Positive urine cultures: A major cause of inappropriate antimicrobial use in hospitals?

The Clinical Profile of Patients With Culture-Positive Urinary Tract Infections Admitting to a Tertiary Hospital in Sri Lanka

Introduction Urinary tract infections (UTIs) are globally prevalent. This study explores the clinical and pathological profile of culture-positive UTI patients at Sri Jayewardenepura General Hospital. Method In this descriptive cross-sectional study conducted at Sri Jayewardenepura General Hospital from December 2020 to May 2021, we evaluated patients over 14 years with positive urine culture reports. Excluding those with HIV, undergoing chemotherapy, or pregnant, we used consecutive sampling. Data were collected via interviewer-administered questionnaires and analyzed using SPSS version 21.0 (IBM Inc., Armonk, New York), employing descriptive statistics and Fisher's exact tests to identify factors associated with urinary tract infections. Results The study involved approximately 278 participants. The mean age remained 60 ± 20.279 years, with over half of the participants being female. Common symptoms like fever and lower abdominal pain were observed in 22.30% of cases. The incidence of acute kidney injury was 30.58%. Escherichia coli (36%) and Klebsiella pneumoniae (26%) were the predominant organisms found. Indwelling catheters and other urinary tract conditions were considered risk factors. Patients with at least one risk factor were more likely to receive antibiotics before the urine culture. Similarly, males exhibited a higher prevalence of at least a risk factor than females. Conclusion UTIs are a significant clinical issue in older populations, with females being more susceptible. Fever and abdominal pain were common symptoms. Escherichia coli and Klebsiella pneumoniae were the most frequent causative agents. Further research is necessary to identify risk factors and predictors of antimicrobial resistance in UTI patients.

''Myth Busting in Infectious Diseases'': A Comprehensive Review

Antibiotics have played a pivotal role in modern medicine, drastically reducing mortality rates associated with bacterial infections. Despite their significant contributions, the emergence of antibiotic resistance has become a formidable challenge, necessitating a re-evaluation of antibiotic use practices. The widespread belief in clinical practice that bactericidal antibiotics are inherently superior to bacteriostatic ones lacks consistent support from evidence in randomized controlled trials (RCTs). With the latest evidence, certain infections have demonstrated equal or even superior efficacy with bacteriostatic agents. Furthermore, within clinical practice, there is a tendency to indiscriminately order urine cultures for febrile patients, even in cases where alternative etiologies might be present. Consequently, upon obtaining a positive urine culture result, patients often receive antimicrobial prescriptions despite the absence of clinical indications warranting such treatment. Furthermore, it is a prevailing notion among physicians that extended durations of antibiotic therapy confer potential benefits and mitigate the emergence of antimicrobial resistance. Contrary to this belief, empirical evidence refutes such assertions. This article aims to address common myths and misconceptions within the field of infectious diseases.

Effect of inpatient antibiotic treatment among older adults with delirium found with a positive urinalysis: a health record review

BACKGROUND

Among older adults with delirium and positive urinalysis, antibiotic treatment for urinary tract infection is common practice, but unsupported by literature or guidelines. We sought to: i) determine the rate of antibiotic treatment and the proportion of asymptomatic patients (other than delirium) in this patient population, and ii) examine the effect of antibiotic treatment on delirium resolution and adverse outcomes.

METHODS

A health record review was conducted at a tertiary academic centre from January to December 2020. Inclusion criteria were age ≥ 65, positive delirium screening assessment, positive urinalysis, and admission to general medical units. Outcomes included rates of antibiotic treatment, delirium on day 7 of admission, and 30-day adverse outcomes. We compared delirium and adverse outcome rates in antibiotic-treated vs. non-treated groups. We conducted subgroup analyses among asymptomatic patients.

RESULTS

We included 150 patients (57% female, mean age 85.4 years). Antibiotics were given to 86%. The asymptomatic subgroup (delirium without urinary symptoms or fever) comprised 38% and antibiotic treatment rate in this subgroup was 68%. There was no significant difference in delirium rate on day 7 between antibiotic-treated vs. non-treated groups, (entire cohort RR 0.94 [0.41-2.16] and asymptomatic subgroup RR 0.69 [0.22-2.15]) or in 30-day adverse outcomes.

CONCLUSIONS

Older adults with delirium and positive urinalysis in general medical inpatient units were frequently treated with antibiotics - often despite the absence of urinary or other infectious symptoms. We failed to find evidence that antibiotic treatment in this population is associated with delirium resolution on day 7 of admission.

Lectin-Functionalized Chitosan Nanoparticle-Based Biosensor for Point-of-Care Detection of Bacterial Infections

The WHO estimates an average of 10 million deaths per year due to the increasing number of infections and the predominance of drug resistance. To improve clinical outcomes and contain the spread of infections, the development of newer diagnostic tools is imperative to reduce the time and cost involved to reach the farthest population. The current study focuses on the development of a point-of-care technology that uses crystal violet entrapped, lectin functionalized chitosan nanoparticles to detect the presence of clinically relevant bacterial infections. Spherical nanoparticles of <200 nm in diameter make up the biosensing nanomaterial, showed specific clumping in the presence of bacteria to form visible aggregates as compared to a nonbacterial sample. Visible agglutination confirmed the presence of bacteria in the samples. The devices require just 100 μL of sample and were tested with various bacteria-spiked saline, simulated urine, artificial sputum, and simulated respiratory and wound swabs. The developed device did not require any sample preparation or sophisticated instruments while enabling rapid differentiation between bacterial and nonbacterial infections within 10 min. The in vitro results with bacteria-spiked simulated samples reveal 100% sensitivity and specificity with a limit of detection of 10⁵ cfu/mL. The nanomaterial developed was found to be stable for more than 90 days at accelerated conditions. The developed device can be a screening tool for home-based or clinical assessment and follow the treatment accordingly, reducing exposure to broad-spectrum antibiotics in the case of nonbacterial infections.

Substantial overlap between symptomatic and asymptomatic genitourinary microbiota states

BACKGROUND

The lack of a definition of urinary microbiome health convolutes diagnosis of urinary tract infections (UTIs), especially when non-traditional uropathogens or paucity of bacteria are recovered from symptomatic patients in routine standard-of-care urine tests. Here, we used shotgun metagenomic sequencing to characterize the microbial composition of asymptomatic volunteers in a set of 30 longitudinally collected urine specimens. Using permutation tests, we established a range of asymptomatic microbiota states, and use these to contextualize the microbiota of 122 urine specimens collected from patients with suspected UTIs diagnostically categorized by standard-of-care urinalysis within that range. Finally, we used a standard-of-care culture protocol to evaluate the efficiency of culture-based recovery of the urinary microbiota.

RESULTS

The majority of genitourinary microbiota in individals suspected to have UTI overlapped with the spectrum of asymptomatic microbiota states. Longitudinal characterization of the genitourinary microbiome in urine specimens collected from asymptomatic volunteers revealed fluctuations of microbial functions and taxonomy over time. White blood cell counts from urinalysis suggested that urine specimens categorized as 'insignificant', 'contaminated', or 'no-growth' by conventional culture methods frequently showed signs of urinary tract inflammation, but this inflammation is not associated with genitourinary microbiota dysbiosis. Comparison of directly sequenced urine specimens with standard-of-care culturing confirmed that culture-based diagnosis biases genitourinary microbiota recovery towards the traditional uropathogens Escherichia coli and Klebsiella pneumoniae.

