Case-Control Study of Risk Factors for Meningococcal Disease in Chile.

An outbreak of meningococcal disease with a case-fatality rate of 30% and caused by predominantly serogroup W of Neisseria meningitidis began in Chile in 2012. This outbreak required a case-control study to assess determinants and risk factors for infection. We identified confirmed cases during January 2012-March 2013 and selected controls by random sampling of the population, matched for age and sex, resulting in 135 case-patients and 618 controls. Sociodemographic variables, habits, and previous illnesses were studied. Analyses yielded adjusted odds ratios as estimators of the probability of disease development. Results indicated that conditions of social vulnerability, such as low income and overcrowding, as well as familial history of this disease and clinical histories, especially chronic diseases and hospitalization for respiratory conditions, increased the probability of illness. Findings should contribute to direction of intersectoral public policies toward a highly vulnerable social group to enable them to improve their living conditions and health.

[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.

[Emergence of W135 meningococcal serogroup in Chile during 2012]. / Emergencia de la cepa W135 causante de enfermedad meningocócica invasora en Chile 2012.

The epidemiologic behavior of the Invasive Meningococcal Disease (IMD) in Chile has changed. At the end of 2011, the W135 serogroup belonging to the hypervirulent clone ST-11 emerged. It affected diverse countries of the world, after the Mecca pilgrimage in 2000. In Chile, there have been 133 IMD cases during 2012. These figures represent an incidence of 0.7 per 100,000 inhabitants, which is 30% higher than expected. Eighty eight percent of cases were confirmed by the National Reference Laboratory at the Chilean Public Health Institute. The serogroup was determined in 103 strains and 58% belonged to the W135 serogroup, surpassing for the first time the B serogroup (37%). The Metropolitan Region concentrated 80% of these cases, and the remaining 20% affected other seven regions of the country. Forty seven percent of cases corresponded to children less than 5 years of age. The predominant clinical presentation of the W135 serogroup was a sepsis in 67% of cases. The fatality ratio of IDM during 2012 was 27%, the highest in the past 20 years. With this information, the Chilean Ministry of Health decreed a sanitary alert and implemented an integrated approach to control and prevent W-135 IDM, denominated "W-135 Action Plan".

[Clinical characterization of cases with meningococcal disease by W135 group in Chile, 2012]. / Caracterización clínica de los casos de enfermedad meningocóccica por serogrupo W135 confirmados durante el año 2012 en Chile.

BACKGROUND: During 2012 in Chile, there were 60 cases of serogroup W135 meningococcal disease, which accounts for 57.7% of identified serogroup cases. AIM: To describe main clinical features of patients with serogroup W135 meningococcal disease confirmed in 2012. MATERIAL AND METHODS: Descriptive study of case series based on retrospective review of medical records. RESULTS: Male patients represented 61.7% and 46.7% were children under 5 years. At first clinical attention, 3.4% of patients were suspected of meningococcal disease, while 83.3% had meningococcemia as final diagnosis. Also at first attention, the most common symptoms or clinical signs were fever ≥ 38.0° C (60.3%), cold symptoms (52.5%), and nausea or vomiting (46.7%). Meningeal signs had a low frequency (8.7%). Diarrhea was the second most common symptom found among deceased patients (55.6%) and statistically higher than survivors (26.8%; p = 0.034). Six cases reported with sequelae: limb amputation, hearing loss or neurological damage, and mortality was 31.7%. DISCUSSION: In 2012, serogroup W135 meningococcal disease reported high mortality, atypical clinical presentation, low initial meningococcal disease diagnosis, and a high number of cases with poor clinical course.

Rubella outbreaks following virus importations: the experience of Chile.

