Objective: To determine the pathogens causing pneumonia in community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) and to investigate serum levels of interleukin-6 (IL-6), interleukin-8 (IL-8) and CRP in pneumonia caused by different aetiological agents.
Study design: Eighty-seven children (mostly < 5 years of age) were recruited in a prospective study, 55 of them with CAP without prior antibiotic treatment and 32 with HAP. Thirty healthy outpatient children served as controls.
Results: The causative micro-organisms were determined by serological and microbiological methods in 40 cases with CAP (72.7%) and 30 with HAP (93.7%). In CAP, M. pneumoniae was the most common causative agent (43.6%), followed by S. pneumoniae (20%) and C. pneumoniae (18.1%). Bacteria alone were the sole causative agents in only 21.8% of cases with HAP. Pseudomonas aeruginosa (34.3%) and K. pneumoniae (32.5%) were the most frequently isolated. Although IL-6 and IL-8 levels were raised, there was no statistical difference between the CAP and HAP groups, or between bacterial and mycoplasma infections; neither was there a difference in CRP levels between these two groups.
Conclusion: The causes of pneumonia differ between CAP and HAP. Levels of IL-6, IL-8 and CRP are raised in pneumonia but are unhelpful in differentiating the various aetiologies.