CONCLUSION

Here, we utilize shotgun metagenomic sequencing to establish a baseline of asymptomatic genitourinary microbiota states. Using this baseline we establish substantial overlap between symptomatic and asymptomatic genitourinary microbiota states. Our results establish that bacterial presence alone does not explain the onset of clinical symptoms. Video Abstract.

Predictive Value of Urinalysis and Recent Antibiotic Exposure to Distinguish Between Bacteriuria, Candiduria, and No-Growth Urine

PURPOSE

Urinary tract infections are diagnosed by clinical symptoms and detection of causative uropathogen. Antibiotics are usually not indicated in candiduria and no-growth urine. We aimed to develop a predictive score to distinguish bacteriuria, candiduria, and no-growth urine, and to describe the distribution of microorganisms in urine.

PATIENTS AND METHODS

A single-center, retrospective cohort study was conducted between January 2017 and November 2017. Patients with concomitant urinalysis and urine culture were randomly sorted for a clinical prediction model. Multivariable regression analysis was performed to determine factors associated with bacteriuria, candiduria, and no-growth urine. A scoring system was constructed by rounding the regression coefficient for each predictor to integers. Accuracy of the score was measured by the concordance index (c-index).

RESULTS

There were 8091 positive urine cultures: bacteria 85.6%, Candida 13.7%. Randomly selected cases were sorted into derivation and validation cohorts (448 cases and 272 cases, respectively). Numerous yeast on urinalysis predicted candiduria with complete accuracy; therefore, it was excluded from a score construction. We developed a NABY score based on: positive nitrite, 1 point; Antibiotic exposure within 30 days, -2 points; numerous Bacteria in urine, 2 points; few Yeast in urine, -2 points; moderate Yeast in urine, -5 points. The c-index was 0.85 (derivation) and 0.82 (validation). A score ≥0 predicted 76% and 54% of bacteriuria in the derivation and validation cohorts, respectively. A score ≤-3 predicted 96% of candiduria in both cohorts.

CONCLUSION

Numerous yeast on urinalysis and the NABY score may help identify patients with a low risk of bacteriuria in whom empiric antibiotics for UTIs can be avoided.

Impact of the implementation of a standard for preanalytical handling of samples for microbiological diagnostics on the quality of results at a neurocritical care unit

ABSTRACT

Antibiotic stewardship (ABS) programs intend to improve outcomes of nosocomial infections and to counteract the emergence of further antimicrobial resistances. At the anesthesiologic-neurosurgical intensive care unit (ICU) of the University Medical Center Regensburg (Germany) we implemented a standard operating procedure (SOP) with clear instructions for the preanalytical handling and storage of microbiological samples. We intended to find out whether the instructions given in the SOP led to a higher rate of ideal material being sent to the laboratory and to overall better quality of the received results.We retraced retrospectively all samples taken in cases of suspected pneumonia, urinary tract infection, bloodstream infection, catheter infection associated with a central venous or arterial catheter and ventriculitis due to external ventricular drainage as well as all smears taken for the screening for multi-resistant bacteria within a time period of 1 year before to 1 year after the implementation of the SOP.In the case of suspected pneumonia and urinary tract infection, large amounts of ideal material were sent to the microbiological laboratory. A remarkable improvement after the implementation of the SOP, however, could only be observed regarding the number of urine samples taken from older urinary catheters, which was significantly lower in the "SOP group". Samples for microbiological diagnostics were taken much more often in the daytime, although storage of the probes did not lead to worse results.Concrete instructions enable adequate preanalytical handling of microbiological probes. However, we could not recognize substantial improvements probably due to a preexisting high process quality on the ICU. Microbiological diagnostics during the night shift has to be improved.

Treatment of Asymptomatic Bacteriuria after Implementation of an Inpatient Urine Culture Algorithm in the Electronic Medical Record

Ordering urine cultures in patients without pyuria is associated with the inappropriate treatment of asymptomatic bacteriuria (ASB). In 2015, our institution implemented recommendations based on practice guidelines for the management of ASB and revised the urine culture ordering process to limit cultures in immunocompetent patients without pyuria. The purpose of this study was to determine how the treatment of ASB has changed over time since altering the urine culture ordering process to reduce unnecessary cultures at an academic medical center. A quasi-experimental study was conducted for inpatients with urine cultures from January to March of 2014, 2015, 2016 and 2020. The primary outcome was the antibiotic treatment of asymptomatic bacteriuria for over 24 h. The secondary outcomes were the total days of antibiotic therapy, type of antibiotic prescribed and overall urine culture rates at the hospital. A total of 200 inpatients with ASB were included, 50 at random from each year. In both 2014 and 2015, 70% of the patients with ASB received antibiotic treatment. Antibiotics were prescribed to 68% and 54% of patients with ASB in 2016 and 2020, respectively. The average duration of therapy decreased from 5.12 days in 2014 to 3.46 days in 2020. Although the urine cultures were reduced, there was no immediate impact in the prescribing rates for patients with ASB after implementing this institutional guidance and an altered urine culture ordering process. Over time, there was an observed improvement in prescribing and the total days of antibiotic therapy. This could be attributed to increased familiarity with the guidelines, culture ordering practices or improved documentation. Based on these findings, additional provider education is needed to reinforce the guideline recommendations on the management of ASB.

Thinking Beyond the "Core" Antibiotic Stewardship Interventions: Shifting the Onus for Appropriate Antibiotic Use from Stewardship Teams to Prescribing Clinicians

United States guidance for hospital antibiotic stewardship has emphasized prospective audit and feedback and prior authorization of select antibiotics as core interventions. These remain the most common interventions implemented by stewardship programs. Although these approaches have been shown to reduce unnecessary antibiotic use, they incorrectly put the onus for appropriate antibiotic use on the stewardship team rather than the prescribing clinician. We propose that a primary focus of stewardship programs should be implementation of broader interventions that engage frontline clinicians and equip them with tools to integrate antibiotic stewardship into their own daily practice, thus reducing the need for day-to-day stewardship team oversite. We discuss a framework of broader interventions and policies that will facilitate this paradigm shift.

A New Gold Rush: A Review of Current and Developing Diagnostic Tools for Urinary Tract Infections

Urinary tract infections (UTIs) are one of the most common infections in the United States and consequently are responsible for significant healthcare expenditure. The standard urine culture is the current gold standard for diagnosing urinary tract infections, however there are limitations of the test that directly contribute to increased healthcare costs. As a result, new and innovative techniques have been developed to address the inefficiencies of the current standard-it remains to be seen whether these tests should be performed adjunctly to, or perhaps even replace the urine culture. This review aims to analyze the advantages and disadvantages of the newer and emerging diagnostic techniques such as PCR, expanded quantitative urine culture (EQUC), and next generation sequencing (NGS).

Reliability of nonlocalizing signs and symptoms as indicators of the presence of infection in nursing-home residents

Antibiotics are among the most common medications prescribed in nursing homes. The annual prevalence of antibiotic use in residents of nursing homes ranges from 47% to 79%, and more than half of antibiotic courses initiated in nursing-home settings are unnecessary or prescribed inappropriately (wrong drug, dose, or duration). Inappropriate antibiotic use is associated with a variety of negative consequences including Clostridioides difficile infection (CDI), adverse drug effects, drug-drug interactions, and antimicrobial resistance. In response to this problem, public health authorities have called for efforts to improve the quality of antibiotic prescribing in nursing homes.

