The prevalence and utility of screening for urinary tract infection at the time of presumed multiple sclerosis relapse.

BACKGROUND

Methods of screening for infections at the time of suspected relapse in people with multiple sclerosis (MS) vary across physicians. People with multiple sclerosis (MS) are at an increased risk of urinary tract infection (UTI). Data evaluating the utility of screening for potential UTI at the time of suspected relapse and whether there are key subgroups of patients in which screening would be most effective are sparse.

OBJECTIVES

To evaluate demographic and clinical predictors of UTI in the context of a suspected acute relapse in (1) a retrospective hospital admission cohort and (2) a prospectively-enrolled, ambulatory care-based cohort, and to determine an approximate number needed to screen to detect one UTI in both healthcare settings.

METHODS

For the hospital admissions cohort, we included individuals with a known or new diagnosis of MS or clinically isolated syndrome who were admitted at least once to the Johns Hopkins Neurology Inpatient Service (March 2012 to December 2014). We considered those screened via urinalysis. Possible UTI was defined as leukocyte esterase OR nitrite positive. For the ambulatory population, we enrolled a cohort of RRMS patients aged 18-65 who were suspected of suffering from an acute MS relapse who either called or came into clinic. Participants were screened via urinalysis; possible UTI was similarly defined. Participants also completed questionnaires (disability, history of Uhthoff's-type phenomenon, recent sexual intercourse, and new urologic symptoms). For both cohorts, we calculated an approximate number needed to screen, and tested if demographic and patient characteristics were associated with possible UTI using logistic regression models.

RESULTS

For the hospital admissions cohort, we included 158 individuals; 48 (30.4%) were identified as possibly having a UTI. For possible UTI, the approximate number needed to screen in order to detect 1 possible UTI is 3 (95% CI: 2, 6). Female sex was the only factor associated with increased odds of UTI (odds ratio [OR]: 3.90; 95% CI: 1.59-9.61; p = 0.003). For the ambulatory cohort, we included 50 participants; 10 (20.0%) with possible UTI. The approximate number needed to screen in order to detect 1 possible UTI was 5 (95% CI: 3, 11) in this cohort. Foul-smelling urine was positively associated with UTI (OR: 5.36; 95% CI: 1.10, 26.17; p = 0.04); no men had a possible UTI in this cohort, so we could not estimate odds ratios associated with sex.

CONCLUSION

UTIs at the time of a suspected MS relapse are relatively uncommon. Female sex is a strong risk factor for UTI in people with MS; foul-smelling urine is a potential predictor of UTI in people with MS. Larger studies are needed to comprehensively evaluate the utility of screening and risk factors for UTI at the time of suspected MS relapse.