Seroprevalence, spatial dispersion and factors associated with flavivirus and chikungunha infection in a risk area: a population-based seroprevalence study in Brazil.

BACKGROUND: The State of Ceará, in Northeastern Brazil, suffers from a triple burden of arboviruses (dengue, Zika and chikungunya). We measured the seroprevalence of chikungunya, dengue and Zika and its associated factors in the population of Juazeiro do Norte, Southern Ceará State, Brazil. METHODS: A cross-sectional study of analytical and spatial analysis was performed to estimate the seroprevalence of dengue, Zika and chikungunya, in the year 2018. Participants were tested for IgM and IgG against these three viruses. Those with IgM and/or IgG positive tests results were considered positive. Poisson regression was used to analyze the factors associated with positive cases, in the same way that the spatial analysis of positive cases was performed to verify whether the cases were grouped. RESULTS: Of the 404 participants, 25.0% (103/404) were positive for CHIKV, 92.0% (373/404) for flavivirus (dengue or Zika) and of these, 37.9% (153/404) samples were classified as probable dengue infection. Of those who reported having had an arbovirus in the past, positive CHIKV cases had 58.7% arthralgia (PR = 4.31; 95% CI: 2.06-9.03; p = 0.000) mainly in the hands, ankles and feet. Age over 60 years had a positive association with cases of flavivirus (PR = 1.29; 95% CI: 1.09-1.54; p = 0.000). Fever, muscle pain, joint pain and skin rash were the most reported symptoms (46.1, 41.0, 38.3 and 28.41%, respectively). The positive cases of chikungunya and dengue or Zika were grouped in space and the city center was most affected area. CONCLUSIONS: Four years after the introduction of CHIKV, where DENV has been in circulation for over 30 years, 1/4 of the population has already been exposed, showing the extent of the epidemic. The measured prevalence was much higher than that reported by local epidemiological surveillance.

Risk analysis for the reintroduction and transmission of measles in the post-elimination period in the Americas.

OBJECTIVE: To propose and test a model for analyzing municipalities' level of risk of reintroduction and transmission of the measles virus in the post-elimination period in the Americas. METHODS: An ecological-analytical study was conducted using data on the measles epidemic that occurred in 2013-2015 in northeastern Brazil. The variables for analysis were selected after an extensive review of scientific literature on the risk of importation of measles cases. A univariate analysis considering the presence or absence of confirmed cases of measles in 184 municipalities in the state of Ceará, Brazil, was carried out to evaluate the association between the dependent variable and 23 independent variables, grouped into four categories: 1) characteristics of the municipalities; 2) quality indicators for immunization programs and epidemiological surveillance; 3) organizational structure for the public health response; and 4) selected impact indicators. A P value < 0.05 was considered significant. All variables with P < 0.200 were analyzed using multivariate logistic regression. Based on the results, the municipalities were categorized by four levels of risk ("low," "medium," "high," and "very high"). RESULTS: The model sensitivity was 95% for concordance between municipalities classified as "high risk" and "very high risk" and those that had an epidemic between 2013 and 2015 in Ceará. Of the 38 municipalities that had an epidemic, 76% (29/38) were classified as "high risk" and "very high risk"; 146 municipalities did not report cases (P < 0.0002). CONCLUSIONS: Given the imminent risk of reintroduction of measles circulation in the post-elimination period in the Americas, this model may be useful in identifying areas at greater risk for reintroduction and continued transmission of measles. Knowledge of vulnerable areas could trigger appropriate surveillance and monitoring to prevent sustained transmission.

The emergence of novel SARS-CoV-2 variant P.1 in Amazonas (Brazil) was temporally associated with a change in the age and sex profile of COVID-19 mortality: A population based ecological study.