Oral and parenteral antibiotic use in Norwegian nursing homes: are primary care institutions becoming our new local hospitals?

Background

Norwegian nursing homes (NHs) have over the last 10 years increasingly applied the use of parenteral treatment, which in turn allows more broad-spectrum use of antibiotics. Previous studies from Norwegian NHs have for the most part not described parenteral formulations.

Objectives

To describe systemic antibiotic use in Norwegian NHs.

Methods

Thirty-seven NHs in the county of Østfold, Norway, were invited to participate in this retrospective cross-sectional study. Associated pharmacies provided sales data for systemic antibiotic use for the participating NHs for 1 year (October 2015 to October 2016). General institutional characteristics were collected through a questionnaire.

Results

Thirty-four NHs participated in the study. Mean use of antibiotics was 9.5 DDD/100 bed days (range 0.6–30.9 DDD/100 bed days). Oral antibiotics accounted for 83% and parenteral antibiotics for 17% of the total antibiotic use. Of parenteral antibiotics, ampicillin was most used (31.1%) followed by cefotaxime (17.7%) and penicillin G (16.6%). The proportion of antibiotics compliant with guideline recommendations was 60%. Being a short-term NH was associated with increased antibiotic use, with an unstandardized coefficient of 13.1 (95% CI 4.2–21.9; P = 0.005).

Conclusions

We found a high level of total and parenteral antibiotic use compared with previous studies from Norwegian NHs. Data showed wide variations in total antibiotic use and that only a moderate proportion of the antibiotic use was considered guideline compliant. This highlights the necessity of further implementation strategies regarding the national guidelines for antibiotic use in NHs.

Antibiotic Resistant Bacterial Pathogens Associated with Blood Stream Infections and Urinary Tract Infections among Intensive Care Unit Patients

Blood Stream Infection (BSI) and Urinary Tract Infection (UTI) being leading causes of morbidity and mortality represent a common complication among critically ill patients. During the last decade, clinicians have observed a rising occurrence of BSIs due to bacterial resistance. Likewise, catheter-associated UTI is a main cause of morbidity and mortality affecting all age groups. Coliforms happen to be the prominent pathogens among our ICU admitted patients. It was alarming to notice 42.9% resistance to tigecycline among K. pneumoniae isolated from blood. K. pneumoniae isolates cultured from urine of ICU patients uniformly displayed 75% resistance to ciprofloxacin, ceftriaxone, cefoxitin and cefepime. Interestingly, it is of respite to observe 85.7% K. pneumoniae isolated from blood and 75% K. pneumoniae isolated from urine being susceptible to a conventional antibiotic, gentamicin. Escherichia coli isolated from urine were 100% susceptible to carbapenems and 91.75% were susceptible to tigecycline. Overall, 90% of Pseudomonas aeruginosa were susceptible to nitrofurantoin. The rapid spread of these MDR pathogens demands for national and regional guidelines. Policies to treat ICU related infections in UAE should be designed based on local microbiological data and resistance profiles of pathogens.

Burning for Treatment: Impact of Staff Education on Asymptomatic Bacteriuria Management in the Elderly

Background

Studies indicate that elderly patients are often inappropriately treated with antimicrobials for asymptomatic bacteriuria (ASB). Interprofessional education may help improve the assessment and management of ASB.

Methods

Retrospective chart audits were conducted on two cohorts of positive urine cultures (n = 201) obtained from a geriatric acute care unit to determine the incidence of treated ASB. The first cohort (n = 101) was analyzed from January to July 2017. Education was provided to unit staff (e.g., nurses, physicians, pharmacists) in Fall 2017. The second cohort (n = 100) was analyzed from January to July 2018. Descriptive statistics were used to summarize and compare the results from the cohorts.

Results

152 patients (n = 201 positive urine cultures) were reviewed: 74% (159) of positive urine cultures were ASB and 21% (42) were urinary tract infections. The incidence of treated ASB was 15% (30) and untreated ASB was 65% (129). The incidence of UTI, treated ASB, and untreated ASB were not significantly different between the two cohorts examined.

Conclusion

The implementation of education did not result in lasting changes in ASB management. Our study suggests that future systemic solutions are necessary to reduce the incidence of treated ASB in the geriatric population.

Safety, effectiveness and sustainability of a laboratory intervention to de-adopt culture of midstream urine samples among hospitalized patients

OBJECTIVE

To assess the safety, sustainability, and effectiveness of a laboratory intervention to reduce processing of midstream urine (MSU) cultures.

DESIGN

Prospective observational cohort.

SETTING

Medical and surgical inpatients in a tertiary-care hospital.

PARTICIPANTS

The study included 1,678 adult inpatients with an order for MSU culture.

METHODS

From 2013 to 2019, ordered MSU cultures were not processed unless the laboratory was called. Patients were interviewed on days 0 and 4; from 2017 to 2019, day-30 follow-up was added. Primary outcome was serious adverse events due to not processing MSU cultures. Secondary outcomes were nonserious adverse events due to not processing MSU cultures, rates of MSU cultures submitted, proportion of MSU cultures processed, proportion of patients prescribed urinary tract infection (UTI)-directed antibiotics, and laboratory workload.

RESULTS

Among 912 and 459 patients followed to days 4 and 30, respectively, no serious adverse events attributable to not processing MSU cultures were identified. However, 6 patients (0.66%) had prolonged urinary symptoms potentially associated with not processing MSU cultures. We estimated that 4 patients missed having empiric antibiotics stopped in response to negative MSU cultures, and 99 antibiotic courses for asymptomatic bacteriuria (ASB) and 8 antibiotic-associated adverse events were avoided. The rate of submitted MSU samples and proportion of patients receiving empiric UTI-directed antibiotics did not change. The proportion of MSU cultures processed declined from 59% to 49% (P < .0001), and total laboratory workload was reduced by 185 hours.

CONCLUSIONS

De-adopting the processing of MSU cultures from medical and surgical inpatient units is safe and sustainable, and it reduces antibiotic prescriptions for ASB at a cost of prolonged urinary symptoms in a small proportion of patients.

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.

Barriers and facilitators and the need for a clinical guideline for microbiological diagnostic testing in the hospital: a qualitative and quantitative study

The appropriate use of microbiological investigations is an important cornerstone of antibiotic stewardship programmes, but receives relatively limited attention. This study aimed to identify influencing factors in performing microbiological diagnostic tests and to assess the need for a clinical guideline. We performed a qualitative (focus group) and quantitative (online questionnaire survey) study among medical specialists and residents to identify physicians' considerations in performing microbiological diagnostic tests and to assess the need for a diagnostic guideline. The questionnaire consisted of 14 statements, divided into three categories: knowledge, influencing factors and presence of guidelines. The questionnaire was sent to physicians of the departments of internal medicine, intensive care, paediatrics and pulmonology in five hospitals in the Netherlands. Sub-analyses for medical specialists versus residents and for paediatric versus non-paediatric departments were performed. We included 187 completed questionnaires in our analyses. The physicians reported having adequate knowledge on methods, time-to-result and accuracy, but inadequate knowledge on costs of the tests. Patients' clinical condition, comorbidity, local guidelines and accuracy of tests were appraised as the four most important influencing factors to perform tests. Over 70% (132/187) of physicians reported being interested in a guideline for microbiological diagnostic testing. Fifteen physicians (8.0%) provided additional comments. This study identifies the influencing factors to microbiological testing and shows the demand for a clinical guideline among physicians. IMPORTANCE: Microbiological diagnostic tests are an important cornerstone within antibiotic stewardship programmes [1-5]. These programmes aim to ameliorate the appropriate use of antibiotics and thus improve clinical outcomes of infectious diseases, whilst reducing the emergence of antimicrobial resistance [6]. However, inappropriate microbiological testing is a widely recognised problem [7-12], and influencing factors to testing have not been studied in the past. Our research shows the demand for a clinical guideline among physicians, and it identifies their influencing factors to testing. These results can be used to create a clinical guideline for microbiological diagnostic testing, thus supporting antibiotic stewardship programmes and reducing antimicrobial resistance.

