Lactancia materna y protección contra las infecciones respiratorias en los primeros meses de vida / Breastfeeding and the protection against respiratory infections in the first months of life

Introducción: entre las ventajas de la lactancia materna (LM) se incluye su papel protector ante infecciones respiratorias (IR). Objetivos: describir el patrón de LM de una cohorte de recién nacidos (RN) y su protección contra las IR en el lactante. Material y métodos: estudio prospectivo de 316 RN, de las áreas 8 y 9 de Madrid, desde el nacimiento mediante llamadas telefónicas quincenales durante el invierno, registrando datos clínicos y epidemiológicos. Si presentaban sintomatología compatible con IR se recogió aspirado nasofaríngeo. Resultados: mil ochocientas sesenta y cinco llamadas (mediana: 4,2 [1-11]) y 106 visitas programadas. Al mes, el 56,1% recibía LM exclusiva; a los tres meses, el 39,4%, y a los cinco meses, el 31,9%. La LM exclusiva se mantuvo 65,1 días (desviación estándar: 43,49) y ningún factor se asoció a una mayor duración. Hubo 89 episodios de IR aguda. Los hermanos escolares multiplican por 1,74 (intervalo de confianza del 95% [IC 95%]: 1,12-2,72) el riesgo de IR en todos los estratos de duración de LM exclusiva. El riesgo de infección se multiplica por cinco (IC 95%: 2,07-12,19) si la LM exclusiva dura menos de un mes, por 9,8 (IC 95%: 4,06-23,66) si dura entre 30 y 60 días y por 3,4 (IC 95%: 1,28-9,19) si dura entre 60 y 90 días. Conclusiones: aunque muchos RN inician LM exclusiva, solo la tercera parte la mantiene a los cinco meses. Ningún factor se asoció a mayor duración de la misma. La LM es un factor protector de IR cuando dura más de 90 días. Se debe fomentar el mantenimiento de la LM más allá del tercer mes, especialmente en aquellos con hermanos escolares (AU)

Background: the protective role against respiratory infections is included among the advantages of breastfeeding (BF). Objective: to describe the pattern of BF in a cohort of newborns and its protective role against respiratory infections (RI) in the infant. Material and methods: a cohort of 316 newborns (NB) from Madrid Health Districts 8 and 9 was followed by telephone calls every fortnight during the winter season recording clinical and epidemiological data. Nasopharyngeal aspirate was obtained in every patient with symptoms compatible with RI. Results: one thousand, eight hundred and sixty-five phone calls [median: 4.2 (1-11)], and 106 scheduled visits were conducted. At the age of 1 month 56.1% of the infants were exclusively breastfed, at 3 months 39.4% and at 5 months 31.9%. The duration of BF was 65.1 days (SD: 43.49) and no factors were associated to a longer duration. Eighty nine acute RI were registered. The presence of siblings in school age increased the risk of RI by 1.74 (CI 95%: 1.12-2.72) in all the strata of duration of exclusive BF. The risk of RI increased by 5 (CI 95%: 2.07-12.19) if breastfeeding lasted less than 1 month, by 9,8 (CI 95%: 4,06-23,66) between 30-60 days and by 3,4 (CI 95%: 1.28-9,19) if it lasted 60-90 days. Conclusions: though many NB begin BF, only a third part of them go on with it at the age of 5 months. No covariant was associated with a longer duration. BF is a protector factor against RI when it lasts more than 90 days. So it must be promoted specially in those infants with siblings in school age (AU)

Infecciones virales de vías respiratorias en los primeros seis meses de vida / Viral respiratory tract infections in the first six months of life

