre foram os sintomas com maior capacidade de predizer a presença de anticorpos. CONCLUSÃO A prevalência de sintomas foi maior entre indivíduos com anticorpos contra SARS-CoV-2. A proporção de indivíduos assintomáticos foi baixa. Alteração de olfato ou paladar e febre foram os sintomas que mais predizem a presença de anticorpos. Esses resultados podem auxiliar a identificação de casos prováveis, contribuindo para o diagnóstico clínico e triagem de pacientes para testagem e orientação de isolamento em casos positivos, especialmente em cenários de escassez de testes diagnósticos de covid-19.

ABSTRACT OBJECTIVE To evaluate the prevalence of reports of symptoms of COVID-19 among individuals with and without antibodies and identify those with greater capability to predict the presence of antibodies against SARS-CoV-2. METHODS The study uses data collected in phases 5 to 8 of Epicovid-19-RS. The presence of antibodies against SARS-CoV-2 was evaluated by a rapid test. The occurrence of cough, fever, palpitations, sore throat, difficulty breathing, changes in taste and smell, vomiting, diarrhea, body pain, shaking, and headache since March 2020 was also evaluated. Then, the capability to predict the evaluated symptoms concerning the presence of antibodies was calculated. RESULTS A total of 18,000 individuals were interviewed and 181 had antibodies against COVID-19 in phases 5 to 8. The proportion of asymptomatic individuals was 19.9% among participants with antibodies and 49.7% among those without antibodies. All symptoms were reported more frequently by individuals with antibodies. The division of the prevalence of symptoms among individuals with antibodies by the prevalence among individuals without antibodies showed the following prevalence ratios: for changes in smell or taste (9.1), fever (4.2), tremors (3.9), breathing difficulty (3.2) and cough (2.8 times). Anosmia and fever were the symptoms with a greater capability to predict the presence of antibodies. CONCLUSION The prevalence of symptoms was higher among individuals with antibodies against SARS-CoV-2. The proportion of asymptomatic individuals was low. Altered smell or taste and fever were the symptoms that most predict the presence of antibodies. These results can help to identify probable cases, contributing to the clinical diagnosis and screening of patients for testing and isolation guidance in positive cases, especially in scenarios of the scarcity of diagnostic COVID-19 tests.

ABSTRACT OBJECTIVE To describe the evolution of seropositivity in the State of Rio Grande do Sul, Brazil, through 10 consecutive surveys conducted between April 2020 and April 2021. METHODS Nine cities covering all regions of the State were studied, 500 households in each city. One resident in each household was randomly selected for testing. In survey rounds 1–8 we used the rapid WONDFO SARS-CoV-2 Antibody Test (Wondfo Biotech Co., Guangzhou, China). In rounds 9–10, we used a direct ELISA test that identifies IgG to the viral S protein (S-UFRJ). In terms of social distancing, individuals were asked three questions, from which we generated an exposure score using principal components analysis. RESULTS Antibody prevalence in early April 2020 was 0.07%, increasing to 10.0% in February 2021, and to 18.2% in April 2021. In round 10, self-reported whites showed the lowest seroprevalence (17.3%), while indigenous individuals presented the highest (44.4%). Seropositivity increased by 40% when comparing the most with the least exposed. CONCLUSIONS The proportion of the population already infected by SARS-Cov-2 in the state is still far from any perspective of herd immunity and the infection affects population groups in very different levels.