Antimicrobial therapy for asymptomatic bacteriuria or candiduria in advanced cancer patients transitioning to comfort measures

Among 300 advanced cancer patients with potential urinary tract infection (UTI), 19 had symptomatic UTI. Among remaining patients (n = 281), 21% had asymptomatic bacteriuria or candiduria, and 14% received inappropriate therapy for 279 antimicrobial days. Bacteriuria or candiduria predicted antimicrobial therapy. At 10,000 to &lt;100,000 CFU/mL, the incidence rate ratio [IRR] was 16.9 (95% confidence interval [CI], 6.0-47.2), and at ≥100,000 CFU/mL, the IRR was 27.9 (95% CI, 10.9-71.2).

The scientific evidence for a potential link between confusion and urinary tract infection in the elderly is still confusing - a systematic literature review

Background

Non-specific symptoms, such as confusion, are often suspected to be caused by urinary tract infection (UTI) and continues to be the most common reason for suspecting a UTI despite many other potential causes. This leads to significant overdiagnosis of UTI, inappropriate antibiotic use and potential harmful outcomes. This problem is particularly prevalent in nursing home settings.

Methods

A systematic review of the literature was conducted assessing the association between confusion and UTI in the elderly. PubMed, Scopus and PsychInfo were searched with the following terms: confusion, delirium, altered mental status, acute confusional state, urinary tract infection, urine infection, urinary infection and bacteriuria. Inclusion criteria and methods were specified in advance and documented in the protocol, which was published with PROSPERO (registration ID: CRD42015025804). Quality assessment was conducted independently by two authors. Data were extracted using a standardised extraction tool and a qualitative synthesis of evidence was made.

Results

One thousand seven hunderd two original records were identified, of which 22 were included in the final analysis. The quality of these included studies varied, with frequent poor case definitions for UTI or confusion contributing to large variation in results and limiting their validity. Eight studies defined confusion using valid criteria; however, no studies defined UTI in accordance with established criteria. As no study used an acceptable definition of confusion and UTI, an association could not be reliably established. Only one study had acceptable definitions of confusion and bacteriuria, reporting an association with the relative risk being 1.4 (95% CI 1.0–1.7, p = 0.034).

Conclusions

Current evidence appears insufficient to accurately determine if UTI and confusion are associated, with estimates varying widely. This was often attributable to poor case definitions for UTI or confusion, or inadequate control of confounding factors. Future well-designed studies, using validated criteria for UTI and confusion are required to examine the relationship between UTI and acute confusion in the elderly. The optimal solution to clarify this clinical issue would be a randomized controlled trial comparing the effect of antibiotics versus placebo in patients with new onset or worsening confusion and presence of bacteriuria while lacking specific urinary tract symptoms.

Reducing unnecessary urine culturing and antibiotic overprescribing in long-term care: a before-and-after analysis

BACKGROUND

Antibiotic use in long-term care homes is highly variable. High rates of antibiotic use are associated with antibiotic resistance and Clostridium difficile infection. We asked 2 questions regarding a program designed to improve diagnosis and management of urinary tract infections in long-term care: whether the program decreased urine culturing and antibiotic prescribing rates and whether specific strategies of the program were more or less likely to be adopted.

METHODS

The study included 10 long-term care homes in Ontario, Canada, between December 2015 and May 2017. We assessed the implementation of the program's 9 strategies via semistructured interviews with key informants. Using a before-and-after study design, and on the basis of monthly facility-level records, we measured changes in the rates of urine specimens sent for culture and susceptibility testing, prescriptions for antibiotics commonly used to treat urinary tract infections and total antibiotic prescriptions, using Poisson regression.

RESULTS

Participating homes implemented an average of 6.1 of the 9 strategies. Urine culturing decreased from 3.20 to 2.09 per 1000 resident-days from the baseline to the intervention phase (adjusted incidence rate ratio [IRR_adjusted] = 0.72, 95% confidence interval [CI] 0.63-0.82), urinary antibiotic prescriptions fell from 1.52 to 0.83 per 1000 resident-days (IRR_adjusted = 0.60, 95% CI 0.47-0.74) and total antibiotic prescriptions fell from 3.85 to 2.60 per 1000 resident-days (IRR_adjusted = 0.74, 95% CI 0.65-0.83). After adjusting for secular trends, these reductions were not statistically significant.

INTERPRETATION

We demonstrated a reduction in urine culturing and antibiotic use following implementation of the Urinary Tract Infection Program. This initial analysis supports a broader implementation of this program, although ongoing evaluation is required to monitor secular trends in urine culturing and antibiotic use.

The clinical impact of a urinary tract infection management bundle in a tertiary-care teaching hospital

Objective

The aim of this study was to assess the impact of a urinary tract infection (UTI) management bundle to reduce the treatment of asymptomatic bacteriuria (AB) and to improve the management of symptomatic UTIs.

Design

Before-and-after intervention study.

Settings

Tertiary-care hospital.

Patients

Consecutive sample of inpatients with positive single or mixed-predominant urine cultures collected and reported while admitted to the hospital.

Methods

The UTI management bundle consisted of nursing and prescriber education, modification of the reporting of positive urine cultures, and pharmacists’ prospective audit and feedback. A retrospective chart review of consecutive inpatients with positive urinary cultures was performed before and after implementation of the management bundle.

Results

Prior to the implementation of the management bundle, 276 patients were eligible criteria for chart review. Of these 276 patients, 165 (59·8%) were found to have AB; of these 165 patients with AB, 111 (67·3%) were treated with antimicrobials. Moreover, 268 patients met eligibility criteria for postintervention review. Of these 268, 133 patients (49·6%) were found to have AB; of these 133 with AB, 22 (16·5%) were treated with antimicrobials. Thus, a 75·5% reduction of AB treatment was achieved. Educational components of the bundle resulted in a substantial decrease in nonphysician-directed urine sample submission. Adherence to a UTI management algorithm improved substantially in the intervention period, with a notable decrease in fluoroquinolone prescription for empiric UTI treatment.

Conclusions

A UTI management bundle resulted in a dramatic improvement in the management of urinary tract infection, particularly a reduction in the treatment of AB and improved management of symptomatic UTI.

Impact of order set design on urine culturing practices at an academic medical centre emergency department

BACKGROUND

Urinalysis and urine culture are commonly ordered tests in the emergency department (ED). We evaluated the impact of removal of order sets from the 'frequently ordered test' in the computerised physician order entry system (CPOE) on urine testing practices.

METHODS

We conducted a before (1 September to 20 October 2015) and after (21 October to 30 November 2015) study of ED patients. The intervention consisted of retaining 'urinalysis with reflex to microscopy' as the only urine test in a highly accessible list of frequently ordered tests in the CPOE system. All other urine tests required use of additional order screens via additional mouse clicks. The frequency of urine testing before and after the intervention was compared, adjusting for temporal trends.