Antecedentes: El virus respiratorio sincitial (VRS) y otros virus son causas conocidas de hospitalización en lactantes. Menos conocido es el patrón de virus en infecciones extrahospitalarias en menores de 6 meses. Objetivo: El objetivo de este estudio es describir las características clínicas y los factores epidemiológicos asociados con las infecciones respiratorias virales de ámbito extrahospitalario en menores de 6 meses. Pacientes y métodos: Estudio prospectivo en cohorte de niños de las áreas 8 y 9 de Madrid controlados desde el nacimiento mediante llamadas telefónicas quincenales durante una temporada invernal. Se registraron datos clínicos y epidemiológicos en cuestionarios prediseñados. Se exploró y recogió el aspirado nasofaríngeo (ANF) cuando el paciente presentó sintomatología compatible con una infección respiratoria. El diagnóstico de los virus más comunes se realizó con inmunofluorescencia directa (IFD) y amplificación genómica (PCR). Resultados: Fueron seleccionados 316 recién nacidos. Se realizaron 1.865 llamadas telefónicas (mediana 4), y 106 visitas, en 89 de las cuales se confirmó la enfermedad. Los síntomas más frecuentes fueron rinitis (91 %) y tos (69 %). El diagnóstico clínico principal fue infección respiratoria de vías altas (82 %); 17 de 72 ANF realizados (23,2 %) fueron positivos. Se detectaron rinovirus (41,1 %) y VRS (35,2 %). Ingresaron un 16 % (17/106) de los niños atendidos por enfermedad (el 5,3 % de la cohorte), diagnosticados de síndrome febril y de bronquiolitis. No encontramos ningún factor epidemiológico asociado con la infección respiratoria viral en los casos positivos. Conclusiones: En nuestro medio las infecciones respiratorias de los lactantes son en su mayoría banales y no precisan atención hospitalaria. El rinovirus y el VRS son los principales agentes etiológicos. No se encontraron factores epidemiológicos relacionados con la infección respiratoria asociada a virus (AU)

Background: Respiratory syncytial virus and Influenza virus infections are known causes of hospital admission in infants. It is less well known the pattern of virus infections in infants under 6 months of age in the outpatient setting. Objective: To describe the clinical and epidemiological pattern of community-acquired viral respiratory infections in infants under 6 months. Patients and methods: A cohort of infants from the 8 and 9 Madrid Health Districts was followed by telephone calls every two weeks since birth during the epidemic winter season. Clinical and epidemiological data were collected in pre-designed questionnaires. Nasopharyngeal aspirate was obtained in every patient with symptoms compatible with respiratory infection. Diagnosis of the more common virus was made with direct immunofluorescence and nucleic acid amplification test (PCR). Results: Were recruited 316 newborns. The 1,865 phone calls made (median 4 for every child), produced 106 visits, and the illness confirmed in 89 illness. Rhinitis (91 %) and cough (69 %) were the most common symptoms. Upper respiratory infection was the principal clinical diagnosis (84.5 %), and 17 of the 72 samples (23.2 %) were positive. Most common viruses were RSV (41.1 %) and rhinovirus (35.2 %). Of the children visited, 17 out of 106 (16 %) (5.3 % of the cohort) were admitted to hospital. Diagnoses were febrile syndrome and bronchiolitis. We did not find any epidemiological factor associated with viral respiratory infection in positive cases. Conclusions: In our population most of the respiratory infections in infants are minor and do not need hospital assistance. Rhinovirus and RSV are the major pathogens. We did not find any epidemiological factor associated with viral respiratory infection (AU)

[Viral respiratory tract infections in the first six months of life]. / Infecciones virales de vías respiratorias en los primeros seis meses de vida.

BACKGROUND: Respiratory syncytial virus and Influenza virus infections are known causes of hospital admission in infants. It is less well known the pattern of virus infections in infants under 6 months of age in the outpatient setting. OBJECTIVE: To describe the clinical and epidemiological pattern of community-acquired viral respiratory infections in infants under 6 months. PATIENTS AND METHODS: A cohort of infants from the 8 and 9 Madrid Health Districts was followed by telephone calls every two weeks since birth during the epidemic winter season. Clinical and epidemiological data were collected in pre-designed questionnaires. Nasopharyngeal aspirate was obtained in every patient with symptoms compatible with respiratory infection. Diagnosis of the more common virus was made with direct immunofluorescence and nucleic acid amplification test (PCR). RESULTS: Were recruited 316 newborns. The 1,865 phone calls made (median 4 for every child), produced 106 visits, and the illness confirmed in 89 illness. Rhinitis (91%) and cough (69%) were the most common symptoms. Upper respiratory infection was the principal clinical diagnosis (84.5%), and 17 of the 72 samples (23.2%) were positive. Most common viruses were RSV (41.1%) and rhinovirus (35.2%). Of the children visited, 17 out of 106 (16%) (5.3% of the cohort) were admitted to hospital. Diagnoses were febrile syndrome and bronchiolitis. We did not find any epidemiological factor associated with viral respiratory infection in positive cases. CONCLUSIONS: In our population most of the respiratory infections in infants are minor and do not need hospital assistance. Rhinovirus and RSV are the major pathogens. We did not find any epidemiological factor associated with viral respiratory infection.

