Reducing Treatment of Asymptomatic Bacteriuria: What Works?

Asymptomatic bacteriuria is common, but usually benign. Inappropriate antimicrobial treatment of asymptomatic bacteriuria contributes to negative antimicrobial outcomes. Optimizing antimicrobial use for bacteriuria is a component of antimicrobial stewardship programs and includes key practices of dissemination and implementation of guidelines, laboratory practices which support stewardship, and programs to monitor and implement optimal antimicrobial treatment for urinary infection. These activities vary in their effectiveness, costs, and complexity to institute. Stewardship strategies targeting unique populations with a high prevalence of bacteriuria and for whom symptom assessment is not straightforward need to be further developed and evaluated to support optimal stewardship.

Asymptomatic Bacteriuria.

Asymptomatic bacteriuria, defined as the presence of bacteria in the urine in the absence of urinary symptoms, is a common clinical finding that often warrants a decision about whether to initiate antimicrobial therapy. There are few indications to treat asymptomatic bacteriuria, and inappropriate treatment contributes to the development of antimicrobial resistance. In 2019, the Infectious Diseases Society of America revised its 2005 guidelines on asymptomatic bacteriuria, incorporating new evidence. The updated guidelines recommend screening and appropriate treatment for asymptomatic bacteriuria in pregnant women and in individuals undergoing endourological procedures associated with mucosal trauma. The guidelines recommend against screening and treatment in infants and children; healthy adults, including nonpregnant pre- and postmenopausal women; and patients with diabetes mellitus, long-term indwelling catheters, or spinal cord injuries. The guidelines also recommend against screening and treatment in patients undergoing nonurological surgery, patients who have had a kidney transplant more than one month prior, recipients of other solid organ transplants, or those with impaired voiding following spinal cord injury. Although delirium in older adults can be caused by a urinary tract infection, the guidelines recommend that patients with delirium and no urinary or systemic symptoms be assessed for other causes of delirium, rather than initiating treatment for asymptomatic bacteriuria, because treatment has not been shown to have any beneficial effect on clinical outcomes.

Clinical Practice Guideline for the Management of Asymptomatic Bacteriuria: 2019 Update by the Infectious Diseases Society of America.

Asymptomatic bacteriuria (ASB) is a common finding in many populations, including healthy women and persons with underlying urologic abnormalities. The 2005 guideline from the Infectious Diseases Society of America recommended that ASB should be screened for and treated only in pregnant women or in an individual prior to undergoing invasive urologic procedures. Treatment was not recommended for healthy women; older women or men; or persons with diabetes, indwelling catheters, or spinal cord injury. The guideline did not address children and some adult populations, including patients with neutropenia, solid organ transplants, and nonurologic surgery. In the years since the publication of the guideline, further information relevant to ASB has become available. In addition, antimicrobial treatment of ASB has been recognized as an important contributor to inappropriate antimicrobial use, which promotes emergence of antimicrobial resistance. The current guideline updates the recommendations of the 2005 guideline, includes new recommendations for populations not previously addressed, and, where relevant, addresses the interpretation of nonlocalizing clinical symptoms in populations with a high prevalence of ASB.

Clinical Practice Guideline for the Management of Asymptomatic Bacteriuria: 2019 Update by the Infectious Diseases Society of America.

Asymptomatic bacteriuria (ASB) is a common finding in many populations, including healthy women and persons with underlying urologic abnormalities. The 2005 guideline from the Infectious Diseases Society of America recommended that ASB should be screened for and treated only in pregnant women or in an individual prior to undergoing invasive urologic procedures. Treatment was not recommended for healthy women; older women or men; or persons with diabetes, indwelling catheters, or spinal cord injury. The guideline did not address children and some adult populations, including patients with neutropenia, solid organ transplants, and nonurologic surgery. In the years since the publication of the guideline, further information relevant to ASB has become available. In addition, antimicrobial treatment of ASB has been recognized as an important contributor to inappropriate antimicrobial use, which promotes emergence of antimicrobial resistance. The current guideline updates the recommendations of the 2005 guideline, includes new recommendations for populations not previously addressed, and, where relevant, addresses the interpretation of nonlocalizing clinical symptoms in populations with a high prevalence of ASB.

Developing key performance indicators for prescription medication systems.