BACKGROUND: Since the end of 2020, there has been a great deal of international concern about the variants of SARS-COV-2 B.1.1.7, identified in the United Kingdom; B.1.351 discovered in South Africa and P.1, originating from the Brazilian state of Amazonas. The three variants were associated with an increase in transmissibility and worsening of the epidemiological situation in the places where they expanded. The lineage B.1.1.7 was associated with the increase in case fatality rate in the United Kingdom. There are still no studies on the case fatality rate of the other two variants. The aim of this study was to analyze the mortality profile before and after the emergence of the P.1 strain in the Amazonas state. METHODS: We analyzed data from the Influenza Epidemiological Surveillance Information System, SIVEP-Gripe (Sistema de Informação de Vigilância Epidemiológica da Gripe), comparing two distinct epidemiological periods: during the peak of the first wave, between April and May 2020, and in January 2021 (the second wave), the month in which the new variant came to predominate. We calculated mortality rates, overall case fatality rate and case fatality rate among hospitalized patients; all rates were calculated by age and gender and 95% confidence intervals (95% CI) were determined. FINDINGS: We observed that in the second wave there were a higher incidence and an increase in the proportion of cases of COVID-19 in the younger age groups. There was also an increase in the proportion of women among Severe Acute Respiratory Infection (SARI) cases from 40% (2,709) in the first wave to 47% (2,898) in the second wave and in the proportion of deaths due to COVID-19 between the two periods varying from 34% (1,051) to 47% (1,724), respectively. In addition, the proportion of deaths among people between 20 and 59 years old has increased in both sexes. The case fatality rate among those hospitalized in the population between 20 and 39 years old during the second wave was 2.7 times the rate observed in the first wave (female rate ratio = 2.71; 95% CI: 1.9-3.9], p <0.0001; male rate ratio = 2.70, 95%CI:2.0-3.7), and in the general population the rate ratios were 1.15 (95% CI: 1.1-1.2) in females and 0.78 (95% CI: 0.7-0.8) in males]. INTERPRETATION: Based on this prompt analysis of the epidemiological scenario in the Amazonas state, the observed changes in the pattern of mortality due to COVID-19 between age groups and gender simultaneously with the emergence of the P.1 strain suggest changes in the pathogenicity and virulence profile of this new variant. Further studies are needed to better understanding of SARS-CoV-2 variants profile and their impact for the health population. FUNDING: There was no funding for this study.

Tracking excess deaths associated with the COVID-19 epidemic as an epidemiological surveillance strategy-preliminary results of the evaluation of six Brazilian capitals.

INTRODUCTION: In March 2020, the World Health Organization declared the coronavirus disease (COVID-19) outbreak a pandemic. In Brazil, 110 thousand cases and 5,901 deaths were confirmed by the end of April 2020. The scarcity of laboratory resources, the overload on the service network, and the broad clinical spectrum of the disease make it difficult to document all the deaths due to COVID-19. The aim of this study was to assess the mortality rate in Brazilian capitals with a high incidence of COVID-19. METHODS: We assessed the weekly mortality between epidemiological week 1 and 16 in 2020 and the corresponding period in 2019. We estimated the expected mortality at 95% confidence interval by projecting the mortality in 2019 to the population in 2020, using data from the National Association of Civil Registrars (ARPEN-Brasil). RESULTS: In the five capitals with the highest incidence of COVID-19, we identified excess deaths during the pandemic. The age group above 60 years was severely affected, while 31% of the excess deaths occurred in the age group of 20-59 years. There was a strong correlation (r = 0.94) between excess deaths and the number of deaths confirmed by epidemiological monitoring. The epidemiological surveillance captured only 52% of all mortality associated with the COVID-19 pandemic in the cities examined. CONCLUSIONS: Considering the simplicity of the method and its low cost, we believe that the assessment of excess mortality associated with the COVID-19 pandemic should be used as a complementary tool for regular epidemiological surveillance.

A major chikungunya epidemic with high mortality in northeastern Brazil.

INTRODUCTION: Chikungunya causes fever and severe and persistent joint pain. METHODS: We reported a chikungunya outbreak that occurred in Ceará State, Brazil between 2016 and 2017 with emphasis on epidemiological characterization of cases, high number of deaths, mortality-associated factors, and spatial and temporal spread of the epidemic among municipalities. RESULTS: In November 2015, the first autochthonous cases of chikungunya were confirmed in Ceará, Brazil. In 2016-2017, 195,993 cases were reported, with an incidence of 2,186.5/100,000 inhabitants and 244 confirmed deaths. CONCLUSIONS: Rapid transmission and high mortality rate are serious problems, especially in regions with co-circulating arboviruses.

