How can we improve investigation, prevention and treatment for recurrent urinary tract infections - ICI-RS 2018

Urine biomarkers individually and as a consensus model show high sensitivity and specificity for detecting UTIs

BACKGROUND

Current diagnoses of urinary tract infection (UTI) by standard urine culture (SUC) has significant limitations in sensitivity, especially for fastidious organisms, and the ability to identify organisms in polymicrobial infections. The significant rate of both SUC "negative" or "mixed flora/contamination" results in UTI cases and the high prevalence of asymptomatic bacteriuria indicate the need for an accurate diagnostic test to help identify true UTI cases. This study aimed to determine if infection-associated urinary biomarkers can differentiate definitive UTI cases from non-UTI controls.

METHODS

Midstream clean-catch voided urine samples were collected from asymptomatic volunteers and symptomatic subjects ≥ 60 years old diagnosed with a UTI in a urology specialty setting. Microbial identification and density were assessed using a multiplex PCR/pooled antibiotic susceptibility test (M-PCR/P-AST) and SUC. Three biomarkers [neutrophil gelatinase-associated lipocalin (NGAL), and Interleukins 8 and 1β (IL-8, and IL-1β)] were also measured via enzyme-linked immunosorbent assay (ELISA). Definitive UTI cases were defined as symptomatic subjects with a UTI diagnosis and positive microorganism detection by SUC and M-PCR, while definitive non-UTI cases were defined as asymptomatic volunteers.

RESULTS

We observed a strong positive correlation (R2 > 0.90; p < 0.0001) between microbial density and the biomarkers NGAL, IL-8, and IL-1β for symptomatic subjects. Biomarker consensus criteria of two or more positive biomarkers had sensitivity 84.0%, specificity 91.2%, positive predictive value 93.7%, negative predictive value 78.8%, accuracy 86.9%, positive likelihood ratio of 9.58, and negative likelihood ratio of 0.17 in differentiating definitive UTI from non-UTI cases, regardless of non-zero microbial density. NGAL, IL-8, and IL-1β showed a significant elevation in symptomatic cases with positive microbe identification compared to asymptomatic cases with or without microbe identification. Biomarker consensus exhibited high accuracy in distinguishing UTI from non-UTI cases.

CONCLUSION

We demonstrated that positive infection-associated urinary biomarkers NGAL, IL-8, and IL-1β, in symptomatic subjects with positive SUC and/or M-PCR results was associated with definitive UTI cases. A consensus criterion with ≥ 2 of the biomarkers meeting the positivity thresholds showed a good balance of sensitivity (84.0%), specificity (91.2%), and accuracy (86.9%). Therefore, this biomarker consensus is an excellent supportive diagnostic tool for resolving the presence of active UTI, particularly if SUC and M-PCR results disagree.

Urinary tract infections: a review of the current diagnostics landscape

Urinary tract infections are the most common bacterial infections worldwide. Infections can range from mild, recurrent (rUTI) to complicated (cUTIs), and are predominantly caused by uropathogenic Escherichia coli (UPEC). Antibiotic therapy is important to tackle infection; however, with the continued emergence of antibiotic resistance there is an urgent need to monitor the use of effective antibiotics through better stewardship measures. Currently, clinical diagnosis of UTIs relies on empiric methods supported by laboratory testing including cellular analysis (of both human and bacterial cells), dipstick analysis and phenotypic culture. Therefore, development of novel, sensitive and specific diagnostics is an important means to rationalise antibiotic therapy in patients. This review discusses the current diagnostic landscape and highlights promising novel diagnostic technologies in development that could aid in treatment and management of antibiotic-resistant UTIs.

Improving Patient Outcomes While Reducing Empirical Treatment with Multiplex-Polymerase-Chain-Reaction/Pooled-Antibiotic-Susceptibility-Testing Assay for Complicated and Recurrent Urinary Tract Infections

This study compared rates of empirical-therapy use and negative patient outcomes between complicated and recurrent urinary tract infection (r/cUTI) cases diagnosed with a multiplex polymerase chain reaction or pooled antibiotic susceptibility testing (M-PCR/P-AST) vs. standard urine culture (SUC). Subjects were 577 symptomatic adults (n = 207 males and n = 370 females) presenting to urology/urogynecology clinics between 03/30/2022 and 05/24/2023. Treatment and outcomes were recorded by the clinician and patient surveys. The M-PCR/P-AST (n = 252) and SUC (n = 146) arms were compared after patient matching for confounding factors. The chi-square and Fisher's exact tests were used to analyze demographics and clinical outcomes between study arms. Reduced empirical-treatment use (28.7% vs. 66.7%), lower composite negative events (34.5% vs. 46.6%, p = 0.018), and fewer individual negative outcomes of UTI-related medical provider visits and UTI-related visits for hospitalization/an urgent care center/an emergency room (p < 0.05) were observed in the M-PCR/P-AST arm compared with the SUC arm. A reduction in UTI symptom recurrence in patients ≥ 60 years old was observed in the M-PCR/P-AST arm (p < 0.05). Study results indicate that use of the M-PCR/P-AST test reduces empirical antibiotic treatment and negative patient outcomes in r/cUTI cases.