[Human bocavirus infections in Spanish 0-14 year-old: clinical and epidemiological characteristics of an emerging respiratory virus]. / Infecciones por bocavirus humano en niños españoles: características clínicas y epidemiológicas de un virus respiratorio emergente.

INTRODUCTION: In 2005 a new respiratory virus, called human bocavirus (HBoV), was cloned from respiratory samples from Swedish infants and children with lower respiratory tract infections. OBJECTIVES: To determine whether HBoV has circulated in Spain, estimate the frequency of HBoV infections in patients hospitalized for respiratory infection and describe the clinical and epidemiological characteristics of these patients. PATIENTS AND METHODS: We performed a descriptive prospective study of confirmed HBoV infections in patients aged < 14 years old, hospitalized for respiratory infections between October 2004 and June 2005. Virologic diagnosis was based on multiple RT-PCR for respiratory syncytial virus (RSV) A and B, influenza A,B, and C, parainfluenza 1-4, adenovirus and rhinovirus; PCR was used for human metapneumovirus (hMPV) and PCR in nasopharyngeal aspirates was used for HBoV. The clinical and epidemiological characteristics of patients were analyzed. RESULTS: Fifty-two cases of HBoV infection were detected, representing 17.1% (95% CI: 13% a 21%) of patients hospitalized for respiratory infections. HBoV was the third most frequent viral agent after RSV (30%) and rhinovirus (25%). In 39 patients (71.1%) coinfection with another respiratory virus was detected. Fifty percent of the patients were aged less than 13.6 months and 75% were aged less than 2 years. The most frequent diagnoses were recurrent wheezing (55.8%), bronchiolitis (21.2%) and pneumonia (15.4%). Clinical sepsis with petechial exanthema was found in two patients. Fever > 38 degrees C was found in 72.1% and radiological infiltrate in 44%. Hypoxia was present in 55.8 % of the patients. HBoV was isolated in distinct episodes in two patients. Coinfections were similar to simple infections except that hypoxia was more frequent in the former (p = 0.038). CONCLUSIONS: HBoV is one of the most frequent viruses in severe respiratory infections in patients aged less than 14 years old. Only RSV and rhinovirus are more frequent. Coinfections are highly frequent. Most patients are infants with recurrent wheezing and bronchiolitis.

[Role of rhinovirus in respiratory tract infections in hospitalized children]. / Papel del rinovirus en las infecciones respiratorias en niños hospitalizados.

BACKGROUND: Rhinovirus is a recognized cause of common cold and has been shown to cause asthma exacerbations in adults and children. The burden of rhinovirus infections in hospitalized children has not been described in Spain. OBJECTIVE: To describe confirmed rhinovirus infections in children hospitalized for respiratory tract infection in a secondary public hospital. PATIENTS AND METHODS: We performed a prospective descriptive study in children admitted to hospital with fever or respiratory tract infection and with a positive isolation of rhinovirus in nasopharyngeal washings between September 2004 and July 2005. Virological diagnosis was made with direct immunofluorescent assay and/or reverse transcription-polymerase chain reaction in specimens obtained from nasopharyngeal washings. The clinical characteristics of the patients were analyzed. RESULTS: There were 76 children with rhinovirus infection, representing 25 % of admissions in 304 children with fever or respiratory tract infection. Rhinovirus was the second most frequent viral agent identified after respiratory syncytial virus (RSV) (29.9 % of admissions). Fifty-four children (71.1 %) were under 2 years of age. The most frequent clinical diagnoses were recurrent wheezing in 60.5 %, bronchiolitis in 23.7 %, pneumonia in 7.9 %, and upper respiratory tract infection in 5.3 %. Fever > 38 degrees C was present in 57.9 % of the patients and radiologic infiltrate was found in 23.7 %. Oxygen saturation less than 95 % was found in 43.4 % of the patients. Of 22 children aged more than 2 years, a diagnosis of asthmatic crisis was made in 21. CONCLUSIONS: Rhinoviruses were frequently identified in hospitalized children with respiratory tract disease and were the second most common viruses after RSV. In our series, it was the most frequent cause of recurrent wheezing in hospitalized children and the second most common cause in infants.

