Epidemiology of respiratory syncytial virus in children with lower respiratory tract infection.

Respiratory syncytial virus (RSV) is the most frequent pathogen found in hospitalized young children with lower respiratory tract infection, and the virus is distributed worldwide. Respiratory distress and respiratory failure are caused by RSV in some severe cases. Its appearance always varies every year and depends on differences of latitudes, altitudes and climates. The purpose of this study was to investigate the epidemiology of hospitalized children from a hospital located in northern Taiwan with RSV induced lower respiratory tract infection. This study was conducted from January 2001 to December 2003, and the selected patients were children aged under five and diagnosed with lower respiratory tract infection. The means adopted in this study were analyses of clinical presentations and laboratory tests (including viral identification with either virus culture or RSV antigen rapid test from the nasopharyngeal aspirate). The results showed that 153 children were positive with RSV identification. These cases were diagnosed in clinical practice all year round, and its peak was in spring, especially in March and April. Thirteen percent of all RSV-infected children in this study presented as severe form with respiratory distress and a need of respiratory support. However, none of these cases died from this disease, and all cases recovered without long-term respiratory complication. We concluded that RSV infection was still a common pathogen for young children in northern Taiwan; in addition, March and April were regarded as peak months of epidemic. Patients aged under 12 months or suffered from underlying cardiopulmonary disease were at high risk of getting severe forms of RSV infection.