[Acute bronchiolitis: a prospective study].

Introduction: Bronchiolitis is the most common lower respiratory infection in children under 2 years old. Respiratory syncytial virus (RSV) is the most frequently involved etiologic agent.

Aims: To identify different viruses causing bronchiolitis and try to correlate them with demographic and clinical variables. To analyze diagnostic and therapeutic approache.

Methods: We conducted a prospective study, between November 2008 and March 2009 (5 months), including children < 2 years with bronchiolitis. Screening for RSV, parainfluenza 1-3 and adenovirus used immunofluorescence tests and screening for influenza A and B, human metapneumovirus (MPvh), human bocavirus (hBoV) and RSV used polymerase chain reaction (PCR) techniques. Data were analysed by using SPSS®.

Results: We included 78 children with 8.5 months mean age (83% < 12 months), 60% were male. The average duration of the disease was 15+5 days. Were on antibiotics 19.2%, because of concomitant acute otitis media (10.2%) or bacterial pneumonia (9%). 53% required hospital admission and the average length of stay was 7 days. Along hospitalization 95% of children required supplemental oxygen, 61% intravenous rehydration and 22% chest physiotherapy. Viral testing was positive in 59/75 children: RSV (69.3%), BoVh (22.7%), MPVh (4%), parainfluenza 3 (27%) and influenza A (2.6%). Co-infection with two viruses was detected in 23% of children. In 88% of children with positive samples for BoVh it has been detected RSV infection simultaneously. Children with co-infection (RSV + BoVh) required more often hospitalization compared with children infected with RSV alone (80% vs 60%, p=0.028), without significant differences in oxygen supplementation need and length of disease.

Conclusions: RSV was the main etiologic agent and oxygen supplementation requirement justified the majority of hospitalizations. There was a high rate of co-infection with RSV and BoVh, but without longer disease. BoVh infection alone was uncommon.