Elevated UTI Biomarkers in Symptomatic Patients with Urine Microbial Densities of 10,000 CFU/mL Indicate a Lower Threshold for Diagnosing UTIs

The literature lacks consensus on the minimum microbial density required for diagnosing urinary tract infections (UTIs). This study categorized the microbial densities of urine specimens from symptomatic UTI patients aged ≥ 60 years and correlated them with detected levels of the immune response biomarkers neutrophil gelatinase-associated lipocalin (NGAL), interleukin-8 (IL-8), and interleukin-1-beta (IL-1β). The objective was to identify the microbial densities associated with significant elevation of these biomarkers in order to determine an optimal threshold for diagnosing symptomatic UTIs. Biobanked midstream voided urine samples were analyzed for microbial identification and quantification using standard urine culture (SUC) and multiplex-polymerase chain reaction (M-PCR) testing, while NGAL, IL-8, and IL-1β levels were measured via enzyme-linked immunosorbent assay (ELISA). NGAL, IL-8, and IL-1β levels were all significantly elevated at microbial densities ≥ 10,000 cells/mL when measured via M-PCR (p < 0.0069) or equivalent colony-forming units (CFUs)/mL via SUC (p < 0.0104) compared to samples with no detectable microbes. With both PCR and SUC, a consensus of two or more elevated biomarkers correlated well with microbial densities > 10,000 cells/mL or CFU/mL, respectively. The association between ≥10,000 cells and CFU per mL with elevated biomarkers in symptomatic patients suggests that this lower threshold may be more suitable than 100,000 CFU/mL for diagnosing UTIs.

The management of recurrent urinary tract infections within a nurse-led urology team

The aim of this article is to share experience and learning of managing recurrent urinary tract infections (UTIs) within a specialist urology nurse-led team based at a district general hospital. It looks at current practice and supporting evidence for how to manage and treat recurrent UTIs in both male and female patients. Two case studies are presented to illustrate the management strategies and outcomes, demonstrating a planned approach that informs the design of a local management guideline to organise patients' care.

The emotional impact of urinary tract infections in women: a qualitative analysis

Background

While many studies address the clinical management of participants with uncomplicated urinary tract infection (uUTI), the emotional impact of uUTIs has been investigated less often. The aim of this qualitative study was to understand the emotional experience of women with uUTIs.

Methods

This was a qualitative, exploratory, in-depth interview-based study conducted among women in the United States (US) and Germany. Women aged ≥ 18 years with at least one uUTI treated with antibiotics in the past year were recruited through a patient community panel and physician referrals. Participants were recruited using purposive sampling to include an equal split of those with 1 or ≥ 2 antibiotics, and an equal split of those treated for a single or recurrent uUTIs (≥ 2 uUTIs in the past year). A structured telephone interview included questions about symptoms, diagnosis, treatment, and retreatment (if any). Each participant was queried about her emotions and the impact of the uUTI on life activities. Thematic analysis of responses was carried out to identify common themes.

Results

A total of 65 participants completed the interview, 40 (61.5%) from the US and 25 (38.5%) from Germany. Major themes that emerged from the analyses included (1) a wide range of negative emotions were experienced due to uUTI symptoms, interference with activities of daily life, and effects on relationships and sleep; (2) varied emotions and understanding related to uUTI treatment and management approaches; (3) treatment failure caused frustration, worry, and anger; and (4) the prospect of recurrent uUTIs provoked dread and helplessness.

Conclusion

Our research uncovered emotions of helplessness and dread experienced by women in the context of uUTI clinical treatment failure and recurrent uUTIs. Knowing patients’ perspectives on UTI management will help guide the development of patient education and improve shared decision-making.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-022-01757-3.

Upper urinary tract function of patients with multiple sclerosis

BACKGROUND

Neurogenic lower urinary tract dysfunction (NLUTD) is frequent in multiple sclerosis (MS) and renal prognosis is a key point of bladder management.

OBJECTIVE

To assess upper urinary tract damage risk using voiding cystourethrography (VCUG) in patients with (PwMS) and NLUTD.