Is the recent increment in attributable deaths to type-2 diabetes (T2D) associated with the latest chikungunya outbreak in a major epidemic area in Brazil?

INTRODUCTION: Chikungunya virus (CHIKV) can negatively influence outcomes in patients with pre-existing conditions. We investigated the association between the recent CHIKV outbreak and increased type 2 diabetes (T2D)-attributable deaths. METHODS: Monthly averages of T2D-attributable deaths between 2001 and 2016 were determined and compared to the equivalent data for 2017 and the recent CHIKV outbreak. RESULTS: CHKV outbreak peaked in April 2017 with 4,394.4 cases/100,000 inhabitants, while T2D-attributable deaths in the same period increased by 35.2%. CONCLUSIONS: T2D-attributable deaths significantly increased compared to the previous data, which overlapped with CHIKV incidence. The pathophysiology of this association warrants further investigations.

Vaccination strategies and results for tackling the measles outbreak in Ceará State, Brazil, 2013-2015. / Estratégias e resultados da vacinação no enfrentamento da epidemia de sarampo no estado do Ceará, 2013-2015.

This study describes the experience and results of the vaccination strategies developed for tackling the measles outbreak in Ceará State, Brazil, from December 2013 to September 2015. Strategies of routine vaccination, community immunity, and vaccination campaigns were conducted, along with searching of unvaccinated people, through rapid monitoring of immunization coverage and scanning. To describe the results, primary data collected in field activities and secondary data on vaccination in a population aged from six months to 49 years, available at the Information System of the National Immunization Program (IS-NIP), were used. The immunization coverage achieved was of >95%. However, this coverage is only administrative and may not represent reality, hence the importance of implementing the nominal information system of the National Immunization Program.

O presente relato descreve a experiência e os resultados das estratégias de vacinação desenvolvidas no enfrentamento da epidemia de sarampo no estado do Ceará, no período de dezembro de 2013 a setembro de 2015. Foram realizadas as estratégias de vacinação de rotina, bloqueio vacinal, campanhas de vacinação, além do resgate de não vacinados a partir do monitoramento rápido de coberturas vacinais e varredura. Para descrição dos resultados, foram utilizados dados primários coletados durante as atividades de campo e dados secundários sobre vacinação na população de seis meses a 49 anos de idade, registrados no Sistema de Informações do Programa Nacional de Imunizações (SI-PNI). Foi alcançada cobertura vacinal >95%. Contudo, cumpre destacar que essa cobertura é apenas administrativa e pode não representar a realidade, sendo necessária a implementação do sistema de informação nominal do Programa Nacional de Imunizações.

El presente relato describe la experiencia y los resultados de las estrategias de vacunación desarrolladas en el enfrentamiento de la epidemia de sarampión en el Estado de Ceará, Brasil, de diciembre de 2013 a septiembre de 2015. Se realizaron las estrategias de vacunación de rutina, bloqueo de vacunación, campañas de vacunación, además del rescate de no vacunados a partir del monitoreo rápido de coberturas de vacunas y barreduras. Para descripción de los resultados, se utilizaron datos primarios recogidos en las actividades de campo y datos secundarios sobre vacunación en la población de seis meses a 49 años de edad, disponibles en el Sistema de Información del Programa Nacional de Inmunizaciones. La cobertura de vacunas alcanzada (>95%) es sólo administrativa y puede no representar la realidad, siendo necesaria la implementación del sistema de información nominal del Programa Nacional de Inmunizaciones.

Measles epidemic in Brazil in the post-elimination period: Coordinated response and containment strategies.

The measles virus circulation was halted in Brazil in 2001 and the country has a routine vaccination coverage against measles, mumps and rubella higher than 95%. In Ceará, the last confirmed case was in 1999. This article describes the strategies adopted and the effectiveness of surveillance and control measures implemented during a measles epidemic in the post-elimination period. The epidemic started in December 2013 and lasted 20 months, reaching 38 cities and 1,052 confirmed cases. The D8 genotype was identified. More than 50,000 samples were tested for measles and 86.4% of the confirmed cases had a laboratory diagnosis. The beginning of an campaign vaccination was delayed in part by the availability of vaccine. The classic control measures were not enough to control the epidemic. The creation of a committee of experts, the agreement signed between managers of the three spheres of government, the conducting of an institutional active search of suspected cases, vaccination door to door at alternative times, the use of micro planning, a broad advertising campaign at local media and technical operative support contributed to containing the epidemic. It is important to recognize the possibility of epidemics at this stage of post-elimination and prepare a sensitive surveillance system for timely response.

