Estudio multicéntrico de casos confirmados de COVID-19: datos preliminares de 2690 pacientes pediátricos en Argentina durante el primer año de la pandemia / A multicenter study of confirmed COVID-19 cases: preliminary data on 2690 pediatric patients in Argentina during the first year of the pandemic

Introducción. La evidencia actual indica que la gravedad de la enfermedad por el coronavirus 2019 (COVID-19, por su sigla en inglés) es menor en la población pediátrica, los datos locales aún son limitados. Objetivo: caracterizar los aspectos clínicos y epidemiológicos de la infección por COVID-19 en menores de 18 años en Argentina. Población y métodos. Estudio transversal, observacional y analítico de casos confirmados de COVID-19 entre 0 y 18 años asistidos entre marzo de 2020 y marzo de 2021 en 19 centros pediátricos de referencia de Argentina. Se realizó un análisis multivariado para identificar las variables predictoras de cuadros graves. Resultados. Se incluyeron 2690 casos de COVID-19: 77,7 % residentes del área metropolitana de Buenos Aires, 50,1 % de sexo masculino, mediana de edad de 5,6 años. El 90 % ocurrió entre las semanas epidemiológicas 20-47 del 2020; 60,4 % con antecedente de contacto con personas con COVID-19; y 96,6 % en el entorno familiar. El 51,4 % presentó síntomas respiratorios; 61,6 % síntomas generales; 18,8 % síntomas gastrointestinales; 17,1 % síntomas neurológicos; 7,2 % otros y 21,5 % fueron asintomáticos. El 59,4 % fue hospitalizado; 7,4 fueron graves o críticos. Se registraron 57 casos de síndrome inflamatorio multisistémico. El antecedente de asma, displasia broncopulmonar, cardiopatía congénita, desnutrición moderada a grave, obesidad, enfermedad neurológica crónica y/o edad menor de 6 meses resultaron predictores independientes de gravedad. Residir en barrios vulnerables resultó protector. Conclusiones. Más de la mitad de los casos refirieron antecedente de contacto con personas con COVID-19 en el entorno familiar. La hospitalización no respondió a criterios clínicos de gravedad. La gravedad se encuentra asociada a la existencia de ciertas comorbilidades.

Introduction. The current evidence indicates that the severity of the coronavirus disease 2019 (COVID-19) is lower in the pediatric population but local data are still limited. Objective: To characterize the clinical and epidemiological aspects of COVID-19 infection in patients younger than 18 years in Argentina. Population and methods. Cross-sectional, observational, and analytical study of confirmed COVID-19 patients aged 0-18 years seen between March 2020 and March 2021 at 19 referral children's hospitals of Argentina. A multivariate analysis was done to identify predictors of severe cases. Results. A total of 2690 COVID-19 cases were included: 77.7% lived in the Metropolitan Area of Buenos Aires; 50.1% were males; patients' median age was 5.6 years. Of them, 90% were seen during epidemiological weeks 20-47 of 2020; 60.4% had a history of contact with COVID-19 patients; and 96.6% in their family setting. Also, 51.4% had respiratory symptoms; 61.6%, general symptoms; 18.8%, gastrointestinal symptoms; 17.1%, neurological symptoms; 7.2%, other symptoms; and 21.5% were asymptomatic. In addition, 59.4% of patients were hospitalized and 7.4% had a severe or critical course. A total of 57 patients developed multisystem inflammatory syndrome. A history of asthma, bronchopulmonary dysplasia, congenital heart disease, moderate to severe malnutrition, obesity, chronic neurological disease and/or age younger than 6 months were independent predictors of severity.Livinginavulnerableneighborhoodwas a protective factor. Conclusions. More than half of cases referred a history of contact with COVID-19 patients in the family setting. Hospitalization was not based on clinical criteria of severity. Severity was associated with the presence of certain comorbidities

Virus sincicial respiratorio en niños nacidos prematuros: 19 años de vigilancia epidemiológica activa en un hospital pediátrico / Respiratory syncytial virus in preterm infants: 19 years of active epidemiological surveillance in a children's hospital

