COMMON PATHOGENS IN PATIENTS WITH COMMUNITY-ACQUIRED PNEUMONIA PRESENTING TO A TERTIARY CARE FACILITY

Abstract

Objective: To determine the frequency of common pathogens and associated factors among patients presenting with community-acquired pneumonia (CAP) at a tertiary care facility.

Methods: This descriptive cross-sectional study was conducted at the Department of Pulmonology, Liaquat University of Medical and Health Sciences (LUMHS), Jamshoro/Hyderabad. A total of 150 patients aged 18–70 years diagnosed with CAP were enrolled through consecutive non-probability sampling. Sputum specimens were collected before antibiotic administration and processed for culture and pathogen identification. Demographic characteristics, comorbid conditions, smoking status, and vaccination history were recorded. Data were analyzed using SPSS version 24. Logistic regression analysis was performed to identify factors associated with Gram-negative pathogen isolation.

Results: The mean age of participants was 51.8 ± 14.6 years, and 92 (61.3%) were male. Klebsiella pneumoniae was the most frequently isolated pathogen, identified in 53 (35.3%) patients, followed by Escherichia coli in 23 (15.3%) and Pseudomonas aeruginosa in 21 (14.0%) patients. Overall, Gram-negative organisms accounted for 70.0% of all isolates, whereas Gram-positive organisms accounted for 18.0%. Diabetes mellitus, COPD, and smoking were significantly associated with Gram-negative pathogen isolation. Multivariable analysis demonstrated that diabetes mellitus (AOR: 2.4, p=0.011), COPD (AOR: 2.1, p=0.028), and smoking (AOR: 1.9, p=0.041) were independent predictors of Gram-negative infection.

Conclusion: Gram-negative organisms, particularly Klebsiella pneumoniae, were the predominant pathogens causing community-acquired pneumonia. Diabetes mellitus, COPD, and smoking were significant predictors of Gram-negative infection. These findings highlight the importance of local microbiological surveillance and tailored empirical antibiotic therapy.