Tracking excess deaths associated with the COVID-19 epidemic as an epidemiological surveillance strategy-preliminary results of the evaluation of six Brazilian capitals

Abstract INTRODUCTION: In March 2020, the World Health Organization declared the coronavirus disease (COVID-19) outbreak a pandemic. In Brazil, 110 thousand cases and 5,901 deaths were confirmed by the end of April 2020. The scarcity of laboratory resources, the overload on the service network, and the broad clinical spectrum of the disease make it difficult to document all the deaths due to COVID-19. The aim of this study was to assess the mortality rate in Brazilian capitals with a high incidence of COVID-19. METHODS: We assessed the weekly mortality between epidemiological week 1 and 16 in 2020 and the corresponding period in 2019. We estimated the expected mortality at 95% confidence interval by projecting the mortality in 2019 to the population in 2020, using data from the National Association of Civil Registrars (ARPEN-Brasil). RESULTS: In the five capitals with the highest incidence of COVID-19, we identified excess deaths during the pandemic. The age group above 60 years was severely affected, while 31% of the excess deaths occurred in the age group of 20-59 years. There was a strong correlation (r = 0.94) between excess deaths and the number of deaths confirmed by epidemiological monitoring. The epidemiological surveillance captured only 52% of all mortality associated with the COVID-19 pandemic in the cities examined. CONCLUSIONS: Considering the simplicity of the method and its low cost, we believe that the assessment of excess mortality associated with the COVID-19 pandemic should be used as a complementary tool for regular epidemiological surveillance.

A major chikungunya epidemic with high mortality in northeastern Brazil

Abstract INTRODUCTION Chikungunya causes fever and severe and persistent joint pain. METHODS We reported a chikungunya outbreak that occurred in Ceará State, Brazil between 2016 and 2017 with emphasis on epidemiological characterization of cases, high number of deaths, mortality-associated factors, and spatial and temporal spread of the epidemic among municipalities. RESULTS: In November 2015, the first autochthonous cases of chikungunya were confirmed in Ceará, Brazil. In 2016-2017, 195,993 cases were reported, with an incidence of 2,186.5/100,000 inhabitants and 244 confirmed deaths. CONCLUSIONS: Rapid transmission and high mortality rate are serious problems, especially in regions with co-circulating arboviruses.

Is the recent increment in attributable deaths to type-2 diabetes (T2D) associated with the latest chikungunya outbreak in a major epidemic area in Brazil?

Abstract INTRODUCTION: Chikungunya virus (CHIKV) can negatively influence outcomes in patients with pre-existing conditions. We investigated the association between the recent CHIKV outbreak and increased type 2 diabetes (T2D)-attributable deaths. METHODS: Monthly averages of T2D-attributable deaths between 2001 and 2016 were determined and compared to the equivalent data for 2017 and the recent CHIKV outbreak. RESULTS: CHKV outbreak peaked in April 2017 with 4,394.4 cases/100,000 inhabitants, while T2D-attributable deaths in the same period increased by 35.2%. CONCLUSIONS: T2D-attributable deaths significantly increased compared to the previous data, which overlapped with CHIKV incidence. The pathophysiology of this association warrants further investigations.

Pandemic influenza A (H1N1) 2009: epidemiological analysis of cases in a tropical/semi-arid region of Brazil.

