Evaluation of risk factors for nosocomial multi-drug resistant Pseudomonas aeruginosa infections

Introduction and Aims: Pseudomonas aeruginosa causes serious infections that leads high mortality and morbidity and has intrinsic resistance to multidrug. Acquired resistance and cross-resistance between antimicrobials lead to Multidrug resistant P. aeruginosa (MDR-Pa) problem. In this study, the risk factors of MDR-Pa were evaluated.Material and method: A prospective case-control study was done for evaluation of risk factors of MDR-Pa infections at Dicle University Hospital. The patients were found surveillance of laboratory results that isolated MDR-Pa. The case group was formed from patients with a nosocomial MDR-Pa infection. Two different control groups were structured. The following patients from each case were entered into the control group. The first control group (C-1) was consisted of the patients with non-MDR-Pa infections. The second control group (C-2) was consisted of the patients with non-MDR gram negative bacterial infections. The epidemiological features, laboratory findings and possible risk factors for MDR-Pa of cases and controls were recorded using a standardized data form. The susceptibility of P. aeruginosa strains were confirmed using `disc diffusion test? (Oxoid). The possible risk factors for MDR-Pa acquisition were analyzed with univariate and multivariate logistic regression tests.Results: The mean age was 29.8 ± 27.2-years for the cases, 29.2 ± 25.9-years for C-1 and 46.6 ± 24.8-years for C-2. The ratio of men was 59% in the cases, 69% in the C-1 and 61% in C-2. In the multivariate analyses comparing C-1 group the following variables were found: Use of carbapenem (p<0,011; RR=5,71), long time hospitalization (p<0,006; RR=4,12), number of invasive procedure ?3 (p<0,018; RR=4,68), Chronic care patients (p<0,027; RR=0.35), number of risk factor ?7 (p<0,009; RR=7,41), Previous surgical intervention (p<0,001; RR=0,83) and Total parenteral nutrition (p<0,016; RR=0,14). In the multivariate analyses comparing C?2 group the following variables were found: Use of carbapenem (p<0,022; RR=29,2), long time hospitalization (p<0,041; RR=6,61), number of invasive procedure ?3 (p<0,002; RR=208), Chronic care patients (p<0,018; RR=0.28), Burn (p<0,001; RR=734), Pneumonia (p<0,012; RR=0,17) and Sepsis (p<0,005; RR=0,35)Conclusion: MDR-Pa is a serious healthcare problem in many hospitals. Particularly the patients should be followed carefully if the followings are available: long time hospitalization, multiple invasive procedures, antimicrobial drug use (especially carbapenem) and multiple co-morbidities.