BACKGROUND: Strategies for accelerated control of rubella and congenital rubella syndrome (CRS) in Chile included mass vaccination of women of childbearing age in 1999 but did not include vaccination of adult men. METHODS: We reviewed data from Chile's integrated surveillance system for measles, rubella, and CRS from 2004 through 2009 and describe the epidemiology of rubella outbreaks and implementation of control measures in 2005 and 2007 following mass vaccination of women. Population estimates from census data were used to calculate rubella incidence rates. The age distribution of rubella cases during 2007 was compared with rubella vaccination opportunities by birth cohort to orient mass vaccination of adult men. RESULTS: In 2005, an institutional outbreak of rubella occurred among male naval recruits 18-22 years of age, with 46 confirmed cases over a 5-month period. Beginning in March 2007, rubella outbreaks among young adults in the capital of Santiago spread throughout Chile, resulting in >4000 confirmed rubella cases. Delayed control measures and rapid dissemination among young adults led to widespread transmission. From 2007 through 2009, rubella incidence was highest among adult men not included in previous vaccination strategies. Mass vaccination of men 19-29 years of age was conducted in November 2007 to interrupt rubella transmission. CONCLUSIONS: Chile's experience suggests that vaccination strategies for rubella and CRS elimination need to include both men and women.

National Seroprevalence of Coxiella burnetii in Chile, 2016-2017.

Coxiella burnetii is an intracellular bacterium and the cause of the zoonotic infection, Q fever. National surveillance data on C. burnetii seroprevalence is currently not available for any South American country, making efforts of public health to implement strategies to mitigate infections in different at-risk groups within the population extremely challenging. In the current study, we used two commercial anti-C. burnetii immunoassays to screen sera collected from a sample of the Chilean population as part of a 2016-2017 national health survey (n = 5166), nationwide and age-standardized. The seroprevalence for C. burnetii for persons ≥ 15 years was estimated to be 3.0% (95% CI 2.2-4.0), a level similar to national surveys from The Netherlands (2.4%) and USA (3.1%), but lower than Australia (5.6%). A linear increase of C. burnetii seropositivity was associated with an individual's age, with the peak seroprevalence 5.6% (95% CI 3.6-8.6) observed in the ≥65 years' group. C. burnetii seropositivity was significantly higher in the southern macro-zone 6.0% (95% CI 3.3-10.6) compared to metropolitan region 1.8% (95% CI 0.9-3.3), the former region being home to significant livestock industries, particularly dairy farming. These data will be useful to inform targeted strategies for the prevention of Q fever in at-risk populations in Chile.

[Estimation of the effective reproduction number of measles 2018-2019 in Chile]. / Estimación del número reproductivo efectivo del brote de sarampión 2018-2019 en Chile.

BACKGROUND: Measles cases are reemerging in many countries across the globe. There was an outbreak of imported measles between November 2018 and February 2019 in Chile, raising concern among the public and health authorities. Many were worried about the Chilean measles herd immunity, a factor that relates to the reproductive capacity of the virus (measure of transmissibility of a pathogen). AIM: Here we estimate the effective reproductive number (Re) of this measles outbreak. RESULTS: Although the estimate is highly uncertain due to the low number of cases and the absence of homogeneous mixing of the population, we found Re was approximately 1.5. DISCUSSION AND CONCLUSIONS: Consequently we estimated about 90,3 % had measles immunity, consistent with administrative estimates from the Ministry of Health. These results suggest the Chilean population has established herd immunity against the introduction of imported measles cases, reflecting adequate preventive management of this disease.

Evidence of Q Fever and Rickettsial Disease in Chile.

Q fever and rickettsial diseases occur throughout the world and appear to be emergent zoonoses in Chile. The diagnosis of these diseases is currently uncommon in Chile, as their clinical presentations are non-specific and appropriate diagnostic laboratory assays are of limited availability. During a recent outbreak of undiagnosed human atypical pneumonia, we serologically investigated a series of 357 cases from three regions of southern Chile. The aim was to identify those caused by Coxiella burnetii and/or Rickettsia spp. Serological analysis was performed by ELISA and an immunofluorescence assay (IFA) for acute and convalescence sera of patients. Our results, including data from two international reference laboratories, demonstrate that 71 (20%) of the cases were Q fever, and 44 (15%) were a likely rickettsial infection, although the rickettsial species could not be confirmed by serology. This study is the first report of endemic Q fever and rickettsial disease affecting humans in Chile.

