Causative agents and resistance among hospital-acquired and ventilator-associated pneumonia patients at Srinagarind Hospital, northeastern Thailand.

Abstract. Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) have an impact on health care costs and mortality. The aim of this study was to identify the causative agents, antibiotics prescribed, cost of treatment and drug resistance trends among HAP and VAP patients at a tertiary-care hospital in northeastern Thailand during 2008 and 2009. The incidences of HAP in 2008 and 2009 were 0.7/1,000 and 0.55/1,000 hospital days, respectively. The incidences of VAP in 2008 and 2009 were 13.6/1,000 and 12.6/1,000 ventilator days, respectively. About 70% of HAP were caused by Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae; and 70% of VAP were caused by A. baumannii, P. aeruginosa, and K. pneumoniae. The ranking in the causative agents of HAP and VAP was not different, but more antimicrobial resistant organisms were seen in 2009. More than half of the costs of nosocomial infection treatment in 2008 and 2009 were the costs for HAP and VAP, 16.8 and 17.5 million Baht, respectively. Fewer A. baumannii and P. aeruginosa isolates were sensitive to carbapenems. Only one-fifth of A. baumannii isolates were sensitive to cefoperazone/sulbactam. The only two antimicrobial agents with consistently good activity against A. baumannii were tigecycline (approximately 85%) and colistin (approximately 99%). Fifty-seven point six percent of P. aeruginosa isolates were sensitive to ceftazidime, 72.4% were sensitive to piperacillin/tazobactam, 95.9% were sensitive to netilmycin and 99.2% were sensitive to colistin. Forty-seven percent of K. pneumoniae isolates were extended spectrum beta-lactamase and sensitive to carbapenems. Methicillin-resistant S. aureus was the cause of 6-7% of HAP/VAP cases in our study.