Consequences of asymptomatic bacteriuria in the elderly

Identification of novel factors associated with inappropriate treatment of asymptomatic bacteriuria in acute and long-term care

BACKGROUND

Chart reviews often fall short of determining what drove antibiotic treatment of asymptomatic bacteriuria (ASB). To overcome this shortcoming, we searched providers' free-text for documentation of their decision-making and for misleading signs and symptoms that may trigger unnecessary treatment of ASB.

METHODS

We reviewed a random sample of 10 positive urine cultures per month, per facility, from patients in acute or long-term care wards at 8 Veterans Affairs facilities. Cultures were classified as urinary tract infection (UTI) or ASB, and as treated or untreated. Charts were searched for 13 potentially misleading symptoms, and free-text documentation of providers' decision-making was classified into 5 categories. We used generalized estimating equations logistic regression to identify factors associated with ASB treatment.

RESULTS

One hundred fifty-eight (27.5%) of 575 ASB cases were inappropriately treated with antibiotics. Significant factors associated with inappropriate treatment included: abdominal pain, falls, decreased urine output, urine characteristics, abnormal vital signs, laboratory values, and voiding issues. Providers prescribed an average of 1.4 antimicrobials to patients with ASB, with cephalosporins (41%) and fluoroquinolones (21%) being the most common classes prescribed.

CONCLUSIONS

Chart reviews of providers' decision-making highlighted new factors associated with inappropriate ASB treatment. These findings can help design antibiotic stewardship interventions for ASB.

Risk Factors and Outcomes Associated With Treatment of Asymptomatic Bacteriuria in Hospitalized Patients

IMPORTANCE

Treatment of asymptomatic bacteriuria (ASB) with antibiotics is a common factor in inappropriate antibiotic use, but risk factors and outcomes associated with treatment of ASB in hospitalized patients are not well defined.

OBJECTIVE

To evaluate factors associated with treatment of ASB among hospitalized patients and the possible association between treatment and clinical outcomes.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study was conducted from January 1, 2016, through February 1, 2018, at 46 hospitals participating in the Michigan Hospital Medicine Safety Consortium. A total of 2733 hospitalized medical patients with ASB, defined as a positive urine culture without any documented signs or symptoms attributable to urinary tract infection, were included in the analysis.

EXPOSURES

One or more antibiotic dose for treatment of ASB.

MAIN OUTCOMES AND MEASURES

Estimators of antibiotic treatment of ASB. Secondary outcomes included 30-day mortality, 30-day hospital readmission, 30-day emergency department visit, discharge to post-acute care settings, Clostridioides difficile infection (formerly known as Clostridium difficile) at 30 days, and duration of hospitalization after urine testing.

RESULTS

Of 2733 patients with ASB, 2138 were women (78.2%); median age was 77 years (interquartile range [IQR], 66-86 years). A total of 2259 patients (82.7%) were treated with antibiotics for a median of 7 days (IQR, 4-9 days). Factors associated with ASB treatment included older age (odds ratio [OR], 1.10 per 10-year increase; 95% CI, 1.02-1.18), dementia (OR, 1.57; 95% CI, 1.15-2.13), acutely altered mental status (OR, 1.93; 95% CI, 1.23-3.04), urinary incontinence (OR, 1.81; 95% CI, 1.36-2.41), leukocytosis (white blood cell count >10 000/μL) (OR, 1.55; 95% CI, 1.21-2.00), positive urinalysis (presence of leukocyte esterase or nitrite, or >5 white blood cells per high-power field) (OR, 2.83; 95% CI, 2.05-3.93), and urine culture with a bacterial colony count greater than 100 000 colony-forming units per high-power field (OR, 2.30; 95% CI, 1.83-2.91). Treatment of ASB was associated with longer duration of hospitalization after urine testing (4 vs 3 days; relative risk, 1.37; 95% CI, 1.28-1.47). No other differences in secondary outcomes were identified after propensity weighting.

CONCLUSIONS AND RELEVANCE

Hospitalized patients with ASB commonly receive inappropriate antibiotic therapy. Antibiotic treatment did not appear to be associated with improved outcomes; rather, treatment may be associated with longer duration of hospitalization after urine testing. To possibly reduce inappropriate antibiotic use, stewardship efforts should focus on improving urine testing practices and management strategies for elderly patients with altered mental status.

