[Community-acquired urinary tract infections in the internal and nephrology ward: etiology and selected risk factors].

Background: Community-acquired urinary tract infections (UTI) are one of the most common types of infections. In some cases they become a cause of hospitalization and various, sometimes serious complications.

Objectives: The aim of this study was to analyze community-acquired UTI in patients hospitalized in the internal nephrology ward, taking into account causative pathogens, gender, age as well as selected risk factors.

Material And Methods: The retrospective study analyzed patients hospitalized in the ward from 1 January 2013 till 31 December 2015 (4512 people, 2452 women and 2060 men). During this period 425 patients aged 18 to 101 years (the average age 74.5) were diagnosed with community-acquired UTI. Population was divided into four age groups (I: 18-45, II: 46-65, III: 66-80, IV ≥81). The independence test χ2 with odds ratio (OR) and 95% confidence intervals (CI) were used to analyze statistically possible relationships between pathogens, age groups, gender and selected risk factors.

Results: 425 cases of community- -acquired UTI were diagnosed that accounted for 9,4% of all hospitalized patients. An increased number of diagnosed infections occurred in the subsequent age groups (I-24, II-56, III-161, IV-184). Infections were more frequent in women (63.8%) than men (36.2%). E. coli was the main etiological factor – 74.8% (84.1% in women and 58,4% in men). The contribution of other pathogens was significantly smaller: K. pneumoniae-6.6%, P. mirabilis-5.6%, E. cloacae-3.5%, E. faecalis-1.9%, St. aureus-1.6% and others-3.5%. There was no statistically significant relationship between age groups and the type of bacteria (p>0.05). It was shown that E. coli was a more common causative agent in women (p=0.0001) than in men while P. mirabilis and E. cloacae were more common in men (p=0.0084 and p=0.002 respectively). The most common risk factor in both genders was diabetes mellitus (39.3%). Additionally the presence of catheter in the bladder (p<0.0001), stasis/hydronephrosis (p=0.0067) and cancers of the genitourinary tract (p<0.0001) were significantly more common in men.

Conclusions: E. coli was the most common etiologic agent of community-acquired UTI. Its contribution was significantly smaller in males than in females. The incidence of UTI was the highest in young women and elderly people. Diabetes mellitus was the most common, underlying risk factor of infections. The presence of catheter in the bladder, stasis/hydronephrosis and cancers of the genitourinary tract were significantly more frequent in men with community- acquired UTI.