INTRODUCTION: The year 2009 marked the beginning of a pandemic caused by a new variant of influenza A (H1N1). After spreading through North America, the pandemic influenza virus (H1N1) 2009 spread rapidly throughout the world. The aim of this study was to describe the clinical and epidemiological characteristics of cases of pandemic influenza in a tropical/semi-arid region of Brazil. METHODS: A retrospective study analyzed all suspected cases of pandemic influenza (H1N1) 2009 reported in the Ceará State through the National Information System for Notifiable Diseases during the pandemic period between 28 April, 2009 and November 25, 2010. RESULTS: A total of 616 suspected cases were notified, 58 (9.4%) in the containment phase and 558 (90.6%) in the mitigation phase. Most cases were of affected young people resident in the City of Fortaleza, the largest urban center in the State of Ceará. The most frequent symptoms presented by the cases with confirmed infection were fever, cough, myalgia, arthralgia, and nasal congestion. Mortality rate was 0.0009/1,000 inhabitants and lethality was 5.6%. Deaths were observed only in the mitigation phase. Mortality rates were similar for both sexes but were higher in the age group under 5 years. CONCLUSIONS: The study suggests that the influenza A (H1N1) pandemic in this tropical/semi-arid region had a lower magnitude when compared to states in the Southern and Southeastern regions of Brazil.

Estratégias e resultados da vacinação no enfrentamento da epidemia de sarampo no estado do Ceará, 2013-2015 / Estrategias y resultados de vacunación contra el brote de sarampión en el Estado de Ceará, Brasil, 2013-2015 / Vaccination strategies and results for tackling the measles outbreak in Ceará State, Brazil, 2013-2015

RESUMO O presente relato descreve a experiência e os resultados das estratégias de vacinação desenvolvidas no enfrentamento da epidemia de sarampo no estado do Ceará, no período de dezembro de 2013 a setembro de 2015. Foram realizadas as estratégias de vacinação de rotina, bloqueio vacinal, campanhas de vacinação, além do resgate de não vacinados a partir do monitoramento rápido de coberturas vacinais e varredura. Para descrição dos resultados, foram utilizados dados primários coletados durante as atividades de campo e dados secundários sobre vacinação na população de seis meses a 49 anos de idade, registrados no Sistema de Informações do Programa Nacional de Imunizações (SI-PNI). Foi alcançada cobertura vacinal >95%. Contudo, cumpre destacar que essa cobertura é apenas administrativa e pode não representar a realidade, sendo necessária a implementação do sistema de informação nominal do Programa Nacional de Imunizações.

RESUMEN El presente relato describe la experiencia y los resultados de las estrategias de vacunación desarrolladas en el enfrentamiento de la epidemia de sarampión en el Estado de Ceará, Brasil, de diciembre de 2013 a septiembre de 2015. Se realizaron las estrategias de vacunación de rutina, bloqueo de vacunación, campañas de vacunación, además del rescate de no vacunados a partir del monitoreo rápido de coberturas de vacunas y barreduras. Para descripción de los resultados, se utilizaron datos primarios recogidos en las actividades de campo y datos secundarios sobre vacunación en la población de seis meses a 49 años de edad, disponibles en el Sistema de Información del Programa Nacional de Inmunizaciones. La cobertura de vacunas alcanzada (>95%) es sólo administrativa y puede no representar la realidad, siendo necesaria la implementación del sistema de información nominal del Programa Nacional de Inmunizaciones.

ABSTRACT This study describes the experience and results of the vaccination strategies developed for tackling the measles outbreak in Ceará State, Brazil, from December 2013 to September 2015. Strategies of routine vaccination, community immunity, and vaccination campaigns were conducted, along with searching of unvaccinated people, through rapid monitoring of immunization coverage and scanning. To describe the results, primary data collected in field activities and secondary data on vaccination in a population aged from six months to 49 years, available at the Information System of the National Immunization Program (IS-NIP), were used. The immunization coverage achieved was of >95%. However, this coverage is only administrative and may not represent reality, hence the importance of implementing the nominal information system of the National Immunization Program.

Risk analysis for the reintroduction and transmission of measles in the post-elimination period in the Americas / Análisis del riesgo de reintroducción y transmisión del sarampión durante el período posterior a la eliminación en la Región de las Américas / Análise do risco de reintrodução e transmissão do sarampo no período pós-eliminação nas Américas