Introducción. El virus sincicial respiratorio (VSR) es el principal agente causal de la infección respiratoria aguda baja (IRAB) en pediatría. Los niños prematuros tienen mayor riesgo de complicaciones asociadas con esta infección. Los objetivos fueron describir y comparar las características clínicas y epidemiológicas asociadas a IRAB por VSR en niños/as nacidos pretérmino y a término, y establecer predictores de letalidad en los prematuros.Métodos. Estudio prospectivo, transversal, de pacientes ingresados por IRAB, en el período 2000-2018. El diagnóstico virológico se realizó mediante inmunofluorescencia indirecta o reacción en cadena de la polimerasa con transcriptasa inversa de aspirados nasofaríngeos. Se registraron las características clínico-epidemiológicas. Se desarrolló un modelo de regresión logística múltiple para establecer los predictores de letalidad en prematuros.Resultados. Se incluyeron 16 018 casos de IRAB; 13 545 (el 84,6 %) fueron estudiados; 6047 (el 45 %) positivos; VSR predominó en el 81,1 % (4907); mostró un patrón epidémico estacional; el 14 % (686) fueron prematuros.Los prematuros mostraron mayor frecuencia de comorbilidades, antecedentes respiratorios perinatales, cardiopatía congénita, desnutrición, enfermedad respiratoria crónica, displasia broncopulmonar, hospitalización previa por IRAB y enfermedad neurológica crónica (p < 0,001); requirieron más cuidados intensivos, mayor tiempo de internación y mayor tasa de letalidad (p < 0,01). La cardiopatía congénita fue predictor independiente de letalidad por VSR en prematuros [OR 3,67 (1,25-10,8), p = 0,01].Conclusión. VSR mostró un patrón epidémico, afectó a prematuros con ciertas comorbilidades con mayor morbimortalidad que los de término. La letalidad por VSR en prematuros se asoció con la cardiopatía congénita.

Introduction. Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection (ALRTI) in pediatrics. Preterm infants are at a higher risk for complications. We aimed to describe and compare the clinical and epidemiological characteristics associated with ALRTI due to RSV in preterm and term infants and to establish the predictors of fatality among preterm infants.Methods. Prospective, cross-sectional study of patients admitted due to ALRTI in the 2000-2018 period. Viral diagnosis was done by indirect immunofluorescence or reverse transcription polymerase chain reaction in nasopharyngeal aspirates. Clinical and epidemiological characteristics were recorded. A multiple logistic regression model established the predictors of fatality among preterm infants.Results. A total of 16 018 ALRTI cases were included; 13 545 (84.6 %) were tested; 6047 (45 %) were positive; RSV was prevalent in 81.1 % (4907), with a seasonal epidemic pattern; 14 % (686) were preterm infants.Comorbidities, perinatal respiratory history, congenital heart disease, malnutrition, chronic respiratory disease, bronchopulmonary dysplasia, prior hospitalization due to ALRTI, and chronic neurological disease (p < 0.001) were more common among preterm infants; they required more intensive care and a longer length of stay, and had a higher fatality rate (p < 0.01). Congenital heart disease was an independent predictor of fatality due to RSV among preterm infants (OR: 3.67 [1.25-10.8], p = 0.01).Conclusion. RSV showed an epidemic pattern and affected more preterm infants with certain comorbidities, with a higher morbidity and mortality, compared to term infants. RSV fatality among preterm infants was associated with congenital heart disease.

Influencia de los virus respiratorios en la evaluación de la efectividad de la vacuna neumocócica de 13 serotipos en menores de 5 años: estudio de series temporales 2001-2013 / Influence of respiratory viruses on the evaluation of the 13-valent pneumococcal conjugate vaccine effectiveness in children under 5 years old: A time-series study for the 2001-2013 period

