Public health responses during measles outbreaks in elimination settings: Strategies and challenges.

In late September 2016, the Americas became the first region in the world to have eliminated endemic transmission of measles virus. Several other countries have also verified measles elimination, and countries in all six World Health Organization regions have adopted measles elimination goals. The public health strategies used to respond to measles outbreaks in elimination settings are thus becoming relevant to more countries. This review highlights the strategies used to limit measles spread in elimination settings: (1) assembly of an outbreak control committee; (2) isolation of measles cases while infectious; (3) exclusion and quarantining of individuals without evidence of immunity; (4) vaccination of susceptible individuals; (5) use of immunoglobulin to prevent measles in exposed susceptible high-risk persons; (6) and maintaining laboratory proficiency for confirmation of measles. Deciding on the extent of containment efforts should be based on the expected benefit of reactive interventions, balanced against the logistical challenges in implementing them.

MMR2 vaccination coverage and timeliness among children born in 2004 – 2009: a national survey in Saint Lucia, 2015

[ABSTRACT]. Objectives. To more accurately determine coverage and timeliness of the second dose of measles-mumps-rubella vaccine (MMR2), while identifying factors associated with low MMR2 vaccination uptake among children in Saint Lucia. Methods. A survey was conducted in October – November 2015 targeting children born in 2004 – 2009. At 86 preschools and primary schools, two children from each grade were randomly selected, yielding an effective sample of 836 children. Health records were reviewed to assess vaccination coverage and timeliness. Parents and/or guardians and principals of all 86 schools were interviewed regarding knowledge, attitudes, and practices related to vaccination. Results. Of 767 children included, 75% were vaccinated with MMR2 (n = 572); 46.7% were vaccinated in a timely manner, i.e., by 5 years of age. Cohorts born in 2004, 2005, and 2008 reported the lowest proportion. ‘Mothers as caregivers’ was positively associated with timely MMR2 vaccination. Although 97% of principals surveyed considered vaccination important, 48.8% were not aware of national legislation requiring complete vaccination prior to school entry. Survey results concurred with the low MMR2 administrative coverage rates reported by Saint Lucia, much lower than the recommended 95%. Conclusions. Based on the results of this survey, Saint Lucia’s national immunization program has lowered the age of MMR2 to 18 months in 2016, increased advocacy with schools to enforce the school-entry law, and is working to vaccinate the cohorts of children who have not received timely MMR2.

[RESUMEN]. Objetivos. Determinar con mayor precisión la cobertura y el respeto de los plazos de vacunación de la segunda dosis de la vacuna contra el sarampión, la rubéola y la parotiditis (triple viral), al tiempo que se detectan los factores asociados con la baja aceptación de esa vacuna en Santa Lucía. Métodos. En octubre y noviembre del 2015 se llevó a cabo una encuesta centrada en niños nacidos entre el 2004 y el 2009. En 86 centros preescolares y primarios se seleccionó al azar a dos niños de cada grado, lo que arrojó un tamaño real de la muestra de 836 niños. Se analizaron los registros de salud para evaluar la cobertura y el respeto de los plazos de vacunación. Se entrevistó a los padres o tutores y los directores de las 86 escuelas sobre conocimientos, actitudes y prácticas en materia de vacunación. Resultados. De los 767 niños incluidos, el 75% fueron vacunados con la segunda dosis de la triple viral (n = 572); el 46,7% fueron vacunados a tiempo, es decir, a los 5 años de edad. La proporción más baja se dio en las cohortes nacidas en el 2004, 2005 y 2008. Se observó que las madres cuidadoras influían positivamente en el respeto de los plazos de vacunación de la segunda dosis de la triple viral. Aunque el 97% de los directores encuestados consideraba que la vacunación era importante, el 48,8% desconocía la legislación nacional que exige la vacunación completa antes de ingresar a la escuela. Los resultados de la encuesta estaban en consonancia con las tasas bajas de cobertura administrativa de la segunda dosis de la triple viral informadas por Santa Lucía, muy por debajo del 95% recomendado. Conclusiones. Según los resultados de esta encuesta, el programa nacional de vacunación de Santa Lucía redujo la edad de la segunda dosis de la triple viral a los 18 meses en el 2016, aumentó las actividades de promoción en las escuelas para fomentar el cumplimiento de la ley que obliga a recibir la vacunación antes de ingresar a la escuela y está trabajando para vacunar a las cohortes de niños que no recibieron la segunda dosis de la triple viral en su debido momento.