RESULTS

During the study period, 6499 (28.2%) of 22 948 ED patients had ≥1 urine test ordered. Urine testing rates for all ED patients decreased in the post intervention period for urinalysis (291.5 pre intervention vs 278.4 per 1000 ED visits post intervention, P=0.03), urine microscopy (196.5vs179.5, P=0.001) and urine culture (54.3vs29.7, P<0.001). When adjusted for temporal trends, the daily culture rate per 1000 ED visits decreased by 46.6% (-46.6%, 95% CI -66.2% to -15.6%), but urinalysis (0.4%, 95% CI -30.1 to 44.4%), microscopy (-6.5%, 95% CI -36.0% to 36.6%) and catheterised urine culture rates (17.9%, 95% CI -16.9 to 67.4) were unchanged.

CONCLUSIONS

A simple intervention of retaining only 'urinalysis with reflex to microscopy' and removing all other urine tests from the 'frequently ordered' window of the ED electronic order set decreased urine cultures ordered by 46.6% after accounting for temporal trends. Given the injudicious use of antimicrobial therapy for asymptomatic bacteriuria, findings from our study suggest that proper design of electronic order sets plays a vital role in reducing excessive ordering of urine cultures.

Inappropriate Management of Asymptomatic Patients With Positive Urine Cultures: A Systematic Review and Meta-analysis

BACKGROUND

Mismanagement of asymptomatic patients with positive urine cultures (referred to as asymptomatic bacteriuria [ASB] in the literature) promotes antimicrobial resistance and results in unnecessary antimicrobial-related adverse events and increased health care costs.

METHODS

We conducted a systematic review and meta-analysis of studies that reported on the rate of inappropriate ASB treatment published from 2004 to August 2016. The appropriateness of antimicrobial administration was based on guidelines published by the Infectious Diseases Society of America.

RESULTS

A total of 2142 nonduplicate articles were identified, and among them 30 fulfilled our inclusion criteria. The pooled prevalence of antimicrobial treatment among 4129 cases who did not require treatment was 45% (95% CI, 39-50). Isolation of gram-negative pathogens (odds ratio [OR], 3.58; 95% CI, 2.12-6.06), pyuria (OR, 2.83; 95% CI, 1.9-4.22), nitrite positivity (OR, 3.83; 95% CI, 2.24-6.54), and female sex (OR, 2.11; 95% CI, 1.46-3.06) increased the odds of receiving treatment. The rates of treatment were higher in studies with ≥100 000 cfu/mL cutoff values compared with <10 000 cfu/mL for bacterial growth (P, .011). The implementation of educational and organizational interventions designed to eliminate the overtreatment of ASB resulted in a median absolute risk reduction of 33% (rangeARR, 16-36%, medianRRR, 53%; rangeRRR, 25-80%).

CONCLUSION

The mismanagement of ASB remains extremely frequent. Female sex and the overinterpretation of certain laboratory data (positive nitrites, pyuria, isolation of gram-negative bacteria and cultures with higher microbial count) are associated with overtreatment. Even simple stewardship interventions can be particularly effective, and antimicrobial stewardship programs should focus on the challenge of differentiating true urinary tract infection from ASB.

Management of Asymptomatic Bacteriuria, Urinary Catheters and Symptomatic Urinary Tract Infections in Patients Undergoing Surgery for Joint Replacement: A Position Paper of the Expert Group 'Infection' of swissorthopaedics

In this position paper, we review definitions related to this subject and the corresponding literature. Our recommendations include the following statements. Asymptomatic bacteriuria, asymptomatic leukocyturia, urine discolouration, odd smell or positive nitrite sediments are not an indication for antimicrobial treatment. Antimicrobial treatment of asymptomatic bacteriuria does not prevent periprosthetic joint infection, but is associated with adverse events, costs and antibiotic resistance development. Urine analyses or urine cultures in asymptomatic patients undergoing orthopaedic implants should be avoided. Indwelling urinary catheters are the most frequent reason for healthcare-associated urinary tract infections and should be avoided or removed as soon as possible.

Impact of two-step urine culture ordering in the emergency department: a time series analysis

Background

Despite evidence against the use of antimicrobials for asymptomatic bacteriuria (ASB), they are frequently prescribed leading to unnecessary adverse events. Prior studies have shown that reducing unnecessary urine cultures (UCs) results in decreased antimicrobial utilisation for ASB. Emergency departments (EDs) submit the largest volume of UCs, yet efforts to limit overordering in this patient setting have had limited success.

Methods

A new two-step model of care for urine collection, using a novel UC collection container, was implemented in the ED of a large community hospital. The collection system contains a preservative allowing UCs to be held at room temperature for up to 48 hours before processing. UCs were collected by front-line staff, but only processed in the microbiology lab if requested by ED physicians after clinical assessment.

Results

Following implementation there was a decrease in the percentage of weekly ED visits associated with a processed UC (5.97% vs 4.68%, p<0.001), a decrease in the percentage of monthly ED visits requiring a callback for positive urine culture (1.84% to 1.12%, p<0.001) and a decrease in antimicrobial prescriptions for urinary indication among admitted patients (20.6% to 10.9%, p<0.01). There was a false omission rate of 1.35% (95% CI 0.7% to 2.2%), yet no identified cases of untreated urinary tract infection (UTI), or significant change in repeat ED visits or ED length of stay.

Conclusions

Changing to two-step urine culture ordering in the ED resulted in a decrease in UCs processed, callbacks for positive results and antimicrobial use without evidence of untreated UTIs. This model of care has strong potential to improve the use of hospital resources while minimising detection and inappropriate treatment of ASB.

Advancing antimicrobial stewardship: Summary of the 2015 CIDSC Report

Background

Antimicrobial resistance (AMR) is recognized as an important global public health concern that has a cross-cutting impact on human health, animal health, food and agriculture and the environment. The Communicable and Infectious Disease Steering Committee (CIDSC) of the Pan-Canadian Public Health Network (PHN) created a Task Group on Antimicrobial Stewardship to look at this issue from a Canadian perspective.

Objective

To summarize the key findings of the Task Group Report that identified core components of antimicrobial stewardship programs, best practices, key challenges, gaps and recommendations to advance stewardship across jurisdictions.

Methods

Search strategies were developed to identify scientific literature, grey literature and relevant websites on antimicrobial stewardship. The information was reviewed and based on this evidence, expert opinion and consensus-building, the Task Group identified core components, best practices, key challenges and gaps and developed recommendations to advance stewardship in Canada.

Results

The four components of a promising antimicrobial stewardship initiative were: leadership, interventions, monitoring/evaluation and future research. Best practices include a multi-sectoral/multipronged approach involving a wide range of stakeholders at the national, provincial/territorial, local and health care organizational levels. Key challenges and gaps identified were: the success and sustainability of stewardship undertakings require appropriate and sustained resourcing and expertise; there is limited evidence about how to effectively implement treatment guidance; and there is a challenge in ensuring accessibility, standardization and consistency of use among professionals.​: Recommendations to the CIDSC about how to advance stewardship across jurisdictions included the following: institute a national infrastructure; develop best practices to implement stewardship programs; develop education and promote awareness; establish consistent evidence-based guidance, resources, tools and training; mandate the incorporation of stewardship education; develop audit and feedback tools; establish benchmarks and performance targets for stewardship; and conduct timely evaluation of stewardship programs.