ABSTRACT Objective To propose and test a model for analyzing municipalities' level of risk of reintroduction and transmission of the measles virus in the post-elimination period in the Americas. Methods An ecological-analytical study was conducted using data on the measles epidemic that occurred in 2013-2015 in northeastern Brazil. The variables for analysis were selected after an extensive review of scientific literature on the risk of importation of measles cases. A univariate analysis considering the presence or absence of confirmed cases of measles in 184 municipalities in the state of Ceará, Brazil, was carried out to evaluate the association between the dependent variable and 23 independent variables, grouped into four categories: 1) characteristics of the municipalities; 2) quality indicators for immunization programs and epidemiological surveillance; 3) organizational structure for the public health response; and 4) selected impact indicators. A P value < 0.05 was considered significant. All variables with P < 0.200 were analyzed using multivariate logistic regression. Based on the results, the municipalities were categorized by four levels of risk ("low," "medium," "high," and "very high"). Results The model sensitivity was 95% for concordance between municipalities classified as "high risk" and "very high risk" and those that had an epidemic between 2013 and 2015 in Ceará. Of the 38 municipalities that had an epidemic, 76% (29/38) were classified as "high risk" and "very high risk"; 146 municipalities did not report cases (P < 0.0002). Conclusions Given the imminent risk of reintroduction of measles circulation in the post-elimination period in the Americas, this model may be useful in identifying areas at greater risk for reintroduction and continued transmission of measles. Knowledge of vulnerable areas could trigger appropriate surveillance and monitoring to prevent sustained transmission.

RESUMEN Objetivo Proponer y poner a prueba un modelo para analizar el nivel de riesgo de reintroducción y transmisión del virus del sarampión que existe en los municipios durante el período posterior a la eliminación en la Región de las Américas. Métodos Se realizó un estudio ecológico y analítico empleando datos sobre la epidemia de sarampión que afectó al noreste del Brasil del 2013 al 2015. Las variables para el análisis se seleccionaron después de efectuar un amplio examen de las publicaciones científicas sobre el riesgo de importación de casos de sarampión. Se llevó a cabo un análisis con una sola variable considerando la presencia o ausencia de los casos de sarampión confirmados en 184 municipios del estado de Ceará (Brasil) para evaluar la asociación entre la variable dependiente y 23 variables independientes, que se agruparon en cuatro categorías: 1) características de los municipios; 2) indicadores de calidad de los programas de vacunación y la vigilancia epidemiológica; 3) estructura de organización de la respuesta de salud pública, y 4) indicadores del impacto seleccionados. Se consideró significativo un valor de P < 0,05. Todas las variables con un valor P < 0,200 se analizaron empleando una regresión logística con varias variables. Teniendo en cuenta los resultados, los municipios se clasificaron en función de cuatro niveles de riesgo ("bajo", "medio", "alto" y "muy alto"). Resultados El modelo tenía una sensibilidad de 95% en el caso de la concordancia entre los municipios clasificados dentro de las categorías de "riesgo alto" y "riesgo muy alto" y los que tuvieron una epidemia entre el 2013 y el 2015 en Ceará. De los 38 municipios que tuvieron una epidemia, 76% (29/38) se clasificaron dentro de las categorías de "riesgo alto" y "riesgo muy alto"; 146 municipios no notificaron casos (P < 0,0002). Conclusiones Dado el riesgo inminente de reintroducción de la circulación del sarampión durante el período posterior a la eliminación en la Región de las Américas, este modelo puede ser útil para reconocer las zonas en las que existe un mayor riesgo de reintroducción y transmisión continua del sarampión. El conocimiento de las zonas vulnerables podría desembocar en actividades de vigilancia y seguimiento apropiadas para evitar la transmisión sostenida.