[RESUMO]. Objetivos. Determinar com precisão a cobertura vacinal e o momento oportuno para ministrar a segunda dose da vacina tríplice viral (sarampo, caxumba e rubéola – SCR) e identificar os fatores associados à baixa utilização da vacina em crianças. Métodos. Uma pesquisa direcionada a crianças nascidas de 2004 a 2009 foi realizada em Santa Lúcia em outubro e novembro de 2015. Em 86 unidades de ensino infantil e fundamental, duas crianças de cada série foram selecionadas aleatoriamente, constituindo uma amostra efetiva de 836 crianças. Dados sobre a cobertura e o momento oportuno de vacinação foram obtidos das fichas de saúde. Foram conduzidas entrevistas com os pais e/ou responsáveis e os diretores das 86 escolas sobre conhecimento, atitudes e práticas relacionadas à vacinação. Resultados. Das 767 crianças incluídas na amostra, 75% foram vacinadas com a segunda dose de SCR (n = 572) e 46,7% receberam a vacina no momento oportuno (ou seja, até os 5 anos de idade). Observou-se menor proporção de vacinados nas coortes nascidas em 2004, 2005 e 2008. ‘’Mães como cuidadoras’’ teve uma associação positiva com ministrar a segunda dose de SCR no momento oportuno. Apesar de 97% dos diretores entrevistados considerarem a vacinação importante, 48,8% desconheciam a legislação nacional que exige vacinação completa para a matrícula escolar. Os resultados reforçaram a baixa cobertura vacinal da segunda dose de SCR registrada em Santa Lúcia, bem inferior ao índice recomendado de 95%. Conclusões. A partir dos resultados desta pesquisa, em 2016, o programa nacional de vacinação de Santa Lúcia reduziu para 18 meses a idade de administração da segunda dose de SCR, intensificou a recomendação para que as escolas cumpram com a legislação para matrícula escolar e está empenhado em vacinar as coortes de crianças que não receberam a segunda dose de SCR no momento oportuno.

Enhancing global vaccine pharmacovigilance: Proof-of-concept study on aseptic meningitis and immune thrombocytopenic purpura following measles-mumps containing vaccination.

New vaccines designed to prevent diseases endemic in low and middle-income countries (LMICs) are now being introduced without prior record of utilization in countries with robust pharmacovigilance systems. To address this deficit, our objective was to demonstrate feasibility of an international hospital-based network for the assessment of potential epidemiological associations between serious and rare adverse events and vaccines in any setting. This was done through a proof-of-concept evaluation of the risk of immune thrombocytopenic purpura (ITP) and aseptic meningitis (AM) following administration of the first dose of measles-mumps-containing vaccines using the self-controlled risk interval method in the primary analysis. The World Health Organization (WHO) selected 26 sentinel sites (49 hospitals) distributed in 16 countries of the six WHO regions. Incidence rate ratios (IRR) of 5.0 (95% CI: 2.5-9.7) for ITP following first dose of measles-containing vaccinations, and of 10.9 (95% CI: 4.2-27.8) for AM following mumps-containing vaccinations were found. The strain-specific analyses showed significantly elevated ITP risk for measles vaccines containing Schwarz (IRR: 20.7; 95% CI: 2.7-157.6), Edmonston-Zagreb (IRR: 11.1; 95% CI: 1.4-90.3), and Enders'Edmonston (IRR: 8.5; 95% CI: 1.9-38.1) strains. A significantly elevated AM risk for vaccines containing the Leningrad-Zagreb mumps strain (IRR: 10.8; 95% CI: 1.3-87.4) was also found. This proof-of-concept study has shown, for the first time, that an international hospital-based network for the investigation of rare vaccine adverse events, using common standardized procedures and with high participation of LMICs, is feasible, can produce reliable results, and has the potential to characterize differences in risk between vaccine strains. The completion of this network by adding large reference hospitals, particularly from tropical countries, and the systematic WHO-led implementation of this approach, should permit the rapid post-marketing evaluation of safety signals for serious and rare adverse events for new and existing vaccines in all settings, including LMICs.

Operational lessons learned in conducting a multi-country collaboration for vaccine safety signal verification and hypothesis testing: The global vaccine safety multi country collaboration initiative.