Conclusion

Findings of this report will inform a more systematic approach to addressing antimicrobial stewardship Canada-wide.

Top Ten Myths Regarding the Diagnosis and Treatment of Urinary Tract Infections

BACKGROUND

Urinary tract infections (UTI) are the most common type of infection in the United States. A Centers for Disease Control and Prevention report in March 2014 regarding antibiotic use in hospitals reported "UTI" treatment was avoidable at least 39% of the time. The accurate diagnosis and treatment of UTI plays an important role in cost-effective medical care and appropriate antimicrobial utilization.

OBJECTIVE

We summarize the most common misperceptions of UTI that result in extraneous testing and excessive antimicrobial treatment. We present 10 myths associated with the diagnosis and treatment of UTI and succinctly review the literature pertaining to each myth. We explore the myths associated with pyuria, asymptomatic bacteriuria, candiduria, and the elderly and catheterized patients. We attempt to give guidance for clinicians facing these clinical scenarios.

DISCUSSION

From our ambulatory, emergency department, and hospital experiences, patients often have urine cultures ordered without an appropriate indication, or receive unnecessary antibiotic therapy due to over-interpretation of the urinalysis.

CONCLUSIONS

Asymptomatic bacteriuria is common in all age groups and is frequently over-treated. A UTI diagnosis should be based on a combination of clinical symptoms with supportive laboratory information. This review will assist providers in navigating common pitfalls in the diagnosis of UTI.

How and when nurses collect urine cultures on catheterized patients: A survey of 5 hospitals

BACKGROUND

Obtaining a specimen for urine culture is a key element in evaluating for catheter-associated urinary tract infections (CAUTIs). Evaluating nurses' knowledge regarding appropriate reasons and methods to obtain urine culture specimens are the first steps to improving practice.

METHODS

Nurses at 5 hospitals completed a 40-question survey regarding their knowledge, training, and practices of appropriate reasons for obtaining urine cultures. The survey included different scenarios of patients with urinary catheters and when they would expect to obtain urine cultures. A 12-point scoring system calculated responses regarding urine collection appropriateness.

RESULTS

There were 394 nurses who responded to the survey. Of them, 76.1% reported receiving education on CAUTI risk reduction within the last 12 months. Although 327 (83%) of all nurses surveyed reported that they never collect urine samples by draining directly from the drainage bag, only 58.4% viewed others to be fully compliant with that standard (P < .001). Nurses who considered their knowledge to be above average to excellent had similar knowledge assessment scores (out of 12 points) for triggers to obtain urine cultures (mean score, 4.9 ± 1.72) compared with those that reported average to poor knowledge (mean score, 4.64 ± 1.78; P = .15).

CONCLUSIONS

Important opportunities exist for nurses to optimize the decisions to obtain urine cultures and the process for obtaining them. Addressing nurses' knowledge and practice may lead to more appropriate use of urine cultures.

Impact of Changes in Urine Culture Ordering Practice on Antimicrobial Utilization in Intensive Care Units at an Academic Medical Center

OBJECTIVE To assess antimicrobial utilization before and after a change in urine culture ordering practice in adult intensive care units (ICUs) whereby urine cultures were only performed when pyuria was detected. DESIGN Quasi-experimental study SETTING A 700-bed academic medical center PATIENTS Patients admitted to any adult ICU METHODS Aggregate data for all adult ICUs were obtained for population-level antimicrobial use (days of therapy [DOT]), urine cultures performed, and bacteriuria, all measured per 1,000 patient days before the intervention (January-December 2012) and after the intervention (January-December 2013). These data were compared using interrupted time series negative binomial regression. Randomly selected patient charts from the population of adult ICU patients with orders for urine culture in the presence of indwelling or recently removed urinary catheters were reviewed for demographic, clinical, and antimicrobial use characteristics, and pre- and post-intervention data were compared. RESULTS Statistically significant reductions were observed in aggregate monthly rates of urine cultures performed and bacteriuria detected but not in DOT. At the patient level, compared with the pre-intervention group (n=250), in the post-intervention group (n=250), fewer patients started a new antimicrobial therapy based on urine culture results (23% vs 41%, P=.002), but no difference in the mean total DOT was observed. CONCLUSION A change in urine-culture ordering practice was associated with a decrease in the percentage of patients starting a new antimicrobial therapy based on the index urine-culture order but not in total duration of antimicrobial use in adult ICUs. Other drivers of antimicrobial use in ICU patients need to be evaluated by antimicrobial stewardship teams. Infect.

Treatment for Positive Urine Cultures in Hospitalized Adults: A Survey of Prevalence and Risk Factors in 3 Medical Centers

BACKGROUND

Antibiotic treatment for asymptomatic bacteriuria (ASB) is prevalent but often contrary to published guidelines.

OBJECTIVE

To evaluate risk factors for treatment of ASB.

DESIGN

Retrospective observational study.

SETTING

A tertiary academic hospital, county hospital, and community hospital.

PATIENTS

Hospitalized adults with bacteriuria.

METHODS

Patients without documented symptoms of urinary tract infection per Infectious Diseases Society of America (IDSA) criteria were classified as ASB. We examined ASB treatment risk factors as well as broad-spectrum antibiotic usage and quantified diagnostic concordance between IDSA and National Healthcare Safety Network criteria.

RESULTS

Among 300 patients with bacteriuria, ASB was present in 71% by IDSA criteria. By National Healthcare Safety Network criteria, 71% of patients had ASB; within-patient diagnostic concordance with IDSA was moderate (kappa, 0.52). After excluding those given antibiotics for nonurinary indications, antibiotics were given to 38% (62/164) with ASB. Factors significantly associated with ASB treatment were elevated urine white cell count (65 vs 24 white blood cells per high-powered field, P<.01), hospital identity (hospital C vs A, odds ratio, 0.34 [95% CI, 0.14-0.80], P =.01), presence of leukocyte esterase (5.48 [2.35-12.79], P<.01), presence of nitrites (2.45 [1.11-5.41], P=.03), and Escherichia coli on culture (2.4 [1.2-4.7], P=.01). Of patients treated for ASB, broad-spectrum antibiotics were used in 84%.

CONCLUSIONS

ASB treatment was prevalent across settings and contributed to broad-spectrum antibiotic use. Associating abnormal urinalysis results with the need for antibiotic treatment regardless of symptoms may drive unnecessary antibiotic use.

A Controlled Quasi-Experimental Study of an Educational Intervention to Reduce the Unnecessary Use of Antimicrobials For Asymptomatic Bacteriuria

Background

Asymptomatic bacteriuria (ABU) should only be treated in cases of pregnancy or in-patients undergoing urologic procedures; however, unnecessary treatment of ABU is common in clinical practice.

Objective

To identify risk factors for unnecessary treatment and to assess the impact of an educational intervention focused on these risk factors on treatment of ABU.

Design

Quasi-experimental study with a control group.

Setting

Two tertiary teaching adult care hospitals.

Participants

Consecutive patients with positive urine cultures between January 30^th and April 17^th, 2012 (baseline) and January 30^th and April 30^th, 2013 (intervention).

Intervention

In January 2013, a multifaceted educational intervention based on risk factors identified during the baseline period was provided to medical residents (monthly) on one clinical teaching unit (CTU) at one hospital site, with the CTU of the other hospital serving as the control.