Introducción. Streptococcus pneumoniae es el principal agente de las neumonías consolidantes de causa bacteriana. En 2012, se introdujo la vacuna contra neumococo de 13 serotipos al Calendario Nacional en Argentina para niños inmunocompetentes a partir de los dos meses de edad (2 + 1). Objetivo. Analizar la influencia de los virus respiratorios en la evaluación de la efectividad de la vacuna conjugada contra el neumococo de 13 serotipos en relación con el número de hospitalizaciones por neumonías consolidantes confirmadas por radiología (NCCR). Métodos. Estudio observacional analítico de series temporales. Se incluyeron todos los niños internados con diagnóstico de NCCR según criterios de la Organización Mundial de la Salud, marzo-noviembre de 2001-2013. El diagnóstico viral (virus sincicial respiratorio, adenovirus, influenza y parainfluenza) se realizó por inmunofluorescencia indirecta de aspirados nasofaríngeos o por reacción en cadena de la polimerasa con transcriptasa inversa. Se desarrollaron series temporales que compararon los períodos prevacunación 20012011 y posvacunación 2012-2013. Resultados. De un total de 11 306 niños menores de 5 años con infecciones respiratorias agudas bajas, se incluyeron 4974 con NCCR. Promedio anual de internación por NCCR: 394,8 prevacunación; 315,5 posvacunación (reducción del 20,1%; IC 95% 13,13-26,49%; p <0,001). Promedio anual de internación por NCCR no viral: 255,5 prevacunación; 183 posvacunación (reducción del 28,4%; IC 95% 20,5-35,78%; p <0,001). Promedio anual de internación por NCCR viral: 139,2 prevacunación; 132 posvacunación (reducción del 4,8%; IC 95% 8,38-16,49%; p= 0,4758). La proporción de NCCR con diagnóstico viral positivo fue 35,3% prevacunación y 42% posvacunación (p= 0,001). Conclusiones. Se observó un descenso significativo de las internaciones por NCCR en forma global luego de la introducción de la vacuna contra neumococo de 13 serotipos, particularmente en aquellas de etiología no viral. Es fundamental continuar la vigilancia epidemiológica para evaluar el impacto de esta medida y el comportamiento viral en relación con las NCCR.

Introduction. S treptococcus pneumoniae is the main agent in bacterial consolidated pneumonias. In 2012, the 13-valent pneumococcal conjugate vaccine was introduced in the Argentine national immunization schedule for immunocompetent children as of two months old with a two-dose schedule plus a booster. Objective.To analyze the influence of respiratory viruses on the evaluation of the 13-valent pneumococcal conjugate vaccine effectiveness in relation to the number of hospitalizations for radiologically-confirmed consolidated pneumonias (RCCP). Methods. Observational, analytical, time-series study. All children hospitalized with a diagnosis of RCCP as per the World Health Organization's criteria between March and November throughout the2001-2013period were included. Viral diagnosis (respiratory syncytial virus, adenovirus, influenza and parainfluenza) was performed by indirect immunofluorescence using nasopharyngeal aspirates or by reverse transcription polymerase chain reaction. Time-series were developed to compare preimmunization 2001-2011 and post-immunization 2012-2013 periods. Results. Out of a total of 11,306 children under 5 years old with acute lower respiratory tract infections, 4974 with RCCP were included. Annual average number of hospitalizations for RCCP: 394.8 pre-immunization, 315.5 post-immunization (reduction of 20.1%, 95% confidence interval --CI--: 13.13-26.49%, p < 0.001). Annual average number of hospitalizations for non-viral RCCP: 255.5 pre-immunization, 183 post-immunization (reduction of 28.4%, 95% CI: 20.5-35.78%, p < 0.001). Annual average number of hospitalizations for viral RCCP: 139.2 pre-immunization, 132 post-immunization (reduction of 4.8%, 95% CI: 8.38-16.49%, p= 0.4758). The proportion of RCCP with positive viral diagnosis was 35.3 % pre-immunization and 42% post-immunization (p= 0.001). Conclusions. An overall significant reduction in the number of hospitalizations for RCCP was observed following the introduction of the 13-valent pneumococcal conjugate vaccine, especially in the case of non-viral pneumonias. It is critical to continue with the epidemiological surveillance to evaluate the impact of this intervention and viral behavior in relation to RCCP.