Timely and effective evaluation of vaccine safety signals for newly developed vaccines introduced in low and middle- income countries (LMICs) is essential. The study tested the development of a global network of hospital-based sentinel sites for vaccine safety signal verification and hypothesis testing. Twenty-six sentinel sites in sixteen countries across all WHO regions participated, and 65% of the sites were from LMIC. We describe the process for the establishment and operationalization of such a network and the lessons learned in conducting a multi-country collaborative initiative. 24 out of the 26 sites successfully contributed data for the global analysis using standardised tools and procedures. Our study successfully confirmed the well-known risk estimates for the outcomes of interest. The main challenges faced by investigators were lack of adequate information in the medical records for case ascertainment and classification, and access to immunization data. The results suggest that sentinel hospitals intending to participate in vaccine safety studies strengthen their systems for discharge diagnosis coding, medical records and linkage to vaccination data. Our study confirms that a multi-country hospital-based network initiative for vaccine safety monitoring is feasible and demonstrates the validity and utility of large collaborative international studies to monitor the safety of new vaccines introduced in LMICs.

Building capacity for active surveillance of vaccine adverse events in the Americas: A hospital-based multi-country network.

New vaccines designed to prevent diseases endemic in low and middle-income countries are being introduced without prior utilization in countries with robust vaccine pharmacovigilance systems. Our aim was to build capacity for active surveillance of vaccine adverse events in the Americas. We describe the implementation of a proof-of-concept study for the feasibility of an international collaborative hospital-based active surveillance system for vaccine safety. The study was developed and implemented in 15 sentinel sites located in seven countries of the region of the Americas, under the umbrella of the World Health Organization (WHO) Global Vaccine Safety Initiative. The study evaluated the associations between measles-mumps-rubella vaccines and two well-recognized adverse events: Immune thrombocytopenic purpura (ITP) and aseptic meningitis. The regional network contributed 63 confirmed ITP and 16 confirmed aseptic meningitis eligible cases to the global study, representing, respectively, 33% and 19% of the total cases. To ensure long-term sustainability and usefulness to investigate adverse events following new vaccine introductions in low and middle-income countries, the network needs to be strengthened with additional sites and integrated into national health systems.

MMR2 vaccination coverage and timeliness among children born in 2004 - 2009: a national survey in Saint Lucia, 2015.

OBJECTIVES: To more accurately determine coverage and timeliness of the second dose of measles-mumps-rubella vaccine (MMR2), while identifying factors associated with low MMR2 vaccination uptake among children in Saint Lucia. METHODS: A survey was conducted in October - November 2015 targeting children born in 2004 - 2009. At 86 preschools and primary schools, two children from each grade were randomly selected, yielding an effective sample of 836 children. Health records were reviewed to assess vaccination coverage and timeliness. Parents and/or guardians and principals of all 86 schools were interviewed regarding knowledge, attitudes, and practices related to vaccination. RESULTS: Of 767 children included, 75% were vaccinated with MMR2 (n = 572); 46.7% were vaccinated in a timely manner, i.e., by 5 years of age. Cohorts born in 2004, 2005, and 2008 reported the lowest proportion. 'Mothers as caregivers' was positively associated with timely MMR2 vaccination. Although 97% of principals surveyed considered vaccination important, 48.8% were not aware of national legislation requiring complete vaccination prior to school entry. Survey results concurred with the low MMR2 administrative coverage rates reported by Saint Lucia, much lower than the recommended 95%. CONCLUSIONS: Based on the results of this survey, Saint Lucia's national immunization program has lowered the age of MMR2 to 18 months in 2016, increased advocacy with schools to enforce the school-entry law, and is working to vaccinate the cohorts of children who have not received timely MMR2.

MMR2 vaccination coverage and timeliness among children born in 2004 - 2009: a national survey in Saint Lucia, 2015 / Cobertura de vacunación y respeto de los plazos de la segunda dosis de la vacuna triple viral en los niños nacidos en el período 2004-2009: encuesta nacional realizada en Santa Lucía en el 2015 / Cobertura e momento oportuno de vacinação da segunda dose da vacina tríplice viral em crianças nascidas em 2004-2009: pesquisa nacional em Santa Lúcia, 2015

