Nosocomial urinary tract infections: micro-organisms, antibiotic sensitivities and risk factors

Abstract

Although urinary tract infections (UTIs) are the most common hospital-acquired infections, the epidemiology of these UTIs is not well defined in Turkey. The aim of this surveillance study was to determine micro-organisms responsible for UTI, their antibiotic sensitivities and to describe the incidence and risk factors of nosocomial urinary tract infections (NUTI). This was a prospective surveillance study including cases of NUTI in intensive care units and various inpatient clinics. This study was carried out between November 2000 and January 2002. The following information was recorded: patients' age, gender, type of infection (hospital-acquired), presence of urinary catheter, intensive care unit admission, duration of hospital stay, type of organisms isolated and their antimicrobial susceptibility. The diagnosis of NUTI was based on criteria established by the Centers for Disease Control, Atlanta. Mini Api and conventional culture methods were used to determine the causative agents. The agents were isolated on eosin methylene blue agar and 5% sheep blood agar Statistical analyses of data were by chi-square test and logistic regression. In this study, 618 (2.1%) nosocomial infections (NIs) were determined in 29,778 patients, and 178 of these infections were NUTI (28.8%, 178/618). The mean age of NUTI patients was 61.0 +/- 19.4 years (0-91 years) and 82 NUTI patients (46.1%) were male and 96 (53.9%) were female. The most frequently isolated micro-organism was Escherichia coli (31.4%) followed by Candida spp (21.3%), Klebsiella spp (10.6%) and Enterococcus spp (6.9%). Compared to the rate of other NIs, the rate of NUTI increased by 1.011 times per year of age, by 2.052 times in females and by 3.83 times in patients with urinary catheters (p < 0.05). The most effective antibiotics against Gram-negative bacteria were found to be imipenem and meropenem. Important factors to prevent NUTI are to avoid unnecessary urethral catheterization, to choose narrow spectrum antibiotics according to antibiotic sensitivities, to investigate regularly the causative micro-organisms and their resistance patterns and to update the treatment protocols.