**2. Associated risk factors**

symptoms. The majority of the data show a very wide range of prevalence/incidence. This reflects the variability in the cohort (e.g. early or late stage disease) and the frequently small sample sizes, resulting in a low level of evidence in most published data. Spinal cord injury

Spinal cord injury (SCI) is a damage to the spinal cord from traumatic or nontraumatic etiology, as defined by the International Spinal Cord Society (ISCoS) [1]. It is difficult to accurately calculate the worldwide prevalence and incidence of SCI due to the lack of standardized methods of assessment across regions and limited information in the data collected. The incidence varies from 12 to more than 65 cases/million per year. Data from Olmsted County, Minnesota, United States, from 1975 to 1981, showed an age- and sex-adjusted incidence rate of 71 spinal cord injuries/million [2]. The annual incidence of SCI reported for the year 1991 was around 30.0–32.1 persons/million population in the United States, meaning 7500 and 8000 new cases per year at that time [3]. In 2016, the estimated annual incidence of SCI was approximately 54 cases/million population or 17,000 new SCI cases each year [4]. The annual incidence varies widely by country. From 27 per million persons in Japan, 8–13.4 in Switzerland, 12.7 in France, and 16.7 in South Africa [5]. A systematic review in 2010 by Van den Berg et al. showed up to threefold variation in incidence rates between developed countries. The highest rates reported in Canada and Portugal. Most traumatic SCI studies show a bimodal age distribution. The first peak was found in young men between 15 and 29 years of age and the second peak in older adults (mostly ≥65 years old and women) [6]. The National Spinal Cord Injury Statistical Center at the University of Alabama at Birmingham reported approximately 12,000 new cases each year, with 4:1 male-to-female ratio. The average age at injury was 40 years. The most common injury was incomplete tetraplegia at 30%, followed by 25.6% for complete paraplegia, 20.4% for complete tetraplegia, and 18.5% for incomplete paraplegia. In the past, the leading cause of death among SCI patients was the renal failure while nowadays, is pneumonia, pulmonary emboli, and septicemia supersede renal failure. SCI patients seem to have a higher prevalence of several comorbidities than the general population. It is reported high blood pressure (49% vs. 26%, respectively), high cholesterol (47% vs. 30%), and diabetes (19%

patients may be the most studied group among neurogenic patients.

62 Microbiology of Urinary Tract Infections - Microbial Agents and Predisposing Factors

vs. 7%). Obesity is also a significant problem for individuals with SCI (25%).

Spinal cord injury (SCI) patients clinically face urinary incontinence during the bladder filling phase and incomplete emptying during the micturition phase. The main aggravating factors are the increased intravesical pressure and the residual urine. These may result in vesicoureteral reflux, bladder diverticula, and urinary stones formation. These conditions also lead to an increased risk of urinary tract infection (UTI) [7, 8]. Despite improved treatment methods, UTI is considered the second leading cause of death in SCI patients [9]. It is known that UTIs are the most common hospital infections with known repercussions for the patient and the national economy. Approximately 5–10% of patients admitted to hospital are infected during their hospitalization and UTIs account for the highest (40–50%) [10, 11]. In addition, SCI patients usually have asymptomatic bacteriuria. In this way, positive urine culture is not the foundation stone for the diagnosis of urinary tract infection. The clinical signs and symptoms of urinary tract infection are differentiated in these individuals as the neural sensation is affected or absent. The review of the following literature aims to highlight the specificities of urinary tract infections in people with SCI or other neurogenic conditions in order to prevent and treat the infections and recognize asymptomatic bacteriuria without treatment necessity.