ABSTRACT Objectives To more accurately determine coverage and timeliness of the second dose of measles-mumps-rubella vaccine (MMR2), while identifying factors associated with low MMR2 vaccination uptake among children in Saint Lucia. Methods A survey was conducted in October - November 2015 targeting children born in 2004 - 2009. At 86 preschools and primary schools, two children from each grade were randomly selected, yielding an effective sample of 836 children. Health records were reviewed to assess vaccination coverage and timeliness. Parents and/or guardians and principals of all 86 schools were interviewed regarding knowledge, attitudes, and practices related to vaccination. Results Of 767 children included, 75% were vaccinated with MMR2 (n = 572); 46.7% were vaccinated in a timely manner, i.e., by 5 years of age. Cohorts born in 2004, 2005, and 2008 reported the lowest proportion. 'Mothers as caregivers' was positively associated with timely MMR2 vaccination. Although 97% of principals surveyed considered vaccination important, 48.8% were not aware of national legislation requiring complete vaccination prior to school entry. Survey results concurred with the low MMR2 administrative coverage rates reported by Saint Lucia, much lower than the recommended 95%. Conclusions Based on the results of this survey, Saint Lucia's national immunization program has lowered the age of MMR2 to 18 months in 2016, increased advocacy with schools to enforce the school-entry law, and is working to vaccinate the cohorts of children who have not received timely MMR2.

RESUMEN Objetivos Determinar con mayor precisión la cobertura y el respeto de los plazos de vacunación de la segunda dosis de la vacuna contra el sarampión, la rubéola y la parotiditis (triple viral), al tiempo que se detectan los factores asociados con la baja aceptación de esa vacuna en Santa Lucía. Métodos En octubre y noviembre del 2015 se llevó a cabo una encuesta centrada en niños nacidos entre el 2004 y el 2009. En 86 centros preescolares y primarios se seleccionó al azar a dos niños de cada grado, lo que arrojó un tamaño real de la muestra de 836 niños. Se analizaron los registros de salud para evaluar la cobertura y el respeto de los plazos de vacunación. Se entrevistó a los padres o tutores y los directores de las 86 escuelas sobre conocimientos, actitudes y prácticas en materia de vacunación. Resultados De los 767 niños incluidos, el 75% fueron vacunados con la segunda dosis de la triple viral (n = 572); el 46,7% fueron vacunados a tiempo, es decir, a los 5 años de edad. La proporción más baja se dio en las cohortes nacidas en el 2004, 2005 y 2008. Se observó que las madres cuidadoras influían positivamente en el respeto de los plazos de vacunación de la segunda dosis de la triple viral. Aunque el 97% de los directores encuestados consideraba que la vacunación era importante, el 48,8% desconocía la legislación nacional que exige la vacunación completa antes de ingresar a la escuela. Los resultados de la encuesta estaban en consonancia con las tasas bajas de cobertura administrativa de la segunda dosis de la triple viral informadas por Santa Lucía, muy por debajo del 95% recomendado. Conclusiones Según los resultados de esta encuesta, el programa nacional de vacunación de Santa Lucía redujo la edad de la segunda dosis de la triple viral a los 18 meses en el 2016, aumentó las actividades de promoción en las escuelas para fomentar el cumplimiento de la ley que obliga a recibir la vacunación antes de ingresar a la escuela y está trabajando para vacunar a las cohortes de niños que no recibieron la segunda dosis de la triple viral en su debido momento.

RESUMO Objetivos Determinar com precisão a cobertura vacinal e o momento oportuno para ministrar a segunda dose da vacina tríplice viral (sarampo, caxumba e rubéola - SCR) e identificar os fatores associados à baixa utilização da vacina em crianças. Métodos Uma pesquisa direcionada a crianças nascidas de 2004 a 2009 foi realizada em Santa Lúcia em outubro e novembro de 2015. Em 86 unidades de ensino infantil e fundamental, duas crianças de cada série foram selecionadas aleatoriamente, constituindo uma amostra efetiva de 836 crianças. Dados sobre a cobertura e o momento oportuno de vacinação foram obtidos das fichas de saúde. Foram conduzidas entrevistas com os pais e/ou responsáveis e os diretores das 86 escolas sobre conhecimento, atitudes e práticas relacionadas à vacinação. Resultados Das 767 crianças incluídas na amostra, 75% foram vacinadas com a segunda dose de SCR (n = 572) e 46,7% receberam a vacina no momento oportuno (ou seja, até os 5 anos de idade). Observou-se menor proporção de vacinados nas coortes nascidas em 2004, 2005 e 2008. "Mães como cuidadoras" teve uma associação positiva com ministrar a segunda dose de SCR no momento oportuno. Apesar de 97% dos diretores entrevistados considerarem a vacinação importante, 48,8% desconheciam a legislação nacional que exige vacinação completa para a matrícula escolar. Os resultados reforçaram a baixa cobertura vacinal da segunda dose de SCR registrada em Santa Lúcia, bem inferior ao índice recomendado de 95%. Conclusões A partir dos resultados desta pesquisa, em 2016, o programa nacional de vacinação de Santa Lúcia reduziu para 18 meses a idade de administração da segunda dose de SCR, intensificou a recomendação para que as escolas cumpram com a legislação para matrícula escolar e está empenhado em vacinar as coortes de crianças que não receberam a segunda dose de SCR no momento oportuno.

