Etiology of Hospital-Acquired Pneumonia (HAP) and Ventilator-Associated Pneumonia (VAP) in Tertiary-Care Hospitals in Thailand: A Multicenter, Retrospective Cohort Study

Abstract

Purpose: To describe the top three causative organisms of hospital acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) in Thailand. Patients and Methods: This multi-center retrospective cohort study included HAP/VAP patients hospitalized in 2019 in three university-affiliated hospitals and a private hospital in Bangkok, Thailand. Medical records of patients with a documented diagnosis of nosocomial pneumonia (NP) were systematically reviewed to collect data on demographic, clinical, microbiological, and 30-day readmission due to NP. Results: A total of 240 patients were included in the study, comprises patients with VAP (62.9%), HAP (36.7%), and ventilated HAP (vHAP) (0.4%). All of the patients had late-onset NP, occurring after five days of hospitalization with median time to NP of 13 days (interquartile range [IQR] 6–25 days) from admission. The top three causative pathogens of NP were Acinetobacter baumannii (44.2%), Pseudomonas aeruginosa (34.6%), and Klebsiella pneumoniae (28.3%). A high rate of carbapenem resistance (CR) in A. baumannii (92.5%) was observed. Lower rates of CR were observed in K. pneumoniae (20.6%) and P. aeruginosa isolates (16.9%). Readmission rate due to NP within 30 days after discharge was less than 2% with median time of 4 days (IQR 3–20 days) after discharge. After diagnosis of NP, 19 patients were transferred to intensive care units with median length of stays of 11 days (IQR 3–24 days). Fifty-one percent of HAP patients received mechanical ventilation support after the diagnosis of NP with median length of mechanical ventilation use of 12 days (IQR 6–22 days). Conclusion: A. baumannii, with its significant carbapenem resistance, presents a major HAP/VAP pathogens and imposes a substantial burden on healthcare resources in this study. Implementation of regular surveillance for causative organisms of NP and their susceptibility profiles are critical for the success of HAP/VAP management, and reducing the related burden of healthcare resources.