Human Metapneumovirus bronchiolitis in infancy is an important risk factor for asthma at age 5

Background Human metapneumovirus (hMPV) infection plays an important role in the pediatric respiratory infections. However, little is known about the relationship between hMPV-bronchiolitis and the development of subsequent wheezing. The aim of this study was to evaluate the outcome at third to fifth year after admission for hMPV-bronchiolitis and to compare it with children admitted for respiratory syncytial virus (RSV)-bronchiolitis and with children without lower respiratory disease in the first 2 years of life. Methods We studied 55 children (23 hMPV and 32 RSV acute bronchiolitis) aged 3-5 years and hospitalized during the seasons 2000-2005. Thirty-eight children admitted due to acute rotavirus gastroenteritis in the same seasons, and without bronchiolitis during infancy, were also analyzed. Clinical data were collected through structured clinical interviews at the follow-up visit. Skin prick tests to food and inhaled allergens were performed. Results Asthma was significantly more frequent in children with hMPV-bronchiolitis (odds ratio (OR) = 5.21), RSV-bronchiolitis (OR = 4.68), allergic rhinitis (OR = 1.7), and siblings with atopy (OR = 1.75). In the multivariate analyses, hMPV was the most important risk factor for asthma in preschool years (OR = 15.9), followed by RSV-bronchiolitis (OR = 10. 1) and allergic rhinitis (OR = 4.9). No differences were found with respect to allergic rhinitis, atopic dermatitis, food allergy, proportion of positive prick tests, family history of atopy, and asthma. Conclusions hMPV-bronchiolitis in infancy was strongly associated with asthma as well as other forms of bronchial obstructive disease at third and fifth year of life. This association is, at least, as strong as the association observed with RSV infections. Pediatr Pulmonol. 2007; 42:458-464. (C) 2007 Wiley-Liss, Inc.