Papel del rinovirus en las infecciones respiratorias en niños hospitalizados / Role of rhinovirus in respiratory tract infections in hospitalized children

Antecedentes El rinovirus se considera un agente causal de cuadros catarrales banales, sin embargo se ha descrito como un agente inductor de exacerbaciones asmáticas en adultos y niños mayores. En nuestro medio no se ha descrito el papel del rinovirus en infecciones respiratorias de niños hospitalizados. Objetivos Describir las infecciones confirmadas por rinovirus en niños hospitalizados por infección respiratoria en un hospital de segundo nivel. Pacientes y métodos Estudio descriptivo prospectivo de las infecciones confirmadas por rinovirus en niños hospitalizados por fiebre o infección respiratoria en la temporada 2004-2005. Para el diagnóstico virológico se realizó inmunofluorescencia y reacción en cadena de la polimerasa (PCR) en aspirado nasofaríngeo. Se describen las características clínicas de los pacientes. Resultados Se describen un total de 76 niños hospitalizados con infección por rinovirus, lo que supuso el 25 % de los pacientes hospitalizados por procesos respiratorios o fiebre. El rinovirus fue el segundo agente viral identificado tras el virus respiratorio sincitial (29,9 % de los hospitalizados). El 71,1 % de los pacientes fueron menores de 2 años. Los diagnósticos más frecuentes fueron sibilancias recurrentes en el 60,5 %, bronquiolitis en 23,7 %, neumonía en el 7,9 % e infección respiratoria de vías altas en el 5,3 %. Presentaron fiebre de más de 38 °C el 57,9 % de los niños e infiltrado radiológico el 23,7 %. Presentaron hipoxia el 43,4 % de los niños. En niños mayores de 2 años el diagnóstico fue crisis asmática en 21 de los 22 casos. Conclusiones Los rinovirus se detectaron en un importante porcentaje de los niños hospitalizados a consecuencia de infección respiratoria, siendo precedidos en frecuencia sólo por el virus respiratorio sincitial. En nuestra serie es el agente viral más frecuentemente asociado con episodios de sibilancias recurrentes en niños mayores de 2 años, y el segundo en los más pequeños

Background Rhinovirus is a recognized cause of common cold and has been shown to cause asthma exacerbations in adults and children. The burden of rhinovirus infections in hospitalized children has not been described in Spain. Objective To describe confirmed rhinovirus infections in children hospitalized for respiratory tract infection in a secondary public hospital. Patients and methods We performed a prospective descriptive study in children admitted to hospital with fever or respiratory tract infection and with a positive isolation of rhinovirus in nasopharyngeal washings between September 2004 and July 2005. Virological diagnosis was made with direct immunofluorescent assay and/or reverse transcription-polymerase chain reaction in specimens obtained from nasopharyngeal washings. The clinical characteristics of the patients were analyzed. Results There were 76 children with rhinovirus infection, representing 25 % of admissions in 304 children with fever or respiratory tract infection. Rhinovirus was the second most frequent viral agent identified after respiratory syncytial virus (RSV) (29.9 % of admissions). Fifty-four children (71.1 %) were under 2 years of age. The most frequent clinical diagnoses were recurrent wheezing in 60.5 %, bronchiolitis in 23.7 %, pneumonia in 7.9 %, and upper respiratory tract infection in 5.3 %. Fever > 38 °C was present in 57.9 % of the patients and radiologic infiltrate was found in 23.7 %. Oxygen saturation less than 95 % was found in 43.4 % of the patients. Of 22 children aged more than 2 years, a diagnosis of asthmatic crisis was made in 21. Conclusions Rhinoviruses were frequently identified in hospitalized children with respiratory tract disease and were the second most common viruses after RSV. In our series, it was the most frequent cause of recurrent wheezing in hospitalized children and the second most common cause in infants

[Influenza virus infections in infants aged less than two years old]. / Infecciones por virus de la gripe en menores de dos años.

