Aetiological agent in community acquired pneumonia in patients requiring hospitalization

This study was carried out to determine the etiological agents in patients with community-acquired pneumonia (CAP). Ninety-three patients with radiologically confirmed pneumonia admitted to the Medical City, Baghdad Teaching Hospital through the period extended from October 2001 till March 2002. Also to investigate a possible correlation between etiological agents in patients with CAP and comorbid factors including age. The etiological agents were identified from 50 (53.8%) patients with CAP, while no agents were detected in 43 (46.2%) patients. Blood samples were taken from all patients for identification of Chlamydia pneumoniae and Mycoplasma pneumoniae infection. Sputum samples for culture were taken from 76 (81.7%) patients; bacterial species were isolated from 22 (23.7%) samples. Streptococcus pneumoniae was the most frequent typical bacterial pathogen isolated from 17 (18.3%) patients. Atypical pathogens (C. pneumoniae and M. pneumoniae) using ELISA technique were identified in 22 (23.6%) and 20 (21.5%) respectively. Atypical pathogens were a most common causes of CAP identified from (39.8%) cases. Sixteen (17.2%) of the patients had mixed infections (two pathogens were identified in 12 (75%) and three pathogens in 4 (25%) patients). C. pneumoniae and S. pneumoniae were the most common mixed organisms found in 6 (37.5%) of patients