Deliberate Establishment of Asymptomatic Bacteriuria-A Novel Strategy to Prevent Recurrent UTI

We have established a novel strategy to reduce the risk for recurrent urinary tract infection (UTI), where rapidly increasing antibiotic resistance poses a major threat. Epidemiologic studies have demonstrated that asymptomatic bacteriuria (ABU) protects the host against symptomatic infections with more virulent strains. To mimic this protective effect, we deliberately establish ABU in UTI-prone patients, who are refractory to conventional therapy. The patients are inoculated with Escherichia coli (E. coli) 83972, now widely used as a prototype ABU strain. Therapeutic efficacy has been demonstrated in a placebo-controlled trial, supporting the feasibility of using E. coli 83972 as a tool to prevent recurrent UTI and, potentially, to outcompete antibiotic-resistant strains from the human urinary tract. In addition, the human inoculation protocol offers unique opportunities to study host-parasite interaction in vivo in the human urinary tract. Here, we review the clinical evidence for protection using this approach as well as some molecular insights into the pathogenesis of UTI that have been gained during these studies.

Evidence-based protocol: diagnosis and treatment of catheter-associated urinary tract infection within adult neurocritical care patient population

Evidence exists that patients requiring neurologic ICU admission have concomitant immunosuppression that makes them more prone to acquiring nosocomial infections. The risk of infection is highest in the acute phase after stroke, which may be attributed to stroke-induced immunodepression syndrome. Significant numbers of patients are being diagnosed inappropriately with catheter-associated urinary tract infection, for which they receive treatment that is not recommended. Protocol-based care enables providers to translate evidence into practice.

Clean intermittent catheterization and urinary tract infection: review and guide for future research

What's known on the subject? and What does the study add? Clean intermittent catheterization (CIC) is considered the method of choice for bladder emptying when neurological or non-neurological causes make normal voiding impossible or incomplete. The outcome is overall good, also in the long-term. There is neither one best technique nor one best material, as both depend greatly on patients' individual anatomic, social and economic possibilities. The most frequent complication is urinary tract infection (UTI). Studies differ in the definition criteria for UTI, methods for evaluation, CIC techniques, frequency of urine analysis, prophylaxis and patients studied. The study provides a literature review and shows that most studies do not have a high level of evidence. There are various risk factors for UTI and phenotyping them helps to assess prognosis by considering what can happen if treatment is not initiated. The study concludes, that the role of biofilms in CIC deserves more attention and that diagnosis should be made on urine sample obtained with catheterization, because symptoms are often less reliable. It also concludes that treatment in those who catheterize for a long time is only necessary for symptomatic infections. The study identifies the following areas for further research: prevention of UTI in patients performing CIC; the use of special catheter types; and the role of frequency of catheterization, prophylactic antibiotics and preservation of natural defence mechanisms in the lower urinary tract.

OBJECTIVE

• To review the factors related to urinary tract infection (UTI), the most prevalent complication in patients who perform clean intermittent catheterization (CIC).

METHODS

• We conducted a literature search then a group discussion to gather relevant information on aspects of UTI to guide future research and to help provide clearer recommendations for the prevention of UTI in patients performing CIC.

RESULTS

• UTI is a major complication of CIC, the incidence of which varies widely in the literature owing to differences in methodology and definitions. • Phenotyping the risk factors for UTI helps to assess prognosis by considering what can happen if treatment is not initiated. The role of biofilms in CIC deserves more attention. • Diagnosis is made using the urine sample obtained by catheterization. Because of neurological or other deficiencies in patients performing CIC, symptoms are less reliable. Thorough evaluation for the source of signs and symptoms should be made before attributing them to UTI. • There have been many different proposals for the prevention of UTI in patients performing CIC, but most need more research. The role of the type of catheter is unclear but further exploration of special catheter types might be worthwhile. • Treatment in those who perform CIC for a long time is best reserved for symptomatic infections.

CONCLUSIONS

• Several mechanisms are relevant in UTI related to CIC. • As UTI is prevalent, more research into its prevention is needed.

Complicated urinary tract infection in adults

BACKGROUND

Complicated urinary tract infection occurs in individuals with functional or structural abnormalities of the genitourinary tract.

