ABSTRACT
A.baumannii is a pathogen causing hospital-acquired infections. A.baumanii infections are difficult to treat because this organism is usually multi-drug resistant. Objective: To determine the epidemiology of A. baumannii infections in Siriraj Hospital in 2002. Methods: From January to December 2002, we prospectively studied hospitalized patients in Siriraj Hospital who had A.baumannii isolated from their clinical specimens. Results: During the study period, A.baumannii was isolated from clinical specimens of 208 cases. Eighty-six patients (41.3%) had A. baumannii infections whereas 122 patients (58.7%) had A. baumannii colonization. Of the 86 patients with A.baumannii infections, 54.7% were males and 45.3% were females. The mean age of patients was 56.1 years. Ninety-eight percent of the infections were hospital-acquired. The patients developed infection after an average of 26 days of hospitalization. Fifty-two percent of the patients were in the general wards, whereas 48% of them were in ICU. The common sites of infection were respiratory tract and skin and soft tissues. Factors associated with A.baumannii infection were identified in 98.8% of the patients. The most common factors were prior use of antibiotics especially ceftazidime and indwelling medical devices. The susceptibility of A.baumannii to carbapenems, aminoglycosides, beta-lactam/ beta-lactamase inhibitors, co-trimoxazole, fluoroquinolone, 4th generation cephalosporins and 3rd generation cephalosporins was 32%, 16%, 12 %, 9%, 7%, 4% and 3%, respectively. Fifty-seven percent of A.baumannii isolates were resistant to all antimicrobials currently available in Thailand. The overall mortality rate of the patients infected with A.baumannii was 54.7%. Conclusion: Most A.baumannii infections in Siriraj were hospital-acquired. The most common site of infection was the respiratory tract. The majority of A.baumannii isolates was multi-drug resistant. The mortality rate of A.baumannii infections was high.