RESUMO OBJETIVO Avaliar prevalência de relato de sintomas característicos de covid-19 entre indivíduos com e sem anticorpos e identificar aqueles com maior capacidade de predição da presença de anticorpos contra o SARS-CoV-2. MÉTODOS O presente estudo usa dados coletados nas fases de 5 a 8 do Epicovid-19-RS. A presença de anticorpos contra o SARS-CoV-2 foi avaliada por um teste rápido. Avaliou-se também a ocorrência dos sintomas tosse, febre, palpitações, dor de garganta, dificuldade para respirar, alterações no paladar e olfato, vômito, diarreia, dor no corpo, tremedeira e dor de cabeça, desde março de 2020. Então, calculou-se a capacidade de predição dos sintomas avaliados em relação a presença de anticorpos. RESULTADOS Nas fases de 5 a 8, 18 mil indivíduos foram entrevistados e 181 apresentaram anticorpos contra covid-19. A proporção de indivíduos assintomáticos foi de 19,9% entre participantes com anticorpos e 49,7% entre aqueles sem anticorpos. Todos os sintomas foram relatados com maior frequência por indivíduos com presença de anticorpos. A divisão da prevalência de sintomas entre indivíduos com anticorpos pela prevalência entre indivíduos sem anticorpos evidenciou as seguintes razões de prevalência: para alterações de olfato ou paladar (9,1), febre (4,2), tremedeira (3,9), dificuldade respiratória (3,2) e tosse (2,8 vezes). Anosmia e febre foram os sintomas com maior capacidade de predizer a presença de anticorpos. CONCLUSÃO A prevalência de sintomas foi maior entre indivíduos com anticorpos contra SARS-CoV-2. A proporção de indivíduos assintomáticos foi baixa. Alteração de olfato ou paladar e febre foram os sintomas que mais predizem a presença de anticorpos. Esses resultados podem auxiliar a identificação de casos prováveis, contribuindo para o diagnóstico clínico e triagem de pacientes para testagem e orientação de isolamento em casos positivos, especialmente em cenários de escassez de testes diagnósticos de covid-19.

ABSTRACT OBJECTIVE To evaluate the prevalence of reports of symptoms of COVID-19 among individuals with and without antibodies and identify those with greater capability to predict the presence of antibodies against SARS-CoV-2. METHODS The study uses data collected in phases 5 to 8 of Epicovid-19-RS. The presence of antibodies against SARS-CoV-2 was evaluated by a rapid test. The occurrence of cough, fever, palpitations, sore throat, difficulty breathing, changes in taste and smell, vomiting, diarrhea, body pain, shaking, and headache since March 2020 was also evaluated. Then, the capability to predict the evaluated symptoms concerning the presence of antibodies was calculated. RESULTS A total of 18,000 individuals were interviewed and 181 had antibodies against COVID-19 in phases 5 to 8. The proportion of asymptomatic individuals was 19.9% among participants with antibodies and 49.7% among those without antibodies. All symptoms were reported more frequently by individuals with antibodies. The division of the prevalence of symptoms among individuals with antibodies by the prevalence among individuals without antibodies showed the following prevalence ratios: for changes in smell or taste (9.1), fever (4.2), tremors (3.9), breathing difficulty (3.2) and cough (2.8 times). Anosmia and fever were the symptoms with a greater capability to predict the presence of antibodies. CONCLUSION The prevalence of symptoms was higher among individuals with antibodies against SARS-CoV-2. The proportion of asymptomatic individuals was low. Altered smell or taste and fever were the symptoms that most predict the presence of antibodies. These results can help to identify probable cases, contributing to the clinical diagnosis and screening of patients for testing and isolation guidance in positive cases, especially in scenarios of the scarcity of diagnostic COVID-19 tests.

RESUMO 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.

ABSTRACT OBJECTIVE Describing the prevalence of chronic diseases and associated socioeconomic and demographic factors, evaluating the patterns of social distancing and the antibodies prevalence against SARS-CoV-2 and COVID-19 symptoms in carriers and non-carriers of chronic diseases. METHODS Data from 77,075 individuals aged 20 to 59 from three steps of the EPICOVID-19 Brazil (a nationwide serological survey conducted between May and June, 2021) were assessed. The presence of antibodies against SARS-CoV-2 was examined by rapid tests. Self-reported prevalence of hypertension, diabetes, asthma, cancer, chronic kidney disease and heart disease were investigated. The prevalence of mask use, adherence to isolation measures and antibodies were evaluated separately amid carriers and non-carriers of chronic diseases. The prevalence of symptoms was analyzed among carriers and non-carriers of chronic diseases with antibodies. RESULTS The prevalence of at least one chronic disease was 43%, higher in the Southeast region, among white and indigenous individuals, women, less schooled and in lower socioeconomic position. The use of masks when leaving home was similar among carriers and non-carriers of chronic diseases (98%). The proportion of participants who reported adherence to isolation measures was higher amid carriers (15.9%) than non-carriers (24.9%) of chronic diseases. The prevalence of antibodies to SARS-CoV-2 was similar amongst carriers and non-carriers (2.4% and 2.3%). The prevalence of cough, dyspnea, palpitations and myalgia was significantly higher among carriers, but the proportion of symptomatic patients was similar between groups. CONCLUSION The prevalence of chronic diseases in Brazil is high and the COVID-19 pandemic affects carriers and non-carriers of chronic diseases similarly. Carriers present more severe forms of COVID-19 and higher prevalence of symptoms. Greater adherence to social distancing measures among chronic patients is disassociated from a lower incidence of COVID-19 in this group.