INTRODUCTION: Influenza is a major cause of respiratory tract illness in infants. The clinical characteristics of these infections are non-specific and the burden of influenza is frequently underestimated in very young children. The objective of this study was to describe confirmed influenza infections in infants < 2 years attended in a level II public hospital. A second-rate aim was to compare influenza infections in hospitalized infants with respiratory syncytial virus (VRS) infection in the same population. PATIENTS AND METHODS: We performed a descriptive, prospective study between 1991 and 2003 in infants younger than 24 months of age, who were admitted to the Severo Ochoa Hospital (Leganés. Madrid) with fever or respiratory tract infection. Virological diagnosis was made with direct immunofluorescent assay and/or reverse transcription-polymerase chain reaction on specimens obtained from nasopharyngeal washings. The patients' clinical characteristics were recorded. Patients with influenza infection were compared with a similar group of infants with RSV infection. RESULTS: We analyzed hospitalized 100 infants with influenza infection. Influenza caused 4.1% of the admissions in infants with fever or respiratory tract infection. Influenza A was isolated in 83%, influenza B in 12% and influenza C in 5% of the patients. The mean age of hospitalized infants was 8.3 +/- 5.9 months and the most frequent clinical diagnoses were bronchiolitis in 38%, recurrent wheezing in 25%, upper respiratory tract infection in 19% and pneumonia in 9%. Fever > 38 degrees C was present in 83% of the patients. Radiologic infiltrate was found in 65% of the children. Oxygen saturation less then 95% was present in 44%. In children under 6 months of age fever was less frequent (p = 0.049) and upper respiratory tract infection was more frequent (p = 0.01). Patients with influenza virus infection were older (p = 0.002), more frequently presented fever (p < 0.0001) and radiologic infiltrate (p < 0.001) than infants with RSV infection. Bronchiolitis was more frequent in the RSV group (p = 0.006). CONCLUSIONS: Influenza infection is a major cause of respiratory tract disease in hospitalized infants. It is an etiologic cause of bronchiolitis, recurrent wheezing, and fever and radiologic consolidations are frequent. Clinical presentation is milder in children under 6 month of age. The characteristics of influenza infection differ substantially from those of RSV infection.

Infecciones por virus de la gripe en menores de dos años / Influenza virus infections in infants aged less than two years old

Introducción. Las infecciones por virus influenza son una importante causa de morbilidad en lactantes. El cuadro clínico es inespecífico y a menudo se infraestima la importancia de la gripe en los menores de 2 años. El objetivo del estudio fue describir las infecciones confirmadas por virus influenza en niños menores de 2 años atendidos en un hospital de segundo nivel. Como objetivo secundario, se pretende comparar las infecciones por gripe en lactantes hospitalizados con las infecciones por virus respiratorio sincitial (VRS) en la misma población. Pacientes y métodos. Estudio descriptivo prospectivo de las infecciones confirmadas por virus influenza en los niños menores de 2 años hospitalizados por fiebre o infección respiratoria entre 1991 y 2003. Para el diagnóstico virológico se realizó inmunofluorescencia y reacción en cadena de la polimerasa en el aspirado nasofaríngeo. Se describen las características clínicas de los pacientes. Se realiza una comparación con un grupo de lactantes de similares características ingresados por infección por VRS. Resultados. Se describen 100 lactantes hospitalizados con infección por virus influenza. Las infecciones gripales supusieron el 4,1 % de los pacientes hospitalizados por procesos respiratorios o fiebre. Se aisló virus influenza tipo A en el 83 % de los casos, tipo B en el 12 % y tipo C en el 5 %. La edad media fue 8,3 6 5,9 meses, y los diagnósticos más frecuentes fueron bronquiolitis en el 38 %, sibilancias recurrentes en el 25 %, infección respiratoria de vías altas en el 19 % y neumonía en el 9 %. Presentaron fiebre superior a 38 °C el 83 % de los niños e infiltrado radiológico el 65 %. Presentaron hipoxia el 44 % de los niños. En los niños menores de 6 meses la fiebre fue menos frecuente (p 5 0,049), y en los diagnósticos predominaron las infecciones respiratorias de vías altas (p 5 0,01). Los niños afectados de infección por virus influenza tuvieron mayor edad (p 5 0,002), presentaron con mayor frecuencia fiebre (p < 0,0001), así como un porcentaje más elevado de infiltrados radiológicos (p < 0,001) que los niños con infección por VRS. Se encontró mayor porcentaje de bronquiolitis en el grupo de VRS (p 5 0,006). Conclusiones. Las infecciones por virus influenza son responsables de un importante porcentaje de los ingresos por infección respiratoria en lactantes. Suelen causar fiebre elevada, pueden manifestarse como bronquiolitis o episodio de sibilancias recurrentes y se acompañan con frecuencia de infiltrados radiológicos. Los menores de 6 meses presentan un cuadro clínico algo más leve. Existen diferencias importantes en el cuadro clínico que produce la gripe respecto a la infección por VRS