OBJECTIVE: To develop key performance indicators that evaluate the effectiveness of a prescription medication system. METHODS: A modified RAND/UCLA appropriateness method was used to develop key performance indicators (KPIs) for a prescription medication system. A broad list of potential KPIs was compiled. A multidisciplinary group composed of 21 experts rated the potential KPIs. A face-to-face meeting was held following the first rating exercise to discuss each potential KPI individually. The expert panel undertook a final rating of KPIs. The final set of KPIs were those indicators where at least 80 percent of experts rated the indicator highly i.e. rating of ≥ 7 on a scale from 1 to 9. RESULTS: 292 KPIs were identified from the published literature. After removing duplicates and combining similar indicators 71 KPIs were included. The final ranking resulted in six indicators being ranked 7 or higher by 80% of the respondents and an additional seven indicators being ranked 7 or higher by ≥70 but ≤80% of respondents. The six selected indicators include four specific disease areas, measure structural and process aspects of health service delivery, and assessed three of the domains of healthcare quality: efficiency, effectiveness, and safety. CONCLUSIONS: These indicators are recommended as a starting point to assess the current performance of prescription medication systems. Consideration should be given to developing indicators in additional disease areas as well as indicators that measure the domains of timeliness and patient-centeredness. Future work should focus on the feasibility of measuring these indicators.

The Development of a Decision Tool for the Empiric Treatment of Suspected Urinary Tract Infection in Frail Older Adults: A Delphi Consensus Procedure.

OBJECTIVES: Nonspecific signs and symptoms combined with positive urinalysis results frequently trigger antibiotic therapy in frail older adults. However, there is limited evidence about which signs and symptoms indicate urinary tract infection (UTI) in this population. We aimed to find consensus among an international expert panel on which signs and symptoms, commonly attributed to UTI, should and should not lead to antibiotic prescribing in frail older adults, and to integrate these findings into a decision tool for the empiric treatment of suspected UTI in this population. DESIGN: A Delphi consensus procedure. SETTING AND PARTICIPANTS: An international panel of practitioners recognized as experts in the field of UTI in frail older patients. MEASURES: In 4 questionnaire rounds, the panel (1) evaluated the likelihood that individual signs and symptoms are caused by UTI, (2) indicated whether they would prescribe antibiotics empirically for combinations of signs and symptoms, and (3) provided feedback on a draft decision tool. RESULTS: Experts agreed that the majority of nonspecific signs and symptoms should be evaluated for other causes instead of being attributed to UTI and that urinalysis should not influence treatment decisions unless both nitrite and leukocyte esterase are negative. These and other findings were incorporated into a decision tool for the empiric treatment for suspected UTI in frail older adults with and without an indwelling urinary catheter. CONCLUSIONS: A decision tool for suspected UTI in frail older adults was developed based on consensus among an international expert panel. Studies are needed to evaluate whether this decision tool is effective in reaching its aim: the improvement of diagnostic evaluation and treatment for suspected UTI in frail older adults.

Infectious Diseases in Older Adults of Long-Term Care Facilities: Update on Approach to Diagnosis and Management.

The diagnosis, treatment, and prevention of infectious diseases in older adults in long-term care facilities (LTCFs), particularly nursing facilities, remains a challenge for all health providers who care for this population. This review provides updated information on the currently most important challenges of infectious diseases in LTCFs. With the increasing prescribing of antibiotics in older adults, particularly in LTCFs, the topic of antibiotic stewardship is presented in this review. Following this discussion, salient points on clinical relevance, clinical presentation, diagnostic approach, therapy, and prevention are discussed for skin and soft tissue infections, infectious diarrhea (Clostridium difficile and norovirus infections), bacterial pneumonia, and urinary tract infection, as well as some of the newer approaches to preventive interventions in the LTCF setting.

Urinary Tract Infections in the Older Adult.

Urinary infection is the most common bacterial infection in elderly populations. The high prevalence of asymptomatic bacteriuria in both men and women is benign and should not be treated. A diagnosis of symptomatic infection for elderly residents of long-term care facilities without catheters requires localizing genitourinary findings. Symptomatic urinary infection is overdiagnosed in elderly bacteriuric persons with nonlocalizing clinical presentations, with substantial inappropriate antimicrobial use. Residents with chronic indwelling catheters experience increased morbidity from urinary tract infection. Antimicrobial therapy is selected based on clinical presentation, patient tolerance, and urine culture results.