Estimación del número reproductivo efectivo del brote de sarampión 2018-2019 en Chile / Estimation of the effective reproduction number of measles 2018-2019 in Chile

Resumen Introducción: Los casos de sarampión están resurgiendo en muchos países del mundo. Hubo un brote de sarampión importado entre noviembre de 2018 y febrero de 2019 en Chile, lo que generó preocupación entre el público y las autoridades sanitarias. Muchos se preocuparon por la tasa de inmunización contra el sarampión de la población, un factor que se relaciona con la capacidad reproductiva del virus (medida de transmisibilidad de un patógeno). Objetivo: Aquí estimamos el número reproductivo efectivo (Re) de este brote de sarampión. Resultados: Aunque la estimación tiene mucha incertidumbre por el bajo número de casos y la ausencia de mezcla homogénea de la población, encontramos que Re fue aproximadamente 1,5. Discusión y Conclusiones: En consecuencia estimamos que aproximadamente 90,3% de la población tiene inmunidad al sarampión, lo que coincide con las estimaciones del Ministerio de Salud. Estos resultados sugieren que la población chilena ha establecido la inmunidad colectiva contra la introducción de casos importados de sarampión, lo que refleja un manejo preventivo adecuado de esta enfermedad.

Abstract Background: Measles cases are reemerging in many countries across the globe. There was an outbreak of imported measles between November 2018 and February 2019 in Chile, raising concern among the public and health authorities. Many were worried about the Chilean measles herd immunity, a factor that relates to the reproductive capacity of the virus (measure of transmissibility of a pathogen). Aim: Here we estimate the effective reproductive number (Re) of this measles outbreak. Results: Although the estimate is highly uncertain due to the low number of cases and the absence of homogeneous mixing of the population, we found Re was approximately 1.5. Discussion and Conclusions: Consequently we estimated about 90,3 % had measles immunity, consistent with administrative estimates from the Ministry of Health. These results suggest the Chilean population has established herd immunity against the introduction of imported measles cases, reflecting adequate preventive management of this disease.

[Clinical features and prognostic factors of meningococcal disease: a case series study in Chile during the 2012-2013 outbreak]. / Características clínicas y factores pronósticos de la enfermedad meningocóccica: un estudio de serie de casos en Chile durante el brote 2012-2013.

INTRODUCTION: Meningococcal disease (MD) is a major global problem because of its case fatality rate and sequels. Since 2012 cases of serogroup W have increased in Chile, with nonspecific clinical presentation, high case fatality rate and serious consequences. OBJECTIVE: To characterize the evolution and outcome of MD cases between January 2012 and March 2013 in Chile. MATERIAL AND METHODS: Case series considering 149 MD cases of 7 regions. A questionnaire was applied and clinical records were reviewed, including individual, agent, clinical course and healthcare process variables. The analysis allowed to obtain estimates of the OR as likelihood of dying. RESULTS: 51.5% was meningococcemia, the case fatality rate reached 27%, prevailing serogroup W (46.6%). Factors that increased the probability of dying: > age, belonging to indigenous people, having lived a stressful event, having diarrhea, impaired consciousness, cardiovascular symptoms, low oxygen saturation and low Glasgow coma scale score. DISCUSSION: The case fatality rate exceeded normal levels and was higher in serogroup W. Increasing in this serogroup, associated to the increased presence of nonspecific symptoms or rapid progression to septicemia, hit a health system accustomed to more classic meningococcal disease presentation, which could partly explain the observed increased fatality rate.

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.

Características clínicas y factores pronósticos de la enfermedad meningocóccica: un estudio de serie de casos en Chile durante el brote 2012-2013 / Clinical features and prognostic factors of meningococcal disease: a case series study in Chile during the 2012-2013 outbreak

Introduction: Meningococcal disease (MD) is a major global problem because of its case fatality rate and sequels. Since 2012 cases of serogroup W have increased in Chile, with nonspecific clinical presentation, high case fatality rate and serious consequences. Objective: To characterize the evolution and outcome of MD cases between January 2012 and March 2013 in Chile. Material and Methods: Case series considering149 MD cases of 7 regions. A questionnaire was applied and clinical records were reviewed, including individual, agent, clinical course and healthcare process variables. The analysis allowed to obtain estimates of the OR as likelihoodof dying. Results: 51.5% was meningococcemia, the case fatality rate reached 27%, prevailing serogroup W (46.6%). Factors that increased the probability of dying: > age, belonging to indigenous people, having lived a stressful event, having diarrhea, impaired consciousness, cardiovascular symptoms, low oxygen saturation and low Glasgow coma scale score. Discussion: The case fatality rate exceeded normal levels and was higher in serogroup W. Increasing in this serogroup, associated to the increased presence of nonspecific symptoms or rapid progression to septicemia, hit a health system accustomed to more classic meningococcal disease presentation, which could partly explain the observed increased fatality rate.