RESUMO 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.

ABSTRACT OBJECTIVE Describing the prevalence of chronic diseases and associated socioeconomic and demographic factors, evaluating the patterns of social distancing and the antibodies prevalence against SARS-CoV-2 and COVID-19 symptoms in carriers and non-carriers of chronic diseases. METHODS Data from 77,075 individuals aged 20 to 59 from three steps of the EPICOVID-19 Brazil (a nationwide serological survey conducted between May and June, 2021) were assessed. The presence of antibodies against SARS-CoV-2 was examined by rapid tests. Self-reported prevalence of hypertension, diabetes, asthma, cancer, chronic kidney disease and heart disease were investigated. The prevalence of mask use, adherence to isolation measures and antibodies were evaluated separately amid carriers and non-carriers of chronic diseases. The prevalence of symptoms was analyzed among carriers and non-carriers of chronic diseases with antibodies. RESULTS The prevalence of at least one chronic disease was 43%, higher in the Southeast region, among white and indigenous individuals, women, less schooled and in lower socioeconomic position. The use of masks when leaving home was similar among carriers and non-carriers of chronic diseases (98%). The proportion of participants who reported adherence to isolation measures was higher amid carriers (15.9%) than non-carriers (24.9%) of chronic diseases. The prevalence of antibodies to SARS-CoV-2 was similar amongst carriers and non-carriers (2.4% and 2.3%). The prevalence of cough, dyspnea, palpitations and myalgia was significantly higher among carriers, but the proportion of symptomatic patients was similar between groups. CONCLUSION The prevalence of chronic diseases in Brazil is high and the COVID-19 pandemic affects carriers and non-carriers of chronic diseases similarly. Carriers present more severe forms of COVID-19 and higher prevalence of symptoms. Greater adherence to social distancing measures among chronic patients is disassociated from a lower incidence of COVID-19 in this group.

Resumo A COVID-19 é uma doença produzida pelo vírus SARS-CoV-2. Esse vírus se espalhou rapidamente pelo mundo, o que levou a Organização Mundial da Saúde a classificar a COVID-19 como uma emergência de saúde internacional e, posteriormente, a declará-la uma pandemia. O número de casos confirmados, no dia 11 de abril de 2020, já passa de 1.700.000, porém esses dados não refletem a real prevalência de COVID-19 na população, visto que, em muitos países, os testes são quase que exclusivamente realizados em pessoas com sintomas, especialmente os mais graves. Para definir políticas de enfrentamento, é essencial dispor de dados sobre a prevalência real de infecção na população. Este estudo tem por objetivos avaliar a proporção de indivíduos já infectados pelo SARS-CoV-2 no Rio Grande do Sul, Brasil, analisar a velocidade de expansão da infecção e estimar o percentual de infectados com e sem sintomas. Serão realizados quatro inquéritos sorológicos repetidos a cada 15 dias, com amostragem probabilística de nove cidades sentinela, em todas as sub-regiões do Estado. As entrevistas e testes ocorrerão no âmbito domiciliar. Serão utilizados testes rápidos para detecção de anticorpos, validados previamente ao início da coleta de dados.

Abstract COVID-19, the disease produced by the virus SARS-CoV-2, has spread quickly throughout the world, leading the World Health Organization to first classify it as an international health emergency and, subsequently, declaring it pandemic. The number of confirmed cases, as April 11, surpassed 1,700,000, but this figure does not reflect the prevalence of COVID-19 in the population as, in many countries, tests are almost exclusively performed in people with symptoms, particularly severe cases. To properly assess the magnitude of the problem and to contribute to the design of evidence-based policies for fighting COVID-19, one must accurately estimate the population prevalence of infection. Our study is aimed at estimating the prevalence of infected individuals in the state of Rio Grande do Sul, Brazil, to document how fast the infection spreads, and to estimate the proportion of infected persons who present or presented symptoms, as well as the proportion of asymptomatic infections. Four repeated serological surveys will be conducted in probability samples of nine sentinel cities every two weeks. Tests will be performed in 4,500 participants in each survey, totaling18,000 interviews. Interviews and tests will be conducted at the participants' household. A rapid test for the detection of antibodies will be used; the test was validated prior to the beginning of the fieldwork.