Results

During the baseline period, 160/341 (46.9%) positive urine cultures were obtained from asymptomatic patients at the two hospitals, and 94/160 (58.8%) were inappropriately treated with antibiotics. Risk factors for inappropriate use included: female gender (OR 2.1, 95% CI 1.1-4.3), absence of a catheter (OR 2.5, 1.2-5), bacteriuria versus candiduria (OR 10.6, 3.8-29.4), pyuria (OR 2.0, 1.1-3.8), and positive nitrites (OR 2.2, 1.1-4.5). In 2013, only 2/24 (8%) of ABU patients were inappropriately treated on the intervention CTU as compared to 14/29 (52%) on the control CTU (OR 0.10; 95% CI 0.02-0.49). A reduction was also observed as compared to baseline on the intervention CTU (OR 0.1, 0.02-0.7) with no significant change noted on the control CTU (OR 0.47, 0.13-1.7).

Conclusions

A multifaceted educational intervention geared towards medical residents with a focus on identified risk factors for inappropriate management of ABU was effective in reducing unnecessary antibiotic use.

Lessons from audit and feedback of hospitalized patients with bacteriuria

We sought to prevent the initiation of antimicrobial therapy for asymptomatic bacteriuria (ASB) by providing audit and feedback of newly reported positive urine cultures to test whether this could empower providers to leave ASB untreated. Despite success in providing feedback before antibiotics could be initiated in most cases, these recommendations only reduced treatment duration, without affecting antibiotic initiation. This study highlights the limitations of educational initiatives in overcoming engrained beliefs about bacteriuria even when advice is provided in real time.

Urinary tract infections in the critical care unit: A brief review

The use of indwelling catheters in the Critical Care Units (CCUs) has a major role in determining the incidence and the morbidity as well as mortality from hospital-acquired urinary tract infections (UTIs). Instituting evidence-based protocols can significantly reduce both the prevalence of indwelling catheterization as well as the incidence of hospital-acquired UTIs. The prevalence of catheter-associated urinary tract infections (CAUTIs) in the CCUs is directly linked to the widespread use of indwelling catheters in these settings. CAUTIs result in significant cost escalation for individual hospitals as well as the healthcare system as a whole. A UTI is an inflammatory response to colonization of the urinary tract, most commonly by bacteria or fungi. A UTI should be differentiated from the mere detection of bacteria in the urinary tract. This condition, referred to as asymptomatic bacteriuria, is common and does not require treatment, especially in the patient with an indwelling urinary catheter. A CAUTI occurs when a patient with an indwelling urinary catheter develops 2 or more signs or symptoms of a UTI such as hematuria, fever, suprapubic or flank pain, change in urine character, and altered mental status. CAUTI is classified as a complicated UTI. The current review highlights the important management issues in critical care patients having CAUTI. We performed a MEDLINE search using combinations of keywords such as urinary tract infection, critical care unit and indwelling urinary catheter. We reviewed the relevant publications with regard to CAUTI in patients in CCU.

Antimicrobial treatment of asymptomatic bacteriuria in noncatheterized adults: a systematic review

Asymptomatic bacteriuria (ASB) is a common clinical finding characterized by the presence of bacteria in the urine of an individual without signs or symptoms suggestive of urinary tract infection. Despite available guidelines on the diagnosis and management of ASB, it is often managed inappropriately. We performed a systematic review of clinical trials evaluating antimicrobial therapy for ASB, identified translational barriers to evidence-based practice, and we offer strategies to optimize antimicrobial use for ASB. We conducted a systematic search of the PubMed, International Pharmaceutical Abstracts, Cumulative Index to Nursing and Allied Health databases, and the Cochrane Library. Randomized controlled trials, cohort trials, case-control studies, and meta-analyses published in the English language were included in this review if they addressed treatment of ASB with at least one antimicrobial agent in nonpregnant adults. Articles were excluded if they evaluated patients with indwelling urinary catheters or were not clinical trials. Of the 304 articles identified from the search, 287 were excluded; thus 17 articles met the inclusion criteria. Although treatment of ASB with antimicrobial therapy may improve short-term microbiologic outcomes, the clinical significance is diminished because the effect is not sustained, there is no measurable improvement in morbidity or mortality, and some data indicate that therapy is deleterious. Several translational barriers that preclude adoption of evidence-based practice are identified. Treatment guidelines may not achieve their desired effect and underscore the need for additional methods to translate clinical trial data into practice. Clinical pharmacists are a core member of the antimicrobial stewardship team and in an important position to participate in initiatives that promote appropriate antimicrobial use. We suggest a multifaceted approach consisting of education and frequent routine prospective audits with feedback coupled with appropriate process and outcome measures.

Reducing antimicrobial therapy for asymptomatic bacteriuria among noncatheterized inpatients: a proof-of-concept study

This proof-of-concept study demonstrates that no longer routinely reporting urine culture results from noncatheterized medical and surgical inpatients can greatly reduce unnecessary antimicrobial therapy for asymptomatic bacteriuria without significant additional laboratory workload. Larger studies are needed to confirm the generalizability, safety, and sustainability of this model of care.

Approach to a positive urine culture in a patient without urinary symptoms

Asymptomatic bacteriuria (ASB) is a condition in which bacteria are present in a noncontaminated urine sample collected from a patient without signs or symptoms related to the urinary tract. ASB must be distinguished from symptomatic urinary tract infection (UTI) by the absence of signs and symptoms compatible with UTI or by clinical determination that a nonurinary cause accounts for the patient's symptoms. The overall purpose of this review is to promote an awareness of ASB as a distinct condition from UTI and to empower clinicians to withhold antibiotics in situations in which antimicrobial treatment of bacteriuria is not indicated.

Vancomycin resistance has no influence on outcomes of enterococcal bacteriuria

BACKGROUND

Infections with vancomycin-resistant enterococci (VRE) are a growing concern in hospitals. The impact of vancomycin resistance in enterococcal urinary tract infection is not well-defined.

AIM

To describe the epidemiology of enterococcal bacteriuria in a hospital and compare the clinical picture and patient outcomes depending on vancomycin resistance.

METHODS

This was a 6-month prospective cohort study of hospital patients who were admitted with or who developed enterococcal bacteriuria in a 1250-bed tertiary care hospital. We examined clinical presentation, diagnostic work-up, management, and outcomes.

FINDINGS

We included 254 patients with enterococcal bacteriuria; 160 (63%) were female and median age was 65 years (range: 17-96). A total of 116 (46%) bacteriurias were hospital-acquired and 145 (57%) catheter-associated. Most patients presented with asymptomatic bacteriuria (ASB) (119; 47%) or pyelonephritis (64; 25%); 51 (20%) had unclassifiable bacteriuria and 20 (8%) had cystitis. Secondary bloodstream infection was detected in 8 (3%) patients. Seventy of 119 (59%) with ASB received antibiotics (mostly vancomycin). There were 74 (29%) VRE bacteriurias. VRE and vancomycin-susceptible enterococci (VSE) produced similar rates of pyelonephritis [19 (25%) vs 45 (25%); P = 0.2], cystitis, and ASB. Outcomes such as ICU transfer [10 (14%) VRE vs 17 (9%) VSE; P = 0.3], hospital length of stay (6.8 vs 5.0 days; P = 0.08), and mortality [10 (14%) vs 13 (7%); P = 0.1] did not vary with vancomycin susceptibility.

