Epidemiology of Respiratory Syncytial Virus Infection in Northern Taiwan, 2001-2005 -- Seasonality, Clinical Characteristics, and Disease Burden

Background And Purpose: Respiratory syncytial virus (RSV) is an important pathogen in children less than 2 years old. However, there is limited epidemiological data about RSV infection in Taiwan. This study aimed to investigate the clinical, epidemiological, virological, and economical aspects of RSV infections in Taiwan.

Methods: We collected data of children with positive RSV respiratory specimens at the Laboratory of Virology, National Taiwan University Hospital, between January 2001 and December 2005. Medical charts were reviewed retrospectively.

Results: 892 children in whom acute bronchiolitis was the predominant diagnosis (60.7%) were enrolled. Compared with those without underlying disease (n = 630), children with underlying disease (n = 262) were older (11 vs 9 months), required longer oxygen therapies (7 vs 4 days), were more likely to have lower respiratory tract involvement (96.2% vs 92.3%) and intensive care unit stays (49.0% vs 9.4%), endotracheal intubations (21.0% vs 2.0%), ribavirin use (35.0% vs 1.4%), and had higher medical costs (US$ 1250 vs 688), and nosocomial infection (24.8% vs 1.0%). Compared with those without endotracheal intubation (n = 824), cases requiring endotracheal intubation (n = 68) had higher rates of underlying diseases (80.9% vs 25.1%), especially congenital heart diseases (45.6% vs 8.1%), chronic lung disease (13.2% vs 3.2%) and neurological disorders (17.6% vs 3.5%). There was a biennial pattern with peaks in the spring and fall. Medical cost was estimated to be US$ 250,000 annually in our hospital.

Conclusion: In children with underlying diseases, RSV infection is associated with significant morbidity, and even mortality. Nosocomial infections appear to be an important cause of RSV transmission. The seasonality of RSV infections in Taiwan showed a biennial pattern with peaks in spring and fall.