OBJECTIVETo investigate the spectrum of pathogens for community-acquired pneumonia (CAP) in children, and to provide a basis for the diagnosis and treatment of CAP.

METHODSRespiratory secretions and venous blood samples were collected from 1560 children with CAP aged from one month to 9 years within 2 hours after admission, for detection of multiple pathogens. Respiratory virus antigens in nasopharyngeal swab specimens were detected by immunofluorescence. Sputum was used for bacterial culture. Levels of Mycoplasma pneumoniae (MP)-IgM and Chlamydia pneumoniae (CP)-IgM in venous blood were measured by enzyme-linked immunosorbent assay.

RESULTSA total of 579 strains of bacteria were isolated from all respiratory secretions, including 213 (36.8%) Gram-positive strains and 366 (63.2%) Gram-negative strains. The five most common strains were Haemophilus influenzae (7.50%), Streptococcus pneumoniae (6.73%), Staphylococcus aureus (6.35%), Moraxella catarrhalis (5.19%), and Escherichia coli (3.46%), wherein the beta-lactamase-producing strains accounted for 3.3% of all strains. The non-bacterial pathogens mainly included respiratory syncytial virus (12.88%), MP (7.88%), and CP (8.91%). Mixed infection of pathogens was serious, and the mixed infection of respiratory syncytial virus with Haemophilus influenzae infections were the most common. For most pathogens, the infection rate was higher in children aged under one year than in those aged over one year.

CONCLUSIONSHaemophilus influenzae, respiratory syncytial virus, MP and CP are the main pathogens for children with CAP. For most pathogens, the infection rate is higher in children aged under one year than in those aged over one year. Mixed infection rate of pathogens is high.