Susceptibility patterns and ESBL rates of Escherichia coli from urinary tract infections in Canada and the United States, SMART 2010-2014.

Increasing antimicrobial resistance in urinary tract infections (UTI) is a concern. To evaluate resistance trends, 3498 Escherichia coli UTI isolates were collected from 2010 to 2014 in the Study for Monitoring Antimicrobial Resistance Trends (SMART) in Canada and United States (US). ESBL phenotype and susceptibility were determined using CLSI microdilution and breakpoints. US ESBL rates increased in 2010-2014 (7.8-18.3%, P < 0.0001), especially among hospital-associated (HA) infections, males, and older patients (≥65 years). Overall, ESBL rates in Canada showed no significant trend (10.4-13.0%. P = 0.079), and were lower than US rates in recent years, but increased significantly among community-associated (CA) infections, females, and older patients. In the US, but not Canada, susceptibility to cephalosporins and fluoroquinolones among 2013-2014 isolates was significantly lower in isolates from HA than CA UTI, males than females, and ≥65- than <65-year-olds. These observations confirm increasing resistance in E. coli. Subgroup analyses like these may help direct empirical therapy.

The Paradigm Shift to Non-Treatment of Asymptomatic Bacteriuria.

Asymptomatic bacteriuria, also called asymptomatic urinary infection, is a common finding in healthy women, and in women and men with abnormalities of the genitourinary tract. The characterization and introduction of the quantitative urine culture in the 1950s first allowed the reliable recognition of asymptomatic bacteriuria. The observations that a substantial proportion of patients with chronic pyelonephritis at autopsy had no history of symptomatic urinary infection, and the high frequency of pyelonephritis observed in pregnant women with untreated asymptomatic bacteriuria, supported a conclusion that asymptomatic bacteriuria was harmful. Subsequent screening and long term follow-up programs for asymptomatic bacteriuria in schoolgirls and women reported an increased frequency of symptomatic urinary tract infection for subjects with asymptomatic bacteriuria, but no increased morbidity from renal failure or hypertension, or increased mortality. Treatment of asymptomatic bacteriuria did not decrease the frequency of symptomatic infection. Prospective, randomized, comparative trials enrolling premenopausal women, children, elderly populations, patients with long term catheters, and diabetic patients consistently report no benefits with antimicrobial treatment of asymptomatic bacteriuria, and some evidence of harm. Several studies have also reported that antimicrobial treatment of asymptomatic bacteriuria increases the short term risk of pyelonephritis. Current investigations are exploring the potential therapeutic intervention of establishing asymptomatic bacteriuria with an avirulent Escherichia coli strain to prevent symptomatic urinary tract infection for selected patients.

Asymptomatic Bacteriuria and Bacterial Interference.

Asymptomatic bacteriuria is very common. In healthy women, asymptomatic bacteriuria increases with age, from <1% in newborns to 10% to 20% of women age 80 years, but is uncommon in men until after age 50 years. Individuals with underlying genitourinary abnormalities, including indwelling devices, may also have a high frequency of asymptomatic bacteriuria, irrespective of age or gender. The prevalence is very high in residents of long-term-care facilities, from 25% to 50% of women and 15% to 40% of men. Escherichia coli is the most frequent organism isolated, but a wide variety of other organisms may occur. Bacteriuria may be transient or persist for a prolonged period. Pregnant women with asymptomatic bacteriuria identified in early pregnancy and who are untreated have a risk of pyelonephritis later in pregnancy of 20% to 30%. Bacteremia is frequent in bacteriuric subjects following mucosal trauma with bleeding, with 5% to 10% of patients developing severe sepsis or septic shock. These two groups with clear evidence of negative outcomes should be screened for bacteriuria and appropriately treated. Asymptomatic bacteriuria in other populations is benign and screening and treatment are not indicated. Antimicrobial treatment has no benefits but is associated with negative outcomes including reinfection with antimicrobial resistant organisms and a short-term increased frequency of symptomatic infection post-treatment. The observation of increased symptomatic infection post-treatment, however, has led to active investigation of bacterial interference as a strategy to prevent symptomatic episodes in selected high risk patients.