METHODS

We conducted a retrospective study between 2010 and 2020. Demographic data, urinary symptoms, urinary tract infection (UTI), renal ultrasounds findings, glomerular filtration rate (GFR), VCUG data, and urodynamic parameters were collected in PwMS with NLUTD.

RESULTS

Among 325 PwMS included, 67% were female, mean age was 51.6 ± 12.0 years, and mean EDSS 4.6 ± 1.8. VCUG showed vesicoureteral reflux (VUR) in 18 patients. A link was found between VUR and progressive MS course (p = 0.04), hydronephrosis (odds ratio [OR] = 17.44; 95% confidence interval [CI] = 3.46-87.87; p = 0.001), low GFR (p < 0.001), and detrusor overactivity (p = 0.04). No association with UTIs, EDSS, detrusor sphincter dyssynergia, were elicited. On multivariate analysis, alteration of GFR was independently related to the presence of VUR (OR = 0.95; 95% CI = 0.92-0.98).

CONCLUSIONS

VUR elicited on VCUG is associated with lower GFR and hydronephrosis. However, due to the low prevalence (5.5%) of this abnormality in PwMS, VCUG should be performed in selected cases and not in routinary practice.

The microbiome and host mucosal interactions in urinary tract diseases

The urinary tract consists of the bladder, ureters, and kidneys, and is an essential organ system for filtration and excretion of waste products and maintaining systemic homeostasis. In this capacity, the urinary tract is impacted by its interactions with other mucosal sites, including the genitourinary and gastrointestinal systems. Each of these sites harbors diverse ecosystems of microbes termed the microbiota, that regulates complex interactions with the local and systemic immune system. It remains unclear whether changes in the microbiota and associated metabolites may be a consequence or a driver of urinary tract diseases. Here, we review the current literature, investigating the impact of the microbiota on the urinary tract in homeostasis and disease including urinary stones, acute kidney injury, chronic kidney disease, and urinary tract infection. We propose new avenues for exploration of the urinary microbiome using emerging technology and discuss the potential of microbiome-based medicine for urinary tract conditions.

Effect of antibiotics on urine leakage in women with refractory detrusor overactivity: A phase IIb randomized trial

AIM

Because bacterial cystitis is common in women with refractory detrusor overactivity, the aim was to compare the efficacy of 6 weeks of rotating antibiotics versus placebo, in conjunction with an anticholinergic, in controlling the symptoms of urge incontinence.

METHODS

In a multicenter phase IIb double-blinded randomized placebo-controlled trial, women with urodynamically proven refractory detrusor overactivity were randomized in a 2:1 ratio of antibiotics versus placebo for 6 weeks, in addition to darifenacin for 6 months. Any woman with disabling cystitis symptoms was given appropriate antibiotics ("clinical override"). The primary outcome was the degree of urge incontinence change at 6 weeks and 6 months on 24-h pad test. Secondary outcomes were changes in leaks and voids per day measured on 3-day bladder diary and quality of life measures. Microbiological data were collected at all visits.

RESULTS

Although 278 women were screened, only 36 were randomized and 33 (91.7%) completed the trial. Leakage on 24-h pad test decreased at 6 months by 75 g in patients receiving antibiotics versus 35 g in placebo. Cure of urge incontinence occurred at 6 months in 10/21 (48%) of antibiotics versus 2/12 (17%) of placebo. Clinical override, necessitating treatment of cystitis, occurred in 41.6% of placebo versus 16.7% of the antibiotic group by 6 months.

CONCLUSION

Despite the small sample size, the study showed a significant reduction in pad leakage and leaks per day over 24 h in the active treatment group over a 6-month period. Nearly half of patients on placebo had disabling urinary tract infection symptoms that required clinical override treatment.

Management of recurrent urinary tract infections in women

Urinary tract infections are highly prevalent and result in significant patient morbidity as well as large financial costs to healthcare systems. Recurrent urinary tract infections can be challenging for many healthcare professionals, and the repeated use of antibiotics in this patient cohort inevitably contributes to the growing issue of antimicrobial resistance and superbugs. It is essential that these patients are appropriately diagnosed and managed to ensure rapid resolution of symptoms and the prevention of chronic or recurrent urinary tract infections. There are several antibiotic-based options available for the prophylaxis of recurrent urinary tract infections however, in the current era of rising antimicrobial resistance, an awareness of antibiotic stewardship and the use of non-antibiotic alternatives for the treatment and prevention of urinary tract infections is of critical importance. We present a case-based multidisciplinary team discussion to highlight how women with recurrent urinary tract infections should be managed, encouraging the use of non-antibiotic prophylactic measures when suitable.

Level of evidence:

Level 5