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

Matriz de riesgo para estimar brotes importados de sarampión o rubéola aplicada a Chile / Risk matrix for estimating imported outbreaks of measles or rubella in Chile / Matriz de risco para estimar surtos importados de sarampo ou rubéola aplicada ao Chile

[Español]. Objetivo. Desarrollar una matriz de riesgo para evaluar el riesgo continuo de brotes de sarampión y rubéola asociados con la importación de casos en Chile. Métodos. El desarrollo de herramientas de evaluación de riesgos se realizó en las siguientes etapas: preparación y aprobación de variables biológicas, programáticas y demográficas, ponderación por un panel de expertos de las variables seleccionadas, cálculo del índice de riesgo, espacialización, y transferencia de conocimiento. Resultados. De las 346 comunas de Chile analizadas, 34% se encontraba en el intervalo de riesgo alto de desarrollar un brote de sarampión y rubéola si se producía la introducción del virus, 59%, en el intervalo de riesgo medio, y 3%, en el intervalo de riesgo bajo. El porcentaje restante correspondió a comunas carentes de datos en al menos una de las trece variables requeridas para el cálculo del índice de riesgo. Conclusión. La utilización de esta herramienta permitirá a los equipos subnacionales emplear sus propios datos para evaluar el riesgo de brotes en sus áreas y realizar acciones correctivas para responder rápidamente a cualquier importación de virus en la fase posterior a la eliminación.

[English]. Objective. Develop a risk matrix to evaluate the ongoing risk of measles and rubella outbreaks associated with imported cases in Chile. Methods. The risk assessment tools were developed in the following stages: preparation and approval of biological, programmatic, and demographic variables; weighting of the selected variables by a panel of experts; calculation of the risk index; specialization; and knowledge transfer. Results. Of the 346 Chilean communes analyzed, 34% were in the high-risk interval for experiencing a measles and rubella outbreak with the introduction of the virus, 59%, in the average-risk interval, and 3%, in the low-risk interval. The remaining percentage corresponded to communes lacking data in at least one of the 13 variables required for calculating the risk index. Conclusion. Use of this tool will enable subnational teams to use their own data to evaluate the risk of outbreaks in their area and take corrective action for a rapid response to any importation of these viruses in the post-elimination phase.

[Português]. Objetivo. Desenvolver uma matriz de risco para avaliar o risco contínuo de surtos de sarampo e rubéola associados com a importação de casos no Chile. Métodos. As ferramentas de avaliação de riscos foram desenvolvidas nas seguintes etapas: preparação e aprovação das variáveis biológicas, programáticas e demográficas, consideração das variáveis selecionadas por painel de especialistas, cálculo do índice de risco, especialização e transferência de conhecimento. Resultados. Das 346 comunidades analisadas, 34% estavam dentro da faixa de alto risco de ter um surto de sarampo e rubéola com a introdução do vírus, 59% na faixa de risco intermediário e 3% na faixa de baixo risco. O percentual restante correspondeu a comunidades com dados insuficientes em pelo menos uma das 13 variáveis necessárias ao cálculo do índice de risco. Conclusão. A utilização desta ferramenta permitirá às equipes subnacionais lancer mão de dados próprios para avaliar o risco de surtos e realizar medidas corretivas para responder rapidamente a qualquer importação de vírus na fase posterior à eliminação.

Development of a District-Level Programmatic Assessment Tool for Risk of Measles Virus Transmission.