Influencia de los virus respiratorios en la evaluación de la efectividad de la vacuna neumocócica de 13 serotipos en menores de 5 años: estudio de series temporales 2001-2013 / Influence of respiratory viruses on the evaluation of the 13-valent pneumococcal conjugate vaccine effectiveness in children under 5 years old: A time-series study for the 2001-2013 period

Introducción. Streptococcus pneumoniae es el principal agente de las neumonías consolidantes de causa bacteriana. En 2012, se introdujo la vacuna contra neumococo de 13 serotipos al Calendario Nacional en Argentina para niños inmunocompetentes a partir de los dos meses de edad (2 + 1). Objetivo. Analizar la influencia de los virus respiratorios en la evaluación de la efectividad de la vacuna conjugada contra el neumococo de 13 serotipos en relación con el número de hospitalizaciones por neumonías consolidantes confirmadas por radiología (NCCR). Métodos. Estudio observacional analítico de series temporales. Se incluyeron todos los niños internados con diagnóstico de NCCR según criterios de la Organización Mundial de la Salud, marzo-noviembre de 2001-2013. El diagnóstico viral (virus sincicial respiratorio, adenovirus, influenza y parainfluenza) se realizó por inmunofluorescencia indirecta de aspirados nasofaríngeos o por reacción en cadena de la polimerasa con transcriptasa inversa. Se desarrollaron series temporales que compararon los períodos prevacunación 20012011 y posvacunación 2012-2013. Resultados. De un total de 11 306 niños menores de 5 años con infecciones respiratorias agudas bajas, se incluyeron 4974 con NCCR. Promedio anual de internación por NCCR: 394,8 prevacunación; 315,5 posvacunación (reducción del 20,1%; IC 95% 13,13-26,49%; p <0,001). Promedio anual de internación por NCCR no viral: 255,5 prevacunación; 183 posvacunación (reducción del 28,4%; IC 95% 20,5-35,78%; p <0,001). Promedio anual de internación por NCCR viral: 139,2 prevacunación; 132 posvacunación (reducción del 4,8%; IC 95% 8,38-16,49%; p= 0,4758). La proporción de NCCR con diagnóstico viral positivo fue 35,3% prevacunación y 42% posvacunación (p= 0,001). Conclusiones. Se observó un descenso significativo de las internaciones por NCCR en forma global luego de la introducción de la vacuna contra neumococo de 13 serotipos, particularmente en aquellas de etiología no viral. Es fundamental continuar la vigilancia epidemiológica para evaluar el impacto de esta medida y el comportamiento viral en relación con las NCCR.(AU)

Introduction. S treptococcus pneumoniae is the main agent in bacterial consolidated pneumonias. In 2012, the 13-valent pneumococcal conjugate vaccine was introduced in the Argentine national immunization schedule for immunocompetent children as of two months old with a two-dose schedule plus a booster. Objective.To analyze the influence of respiratory viruses on the evaluation of the 13-valent pneumococcal conjugate vaccine effectiveness in relation to the number of hospitalizations for radiologically-confirmed consolidated pneumonias (RCCP). Methods. Observational, analytical, time-series study. All children hospitalized with a diagnosis of RCCP as per the World Health Organizations criteria between March and November throughout the2001-2013period were included. Viral diagnosis (respiratory syncytial virus, adenovirus, influenza and parainfluenza) was performed by indirect immunofluorescence using nasopharyngeal aspirates or by reverse transcription polymerase chain reaction. Time-series were developed to compare preimmunization 2001-2011 and post-immunization 2012-2013 periods. Results. Out of a total of 11,306 children under 5 years old with acute lower respiratory tract infections, 4974 with RCCP were included. Annual average number of hospitalizations for RCCP: 394.8 pre-immunization, 315.5 post-immunization (reduction of 20.1%, 95% confidence interval |-CI-|: 13.13-26.49%, p < 0.001). Annual average number of hospitalizations for non-viral RCCP: 255.5 pre-immunization, 183 post-immunization (reduction of 28.4%, 95% CI: 20.5-35.78%, p < 0.001). Annual average number of hospitalizations for viral RCCP: 139.2 pre-immunization, 132 post-immunization (reduction of 4.8%, 95% CI: 8.38-16.49%, p= 0.4758). The proportion of RCCP with positive viral diagnosis was 35.3 % pre-immunization and 42% post-immunization (p= 0.001). Conclusions. An overall significant reduction in the number of hospitalizations for RCCP was observed following the introduction of the 13-valent pneumococcal conjugate vaccine, especially in the case of non-viral pneumonias. It is critical to continue with the epidemiological surveillance to evaluate the impact of this intervention and viral behavior in relation to RCCP.(AU)

Epidemiología de Bordetella pertussis en un hospital pediátrico / Epidemiology of Bordetella pertussis in a childrens hospital