Introduction. Influenza is a major cause of respiratory tract illness in infants. The clinical characteristics of these infections are non-specific and the burden of influenza is frequently underestimated in very young children. The objective of this study was to describe confirmed influenza infections in infants 38 °C was present in 83 % of the patients. Radiologic infiltrate was found in 65 % of the children. Oxygen saturation less then 95 % was present in 44 %. In children under 6 months of age fever was less frequent (p 5 0.049) and upper respiratory tract infection was more frequent (p 5 0.01). Patients with influenza virus infection were older (p 5 0.002), more frequently presented fever (p < 0.0001) and radiologic infiltrate (p < 0.001) than infants with RSV infection. Bronchiolitis was more frequent in the RSV group (p 5 0.006). Conclusions. Influenza infection is a major cause of respiratory tract disease in hospitalized infants. It is an etiologic cause of bronchiolitis, recurrent wheezing, and fever and radiologic consolidations are frequent. Clinical presentation is milder in children under 6 month of age. The characteristics of influenza infection differ substantially from those of RSV infection

[Respiratory infections due to metapneumovirus in hospitalized infants]. / Infecciones respiratorias por metapneumovirus en lactantes hospitalizados.

BACKGROUND: Human metapneumovirus (hPMV) is a recently identified virus that is recognized as a cause of respiratory tract illness in the pediatric population. OBJECTIVES: To determine the incidence of respiratory tract infections caused by hPMV in hospitalized infants and to describe the clinical characteristics and possible presence of coinfection with other viral agents. PATIENTS AND METHODS: We performed a prospective study from September to June 2003 in all children aged less than 24 months who were admitted to the Severo Ochoa Hospital (Leganés, Madrid) with a respiratory tract infection. Virological diagnosis was made with a direct immunofluorescent assay and/or reverse transcriptase-polymerase chain reaction on specimens obtained from nasopharyngeal washing. Demographic and clinical data from patients with an hPMV respiratory tract infection were analyzed. RESULTS: During the study period, 200 infants were admitted with a respiratory tract infection, of which 18 (9 %) had an hPMV infection. HPMV was the viral agent isolated in 13.8 % of positive nasopharyngeal washings. All patients were admitted between March and April. The mean age was 6.7 +/- 6.1 months. The most common diagnoses were recurrent wheezing (55.5 %) and bronchiolitis (38.8 %). Oxygen therapy was required by 55.5 % of infants during hospitalization. Coinfection with other respiratory viruses was confirmed in 33.3 % of the patients. CONCLUSIONS: Human metapneumovirus is a major cause of respiratory tract illness in hospitalized infants. This virus causes mainly bronchiolitis and recurrent wheezing and is more frequent in spring. Coinfection with other respiratory viruses is frequent.

Infecciones respiratorias por metapneumovirus en lactantes hospitalizados / Respiratory infections dur to metapneumovirus in hospitalized infants

Antecedentes El metapneumovirus humano es un virus de reciente descripción al que se atribuyen infecciones respiratorias que afectan fundamentalmente a la población infantil. Objetivos Conocer la incidencia de infecciones por metapneumovirus en lactantes hospitalizados, así como sus características clínicas y la posible presencia de coinfecciones con otros agentes virales. Pacientes y métodos Estudio prospectivo realizado de septiembre a junio de 2003 en todos los niños menores de 2 años ingresados en la Unidad de Lactantes del Hospital Severo Ochoa de Leganés (Madrid), por infección respiratoria. La detección de agentes virales se realizó mediante recogida de aspirado nasofaríngeo y realización de inmunofluorescencia directa y/o reacción en cadena de la polimerasa-transcripción inversa (RT-PCR). Descripción de las características clínicas y epidemiológicas de los procesos respiratorios de los pacientes con detección positiva para metapneumovirus humano. Resultados Ingresaron 200 lactantes con patología respiratoria durante el período mencionado, de los cuales en 18 se detectó infección por metapneumovirus humano (9 por ciento de los pacientes). El metapneumovirus humano supuso un 13,8 por ciento de los aislamientos virales positivos. El 100 por ciento de estos niños ingresaron en marzo-abril. La edad media fue de 6,7+/-6,1 meses. El 38,8 por ciento desarrolló una bronquiolitis y en el 55,5 por ciento se objetivó un episodio recurrente de sibilancias. El 55,5 por ciento de los niños precisó oxigenoterapia durante el ingreso. Se encontraron coinfecciones con otros agentes virales en el 33,3 por ciento de estos pacientes. Conclusiones El metapneumovirus humano es un agente viral muy frecuente en los lactantes afectados de enfermedad respiratoria, causando fundamentalmente bronquiolitis y episodios recurrentes de sibilancias. Es más frecuente en primavera y tiene una alta tendencia a la coinfección con otros virus (AU)