Bronchiolitis caused by respiratory syncytial virus in the period from 2003 to 2009

Abstract

Respiratory syncytial virus (RSV) causes acute respiratory tract illness in persons of all ages. Lower respiratory tract infection is usually the result of primary infection of infants and small children as well as secondary infection of older adults and immunodeficient persons. Healthy older children and adults typically have symptoms restricted to the upper respiratory tract. Almost all children acquire primary RSV infection during the first two years of life and reinfections occur throughout lifetime. RSV is the most important cause of lower respiratory tract infections, especially of bronchiolitis, in infants. Seasonal outbreaks are typically seen from late autumn to early spring peaking in January and February. RSV infection manifests as upper respiratory tract infection, acute otitis media, tracheobronchitis, bronchiolitis or pneumonia. The laboratory diagnosis of RSV infection is made by analysis of respiratory secretions with rapid assays utilizing antigen capture technology. Their sensitivity and specificity ex ceed 90 percent. Supportive care is the mainstay of therapy and sometimes includes oxygenotherapy. Bronchodilators and corticosteroids are widely used, although no convincing data exist for their efficacy. Nebulized ribavirin is reserved for severe infections. In some patients RSV infection is correlated with recurrent wheezing. Immunoprophylaxis with palivizumab, a humanized monoclonal antibody against the RSV F glycoprotein, is indicated for children at high risk for serious infection. During the period of six years 422 children with RSV bronchiolitis were treated at our hospital. We found expected age, sex and seasonal distribution of our patients. Seventeen children (4 %) required mechanical ventilation and one child died (mortality 0.24 %). More than half of the patients requiring mechanical ventilation had at least one risk factor for severe infection. Seasonal variations in the number of mechanically ventilated patients are probably the result of virulence of circulating strain of virus.