Viruses and atypical bacteria associated with asthma exacerbations in hospitalized children.

UNLABELLED: OBJECTIVES AND WORKING HYPOTHESIS: To evaluate the prevalence of respiratory viruses Mycoplasma pneumoniae and Chlamydophila pneumoniae and gain insight into their seasonal circulation pattern in children with acute asthma exacerbations in a temperate southern hemisphere region. STUDY DESIGN: Patients hospitalized between 3 months and 16 years of age were included in a 1-year prospective, observational, cross-sectional study. Respiratory secretions were collected and the presence of different viruses and atypical bacteria analyzed by immunofluorescence and polymerase chain reaction. RESULTS: Two hundred nine patients (118 females) aged (mean +/- SD) 4.4 +/- 4 years were included. A potential causative agent was detected in 78% of the patients. The most frequently detected viruses were respiratory syncytial virus (HRSV) (n = 85; 40%) and rhinovirus (HRV) (n = 52; 24.5%); M. pneumoniae and C. pneumoniae were detected in 4.5% and 2% of the cases, respectively. Patients with HRSV (vs. HRV) were hospitalized for a longer time (6.7 vs. 5.2 days, P = 0.012), required more days of oxygen supply (5.1 vs. 3.4, P = 0.005), had a longer duration of the exacerbation before hospitalization (3.6 vs. 1.9 days, P = 0.001) and were younger (3.7 vs. 5.1 years, P = 0.012). Three peaks of admissions were observed. A first peak (early autumn) caused by HRV, a second peak (winter) caused mainly by HRSV and a third one (spring), caused by HRSV, an increase in HMPV together with a second outbreak of HRV. CONCLUSIONS: Children with an acute asthma exacerbation presented a high prevalence of respiratory viruses. Most hospitalizations corresponded to seasonal increases in prevalence of HRV and HRSV.

[New respiratory viruses in children 2 months to 3 years old with recurrent wheeze]. / Nuevos virus respiratorios en niños de 2 meses a 3 años con sibilancias recurrentes.

INTRODUCTION: Respiratory viruses are associated with respiratory exacerbations, more frequently Respiratory Syncytial Virus in infants and Rhinovirus in children. OBJECTIVE: To evaluate the prevalence and epidemiological features of newer and traditional respiratory viruses in infants and young children with recurrent wheeze. MATERIAL AND METHODS: Cross sectional, prospective and descriptive study. Patients with recurrent wheeze and risk factors for asthma, age 2 months to 3 years, hospitalized with bronchial obstruction were included. On admission a respiratory sample was obtained through a nasopharyngeal aspirate. Immunofluorescence was performed to detect Respiratory Syncytial Virus, Adenovirus, Parainfluenza 1, 2, 3 and Influenza A and B. Polymerase Chain Reaction was used to detect Rhinovirus, Enterovirus, Metapneumovirus, Bocavirus, Adenovirus and Coronavirus. RESULTS: 119 patients (61 female), age (x E DS) 1.5 E 0.9 years were included. Days on admission and on oxygen requirement were, respectively (x E DS): 6.3 E 2.9 y 4.4 E 2.7. One hundred and two (86%) positive cases were diagnosed. Fifty five percent of the viruses were detected by Immunofluorescence and 45% by Polymerase Chain Reaction. A single virus was present in 75% of the samples, 22% had a double co-infection and 3% a triple virus co-infection. Overall, the prevalence of detected respiratory viruses was: Respiratory Syncytial Virus 55 (43%); Rhinovirus 30 (23%); Metapneumovirus 13 (10%); Influenza A 8 (6%); Enterovirus 6 (5%); Bocavirus 6 (5%); Adenovirus 4 (3%); Coronavirus 3 (2%); Parainfluenza 1: 2 (1%); Influenza B, 1 (1%) and Parainfluenza 3: 1 (1%). CONCLUSIONS: Infants and young children with recurrent wheeze and risk factors for asthma hospitalized for bronchial obstruction present a high prevalence of respiratory viruses. Hospital admissions were more frequent during months of higher respiratory circulation.

Nuevos virus respiratorios en niños de 2 meses a 3 años con sibilancias recurrentes / New respiratory viruses in children 2 months to 3 years old with recurrent wheeze

Introducción. Los virus respiratorios son los agentes que con más frecuencia desencadenan sibilancias, especialmente, el virus sincicial respiratorio en los lactantes y los rinovirus en niños mayores.Objetivos. Conocer la prevalencia y la circulación estacional de los virus respiratorios nuevos y tradicionalesen lactantes y niños pequeños con sibilancias recurrentes.Material y métodos. Estudio de corte transversal, prospectivo y descriptivo. Se incluyeron pacientes de 2 meses a 3 años con sibilancias recurrentes yfactores de riesgo para desarrollar asma hospitalizados por obstrucción bronquial. Se obtuvo una muestra de secreciones respiratorias por aspiradonasofaríngeo y se utilizó la técnica de inmunofluorescencia para detectar Virus Sincicial Respiratorio, Adenovirus, Parainfluenza 1, 2 y 3 e Influenza A y B,y la Reacción en Cadena de la olimerasa para determinar Rinovirus, Enterovirus, Virus Sincicial Respiratorio, Bocavirus, Adenovirus y Coronavirus.Resultados. Se evaluaron 119 pacientes (61 femeninos), edad (x más menos DE) 1,5 más menos 0,9 años. Los días de internación y de requerimientos de oxígeno fueron(x más menos DE): 6,3 más menos 2,9 y 4,4 más menos 2,7 respectivamente. Se hallaron 102 (86 por ciento) casos positivos. El 55 por ciento de los virus se detectó por Inmunofluorescencia y el 45 por cientopor Reacción en Cadena de la polimerasa. El 75 por ciento delas muestras respiratorias presentó un solo agente viral, el 22 por ciento una coinfección doble y el 3 por ciento unacoinfección triple. Las prevalencias de los virus respiratorios detectados fueron: Virus Sincicial Respiratorio55 (43 por ciento); Rinovirus 30 (23 por ciento); Metapneumovirus13 (10 por ciento); Influenza A 8 (6 por ciento), Enterovirus 6 (5 por ciento); Bocavirus 6 (5 por ciento); Adenovirus 4 (3 por ciento); Coronavirus3 (2 por ciento); Parainfluenza 1: 2 (1 por ciento); Influenza B, 1(1 por ciento) y Parainfluenza 3: 1 (1 por ciento).