Introducción. La tos ferina o coqueluche continúa siendo una importante causa de morbimortalidad en los menores de un año. Objetivos. Describir el perfil clínico-epidemiológico de Bordetella pertussis, y analizar los factores asociados a la confrmación por PCR y la letalidad. Materiales y métodos. Estudio prospectivo de cohorte realizado entre diciembre de 2003 y diciembre de 2011. Se incluyeron niños asistidos en el Hospital de Niños Ricardo Gutiérrez con sospecha de padecer la enfermedad. Se estudiaron los factores asociados a confrmación por PCR y letalidad mediante riesgo relativo (RR) con intervalo del 95%. Resultados. Se incluyeron 620 pacientes con una positividad del 38% (236/620), 3 casos se confrmaron por nexo. Los confrmados (239) presentaron un patrón estacional de septiembre a febrero, una mediana de edad de 3 meses, y 89%, menos de tres dosis de vacuna. El 86% se internaron: la mediana de estadía fue de 7 días. Un 99% de los pacientes eran eutrófcos, 98% inmunocompetentes y 17,5% requirieron cuidados intensivos. Se analizó la clínica en 480 pacientes. El 38% (184) tuvieron PCR positiva y presentaron: 96,2% tos, 76,5% tos paroxística, 57,9% cianosis, 55,7% difcultad respiratoria, 29% febre, 22,4% apnea, 21,9% vómitos postusígenos. El análisis multivariado identifcó, como predictores independientes asociados a la confrmación de coqueluche por PCR: tos paroxística (OR 2,52: 1,50 a 4,22; p= 0,000) y leucocitosis al ingre s a r ≥20 000 glóbulos blancos/ mm³ (OR 7,96: 4,82 a 13,17; p= 0,000); haber presentado febre disminuyó la probabilidad de obtener un resultado de PCR positivo (OR 0,47: 0,29 a 0,77; p = 0,003). La letalidad en los pacientes internados fue de 6,8%. Una leucocitosis ≥ 30 000 glóbulos blancos/mm³ fue un predictor de letalidad (RR 6,7: 1,88 a 23,9; p= 0,001). Conclusiones. Los casos confirmados correspondieron, en su mayoría, a menores de un año antes sanos y que no habían completado el esquema de vacunación primario. La tos paroxística y la leucocitosis se asociaron al diagnóstico por PCR, mientras que la leucocitosis fue un predictor de mortalidad.(AU)

Introduction. Pertussis or whooping cough continues to be a major cause of morbidity and mortality in infants younger than 1 year old. Objectives. To describe the clinical and epidemiological profle of Bordetella pertussis and to analyze the factors associated with confrmation by PCR and case fatality rate. Material and Methods. Prospective, cohort study conducted between December 2003 and December 2011. The study included children seen at the Hospital de Niños Ricardo Gutiérrez suspected of pertussis. The factors associated with confrmation by PCR and the case fatality rate by relative risk (RR) with a 95% confdence interval were studied. Results. Six hundred and twenty patients with a 38% of positive cases (236/620) were included, 3 cases were confrmed by epidemiological link. Confrmed cases (239) showed a seasonal pattern from September through February, a median age of 3 months old, and 89% had received less than three vaccine doses. Eighty six percent of patients were hospitalized: their median length of stay was 7 days. A total of 99% of patients were eu-trophic, 98% were immunocompetent and 17.5% required intensive care. The clinical presentation was analyzed in 480 patients. Of them, 38% (184) had a positive PCR result and their symptoms were: 96.2%, cough; 76.5%, paroxysmal cough; 57.9% cyanosis; 55.7%, respiratory distress; 29%, fever; 22.4%, apnea; 21.9%, vomiting after coughing. A multivariate analysis identifed the following as independent predictors associated with confrmation of pertussis by PCR: paroxysmal cough (OR 2.52: 1.50-4.22; p= 0.000) and leu-kocytosis upon admission >20 000 white blood cells/mm³ (OR 7.96: 4.82-13.17; p= 0.000); having developed fever reduced the chance of having a positive PCR result (OR 0.47: 0.29-0.77; p= 0.003). The case fatality rate for hospitalized patients was 6.8%. Leukocytosis >30 000 white blood cells/mm3 was a predictor of fatality (RR 6.7: 1.88-23.9; p= 0.001). Conclusions. Confrmed cases were mostly infants younger than 1 year old who were healthy before and who had not completed their primary immunization schedule. Paroxysmal cough and leukocytosis were associated with PCR diagnosis, while leukocytosis was a predictor of mortality.(AU)