All six World Health Organization (WHO) regions have now set goals for measles elimination by or before 2020. To prioritize measles elimination efforts and use available resources efficiently, there is a need to identify at-risk areas that are offtrack from meeting performance targets and require strengthening of programmatic efforts. This article describes the development of a WHO measles programmatic risk assessment tool to be used for monitoring, guiding, and sustaining measles elimination efforts at the subnational level. We outline the tool development process; the tool specifications and requirements for data inputs; the framework of risk categories, indicators, and scoring; and the risk category assignment. Overall risk was assessed as a function of indicator scores that fall into four main categories: population immunity, surveillance quality, program performance, and threat assessment. On the basis of the overall score, the tool assigns each district a risk of either low, medium, high, or very high. The cut-off criteria for the risk assignment categories were based on the distribution of scores from all possible combinations of individual indicator cutoffs. The results may be used for advocacy to communicate risk to policymakers, mobilize resources for corrective actions, manage population immunity, and prioritize programmatic activities. Ongoing evaluation of indicators will be needed to evaluate programmatic performance and plan risk mitigation activities effectively. The availability of a comprehensive tool that can identify at-risk districts will enhance efforts to prioritize resources and implement strategies for achieving the Global Vaccine Action Plan goals for measles elimination.

[Risk matrix for estimating imported outbreaks of measles or rubella in ChileMatriz de risco para estimar surtos importados de sarampo ou rubéola aplicada ao Chile]. / Matriz de riesgo para estimar brotes importados de sarampión o rubéola aplicada a Chile.

OBJECTIVE: Develop a risk matrix to evaluate the ongoing risk of measles and rubella outbreaks associated with imported cases in Chile. METHODS: The risk assessment tools were developed in the following stages: preparation and approval of biological, programmatic, and demographic variables; weighting of the selected variables by a panel of experts; calculation of the risk index; specialization; and knowledge transfer. RESULTS: Of the 346 Chilean communes analyzed, 34% were in the high-risk interval for experiencing a measles and rubella outbreak with the introduction of the virus, 59%, in the average-risk interval, and 3%, in the low-risk interval. The remaining percentage corresponded to communes lacking data in at least one of the 13 variables required for calculating the risk index. CONCLUSION: Use of this tool will enable subnational teams to use their own data to evaluate the risk of outbreaks in their area and take corrective action for a rapid response to any importation of these viruses in the post-elimination phase.

OBJETIVO: Desenvolver uma matriz de risco para avaliar o risco contínuo de surtos de sarampo e rubéola associados com a importação de casos no Chile. MÉTODOS: As ferramentas de avaliação de riscos foram desenvolvidas nas seguintes etapas: preparação e aprovação das variáveis biológicas, programáticas e demográficas, consideração das variáveis selecionadas por painel de especialistas, cálculo do índice de risco, especialização e transferência de conhecimento. RESULTADOS: Das 346 comunidades analisadas, 34% estavam dentro da faixa de alto risco de ter um surto de sarampo e rubéola com a introdução do vírus, 59% na faixa de risco intermediário e 3% na faixa de baixo risco. O percentual restante correspondeu a comunidades com dados insuficientes em pelo menos uma das 13 variáveis necessárias ao cálculo do índice de risco. CONCLUSÃO: A utilização desta ferramenta permitirá às equipes subnacionais lançar mão de dados próprios para avaliar o risco de surtos e realizar medidas corretivas para responder rapidamente a qualquer importação de vírus na fase posterior à eliminação.

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.

Matriz de riesgo para estimar brotes importados de sarampión o rubéola aplicada a Chile / Risk matrix for estimating imported outbreaks of measles or rubella in Chile / Matriz de risco para estimar surtos importados de sarampo ou rubéola aplicada ao Chile

RESUMEN Objetivo Desarrollar una matriz de riesgo para evaluar el riesgo continuo de brotes de sarampión y rubéola asociados con la importación de casos en Chile. Métodos El desarrollo de herramientas de evaluación de riesgos se realizó en las siguientes etapas: preparación y aprobación de variables biológicas, programáticas y demográficas, ponderación por un panel de expertos de las variables seleccionadas, cálculo del índice de riesgo, espacialización, y transferencia de conocimiento. Resultados De las 346 comunas de Chile analizadas, 34% se encontraba en el intervalo de riesgo alto de desarrollar un brote de sarampión y rubéola si se producía la introducción del virus, 59%, en el intervalo de riesgo medio, y 3%, en el intervalo de riesgo bajo. El porcentaje restante correspondió a comunas carentes de datos en al menos una de las trece variables requeridas para el cálculo del índice de riesgo. Conclusión La utilización de esta herramienta permitirá a los equipos subnacionales emplear sus propios datos para evaluar el riesgo de brotes en sus áreas y realizar acciones correctivas para responder rápidamente a cualquier importación de virus en la fase posterior a la eliminación.