RESUMO OBJETIVO Descrever práticas de distanciamento social em nove municípios do Rio Grande do Sul por sexo, idade, escolaridade e cidade. MÉTODOS Foram realizados dois estudos transversais sequenciais representativos da população urbana nos municípios de Canoas, Caxias do Sul, Ijuí, Passo Fundo, Pelotas, Porto Alegre, Santa Cruz do Sul, Santa Maria e Uruguaiana com o intuito de estimar a prevalência populacional de Covid-19. Foi aplicado questionário contendo três perguntas sobre distanciamento social, cujas práticas foram submetidas a análises descritivas por subgrupos. Os dados foram comparados por testes qui-quadrado. RESULTADOS Em termos de grau de distanciamento social, 25,8% dos entrevistados relataram estar praticamente isolados e 41,1% indicam praticar bastante distanciamento. Relataram ficar em casa o tempo todo 20,1% dos entrevistados, e 44,5% informam que saem apenas para atividades essenciais. Mais da metade dos domicílios não recebe visitas de não moradores. O grupo que relatou menos distanciamento social foi o de adultos entre 20 e 59 anos, enquanto mais de 80% dos entrevistados com 60 anos ou mais relataram estar praticamente isolados ou fazendo bastante distanciamento. As mulheres relataram fazer mais distanciamento que os homens, e os grupos de maior escolaridade foram os que relataram sair diariamente para atividades regulares com mais frequência. CONCLUSÕES Os grupos mais jovens e mais idosos estão mais protegidos pelo distanciamento social, mas há grupos bastante expostos, o que pode ser um limitador importante no controle da progressão da epidemia de Covid-19.

ABSTRACT OBJECTIVE To describe social distancing practices in nine municipalities of the state of Rio Grande do Sul, Brazil, stratified by gender, age, and educational attainment. METHODS Two sequential cross-sectional studies were conducted in the municipalities of Canoas, Caxias do Sul, Ijuí, Passo Fundo, Pelotas, Porto Alegre, Santa Cruz do Sul, Santa Maria, and Uruguaiana to estimate the population prevalence of COVID-19. The study was designed to be representative of the urban population of these municipalities. A questionnaire including three questions about social distancing was also administered to the participants. Here, we present descriptive analyses of social distancing practices by subgroups and use chi-square tests for comparisons. RESULTS In terms of degree of social distancing, 25.8% of the interviewees reported being essentially isolated and 41.1% reported being quite isolated. 20.1% of respondents reported staying at home all the time, while 44.5% left only for essential activities. More than half of households reported receiving no visits from non-residents. Adults aged 20 to 59 reported the least social distancing, while more than 80% of participants aged 60 years or older reported being essentially isolated or quite isolated. Women reported more stringent distancing than men. Groups with higher educational attainment reported going out for daily activities more frequently. CONCLUSIONS The extremes of age are more protected by social distancing, but some groups remain highly exposed. This can be an important limiting factor in controlling progression of the COVID-19 pandemic.

RESUMO OBJETIVO Descrever práticas de distanciamento social em nove municípios do Rio Grande do Sul por sexo, idade, escolaridade e cidade. MÉTODOS Foram realizados dois estudos transversais sequenciais representativos da população urbana nos municípios de Canoas, Caxias do Sul, Ijuí, Passo Fundo, Pelotas, Porto Alegre, Santa Cruz do Sul, Santa Maria e Uruguaiana com o intuito de estimar a prevalência populacional de Covid-19. Foi aplicado questionário contendo três perguntas sobre distanciamento social, cujas práticas foram submetidas a análises descritivas por subgrupos. Os dados foram comparados por testes qui-quadrado. RESULTADOS Em termos de grau de distanciamento social, 25,8% dos entrevistados relataram estar praticamente isolados e 41,1% indicam praticar bastante distanciamento. Relataram ficar em casa o tempo todo 20,1% dos entrevistados, e 44,5% informam que saem apenas para atividades essenciais. Mais da metade dos domicílios não recebe visitas de não moradores. O grupo que relatou menos distanciamento social foi o de adultos entre 20 e 59 anos, enquanto mais de 80% dos entrevistados com 60 anos ou mais relataram estar praticamente isolados ou fazendo bastante distanciamento. As mulheres relataram fazer mais distanciamento que os homens, e os grupos de maior escolaridade foram os que relataram sair diariamente para atividades regulares com mais frequência. CONCLUSÕES Os grupos mais jovens e mais idosos estão mais protegidos pelo distanciamento social, mas há grupos bastante expostos, o que pode ser um limitador importante no controle da progressão da epidemia de Covid-19.

