Evaluation of the design of the influenza-like illness sentinel surveillance system in Brazil.

The influenza-like illness (ILI) sentinel surveillance operates in Brazil to identify respiratory viruses of public health relevance circulating in the country and was first implemented in 2000. Recently, the COVID-19 pandemic reinforced the importance of early detection of the circulation of new viruses in Brazil. Therefore, an analysis of the design of the ILI sentinel surveillance is timely. To this end, we simulated a sentinel surveillance network, identifying the municipalities that would be part of the network according to the criteria defined in the design of the ILI sentinel surveillance and, based on data from tested cases of severe acute respiratory illness (SARI) from 2014 to 2019, we drew samples for each sentinel municipality per epidemiological week. The draw was performed 1,000 times, obtaining the median and 95% quantile interval (95%QI) of virus positivity by Federative Unit and epidemiological week. According to the ILI sentinel surveillance design criteria, sentinel units would be in 64 municipalities, distributed mainly in capitals and their metropolitan areas, recommending 690 weekly samples. The design showed good sensitivity (91.65% considering the 95%QI) for qualitatively detecting respiratory viruses, even those with low circulation. However, there was important uncertainty in the quantitative estimate of positivity, reaching at least 20% in 11.34% of estimates. The results presented here aim to assist in evaluating and updating the ILI sentinel surveillance design. Strategies to reduce uncertainty in positivity estimates need to be evaluated, as does the need for greater spatial coverage.

Evaluation of the design of the influenza-like illness sentinel surveillance system in Brazil / Evaluación del diseño de la vigilancia centinela de la enfermedad tipo influenza en Brasil / Avaliação do desenho da vigilância sentinela de síndrome gripal no Brasil

Abstract: The influenza-like illness (ILI) sentinel surveillance operates in Brazil to identify respiratory viruses of public health relevance circulating in the country and was first implemented in 2000. Recently, the COVID-19 pandemic reinforced the importance of early detection of the circulation of new viruses in Brazil. Therefore, an analysis of the design of the ILI sentinel surveillance is timely. To this end, we simulated a sentinel surveillance network, identifying the municipalities that would be part of the network according to the criteria defined in the design of the ILI sentinel surveillance and, based on data from tested cases of severe acute respiratory illness (SARI) from 2014 to 2019, we drew samples for each sentinel municipality per epidemiological week. The draw was performed 1,000 times, obtaining the median and 95% quantile interval (95%QI) of virus positivity by Federative Unit and epidemiological week. According to the ILI sentinel surveillance design criteria, sentinel units would be in 64 municipalities, distributed mainly in capitals and their metropolitan areas, recommending 690 weekly samples. The design showed good sensitivity (91.65% considering the 95%QI) for qualitatively detecting respiratory viruses, even those with low circulation. However, there was important uncertainty in the quantitative estimate of positivity, reaching at least 20% in 11.34% of estimates. The results presented here aim to assist in evaluating and updating the ILI sentinel surveillance design. Strategies to reduce uncertainty in positivity estimates need to be evaluated, as does the need for greater spatial coverage.

Resumen: La vigilancia centinela de la enfermedad tipo infuenza (ETI) funciona en Brasil para identificar los virus respiratorios de importancia para la salud pública que circulan en el país y comenzó a ser implementada en 2000. Recientemente, la pandemia de COVID-19 ha reforzado la importancia de la detección temprana de la circulación de nuevos virus en el territorio brasileño. Así, se hace oportuno un análisis del diseño de la vigilancia centinela de la ETI. Para ello, simulamos una red centinela identificando los municipios que formarían parte de la red según los criterios definidos en el diseño de la vigilancia centinela de la ETI y, a partir de los datos de casos testados de infección respiratoria aguda grave (IRAG) de 2014 a 2019, se extrajeron muestras para cada municipio centinela por semana epidemiológica. El sorteo se repitió 1.000 veces y se obtuvo la mediana y el intervalo cuantílico del 95% (IC95%) de la positividad por virus, por Unidad Federativa y semana epidemiológica. Según los criterios del diseño de la vigilancia centinela de la ETI, unidades centinelas estarían en 64 municipios, distribuidas principalmente en capitales y zonas metropolitanas de las capitales, preconizando 690 muestras semanales. El diseño presentó una buena sensibilidad (total de 91,65% considerando el IC95%) para la detección cualitativa de los virus respiratorios, incluso los de baja circulación. Sin embargo, hubo una importante incertidumbre en la estimación cuantitativa de la positividad, alcanzando al menos el 20% en el 11,34% de las estimaciones. Los resultados presentados aquí tienen como objetivo ayudar en la evaluación y actualización del diseño de la red centinela. Es necesario evaluar las estrategias para reducir la incertidumbre en las estimaciones de positividad, al igual que la necesidad de una mayor cobertura espacial.