RESUMO Objetivo Elaborar e testar um modelo para analisar o risco de reintrodução e transmissão do vírus do sarampo ao nível municipal no período pós-eliminação nas Américas. Métodos Um estudo analítico-ecológico foi realizado com base nos dados da epidemia de sarampo ocorrida em 2013-2015 no nordeste do Brasil. As variáveis para análise foram selecionadas após extensa revisão da literatura científica sobre o risco de importação de casos de sarampo. Uma análise univariada considerando a presença ou a ausência de casos confirmados de sarampo em 184 municípios no Estado do Ceará foi conduzida para avaliar a associação entre a variável dependente e 23 variáveis independentes divididas em quatro grupos: 1) características dos municípios, 2) indicadores de qualidade dos programas de vacinação e da vigilância epidemiológica, 3) estrutura organizacional para resposta em saúde pública e 4) indicadores de impacto selecionados. Um nível de significância de 5% foi definido. Todas as variáveis com P < 0,200 foram analisadas por regressão logística multivariada e, segundo os resultados, os municípios foram categorizados em quatro níveis de risco: baixo, intermediário, alto e muito alto. Resultados A sensibilidade do modelo foi de 95% para concordância entre os municípios categorizados como "risco alto" e "risco muito alto" e os que registraram a ocorrência de epidemia entre 2013 e 2015 no Ceará. Dos 38 municípios onde ocorreu uma epidemia, 76% (29/38) apresentaram "risco alto" e "risco muito alto" de reintrodução e transmissão do vírus do sarampo e 146 municípios não notificaram casos (P < 0,0002). Conclusão Diante do risco iminente de reintrodução da circulação do vírus do sarampo no período pós-eliminação nas Américas, este modelo pode servir para identificar as áreas de maior risco de reintrodução e transmissão contínua do vírus do sarampo. Conhecer as áreas vulneráveis incentiva a adoção de procedimentos adequados de vigilância e monitoramento a fim de prevenir a transmissão sustentada.

Risk analysis for the reintroduction and transmission of measles in the post-elimination period in the Americas

[ABSTRACT]. Objective. To propose and test a model for analyzing municipalities’ level of risk of reintroduction and transmission of the measles virus in the post-elimination period in the Americas. Methods. An ecological-analytical study was conducted using data on the measles epidemic that occurred in 2013–2015 in northeastern Brazil. The variables for analysis were selected after an extensive review of scientific literature on the risk of importation of measles cases. A univariate analysis considering the presence or absence of confirmed cases of measles in 184 municipalities in the state of Ceará, Brazil, was carried out to evaluate the association between the dependent variable and 23 independent variables, grouped into four categories: 1) characteristics of the municipalities; 2) quality indicators for immunization programs and epidemiological surveillance; 3) organizational structure for the public health response; and 4) selected impact indicators. A P value < 0.05 was considered significant. All variables with P < 0.200 were analyzed using multivariate logistic regression. Based on the results, the municipalities were categorized by four levels of risk (“low,” “medium,” “high,” and “very high”). Results. The model sensitivity was 95% for concordance between municipalities classified as “high risk” and “very high risk” and those that had an epidemic between 2013 and 2015 in Ceará. Of the 38 municipalities that had an epidemic, 76% (29/38) were classified as “high risk” and “very high risk”; 146 municipalities did not report cases (P < 0.0002). Conclusions. Given the imminent risk of reintroduction of measles circulation in the post-elimination period in the Americas, this model may be useful in identifying areas at greater risk for reintroduction and continued transmission of measles. Knowledge of vulnerable areas could trigger appropriate surveillance and monitoring to prevent sustained transmission.

[RESUMEN]. Objetivo. Proponer y poner a prueba un modelo para analizar el nivel de riesgo de reintroducción y transmisión del virus del sarampión que existe en los municipios durante el período posterior a la eliminación en la Región de las Américas. Métodos. Se realizó un estudio ecológico y analítico empleando datos sobre la epidemia de sarampión que afectó al noreste del Brasil del 2013 al 2015. Las variables para el análisis se seleccionaron después de efectuar un amplio examen de las publicaciones científicas sobre el riesgo de importación de casos de sarampión. Se llevó a cabo un análisis con una sola variable considerando la presencia o ausencia de los casos de sarampión confirmados en 184 municipios del estado de Ceará (Brasil) para evaluar la asociación entre la variable dependiente y 23 variables independientes, que se agruparon en cuatro categorías: 1) características de los municipios; 2) indicadores de calidad de los programas de vacunación y la vigilancia epidemiológica; 3) estructura de organización de la respuesta de salud pública, y 4) indicadores del impacto seleccionados. Se consideró significativo un valor de P < 0,05. Todas las variables con un valor P < 0,200 se analizaron empleando una regresión logística con varias variables. Teniendo en cuenta los resultados, los municipios se clasificaron en función de cuatro niveles de riesgo (“bajo”, “medio”, “alto” y “muy alto”). Resultados. El modelo tenía una sensibilidad de 95% en el caso de la concordancia entre los municipios clasificados dentro de las categorías de “riesgo alto” y “riesgo muy alto” y los que tuvieron una epidemia entre el 2013 y el 2015 en Ceará. De los 38 municipios que tuvieron una epidemia, 76% (29/38) se clasificaron dentro de las categorías de “riesgo alto” y “riesgo muy alto”; 146 municipios no notificaron casos (P < 0,0002). Conclusiones. Dado el riesgo inminente de reintroducción de la circulación del sarampión durante el período posterior a la eliminación en la Región de las Américas, este modelo puede ser útil para reconocer las zonas en las que existe un mayor riesgo de reintroducción y transmisión continua del sarampión. El conocimiento de las zonas vulnerables podría desembocar en actividades de vigilancia y seguimiento apropiadas para evitar la transmisión sostenida.

