OBJECTIVETo investigate the etiology and epidemic characteristics of hospital acquired pneumonia (HAP) in children.

METHODA retrospective hospital infection study was performed in 52,639 children admitted to our hospital from January 2005 to December 2008.

RESULTSix hundred and ninety eight patients were diagnosed as HAP. The incidence of HAP was 1.33%, among which, 108 (15.47%) cases were early-onset HAP and 590 (84.53%) were late-onset HAP. The HAP patients aged 3 days to 15 years (503 male and 195 female). The proportion of patients younger than 1 year was 51.4%. Main underlying diseases were cytomegalovirus hepatitis, congenital heart disease, malignant tumor, granulocytopenia or agranulocytosis, prematurity and low birth weight. There was significant difference in the incidences among different departments with the highest one seen in ICU, followed by departments of infectious diseases, hematology and digestive diseases. Two hundred and thirty one stains of pathogens were identified from sputum of 355 cases. One hundred and fifty six (67.5%) strains were Gram-negative bacteria, which accounted for the highest proportion. There were 30 (13.0%) Gram-positive bacterial strains, and 29 (12.6%) respiratory tract virus strains, and 15 (6.5%) fungal strains, and 1 (0.4%) mycoplasma strain. The predominant bacterial pathogens were Klebsiella pneumoniae, followed by Stenotrophomonas maltophilia, Burkholderia cepacia, Escherichia coli and Acinetobacter baumannii. The isolation rates of Klebsiella pneumoniae and Escherichia coli with positive extended-spectrum beta-lactamases (ESBLs) were 94.8% and 85.7%, respectively. Those two bacteria were universally resistant to the third and forth generations cephalosporins. The main pathogens of early-onset HAP were respiratory syncytial virus (RSV), Streptococcus mitis, Streptococcus pneumonia, Haemophilus influenzae and Klebsiella pneumoniae, while the main pathogens of late-onset HAP were ESBLs-positive Klebsiella pneumonia, Stenotrophomonas maltophilia, Burkholderia cepacia, Escherichia coli and Acinetobacter baumannii.

CONCLUSIONHAP in children is most common in children younger than 1 year and with underlying diseases. The main pathogens are Gram-negative bacteria. RSV was an important pathogen of HAP. The pathogens of early-onset HAP are different from those of late-onset HAP. These results may be of some help in prevention and control of HAP in children and in guiding for rational application of antibiotics, especially the empirical antibiotic choice.