Virus respiratorio sincicial: Patrón clínico epidemiológico en niños internados en un hospital pediátrico durante los años 2000-2013 / Respiratory syncytial virus: Clinical and epidemiological pattern in pediatric patients admitted to a childrens hospital between 2000 and 2013

Introducción. El virus respiratorio sincicial (VRS) es el principal agente asociado a infección respiratoria aguda baja en niños. El objetivo de este estudio fue describir el patrón clínico-epidemiológico e identificar los factores de riesgo de infección por VRS. Población y métodos. Estudio prospectivo de cohorte de pacientes internados por infección respiratoria aguda baja en el Hospital de Niños Ricardo Gutiérrez, marzo-noviembre, 20002013. El diagnóstico viral para VRS, adenovirus, influenza y parainfluenza se realizó por inmunofluorescencia indirecta de aspirados nasofaríngeos. Resultados. Se incluyeron 12 555 niños; 38,2% (4798) presentaron rescate viral; el VRS representó el 81,8% (3924/4798) sin variaciones anuales significativas (71,2-88,1), con patrón epidémico estacional (mayo-julio); fue seguido por influenza (7,6%), parainfluenza (5,9%) y adenovirus (4,7%). Los casos con rescate de VRS (3924) tuvieron una mediana de edad de 7 meses (0-214 meses); 74,2% eran menores de 1 año; 43,1%, menores de 6 meses; 56,5%, varones; y la manifestación clínica más frecuente fue bronquiolitis (60,7%). El 41,6% tenía comorbilidades; las más frecuentes, enfermedad respiratoria crónica (74%), cardiopatías congénitas (14%) y enfermedad neurológica crónica (10,2%). El 25% presentó complicaciones. La letalidad fue 1,9% (74/3888). Los predictores independientes de infección por VRS fueron la edad < 3 meses OR 2,8 (2,14-3,67), p < 0,01 , la bronquiolitis como presentación clínica OR 1,54 (1,32-1,79), p < 0,01 y la presencia de hipoxemia al momento del ingreso OR 1,84 (1,42-2,37), p < 0,01 . Conclusiones. La infección por VRS presentó un patrón epidémico estacional y se asoció más a niños pequeños menores de tres meses con bronquiolitis e hipoxemia al momento del ingreso.(AU)

.(AU)

Situación epidemiológica de coqueluche y estrategias para su control: Argentina, 2002-2011 / Epidemiological situation of pertussis and strategies to control it: Argentina, 2002-2011

Introducción. Coqueluche constituye un problema de salud pública. Objetivos: Describir la morbimortalidad y coberturas de vacunación entre 2002 y 2011, el perfil de los casos de 2011 y las estrategias de control implementadas por el Ministerio de Salud (MSN). Métodos. Estudio descriptivo de vigilancia epidemiológica. Los datos de morbilidad se tomaron del Sistema Nacional de Vigilancia, y los de mortalidad, de la Dirección de Estadística e Información en Salud del MSN y de los informes oficiales de las jurisdicciones. Se utilizó la cobertura administrativa de vacunación a partir de datos provistos por las jurisdicciones al MSN. Se analizó con Epiinfo 7.1.2. Resultados. Entre 2002 y 2011, la notificación de casos de coqueluche y de fallecimientos se incrementó y alcanzó los mayores valores en 2011: tasa de 16 x 100 000 habitantes y 76 fallecidos. Las muertes ocurrieron mayoritariamente en <1 año y las coberturas nacionales de vacunación para 3ra dosis e ingreso escolar fueron >90% y para el primer refuerzo, 80-90%. En 2011, se notificaron 2821 casos confirmados (incidencia 7 x 100 000 hab.): 84% <1 año; 76 fallecidos: 97% <1 año (60,5% <2 meses). Entre las estrategias implementadas, se consolidaron 906 nodos clínicos y 405 de laboratorio; se implementaron la reacción en cadena de la polimerasa como método diagnóstico y la clasificación diferencial de los casos, y se incorporaron dosis adicionales de vacunación. Conclusiones . Entre 2002 y 2011, aumentaron los casos de coqueluche; la mayor morbimortalidad fue en <1 año, con coberturas de vacunación de 80 y 90%. . El mayor número de fallecidos por coqueluche fue en el año 2011. . El MSN fortaleció la vigilancia epidemiológica y orientó las medidas de control.(AU)

