ABSTRACT
One hundred and sixty cases of "pneumonia" with proved clinical and radiological evidence from the Chest Departments in Cairo and Tanta University Hospitals during the year 2007, were the subjects of a conventional bacteriologic study having in mind the empirical approach in the antibiotic therapy. They represented 4.06% of the yearly admissions. The major age incidence was 16 year with more sex predilection. 92.5% belonged to CAP [community acquired pneumonia] and only 7.5% to HAP [hospital acquired pneumonia], VAP [ventilator associated pneumonia] being excluded. 80.6% were primary; with no antedating pathology in the patients, while 19.4% were secondary with co-morbidity in such patients; out which malignancy and COPD were the main associations in older age groups and foreign body in younger ages. The causative organisms were bacteriologically identified only in 53.7% of cases. The main organism in the causation of CAP was Streptococcus pneumoniae in 51.7% of the cases, followed by Hemophilus influenzae in 15.5%, while in HAP, 2 major organisms were responsible for the disease; namely Streptococcus pneumoniae and Klebsiella pneumoniae; 33.3% for each, followed by Hemophilus influenzae and Streptococcus pyogenes; 11.1% for each, but the number of cases in HAP is too small to draw valid conclusions. The organism detected, in primary pneumonia was also essentially Streptococcus pneumoniae 57.6%, while in secondary pneumonia the same organism was encountered in only 33.3% of the cases. Concerning the lobar and lobular distribution of the disease the S. pneumoniae was overwhelming in the lobar type: 84.2%, while in the lobular bronchopneumonic type the main organisms, besides S. pneumoniae which was responsible for 22.2% of the cases were S. pyogenes was responsible for one quarter of the cases and H. influenzae which was encountered in 22.2%. Figures for other organisms are detailed in the text with their relation to other parameters of the study