Objective Develop a risk matrix to evaluate the ongoing risk of measles and rubella outbreaks associated with imported cases in Chile. Methods The risk assessment tools were developed in the following stages: preparation and approval of biological, programmatic, and demographic variables; weighting of the selected variables by a panel of experts; calculation of the risk index; specialization; and knowledge transfer. Results Of the 346 Chilean communes analyzed, 34% were in the high-risk interval for experiencing a measles and rubella outbreak with the introduction of the virus, 59%, in the average-risk interval, and 3%, in the low-risk interval. The remaining percentage corresponded to communes lacking data in at least one of the 13 variables required for calculating the risk index. Conclusion Use of this tool will enable subnational teams to use their own data to evaluate the risk of outbreaks in their area and take corrective action for a rapid response to any importation of these viruses in the post-elimination phase.

RESUMO Objetivo Desenvolver uma matriz de risco para avaliar o risco contínuo de surtos de sarampo e rubéola associados com a importação de casos no Chile. Métodos As ferramentas de avaliação de riscos foram desenvolvidas nas seguintes etapas: preparação e aprovação das variáveis biológicas, programáticas e demográficas, consideração das variáveis selecionadas por painel de especialistas, cálculo do índice de risco, especialização e transferência de conhecimento. Resultados Das 346 comunidades analisadas, 34% estavam dentro da faixa de alto risco de ter um surto de sarampo e rubéola com a introdução do vírus, 59% na faixa de risco intermediário e 3% na faixa de baixo risco. O percentual restante correspondeu a comunidades com dados insuficientes em pelo menos uma das 13 variáveis necessárias ao cálculo do índice de risco. Conclusão A utilização desta ferramenta permitirá às equipes subnacionais lançar mão de dados próprios para avaliar o risco de surtos e realizar medidas corretivas para responder rapidamente a qualquer importação de vírus na fase posterior à eliminação.

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.

Missed Opportunities for Vaccination in the Dominican Republic: Results of an Operational Investigation.

Background. Despite the success of the Dominican Republic's National Immunization Program, homogenous vaccine coverage has not been achieved. In October 2012, the country implemented a study on missed opportunities for vaccination (MOVs) in children aged <5 years. Methods. A cross-sectional study of 102 healthcare facilities was implemented in 30 high-risk municipalities. Overall, 1500 parents and guardians of children aged <5 years were interviewed. A MOV is defined as when a person who is eligible for vaccination and with no contraindications visits a health facility and does not receive a required vaccine. We evaluated the causes of MOVs and identified risk factors associated with MOVs in the Dominican Republic. Results. Of the 514 children with available and reliable vaccination histories, 293 (57.0%) were undervaccinated after contact with a health provider. Undervaccinated children had 836 opportunities to receive a needed vaccine. Of these, 358 (42.8%) qualified as MOVs, with at least one MOV observed in 225 children (43.7%). Factors associated with MOVs included urban geographic area (OR = 1.80; p = 0.02), age 1-4 years (OR = 3.63; p ≤ 0.0001), and the purpose of the health visit being a sick visit (OR = 1.65; p = 0.02). Conclusions. MOVs were associated primarily with health workers failing to request and review patients' immunization cards.

Lessons learned from the development of a new methodology to assess missed opportunities for vaccination in Latin America and the Caribbean.

The Pan American Health Organization recently developed a practical guide for evaluating missed opportunities for vaccination among children aged <5 years. A missed opportunity occurs when an individual eligible for vaccination has contact with a health facility and does not receive a needed vaccine, despite having no contraindications. In this article, we discuss the strengths and limitations of this new methodology and present lessons learned from recent studies on undervaccination in Latin America. Our findings should be useful to countries embarking on assessing the magnitude and the causes of missed opportunities for vaccination children experience at health facilities.

Understanding the main barriers to immunization in Colombia to better tailor communication strategies.