ABSTRACT OBJECTIVE To describe social distancing practices in nine municipalities of the state of Rio Grande do Sul, Brazil, stratified by gender, age, and educational attainment. METHODS Two sequential cross-sectional studies were conducted in the municipalities of Canoas, Caxias do Sul, Ijuí, Passo Fundo, Pelotas, Porto Alegre, Santa Cruz do Sul, Santa Maria, and Uruguaiana to estimate the population prevalence of COVID-19. The study was designed to be representative of the urban population of these municipalities. A questionnaire including three questions about social distancing was also administered to the participants. Here, we present descriptive analyses of social distancing practices by subgroups and use chi-square tests for comparisons. RESULTS In terms of degree of social distancing, 25.8% of the interviewees reported being essentially isolated and 41.1% reported being quite isolated. 20.1% of respondents reported staying at home all the time, while 44.5% left only for essential activities. More than half of households reported receiving no visits from non-residents. Adults aged 20 to 59 reported the least social distancing, while more than 80% of participants aged 60 years or older reported being essentially isolated or quite isolated. Women reported more stringent distancing than men. Groups with higher educational attainment reported going out for daily activities more frequently. CONCLUSIONS The extremes of age are more protected by social distancing, but some groups remain highly exposed. This can be an important limiting factor in controlling progression of the COVID-19 pandemic.

Resumo A COVID-19 é uma doença produzida pelo vírus SARS-CoV-2. Esse vírus se espalhou rapidamente pelo mundo, o que levou a Organização Mundial da Saúde a classificar a COVID-19 como uma emergência de saúde internacional e, posteriormente, a declará-la uma pandemia. O número de casos confirmados, no dia 11 de abril de 2020, já passa de 1.700.000, porém esses dados não refletem a real prevalência de COVID-19 na população, visto que, em muitos países, os testes são quase que exclusivamente realizados em pessoas com sintomas, especialmente os mais graves. Para definir políticas de enfrentamento, é essencial dispor de dados sobre a prevalência real de infecção na população. Este estudo tem por objetivos avaliar a proporção de indivíduos já infectados pelo SARS-CoV-2 no Rio Grande do Sul, Brasil, analisar a velocidade de expansão da infecção e estimar o percentual de infectados com e sem sintomas. Serão realizados quatro inquéritos sorológicos repetidos a cada 15 dias, com amostragem probabilística de nove cidades sentinela, em todas as sub-regiões do Estado. As entrevistas e testes ocorrerão no âmbito domiciliar. Serão utilizados testes rápidos para detecção de anticorpos, validados previamente ao início da coleta de dados.

Abstract COVID-19, the disease produced by the virus SARS-CoV-2, has spread quickly throughout the world, leading the World Health Organization to first classify it as an international health emergency and, subsequently, declaring it pandemic. The number of confirmed cases, as April 11, surpassed 1,700,000, but this figure does not reflect the prevalence of COVID-19 in the population as, in many countries, tests are almost exclusively performed in people with symptoms, particularly severe cases. To properly assess the magnitude of the problem and to contribute to the design of evidence-based policies for fighting COVID-19, one must accurately estimate the population prevalence of infection. Our study is aimed at estimating the prevalence of infected individuals in the state of Rio Grande do Sul, Brazil, to document how fast the infection spreads, and to estimate the proportion of infected persons who present or presented symptoms, as well as the proportion of asymptomatic infections. Four repeated serological surveys will be conducted in probability samples of nine sentinel cities every two weeks. Tests will be performed in 4,500 participants in each survey, totaling18,000 interviews. Interviews and tests will be conducted at the participants' household. A rapid test for the detection of antibodies will be used; the test was validated prior to the beginning of the fieldwork.