Introducción: La enfermedad meningocóccica (EM) es un importante problema mundial por su letalidad y secuelas. Desde 2012 aumentaron en Chile los casos por serogrupo W, con presentación clínica inespecífica, elevada letalidad y secuelas graves. Objetivo: Caracterizar la evolución y desenlace de EM en casos desde enero de 2012 a marzo de 2013 en Chile. Material y Método: Serie de 149 casos de EM de siete regiones. Se aplicó un cuestionario y se revisaron registros clínicos, incluyendo variables del individuo, agente, curso clínico y proceso de atención. Los análisis permitieron obtener OR como estimadores de la probabilidad de fallecer. Resultados: El 51,5% se presentó como meningococcemia, la letalidad alcanzó a 27%, predominando el serogrupo W (46,6%). Aumentaron la probabilidad de fallecer: una mayor edad, pertenencia a pueblos originarios, haber vivido evento estresante, presentar diarrea, compromiso de conciencia, síntomas cardiovasculares, baja saturación de oxígeno y bajo puntaje de Glasgow. Discusión: La letalidad superó las frecuencias habituales y fue mayor en el serogrupo W. El aumento de este serogrupo, asociado a la mayor presencia de síntomas inespecíficos o a la rápida progresión a septicemia, impactó en un sistema de salud habituado a cuadros más clásicos de EM, lo que podría explicar en parte, la mayor letalidad observada.

Caracterización clínica de los casos de enfermedad meningocóccica por serogrupo W135 confirmados durante el año 2012 en Chile / Clinical characterization of cases with meningococcal disease by W135 group in Chile, 2012

Background: During 2012 in Chile, there were 60 cases of serogroup W135 meningococcal disease, which accounts for 57.7% of identified serogroup cases. Aim: To describe main clinical features of patients with serogroup W135 meningococcal disease confirmed in 2012. Material and Methods: Descriptive study of case series based on retrospective review of medical records. Results: Male patients represented 61.7% and 46.7% were children under 5 years. At first clinical attention, 3.4% of patients were suspected of meningococcal disease, while 83.3% had meningococcemia as final diagnosis. Also at first attention, the most common symptoms or clinical signs were fever ≥ 38.0° C (60.3%), cold symptoms (52.5%), and nausea or vomiting (46.7%). Meningeal signs had a low frequency (8.7%). Diarrhea was the second most common symptom found among deceased patients (55.6%) and statistically higher than survivors (26.8%; p = 0.034). Six cases reported with sequelae: limb amputation, hearing loss or neurological damage, and mortality was 31.7%. Discussion: In 2012, serogroup W135 meningococcal disease reported high mortality, atypical clinical presentation, low initial meningococcal disease diagnosis, and a high number of cases with poor clinical course.

Introducción: En el año 2012 en Chile, se presentaron 60 casos de enfermedad meningocóccica (EM) causadas por serogrupo W135, que representa 57,7% de los casos seroagrupables. Objetivo: Describir las características clínicas de los casos de EM por serogrupo W135 confirmados durante el año 2012. Material y Métodos: Estudio descriptivo, de series de casos basada en la revisión de las fichas clínicas. Resultados: El 61,7% de los casos fueron varones y 46,7% tenía menos de 5 años. En la primera consulta, 3,4% tuvo sospecha de EM, en tanto 83,3% tuvo diagnóstico final de meningococcemia. En la primera consulta, los síntomas y/o signos más frecuentes fueron fiebre ≥ 38,0°C (60,3%), cuadro catarral respiratorio (52,5%) y náuseas y/o vómitos (46,7%). Mientras que los signos de irritación meníngea se presentaron en 8,7%. En los fallecidos la diarrea fue el segundo síntoma más frecuente (55,6%), y estadísticamente superior respecto de los sobrevivientes (26,8%; p = 0,034). Seis casos presentaron secuelas: amputaciones de extremidades, hipoacusia o daño neurológico y la letalidad fue de 31,7%. Discusión: la EM por el serogrupo W135 en el año 2012, tuvo una elevada letalidad, presentación clínica inespecífica, sospecha diagnóstica inicial baja y un alto número de casos cursaron con una mala evolución.

