1º Autor: Sílvia Raquel Santos
Unidade Local de Saúde de Braga
Coautores: Inês Mamede, Escola de Medicina da Universidade do Minho; Maria Helena Barroso, Serviço de Infeciologia da Unidade Local de Saúde de Braga; Beatriz Araújo, Serviço de Patologia Clínica da Unidade Local de Saúde de Braga; Aurélio Mesquita, Serviço de Patologia Clínica da Unidade Local de Saúde de Braga
Resumo
Background: Spinal cord injury (SCI) patients experience a disproportionately high burden of urinary tract infections (UTIs) due to neurogenic bladder dysfunction and frequent catheterization. The diagnostic distinction between UTIs and asymptomatic bacteriuria (AB) is particularly challenging in this population, as classical symptoms are often absent and colonization is common. Despite international guidelines discouraging treatment of AB, empirical antibiotics remain widely prescribed, fueling antimicrobial resistance. Furthermore, there is currently no universally accepted gold standard for UTI diagnosis in patients with neurogenic bladder, resulting in marked variability in clinical practice and limited evidence to guide stewardship interventions.
Aims: To characterize UTIs and AB in hospitalized SCI, analyzing diagnostic markers, bladder management methods, and antimicrobial resistance patterns to support evidence-based infection prevention and stewardship strategies.
Methods: A retrospective observational study was conducted including 110 hospitalized SCI patients admitted to the Department of Physical and Rehabilitation Medicine between 2020 and 2024. Demographic, clinical, and functional data were collected alongside urinary summary, sediment and microbiological analysis. The definition of UTI and AB followed the diagnostic criteria recommended by the American Urological Association (AUA) and the European Association of Urology (EAU) guidelines for patients with neurogenic lower urinary tract dysfunction.
Results: A total of 207 microbiological urine cultures were analyzed: 37.2% were classified as UTI and 38.6% as AB. Patients had a mean age of 58 years (SD ±14.9), and most were male (71.8%). Traumatic etiology accounted for 55.5% of cases, with cervical injuries predominating (60.4%). Regarding the clinical justification for urine testing, 70 (33.8%) requests were considered inappropriate, despite international guidelines discouraging routine screening in asymptomatic patients. AB was significantly associated with indwelling urethral catheterization (p=0.020; ɸc=0.214), while spontaneous voiding was protective. UTI occurrence correlated with elevated CRP levels (p<0.001), leukocyturia on sediment (p=0.004), and positive bacterial isolates (p<0.001). Logistic regression identified CRP as an independent predictor of UTI (OR=0.295; 95% CI: 0.156–0.560). Microbiological analysis yielded 184 isolates, of which Klebsiella pneumoniae was the most frequent (44.6%), followed by Escherichia coli (28.8%) and Pseudomonas aeruginosa (10.3%). Microorganism distribution varied according to bladder emptying method (p=0.016; ɸc=0.220): K. pneumoniae predominated in patients with indwelling catheters and was disproportionately frequent in our cohort. While E. coli was more common in spontaneous voiding or intermittent catheterization. Alarmingly, 39.7% of isolates were multidrug-resistant (MDR), with extended-spectrum beta-lactamase (ESBL) production in 29.9%, carbapenemase production in 8.2%, and combined resistance mechanisms in a smaller subset. No significant sociodemographic and clinical predictors of MDR carriage were identified.
Conclusions: This study demonstrates the dual epidemiological challenge in SCI patients: the high prevalence of both AB and UTI, and the predominance of MDR pathogens, particularly K. pneumoniae. Catheterization was a significant risk factor for AB, while CRP proved useful as a diagnostic marker of UTI. Strong associations between laboratory findings and infection status highlight the value of combining clinical, biomarker, and microbiological data. These findings emphasize the urgent need for targeted infection prevention, optimized bladder management, and continuous surveillance of antimicrobial resistance in this vulnerable population.