Carbapenem-resistance pathogens in HAP/VAP patients in US hospitals between 2010 and 2015

Abstract

Background: Carbapenem-resistant (CR) Gram-negative (GN) pathogens are on the top of global priority pathogens list. Aims: Assess the rate and clinical impact of CR pathogens in respiratory cultures from patients diagnosed with hospital-acquired pneumonia (HAP) or ventilator-associated pneumonia (VAP). Methods: HAP/VAP patients and their microbiology data were obtained from the US Premier Healthcare Database. The pathogen was defined CR if the result was resistant or intermediate to any carbapenem, excluding ertapenem for A. baumannii or P. aeruginosa. All S. maltophilia infections were assumed CR due to intrinsic resistance. Results: 49.3% (4585 of 9294) and 56.6% (1898 of 3352) of cultures from HAP and VAP patients, respectively, grew GN pathogens. Overall 51.1% of these GN cultures were tested for carbapenem susceptibility (42.4% of HAP and 72.0% of VAP). The CR rate was 9.9% in HAP patients and 27.6% in VAP patients. 32.1% of CR cases and 21.7% of CS cases were admitted from health care facilities. Among HAP patients, CR cases had a higher crude mortality than CS cases (28.6% vs. 22.0%) and a longer median total hospital stay (28 days vs. 19 days). Non-fermenters (A. baumannii, P. aeruginosa and S. maltophilia) contributed 80.6% of CR cases and had a higher crude mortality in CR cases than in CS cases (30.2% vs 22.7% in HAP, and 18.9% vs 14.4% in VAP). Conclusion: VAP patients had a higher rate of carbapenem susceptibility testing than HAP patients and about a 3 times higher rate of CR than HAP patients. Non-fermenters are predominant contributors to CR respiratory infections for both HAP and VAP patients. CR cases had a higher crude mortality and a longer hospitalization than CS cases.