BACKGROUND: The Expanded Program on Immunization (EPI) in Colombia has made great advances since its inception in 1979; however, by 2010 vaccination coverage rates had been declining. In 2010, the EPI commissioned a nationwide study on practices on immunization, attitudes and knowledge, perceived service quality, and barriers to childhood immunization in order to tailor EPI communication strategies. METHODS: Colombia's 32 geographical departments were divided into 10 regions. Interviewers from an independent polling company administered a survey to 4802 parents and guardians of children aged <5 years in these regions. To better assess barriers to vaccination, the study was designed to have 70% of participants who had children with incomplete vaccination schedules. Explanatory factorial, principal component, and cluster analyses were performed to place participants into a group (segment) representing the primary category of reasons respondents offered for not vaccinating their children. Types of barriers were then compared to other variables, such as service quality, communication preferences, and parental attitudes on vaccination. RESULTS: Although all respondents indicated that vaccines have health benefits, and 4738 (98.7%) possessed vaccination cards for their children, attitudes and knowledge were not always favorable to immunization. Six groups of immunization barriers were identified: 1) factors related to caregivers (24.4%), 2) vaccinators (19.7%), 3) health centers (18.0%), 4) the health system (13.4%), 5) concerns about adverse events (13.1%), and 6) cultural and religious beliefs (11.4%); groups 1, 5 and 6 together represented almost half (48.9%) of users, indicating problems related to the demand for vaccines as the primary barriers to immunization. Differences in demographics, communication preferences, and reported service quality were found among participants in the six groups and among participants in the 10 regions. Additionally, differences between how participants reported receiving information on vaccination and how they believed such information should be communicated were observed. CONCLUSIONS: Better understanding immunization barriers and the users of the EPI can help tailor communication strategies to increase demand for immunization services. Results of the study have been used by Colombia's EPI to inform the design of new communication strategies.

From the parents' perspective: a user-satisfaction survey of immunization services in Guatemala.

BACKGROUND: Immunization coverage levels in Guatemala have increased over the last two decades, but national targets of ≥95% have yet to be reached. To determine factors related to undervaccination, Guatemala's National Immunization Program conducted a user-satisfaction survey of parents and guardians of children aged 0-5 years. Variables evaluated included parental immunization attitudes, preferences, and practices; the impact of immunization campaigns and marketing strategies; and factors inhibiting immunization. METHODS: Based on administrative coverage levels and socio-demographic indicators in Guatemala's 22 geographical departments, five were designated as low-coverage and five as high-coverage areas. Overall, 1194 parents and guardians of children aged 0-5 years were interviewed in these 10 departments. We compared indicators between low- and high-coverage areas and identified risk factors associated with undervaccination. RESULTS: Of the 1593 children studied, 29 (1.8%) were determined to be unvaccinated, 458 (28.8%) undervaccinated, and 1106 (69.4%) fully vaccinated. In low-coverage areas, children of less educated (no education: RR=1.49, p=0.01; primary or less: 1.39, p=0.009), older (aged>39 years: RR=1.31, p=0.05), and single (RR=1.32, p=0.03) parents were more likely to have incomplete vaccination schedules. Similarly, factors associated with undervaccination in high-coverage areas included the caregiver's lack of education (none: RR=1.72, p=0.0007; primary or less: RR=1.30, p=0.05) and single marital status (RR=1.36, p=0.03), as well as the child's birth order (second: RR=1.68, p=0.003). Although users generally approved of immunization services, problems in service quality were identified. According to participants, topics such as the risk of adverse events (47.4%) and next vaccination appointments (32.3%) were inconsistently communicated to parents. Additionally, 179 (15.0%) participants reported the inability to vaccinate their child on at least one occasion. Compared to high-coverage areas, participants in low-coverage areas reported poorer service, longer wait times, and greater distances to health centers. In high-coverage areas, participants reported less knowledge about the availability of services. CONCLUSIONS: Generally, immunization barriers in Guatemala are related to problems in accessing and attaining high-quality immunization services rather than to a population that does not adequately value vaccination. We provide recommendations to aid the country in maintaining its achievements and addressing new challenges.

Elimination of rubella and congenital rubella syndrome in the Americas.

In 2003, the Pan American Health Organization (PAHO) adopted a resolution calling for rubella and congenital rubella syndrome (CRS) elimination in the Americas by the year 2010. To accomplish this goal, PAHO advanced a rubella and CRS elimination strategy including introduction of rubella-containing vaccines into routine vaccination programs accompanied by high immunization coverage, interruption of rubella transmission through mass vaccination of adolescents and adults, and strengthened surveillance for rubella and CRS. The rubella elimination strategies were aligned with the successful measles elimination strategies. By the end of 2009, all countries routinely vaccinated children against rubella, an estimated 450 million people had been vaccinated against measles and rubella in supplementary immunization activities, and rubella transmission had been interrupted. This article describes how the region eliminated rubella and CRS.