RESUMO OBJETIVO Quantificar as despesas domiciliares per capita e estimar o percentual de domicílios brasileiros que gastaram com planos exclusivamente odontológicos. MÉTODOS Foram analisados dados de 55.970 domicílios que participaram da Pesquisa de Orçamentos Familiares em 2008–2009. Os gastos domiciliares anuais per capita com planos exclusivamente odontológicos (empresarial e particular) foram analisados segundo os estados da federação e as características socioeconômicas e demográficas dos domicílios (sexo, idade, cor da pele e escolaridade do chefe do domicílio, renda familiar e presença de idoso no domicílio). RESULTADOS Apenas 2,5% dos domicílios brasileiros relataram gastos com planos exclusivamente odontológicos. O valor per capita despendido somou em média R$5,10, sendo a maior parte composta por planos odontológicos particulares (R$4,70). Entre as caraterísticas do domicílio, maior escolaridade e renda estiveram associadas com maior gasto. São Paulo foi o estado com maior gasto domiciliar per capita (R$10,90) e maior prevalência de domicílios com dispêndios (4,6%), enquanto Amazonas e Tocantins apresentaram os menores valores, ambos com gasto inferior a R$1,00 e com menos de 0,1% de domicílios, respectivamente. CONCLUSÕES Apenas uma pequena parcela dos domicílios brasileiros desembolsa com planos exclusivamente odontológicos. O mercado de odontologia suplementar na assistência em saúde bucal abrange uma restrita parcela da população brasileira.

ABSTRACT OBJECTIVE To quantify the household expenditure per capita and to estimate the percentage of Brazilian households that have spent with dental insurance. METHODS We analyzed data from 55,970 households that participated in the research Pesquisa de Orçamentos Familiares in 2008–2009. We have analyzed the annual household expenditure per capita with dental insurance (business and private) according to the Brazilian states and the socioeconomic and demographic characteristics of the households (sex, age, race, and educational level of the head of the household, family income, and presence of an older adult in the household). RESULTS Only 2.5% of Brazilian households have reported spending on dental insurance. The amount spent per capita amounted to R$5.10 on average, most of which consisted of private dental insurance (R$4.70). Among the characteristics of the household, higher educational level and income were associated with higher spending. São Paulo was the state with the highest household expenditure per capita (R$10.90) and with the highest prevalence of households with expenditures (4.6%), while Amazonas and Tocantins had the lowest values, in which both spent less than R$1.00 and had a prevalence of less than 0.1% of households, respectively. CONCLUSIONS Only a small portion of the Brazilian households has dental insurance expenditure. The market for supplementary dentistry in oral health care covers a restricted portion of the Brazilian population.

RESUMO OBJETIVO Quantificar as despesas domiciliares per capita e estimar o percentual de domicílios brasileiros que gastaram com planos exclusivamente odontológicos. MÉTODOS Foram analisados dados de 55.970 domicílios que participaram da Pesquisa de Orçamentos Familiares em 2008–2009. Os gastos domiciliares anuais per capita com planos exclusivamente odontológicos (empresarial e particular) foram analisados segundo os estados da federação e as características socioeconômicas e demográficas dos domicílios (sexo, idade, cor da pele e escolaridade do chefe do domicílio, renda familiar e presença de idoso no domicílio). RESULTADOS Apenas 2,5% dos domicílios brasileiros relataram gastos com planos exclusivamente odontológicos. O valor per capita despendido somou em média R$5,10, sendo a maior parte composta por planos odontológicos particulares (R$4,70). Entre as caraterísticas do domicílio, maior escolaridade e renda estiveram associadas com maior gasto. São Paulo foi o estado com maior gasto domiciliar per capita (R$10,90) e maior prevalência de domicílios com dispêndios (4,6%), enquanto Amazonas e Tocantins apresentaram os menores valores, ambos com gasto inferior a R$1,00 e com menos de 0,1% de domicílios, respectivamente. CONCLUSÕES Apenas uma pequena parcela dos domicílios brasileiros desembolsa com planos exclusivamente odontológicos. O mercado de odontologia suplementar na assistência em saúde bucal abrange uma restrita parcela da população brasileira.