OBJECTIVE

To review current knowledge relevant to complicated urinary tract infection, and to provide evidence-based recommendations for management.

METHODS

The literature was reviewed through a PubMed search, and additional articles were identified by journal reference review. A draft guideline was prepared and critically reviewed by members of the Association of Medical Microbiology and Infectious Disease Canada Guidelines Committee, with modifications incorporated following the review.

RESULTS

Many urological abnormalities may be associated with complicated urinary infection. There is a wide spectrum of potential infecting organisms, and isolated bacteria tend to be more resistant to antimicrobial therapy. Morbidity and infection outcomes in subjects with complicated urinary infection are principally determined by the underlying abnormality rather than the infection. Principles of management include uniform collection of a urine specimen for culture before antimicrobial therapy, characterization of the underlying genitourinary abnormality, and nontreatment of asymptomatic bacteriuria except before an invasive genitourinary procedure. The antimicrobial regimen is determined by clinical presentation, patient tolerance, renal function and known or anticipated infecting organisms. If the underlying abnormality contributing to the urinary infection cannot be corrected, then early post-treatment recurrence of infection is anticipated.

CONCLUSIONS

The management of complicated urinary infection is individualized depending on patient variables and the infecting organism. Further clinical investigations are necessary to assist in determining optimal antimicrobial regimens.

Diagnosis, prevention, and treatment of catheter-associated urinary tract infection in adults: 2009 International Clinical Practice Guidelines from the Infectious Diseases Society of America

Guidelines for the diagnosis, prevention, and management of persons with catheter-associated urinary tract infection (CA-UTI), both symptomatic and asymptomatic, were prepared by an Expert Panel of the Infectious Diseases Society of America. The evidence-based guidelines encompass diagnostic criteria, strategies to reduce the risk of CA-UTIs, strategies that have not been found to reduce the incidence of urinary infections, and management strategies for patients with catheter-associated asymptomatic bacteriuria or symptomatic urinary tract infection. These guidelines are intended for use by physicians in all medical specialties who perform direct patient care, with an emphasis on the care of patients in hospitals and long-term care facilities.

Urinary tract infections in long-term-care facilities

Urinary tract infection (UTI) is the most common bacterial infection occurring in residents of long-term-care facilities. It is a frequent reason for antimicrobial administration, but antimicrobial use for treating UTIs is often inappropriate. Achieving optimal management of UTI in this population is problematic because of the very high prevalence of bacteriuria, evidence that the treatment of asymptomatic bacteriuria is not beneficial, and the clinical and microbiological imprecision in diagnosing symptomatic UTI. This position paper has been developed, using available evidence, to assist facilities and healthcare professionals in managing this common problem.

Asymptomatic bacteriuria in the elderly

Asymptomatic bacteriuria is frequent in elderly, populations. The major contributing factors are selected physiologic aging changes and comorbid illnesses, which occur with increased frequency in these populations. There is little short-term or long-term adverse outcomes attributable to this high prevalence and incidence of asymptomatic bacteriuria and no evidence for an impact on survival. A number of important questions relating to this problem have yet to be resolved. First, further studies in the noninstitutionalized population are needed to characterize the incidence of asymptomatic infection and its relationship to symptomatic infection. In the institutionalized population, studies to refine the clinical diagnosis of symptomatic urinary infection occurring in a population with such a high prevalence of asymptomatic bacteriuria are needed. In addition, further assessment of the impact of the reservoir of asymptomatic bacteriuria in elderly institutionalized subjects as a contributor to the problem of antimicrobial resistance in the institutionalized population should be a priority.

Management of complicated urinary tract infection in older patients

Urinary tract infection (UTI) in older persons is a common medical problem that is seen in both the ambulatory and institutional settings. It affects older women and men with a gender prevalence ratio of 2:1, respectively. UTI in older persons can be a complex problem in terms of the approach to diagnosis, treatment, and prevention. In this report the discussion will begin with the unique aspects of UTI in older persons, particularly as they relate to UTI in the younger, general population. The remaining discussion will then focus on three complicated clinical circumstances and conditions of UTI in the geriatric population: non-catheter recurrent UTI, asymptomatic bacteriuria, and catheter-related bacteriuria and UTI.