Emergencia de la cepa W135 causante de enfermedad meningocócica invasora en Chile 2012 / Emergence of W135 meningococcal serogroup in Chile during 2012

The epidemiologic behavior of the Invasive Meningococcal Disease (IMD) in Chile has changed. At the end of 2011, the W135 serogroup belonging to the hypervirulent clone ST-11 emerged. It affected diverse countries of the world, after the Mecca pilgrimage in 2000. In Chile, there have been 133 IMD cases during 2012. These figures represent an incidence of 0.7 per 100,000 inhabitants, which is 30% higher than expected. Eighty eight percent of cases were confirmed by the National Reference Laboratory at the Chilean Public Health Institute. The serogroup was determined in 103 strains and 58% belonged to the W135 serogroup, surpassing for the first time the B serogroup (37%). The Metropolitan Region concentrated 80% of these cases, and the remaining 20% affected other seven regions of the country. Forty seven percent of cases corresponded to children less than 5 years of age. The predominant clinical presentation of the W135 serogroup was a sepsis in 67% of cases. The fatality ratio of IDM during 2012 was 27%, the highest in the past 20 years. With this information, the Chilean Ministry of Health decreed a sanitary alert and implemented an integrated approach to control and prevent W-135 IDM, denominated "W-135 Action Plan".

Situación epidemiológica y cumplimiento de indicadores de la vigilancia de la enfermedad meningocócica / Epidemiologic status and fulfillment of surveillance indicators of meningococcal disease

La enfermedad meningocócica es de distribución mundial y presenta brotes de gran magnitud en el cinturón de la meningitis (África Subsahariana). A partir de 2001, la tendencia de la enfermedad en Chile disminuye, cambiando su presentación a baja endemia. Así, en el 2010 presentó una incidencia de 0,5 por cien mil habitantes. El grupo más afectado son los menores de 5 años, y de éstos, los menores de un año. Además, desde 1994 el serogrupo C fue considerado reemergente, produciendo brotes en 1999 y 2002. Esta enfermedad es de vigilancia universal e inmediata, cuyo sistema de vigilancia contempla indicadores de calidad, que evalúan los componentes clínico, epidemiológico y laboratorio. Este artículo analiza la situación epidemiológica de la enfermedad en Chile y su tendencia mundial, así como el fundamento para el cumplimiento de indicadores que requieren una respuesta oportuna frente al caso sospechoso sin esperar la confirmación de laboratorio.

Meningococcal disease has worldwide distribution and present large-scale outbreaks on the meningitis belt (sub-Saharian Africa). Since 2001, disease trend in Chile decreases, changing its presentation to low endemicity. Thus, 2010 registered an incidence of 0.5 per 100 thousand habitants. The most affected group was < 5 years old, specifically < 1 year old. Besides,since 1994, serogroup C was considered re-emergent, causing outbreaks in 1999 and 2002. This disease considersimmediate and universal surveillance and comprise quality indicators that assess clinical, epidemiological and laboratory components. This article analyze the epidemiological situation in Chile and its world trend, also the fundamental basis for indicator fullfilments that requires a fast response against a suspected case, without waiting for laboratory confirmation.

Certificación de la eliminación de sarampión, rubéola y SRC en Chile / Certification of elimination of measles, rubella and CRS in Chile

Debido al éxito en la eliminación del sarampión, rubéola y Síndrome Rubéola Congénito alcanzado en América, la Organización Panamericana de la Salud solicitó verificar la eliminación de estas enfermedades en los países de la región. Chile ratificó mediante Resolución a un comité nacional de expertos que revisó la información entregada por los equipos técnicos, en los siguientes componentes: epidemiología del sarampión, rubéola y SRC; calidad de la vigilancia; epidemiología molecular; sostenibilidad del programa de inmunizaciones y cohortes de población vacunada. La información obtenida de diversas fuentes permitió integrar la evidencia y determinar si los datos eran válidos, completos, representativos y consistentes. Esta publicación describe las etapas de la certificación y la información evaluada por el comité nacional ad hoc. Sus conclusiones serán ratificadas por el comité internacional, el que certificará si Chile cumple con los criterios para la eliminación, proceso que se espera culmine en diciembre 2011. Debido al constante riesgo de importación de estos virus desde otras partes del mundo, persisten muchos retos para mantener la eliminación en el tiempo.