Resumo: A vigilância sentinela de síndrome gripal atua no Brasil identificando os vírus respiratórios de importância para a saúde pública circulantes no país, e começou a ser implementada em 2000. Recentemente, a pandemia de COVID-19 reforçou a importância da detecção precoce de novos vírus em circulação no território brasileiro. Assim, se faz oportuna uma análise do desenho da vigilância sentinela de síndrome gripal. Para tal, simulamos uma rede sentinela, identificando os municípios que fariam parte da rede segundo os critérios definidos no desenho da vigilância sentinela de síndrome gripal, e, a partir dos dados de casos testados de síndrome respiratória aguda grave (SRAG) de 2014 a 2019, sorteamos amostras para cada município sentinela por semana epidemiológica. O sorteio foi repetido mil vezes, obtendo-se a mediana e intervalo quantílico de 95% (IQ95%) da positividade para cada vírus por Unidade Federativa e semana epidemiológica. Segundo os critérios do desenho da vigilância sentinela de síndrome gripal, unidades sentinelas estariam em 64 municípios, distribuídas principalmente em capitais e suas zonas metropolitanas, o que preconizou 690 amostras semanais. O desenho apresentou boa sensibilidade (total de 91,65%, considerando o IQ95%) para a detecção qualitativa dos vírus respiratórios, mesmo os de baixa circulação. Porém, houve importante incerteza na estimativa quantitativa de positividade, chegando a, pelo menos, 20% em 11,34% das estimativas. Os resultados aqui apresentados visam auxiliar a avaliação e a atualização do desenho da rede sentinela. Estratégias para reduzir a incerteza nas estimativas de positividade precisam ser avaliadas, assim como a necessidade de maior cobertura espacial.

Description of COVID-19 hospitalized health worker cases in the first nine weeks of the pandemic, Brazil, 2020. / Descrição dos casos hospitalizados pela COVID-19 em profissionais de saúde nas primeiras nove semanas da pandemia, Brasil, 2020.

OBJECTIVE: To describe COVID-19 hospitalized health worker cases in Brazil. METHODS: This was a descriptive case series study; it included cases that became ill between February 21st and April 15th, 2020 registered on the Influenza Surveillance Information System (SIVEP-Gripe, acronym in Portuguese). RESULTS: Of the 184 cases, 110 (59.8%) were female and median age was 44 years (min-max: 23-85); 89 (48.4%) were nursing professionals and 50 (27.2%) were doctors. Ninety-two (50.0%) presented comorbidity, with heart disease predominating (n=37; 40.2%). Of the 112 professionals with a record of case progression, 85 (75.9%) were cured and 27 (24.1%) died, 18 of whom were male. CONCLUSION: The profile of COVID-19 hospitalized health workers is similar to that of the general population with regard to age and comorbidities, but different in relation to sex. The most affected areas were nursing and medicine.

Descrição dos casos hospitalizados pela COVID-19 em profissionais de saúde nas primeiras nove semanas da pandemia, Brasil, 2020 / Descripción de los casos hospitalizados por COVID-19 en profesionales de salud en las primeras nueve semanas de la pandemia, Brasil, 2020 / Description of COVID-19 hospitalized health worker cases in the first nine weeks of the pandemic, Brazil, 2020

Objetivo: Descrever os casos hospitalizados pela COVID-19 em profissionais de saúde no Brasil. Métodos: Estudo descritivo de tipo série de casos; foram incluídos aqueles com adoecimento entre 21 de fevereiro e 15 de abril de 2020, registrados no Sistema de Informação de Vigilância da Gripe (SIVEP-Gripe). Resultados: Dos 184 casos, 110 (59,8%) eram do sexo feminino, com mediana de idade de 44 anos (mínima-máxima: 23-85); 89 (48,4%) eram profissionais da enfermagem e 50 (27,2%) eram médicos. Ainda, 92 (50,0%) apresentavam comorbidade, predominando cardiopatias (n=37; 40,2%). Dos 112 profissionais com registro de evolução, 85 (75,9%) alcançaram cura e 27 (24,1%) foram a óbito, 18 destes do sexo masculino. Conclusão: O perfil dos profissionais de saúde hospitalizados por COVID-19 é semelhante ao da população quanto à idade e comorbidades; porém, diferente quanto ao sexo. As áreas profissionais mais acometidas foram a enfermagem e a medicina.

Objetivo: Describir los casos hospitalizados por COVID-19 en profesionales de salud, en Brasil. Métodos: Estudio descriptivo del tipo serie de casos; se incluyeron aquellos que enfermaron entre el 21 de febrero y el 15 de abril de 2020, registrados en el Sistema de Información de Vigilancia de la Gripe (SIVEP-Gripe). Resultados: De los 184 (1,76%) casos 110 (59,8%) eran del sexo femenino, con promedio de edad de 44 años (mínima-máxima: 23-85), 89 (48,4%) eran profesionales de enfermería y 50 (27,2%) médicos. Además, 92 (50,0%) presentaron comorbilidad, predominando las cardiopatías (n=37; 40,2%). De los 112 profesionales con un historial de evolución, 85 (75,9%) fueron curados y 27 (24,1%) murieron, 18 de los cuales era de sexo masculino. Conclusión: El perfil de los hospitalizados por COVID-19 es similar al de la población en edad y comorbilidades, aunque diferente con relación a sexo. Las áreas más afectadas fueron la enfermería y la medicina.

Objective: To describe COVID-19 hospitalized health worker cases in Brazil. Methods: This was a descriptive case series study; it included cases that became ill between February 21st and April 15th, 2020 registered on the Influenza Surveillance Information System (SIVEP-Gripe, acronym in Portuguese). Results: Of the 184 cases, 110 (59.8%) were female and median age was 44 years (min-max: 23-85); 89 (48.4%) were nursing professionals and 50 (27.2%) were doctors. Ninety-two (50.0%) presented comorbidity, with heart disease predominating (n=37; 40.2%). Of the 112 professionals with a record of case progression, 85 (75.9%) were cured and 27 (24.1%) died, 18 of whom were male. Conclusion: The profile of COVID-19 hospitalized health workers is similar to that of the general population with regard to age and comorbidities, but different in relation to sex. The most affected areas were nursing and medicine.