Etiology of Community-acquired Pneumonia in Hospitalized Children in Northern Taiwan

Background: Pneumonia is the leading reason for hospitalization in children. The heptavalent pneumococcal conjugate vaccine was introduced in Taiwan in October 2005. There has been no comprehensive study of the etiology of childhood community-acquired pneumonia (CAP), either in the pre- or postpneumococcal conjugate vaccine era, in Taiwan. Methods: From August 2001 to July 2002, consecutive children admitted to a teaching hospital with radiologically confirmed CAP were prospectively enrolled. The following were considered indicative of infection when positive: blood or pleural effusion bacterial culture or urinary Streptococcus pneumoniae antigen test (Binax NOW), direct immunofluorescent antigen test for Chlamydia species and viruses, virus isolation and identification and viral, mycoplasmal or chlamydial serologic tests. Results: A total of 209 children were included, and 102 children (48.8%) were male. Patients' ages ranged from 7 months to 16 years with a median of 4 years and 3 months. The combined tests identified at least 1 etiologic agent in 85.6% of all cases, including typical bacterial pathogens in 88 cases (42.1%; 86 S. pneumoniae, 1 methicillin-resistant Staphylococcus aureus and 1 Mycobacterium tuberculosis), Mycoplasma pneumoniae in 77 cases (36.8%), Chlamydia species in 24 cases (11.5%), viral etiology in 86 cases (41.1%) and mixed viral-bacterial infections in 69 cases (33%). Children with S. pneumoniae infection were significantly younger than those with Mycoplasma pneumoniae infection (P = 0.0055) or unknown etiology (P = 0.0140). Conclusion: S. pneumoniae, Mycoplasma pneumoniae and viruses were equally common etiologic agents of childhood CAP in Taiwan. Frequent coinfection increased the difficulty of both predicting the responsible organisms and choosing empiric antibiotics for the management of pediatric CAP.