Introduction. Pertussis is a challenge for public health. Objectives: To describe pertussis-related morbidity and mortality and immunization coverage for the 2002-2011 period, profile of cases for 2011, and control strategies implemented by the Ministry of Health (MoH) of Argentina. Methods. Descriptive, epidemiological surveillance study. Morbidity data were obtained from the National Health Surveillance System, while mortality data were obtained from the MoHs Health Statistics and Information Department and official jurisdictional reports. Administrative immunization coverage was used based on the data provided by the MoHs jurisdictions. The Epi Info software, version 7.1.2, was used for analysis. Results. The number of reported cases of pertussis increased between 2002 and 2011, reaching its peak in 2011: an incidence of 16 x 100 000 inhabitants, and 76 deaths. Most deaths occurred in infants younger than 1 year old. Immunization coverage achieved at a national level with the third dose and the dose administered at the time of starting primary education was >90%, while the coverage achieved with the first booster dose was 80%-90%. In 2011, 2821 confirmed cases were reported (incidence of 7 x 100 000 inhabitants): 84% in infants <1 year old; 76 deaths: 97% in infants <1 year old (60.5% in infants <2 months old). Among the strategies that were deployed, a total of 906 clinical nodes and 405 laboratory nodes were consolidated; the use of the polymerase chain reaction as a diagnostic method and the differential classification of cases were implemented, and additional vaccine doses were administered. Conclusions . The number of pertussis cases increased between2002 and 2011; the highest morbidity and mortality occurred ininfants younger than 1 year old; immunization coverage reached 80%-90%. . The highest number of pertussis-related deaths was recorded in 2011. . The MoH strengthened the epidemiological surveillance and set guidelines for control measures.(AU)

Epidemiology of Bordetella pertussis in a childrens hospital. / Epidemiology of Bordetella pertussis in a childrens hospital.

INTRODUCTION: Pertussis or whooping cough continues to be a major cause of morbidity and mortality in infants younger than 1 year old. OBJECTIVES: To describe the clinical and epidemiological profile of Bordetella pertussis and to analyze the factors associated with confirmation by PCR and case fatality rate. MATERIAL AND METHODS: Prospective, cohort study conducted between December 2003 and December 2011. The study included children seen at the Hospital de Niños Ricardo Gutiérrez suspected of pertussis. The factors associated with confirmation by PCR and the case fatality rate by relative risk (RR) with a 95

confidence interval were studied. RESULTS: Six hundred and twenty patients with a 38

of positive cases (236/620) were included, 3 cases were confirmed by epidemiological link. Confirmed cases (239) showed a seasonal pattern from September through February, a median age of 3 months old, and 89

had received less than three vaccine doses. Eighty six percent of patients were hospitalized: their median length of stay was 7 days. A total of 99

of patients were eu-trophic, 98

were immunocompetent and 17.5

required intensive care. The clinical presentation was analyzed in 480 patients. Of them, 38

(184) had a positive PCR result and their symptoms were: 96.2

, cough; 76.5

, paroxysmal cough; 57.9

cyanosis; 55.7

, respiratory distress; 29

, fever; 22.4

, apnea; 21.9

, vomiting after coughing. A multivariate analysis identified the following as independent predictors associated with confirmation of pertussis by PCR: paroxysmal cough (OR 2.52: 1.50-4.22; p= 0.000) and leukocytosis upon admission >20 000 white blood cells/mm3 (OR 7.96: 4.82-13.17; p= 0.000); having developed fever reduced the chance of having a positive PCR result (OR 0.47: 0.29-0.77; p= 0.003). The case fatality rate for hospitalized patients was 6.8

. Leukocytosis >30 000 white blood cells/mm3 was a predictor of fatality (RR 6.7: 1.88-23.9; p= 0.001). CONCLUSIONS: Confirmed cases were mostly infants younger than 1 year old who were healthy before and who had not completed their primary immunization schedule. Paroxysmal cough and leukocytosis were associated with PCR diagnosis, while leukocytosis was a predictor of mortality.

