Risk factors for non-Escherichia coli community-acquired bacteriuria

Purpose Urinary tract infection (UTI) is one of the most common bacterial infections, with Escherichia coli causing up to 80 % of community-acquired bacteriuria (CA-Bu). The epidemiology and pathogenesis of E. coli have been intensively studied, yet, less is known about risk factors for CA-Bu due to other uropathogens. The purpose of this study was to clarify the latest knowledge. Methods A clinical epidemiological study among adult ambulatory patients was conducted. During November 2009, all urine cultures sent to our Microbiology Laboratory were evaluated, including demographic characteristics of the patients, underlying diseases and antibiotic treatment. Data were analysed by the SPSS statistical package. Results During the study period, 4,653 cultures were sent for evaluation. Of the 1,047 (22.5 %) that were positive, 838 were included in the study; 82.5 % were from females. E. coli was the most common pathogen, comprising 58.6 % of all positive cultures. By multivariate analysis, five independent risk factors were associated with non-E. coli CA-Bu: presence of foreign body in the urinary tract [odds ratio (OR) 5.8], nitrite urine test negative (OR 3.2), male gender (OR 2.5), normal erythrocyte count in urine test (OR 1.5) and recurrent UTI in the past year (OR 1.5). Conclusions For adult outpatients presenting with CABu, five independent factors suggesting the involvement of uropathogens other than E. coli were identified. These should be taken into consideration when empiric antibiotic treatment is prescribed.