[RESUMO]. Objetivo. Elaborar e testar um modelo para analisar o risco de reintrodução e transmissão do vírus do sarampo ao nível municipal no período pós-eliminação nas Américas. Métodos. Um estudo analítico-ecológico foi realizado com base nos dados da epidemia de sarampo ocorrida em 2013–2015 no nordeste do Brasil. As variáveis para análise foram selecionadas após extensa revisão da literatura científica sobre o risco de importação de casos de sarampo. Uma análise univariada considerando a presença ou a ausência de casos confirmados de sarampo em 184 municípios no Estado do Ceará foi conduzida para avaliar a associação entre a variável dependente e 23 variáveis independentes divididas em quatro grupos: 1) características dos municípios, 2) indicadores de qualidade dos programas de vacinação e da vigilância epidemiológica, 3) estrutura organizacional para resposta em saúde pública e 4) indicadores de impacto selecionados. Um nível de significância de 5% foi definido. Todas as variáveis com P < 0,200 foram analisadas por regressão logística multivariada e, segundo os resultados, os municípios foram categorizados em quatro níveis de risco: baixo, intermediário, alto e muito alto. Resultados. A sensibilidade do modelo foi de 95% para concordância entre os municípios categorizados como “risco alto” e “risco muito alto” e os que registraram a ocorrência de epidemia entre 2013 e 2015 no Ceará. Dos 38 municípios onde ocorreu uma epidemia, 76% (29/38) apresentaram “risco alto” e “risco muito alto” de reintrodução e transmissão do vírus do sarampo e 146 municípios não notificaram casos (P < 0,0002). Conclusão. Diante do risco iminente de reintrodução da circulação do vírus do sarampo no período pós-eliminação nas Américas, este modelo pode servir para identificar as áreas de maior risco de reintrodução e transmissão contínua do vírus do sarampo. Conhecer as áreas vulneráveis incentiva a adoção de procedimentos adequados de vigilância e monitoramento a fim de prevenir a transmissão sustentada

Pandemic influenza A (H1N1) 2009: epidemiological analysis of cases in a tropical/semi-arid region of Brazil

Introduction The year 2009 marked the beginning of a pandemic caused by a new variant of influenza A (H1N1). After spreading through North America, the pandemic influenza virus (H1N1) 2009 spread rapidly throughout the world. The aim of this study was to describe the clinical and epidemiological characteristics of cases of pandemic influenza in a tropical/semi-arid region of Brazil. Methods A retrospective study analyzed all suspected cases of pandemic influenza (H1N1) 2009 reported in the Ceará State through the National Information System for Notifiable Diseases during the pandemic period between 28 April, 2009 and November 25, 2010. Results A total of 616 suspected cases were notified, 58 (9.4%) in the containment phase and 558 (90.6%) in the mitigation phase. Most cases were of affected young people resident in the City of Fortaleza, the largest urban center in the State of Ceará. The most frequent symptoms presented by the cases with confirmed infection were fever, cough, myalgia, arthralgia, and nasal congestion. Mortality rate was 0.0009/1,000 inhabitants and lethality was 5.6%. Deaths were observed only in the mitigation phase. Mortality rates were similar for both sexes but were higher in the age group under 5 years. Conclusions The study suggests that the influenza A (H1N1) pandemic in this tropical/semi-arid region had a lower magnitude when compared to states in the Southern and Southeastern regions of Brazil. .