Respiratory syncytial virus: clinical and epidemiological pattern in pediatric patients admitted to a childrens hospital between 2000 and 2013. / Respiratory syncytial virus: clinical and epidemiological pattern in pediatric patients admitted to a childrens hospital between 2000 and 2013.

INTRODUCTION: Respiratory syncytial virus (RSV) is the major causative organism associated with acute lower respiratory tract infections in children.The objective of this study was to describe the clinical and epidemiological pattern of RSV and identify risk factors for RSV infection. POPULATION AND METHODS: Prospective, cohort study on patients hospitalized due to acute lower respiratory tract infection at Hospital de Niños Ricardo Gutiérrez between March and November throughout the 2000-2013 period. The virological diagnosis of RSV, adenovirus, influenza and parainfluenza was performed by indirect immunofluorescence using nasopharyngeal aspirates. RESULTS: A total of 12,555 children were included, 38.2

(4798) had virus rescued from samples. RSV accounted for 81.8

of cases (3924/4798) with no significant annual variations (71.2- 88.1) and with an epidemic seasonal pattern(May through July); RSV was followed by influenza (7.6

), parainfluenza (5.9

), and adenovirus (4.7

).The median age of patients with RSV rescue (3924) was 7 months old (0- 214 months old), while 74.2

were younger than 1 year old, 43.1

were younger than 6 months old, 56.5

were males and the most common clinical presentation was bronchiolitis (60.7

). Comorbidities were observed in 41.6

of cases. The most common comorbidities were chronic respiratory disease (74

), congenital heart disease (14

), and chronic neurological disease (10.2

).Complications occurred in 25

of cases. The case fatality rate was 1.9

(74/3888). Independent predictors of RSV infection were age <3 months old (OR: 2.8 [2.14-3.67], p < 0.01),clinical presentation of bronchiolitis (OR: 1.54 [1.32-1.79], p < 0.01), and hypoxemia at the time of admission (OR: 1.84 [1.42-2.37], p < 0.01). CONCLUSIONS: RSV infection displayed a seasonal pattern and was associated with infants younger than 3 months old with bronchiolitis and hypoxemia at the time of admission.

Epidemiological situation of pertussis and strategies to control it: Argentina, 2002-2011. / Epidemiological situation of pertussis and strategies to control it: Argentina, 2002-2011.

INTRODUCTION: Pertussis is a challenge for public health. OBJECTIVES: To describe pertussis-related morbidity and mortality and immunization coverage for the 2002-2011 period, profile of cases for 2011, and control strategies implemented by the Ministry of Health (MoH) of Argentina. METHODS: Descriptive, epidemiological surveillance study. Morbidity data were obtained from the National Health Surveillance System, while mortality data were obtained from the MoHs Health Statistics and Information Department and official jurisdictional reports. Administrative immunization coverage was used based on the data provided by the MoHs jurisdictions. The Epi Info software, version 7.1.2, was used for analysis. RESULTS: The number of reported cases of pertussis increased between 2002 and 2011, reaching its peak in 2011: an incidence of 16 x 100 000 inhabitants, and 76 deaths. Most deaths occurred in infants younger than 1 year old. Immunization coverage achieved at a national level with the third dose and the dose administered at the time of starting primary education was >90

, while the coverage achieved with the first booster dose was 80

-90

. In 2011, 2821 confirmed cases were reported (incidence of 7 x 100 000 inhabitants): 84

in infants <1 year old; 76 deaths: 97

in infants <1 year old (60.5

in infants <2 months old). Among the strategies that were deployed, a total of 906 clinical nodes and 405 laboratory nodes were consolidated; the use of the polymerase chain reaction as a diagnostic method and the differential classification of cases were implemented, and additional vaccine doses were administered. CONCLUSIONS: The number of pertussis cases increased between 2002 and 2011; the highest morbidity and mortality occurred in infants younger than 1 year old; immunization coverage reached 80

-90

. . The highest number of pertussis-related deaths was recorded in 2011. The MoH strengthened the epidemiological surveillance and set guidelines for control measures.