Viral pathogens of acute lower respiratory tract infection in China.

OBJECTIVES: To document the viral etiology of acute lower respiratory tract infection (ALRIs) in Chinese children. SETTING: Children Hospital, Zhejiang University, China. STUDY DESIGN: Cross-sectional. PARTICIPANTS: 34885 children with ALRI between January 2001 to December 2006. METHODS: Nasopharyngeal aspirates were collected from all subjects. Respiratory syncytial virus (RSV), adenovirus (ADV), type 1 to 3 parainfluenza viruses (PIV), and type A and B influenza virus (Flu) were detected by direct immunofluorescence. RESULTS: Viruses were identified in 32.3% cases, including RSV (23.6%), PIV 3 (4.3%), Flu A (2.0%), ADV (1.7%), PIV I (0.6%), Flu B (0.2%) and PIV 2 (0.1%). RSV and PIV 3 predominated in younger children while Flu A and Flu B predominated in older children (P<0.001, respectively). PIV 1 was more prevalent in children aged 1 to 3 years. The peak frequency of RSV, PIV 3 and Flu A were in early spring, June to August, and August and September, respectively. Flu B had a peak in the winter and spring. Adenovirus infections occurred in all seasons with a relatively constant frequency. CONCLUSIONS: Viruses are an important cause of ALRIs in Chinese children constituting 1/3 of total cases. RSV is the most common pathogen.

Detección viral en infecciones respiratorias agudas del lactante / Viral detection in acute respiratory infections in infants

Los virus respiratorios se detectan en un alto porcentaje en la patología respiratoria aguda que afecta al lactante. No nos debe llamar la atención que un alto porcentaje de virus detectados aparecieron en los cuadros de Neumonitis. Es llamativo el alto porcentaje de positividad viral encontrado en las Bronconeumonias. Por último, el aumento de la detección viral observada en los últimos años se debe fundamentalmente a la introducción de nuevas técnicas, específicamente, la detección de antígenos virales por inmunofluorescencia directa y aislamiento viral a partir del aspirado nasofaríngeo y también, a la adecuada toma, envío y procesamiento de las muestras