Due to the success in the elimination of measles, rubella and CRS reached in the Americas, PAHO requested the verification of the elimination of these diseases in the countries of the region. Chile ratified by means of a resolution a National Committee of Experts, which revised the information provided by the technical teams in the following components: Epidemiology of measles, rubella and CRS; quality of the surveillance; molecular epidemiology; sustainability of the Immunization Program and cohorts of vaccinated population. The information gathered from different sources allowed to integrate the evidence provided and to determine if the data were valid, complete, representatives and consistent. In this paper we describe thecertification steps and the information evaluated by the ad-hoc national committee. Their conclusions will be ratified by the International Committee, which will certify if Chile fulfills the criteria for elimination, a process that is expected to end during December 2011.

Vigilancia de influenza en Chile: 2010 / Influenza surveillance in Chile: 2010

Se analizó el comportamiento de la influenza en el 2010, a través de los componentes de la vigilancia. Desde la semana epidemiológica (SE) 32 aumenta la notificación de ETI en los centinela, con un máximo de casos en la SE 37 (tasa 80 por 105), inferior a 2009. Este aumento coincide con el alza de las consultas respiratorias (especialmente infecciones respiratorias agudas altas e influenza) que llega a 43 por ciento en la SE 36. Destaca la cocirculación de influenza AH1N1 (2009) y H3N2, con predominio de esta última y un máximo en la SE 36. La gravedad (hospitalizaciones por infecciones respiratorias agudas graves y fallecidos) fue menor que en 2009 y se concentró en los casos de H3N2. El aumento observado el 2010 fue de intensidad elevada, de carácter epidémico, y se desplazó a los meses de agosto-septiembre. Se requiere mantener y reforzar los componentes de la vigilancia influenza en el actual período pospandémico.

It was analyzed the 2010 influenza behaviour through surveillance components. Since epidemiologic week (EW) 32, influenza like disease notification increases in sentinel centers, with a maximum of cases on EW 37 (rate of 80 per 105), less than2009. This increase coincide with the rise in respiratory hospital visits (especially upper acute respiratory infections) reaching 43 percent on EW 36. it is registered co-circulation of influenza AH1N1 (2009) and H3N2, the last prevailing over the first one anda maximum on EW 36. Severity (severe acute respiratory infections hospitalizations and deaths) was lower than 2009 and was concentrated in H3N2 cases. The observed increase in 2010 was of high intensity, epidemic nature and shifted to August-September. It is required maintaining and reinforcing influenza surveillance components, in the current pos-pandemic period.

Vigilancia de infecciones respiratorias agudas graves durante la influenza A (H1N1) pandémica en Chile, 2009 / Surveillance of severe acute respiratory infections during influenza A (H1N1) pandemic in Chile, 2009

Se presenta la evolución de la epidemia de la influenza A (H1N1) pandémica en Chile a través de un indicador de gravedad: casos de infecciones respiratorias agudas (IRAG) con evolución grave, y se identifican sus características epidemiológicas utilizando los datos del Ministerio de Salud, incluyendo todos los casos sospechosos y confirmados de influenza. Se notificaron 1.606 casos de IRAG, con una tasa acumulada de 9,4 casos por 100.000 habitantes, inferior a otros países de América. Los mayores riesgos se presentan en el norte y en áreas del extremo sur del país. Los menores de 5 años son el grupo de mayor riesgo (tasa de 30,7 por cien mil hab.), y la tasa de hospitalización de los de 50 y más años también refleja un riesgo de mayor gravedad. Destaca el alto porcentaje de comorbilidad 53 por ciento, similar a lo registrado en Canadá.

The evolution of the epidemic of influenza A (H1N1) pandemic in Chile is presented using an indicator of severity: acute respiratory infections (SARI) with serious evolution, and identifying its epidemiological characteristics. Data from the Ministry of Health, including all suspected and confirmed cases of influenza, is analyzed. SARI cases reported were 1606, with a cumulative rate of 9.4 cases per 100,000 inhabitants, lower than other countries in America. The greatest risks occur in the northern and southernmost areas of the country. All children under 5 years are at greatest risk (rate of 30.7 per 100,000 inhabitants.), and the rate of hospitalization for those 50 and over also reflect a more serious risk. The high percentage of co-morbidity, 53 percent, is similar to that reported in Canada.