ABSTRACT OBJECTIVE To quantify the household expenditure per capita and to estimate the percentage of Brazilian households that have spent with dental insurance. METHODS We analyzed data from 55,970 households that participated in the research Pesquisa de Orçamentos Familiares in 2008–2009. We have analyzed the annual household expenditure per capita with dental insurance (business and private) according to the Brazilian states and the socioeconomic and demographic characteristics of the households (sex, age, race, and educational level of the head of the household, family income, and presence of an older adult in the household). RESULTS Only 2.5% of Brazilian households have reported spending on dental insurance. The amount spent per capita amounted to R$5.10 on average, most of which consisted of private dental insurance (R$4.70). Among the characteristics of the household, higher educational level and income were associated with higher spending. São Paulo was the state with the highest household expenditure per capita (R$10.90) and with the highest prevalence of households with expenditures (4.6%), while Amazonas and Tocantins had the lowest values, in which both spent less than R$1.00 and had a prevalence of less than 0.1% of households, respectively. CONCLUSIONS Only a small portion of the Brazilian households has dental insurance expenditure. The market for supplementary dentistry in oral health care covers a restricted portion of the Brazilian population.

RESUMO OBJETIVO Descrever a utilização de unidades básicas de saúde conforme a cobertura por cartão de desconto e plano de saúde. MÉTODOS Inquérito domiciliar na área de abrangência da Estratégia Saúde da Família de Pelotas, RS, entre dezembro de 2007 e fevereiro de 2008, incluindo pessoas de todas as faixas etárias. A frequência de busca por atendimento (médico ou não) nas unidades básicas de saúde nos últimos seis meses e a prevalência do uso das unidades básicas de saúde para a última consulta médica (caso esta tivesse sido realizada até seis meses atrás, e tivesse tido um motivo que não rotina) foram analisadas por regressão de Poisson ajustada para o delineamento amostral. RESULTADOS Das 1.423 pessoas, 75,6% não estavam cobertas por cartão de desconto ou plano de saúde. A frequência média da busca por atendimento (médico ou não) foi de 1,6 vezes em seis meses (IC95% 1,3-2,0); essa frequência foi 55,8% menor (p < 0,001) entre as pessoas cobertas por plano de saúde em comparação às pessoas sem cartão de desconto ou plano de saúde. Dentre as últimas consultas médicas, 35,8% (IC95% 25,4-47,7) tinham sido realizadas nas unidades básicas de saúde; essa prevalência foi 36,4% menor (p = 0,003) entre as pessoas cobertas por cartão de desconto e 87,7% menor (p = 0,007) entre as pessoas cobertas por plano de saúde em comparação às pessoas com ambas as coberturas. CONCLUSÕES A cobertura por plano de saúde e, em menor grau, a cobertura por cartão de desconto associam-se a uma menor utilização das unidades básicas de saúde. Isso pode ser utilizado para dimensionar a população sob a responsabilidade de cada equipe de Estratégia Saúde da Família, na medida em que os agentes comunitários de saúde sejam capazes de diferenciar cartão de desconto e plano de saúde durante o cadastramento das famílias.

ABSTRACT OBJECTIVE To describe the utilization of basic health units according to coverage by discount card or private health insurance. METHODS Household survey in the area covered by Family Health Strategy in Pelotas, state of Rio Grande do Sul, Brazil, from December 2007 to February 2008, with persons of all age groups. The frequency of (medical or non-medical) healthcare seeking at the basic health units in the last six months and the prevalence of basic health unit utilization for the last medical consultation (in case it had been performed up to six months before, for a non-routine reason) were analyzed by Poisson regression adjusted for the sampling design. RESULTS Of the 1,423 persons, 75.6% had no discount card or private health insurance. The average frequency of (medical or non-medical) healthcare seeking was 1.6 times in six months (95%CI 1.3-2.0); this frequency was 55.8% lower (p < 0.001) among privately insured persons compared to those with no discount card or private health insurance. Among the last medical consultations, 35.8% (95%CI 25.4-47.7) had been performed at the basic health units; this prevalence was 36.4% lower (p = 0.003) among persons covered by discount card and 87.7% lower (p = 0.007) among privately insured persons compared to those without both coverages. CONCLUSIONS Private health insurance and, to a lesser degree, discount card coverage, are related to lower utilization of basic health units. This can be used to size the population under the accountability of each Family Health Strategy team, to the extent that community health workers are able to differentiate discount card from PHI during family registration.