Descentralización del diagnóstico de influenza pandémica en Chile: implementación laboratorios regionales de RT-PCR / Decentralization of pandemic influenza diagnosis in Chile: implementing regional laboratories RT-PCR

Debido a la pandemia de influenza A (H1N1) en el mundo, el Ministerio de Salud en Chile desarrolló un proyectodestinado a fortalecer la capacidad de los laboratorios descentralizados, mediante utilización de la técnica de biología molecular RT-PCR. El proyecto contempló: 1) Readecuación de los espacios físicos en los laboratorios clínicos, 2) compra de equipamiento, 3) adquisición de reactivos e insumos de laboratorio, 4) adquisición de materiales para la toma de muestra, 5) capacitación del recurso humano y 6) verificación del correcto funcionamiento del laboratorio. Al 2010, se encuentran funcionando 6 laboratorios que emplean RT-PCR; se ha obtenido un 100 por ciento de concordancia de las muestras y las autoridades centrales han elaborado un algoritmo de derivación de muestras respiratorias por parte de los 29 Servicios de Salud a los laboratorios regionales, basado en grupos objetivos establecidos en la vigilancia de influenza.

Due to pandemic influenza A (H1N1) in the world, the Ministry of Health in Chile developed a project to strengthen decentralized laboratory capacity through the use of molecular biology technique RT-PCR. The project included: 1) Renovating the physical space in clinical laboratories, 2) purchasing equipment, 3) purchasing laboratory reagents and supplies, 4) acquiring materials for sample collection, 5) human resource training 6) verifying the proper functioning of the laboratory. By 2010, 6 laboratories employing RT-PCR are running, a 100 percent match of the samples has been obtained and the central authorities have developed an algorithm for derivation of respiratory specimens from the 29 Health Services to regional laboratories based on target groups established in the surveillance of influenza.

El brote de influenza AH1N1 en tres colegios de la región metropolitana: impacto de las medidas de control adoptadas / Outbreak of H1N1 influenza in three schools in the metropolitan area: impact of control measures

Se compara el impacto de tres estrategias distintas de medidas no farmacológicas (MNF) en tres colegios de la Región Metropolitana en Chile para controlar el brote de influenza AH1N1: colegio A) con suspensión de clases,colegio B) con suspensión selectiva y colegio C) sin suspensión de clases y sin administración de antivirales. Utilizando cuestionarios e información de los colegios, los datos recolectados indican que la tasa de incidenciaacumulada fue 40,3 por ciento (colegio A), 39,6 por ciento (colegio B) y 42,5 por ciento (colegio C). Al restringir la comparación a los dosúltimos colegios, es decir, aquellos en los que la suspensión de clases fue selectiva o bien no hubo suspensión, larazón de tasas (ajustada) del colegio C vs. B fue 1,09 (p = 0,473). A pesar de no alcanzar significancia estadística,este resultado apoya la hipótesis de que la suspensión selectiva de clases tuvo un impacto en reducir la magnituddel brote infeccioso. Los beneficios de una suspensión selectiva de clases (menor tasa de incidencia acumulada ydensidad de incidencia) tienen asociada, sin embargo, una limitación debido a una mayor inasistencia a clases.

The impact of three different strategies of nonpharmacologic measures (MNF) at three schools in the Metropolitan Region in Chile to control outbreaks of influenza AH1N are compared: school A) suspension of classes, school B) selective suspension, C) no suspension of classes and without administration of antiviral drugs. Data collected through questionnaires and information from schools, indicate that the incidence rate was 40.3 percent (school A), 39.6 percent (school B) and 42.5 percent (school C). Restricting the comparison to the last two schools, ie those in which the suspension of classes was selective or no suspension, the rate ratio (adjusted) of C school vs B was 1.09 (p = 0.473). Although not statistically significant, this result supports the hypothesis that the selective suspension of classes had an impact in reducing the magnitude of the outbreak. The benefits of selectively discontinuing classes (lower cumulative incidence and incidence density) are counterbalanced, however, by the limitation of higher non-attendance to school.