CONCLUSIONS

Vancomycin resistance did not affect the clinical presentation nor did it impact patient outcomes in this cohort of inpatients with enterococcal bacteriuria. Almost half of our cohort had enterococcal ASB; more than 50% of these asymptomatic patients received unnecessary antibiotics. Antimicrobial stewardship efforts should address overtreatment of enterococcal bacteriurias.

A scoping review of important urinary catheter induced complications

This study presents a scoping review of the literature on the morbidity and mortality associated with several common complications of urinary catheterization. Data gathered from the open literature were analyzed graphically to gain insights into the most important urinary catheter induced complications. The results reveal that the most significant catheter complications are severe mechanical trauma (perforation, partial urethral damage and urinary leakage), symptomatic bacterial infection, and anaphylaxis, catheter toxicity and hypersensitivity. The data analysis also revealed that the complications with the highest morbidity are all closely related to the mechanical interaction of the catheter with the urethra. This suggests that there is a strong need for urinary catheter design to be improved to minimize mechanical interaction, especially mechanical damage to the urinary tract, and to enhance patient comfort. Several urinary catheter design directions have been proposed based on tribological principles. Among the key recommendations is that catheter manufacturers develop catheter coatings which are both hydrophilic and antibacterial, and which maintain their antibacterial patency for at least 90 days.

Patient characteristics but not virulence factors discriminate between asymptomatic and symptomatic E. coli bacteriuria in the hospital

Background

Escherichia coli is a common cause of asymptomatic and symptomatic bacteriuria in hospitalized patients. Asymptomatic bacteriuria (ASB) is frequently treated with antibiotics without a clear indication. Our goal was to determine patient and pathogen factors suggestive of ASB.

Methods

We conducted a 12-month prospective cohort study of adult inpatients with E. coli bacteriuria seen at a tertiary care hospital in St. Louis, Missouri, USA. Urine cultures were taken at the discretion of treating physicians. Bacterial isolates were tested for 14 putative virulence genes using high-throughput dot-blot hybridization.

Results

The median age of the 287 study patients was 65 (19–101) years; 78% were female. Seventy percent had community-acquired bacteriuria. One-hundred ten (38.3%) patients had ASB and 177 (61.7%) had symptomatic urinary tract infection (sUTI). Asymptomatic patients were more likely than symptomatic patients to have congestive heart failure (p = 0.03), a history of myocardial infarction (p = 0.01), chronic pulmonary disease (p = 0.045), peripheral vascular disease (p = 0.04), and dementia (p = 0.03). Patients with sUTI were more likely to be neutropenic at the time of bacteriuria (p = 0.046). Chronic pulmonary disease [OR 2.1 (95% CI 1.04, 4.1)] and dementia [OR 2.4 (95% CI 1.02, 5.8)] were independent predictors for asymptomatic bacteriuria. Absence of pyuria was not predictive of ASB. None of the individual virulence genes tested were associated with ASB nor was the total number of genes.

Conclusions

Asymptomatic E. coli bacteriuria in hospitalized patients was frequent and more common in patients with dementia and chronic pulmonary disease. Bacterial virulence factors could not discriminate symptomatic from asymptomatic bacteriurias. Asymptomatic E. coli bacteriuria cannot be predicted by virulence screening.

Development and validation of an algorithm to recalibrate mental models and reduce diagnostic errors associated with catheter-associated bacteriuria

Background

Overtreatment of catheter-associated bacteriuria is a quality and safety problem, despite the availability of evidence-based guidelines. Little is known about how guidelines-based knowledge is integrated into clinicians’ mental models for diagnosing catheter-associated urinary tract infection (CA-UTI). The objectives of this research were to better understand clinicians’ mental models for CA-UTI, and to develop and validate an algorithm to improve diagnostic accuracy for CA-UTI.

Methods

We conducted two phases of this research project. In phase one, 10 clinicians assessed and diagnosed four patient cases of catheter associated bacteriuria (n= 40 total cases). We assessed the clinical cues used when diagnosing these cases to determine if the mental models were IDSA guideline compliant. In phase two, we developed a diagnostic algorithm derived from the IDSA guidelines. IDSA guideline authors and non-expert clinicians evaluated the algorithm for content and face validity. In order to determine if diagnostic accuracy improved using the algorithm, we had experts and non-experts diagnose 71 cases of bacteriuria.

Results

Only 21 (53%) diagnoses made by clinicians without the algorithm were guidelines-concordant with fair inter-rater reliability between clinicians (Fleiss’ kappa = 0.35, 95% Confidence Intervals (CIs) = 0.21 and 0.50). Evidence suggests that clinicians’ mental models are inappropriately constructed in that clinicians endorsed guidelines-discordant cues as influential in their decision-making: pyuria, systemic leukocytosis, organism type and number, weakness, and elderly or frail patient. Using the algorithm, inter-rater reliability between the expert and each non-expert was substantial (Cohen’s kappa = 0.72, 95% CIs = 0.52 and 0.93 between the expert and non-expert #1 and 0.80, 95% CIs = 0.61 and 0.99 between the expert and non-expert #2).

Conclusions

Diagnostic errors occur when clinicians’ mental models for catheter-associated bacteriuria include cues that are guidelines-discordant for CA-UTI. The understanding we gained of clinicians’ mental models, especially diagnostic errors, and the algorithm developed to address these errors will inform interventions to improve the accuracy and reliability of CA-UTI diagnoses.

Antibiotic prescribing practices for catheter urine culture results

BACKGROUND

The literature suggests that positive results of catheter urine cultures frequently lead to unnecessary antimicrobial prescribing, which therefore represents an important target for stewardship.

OBJECTIVE

To assess the appropriateness of antibiotic prescribing in response to the results of urine cultures from patients with indwelling urinary catheters.

METHODS

This retrospective study was conducted at a tertiary care centre and involved adults with indwelling urinary catheters from whom urine specimens were obtained for culture. Patients with positive or negative culture results were identified from microbiology laboratory reports. The medical records of consecutive patients were screened to select a sample of 80 inpatients (40 per group). Abstracted patient histories were independently evaluated by an expert panel of 3 infectious diseases consultants blinded to the decisions of prescribers and of fellow panelists. The primary end point was concordance of each patient's treatment decision (with respect to the indication) between the expert panel (based on majority agreement, i.e., at least 2 of the 3 expert panelists) and the prescriber. The secondary end points were unnecessary days of therapy and selected outcomes over a predefined period after urine was obtained for culture.

RESULTS

A total of 591 charts were screened to generate the targeted number of patients. Baseline demographic characteristics were comparable for the 2 groups, except antibiotic exposure before urine collection was significantly more frequent for the group with negative culture results. The treatment decision was concordant in 40% (16/40) of the patients with a positive culture result and 85% (34/40) of those with a negative culture result (p < 0.001). The most common reason for discordance was administration of antibiotics when not indicated (23 of 24 patients with a positive result and 5 of 6 patients with a negative result), which accounted for 165 and 32 unnecessary days of therapy per 1000 inpatient-days, respectively (p < 0.001). Adverse effects occurred in 2 of the 23 patients with a positive result who received antibiotics that were not indicated.

CONCLUSIONS

Appropriateness of antibiotic prescribing, as measured by concordance of decisions between the expert panel and prescribers, was more common among patients with negative urine culture results than among those with positive results. However, there is an opportunity to improve prescribing for both groups through antimicrobial stewardship initiatives. Unnecessary days of therapy and adverse effects were more common in patients with a positive culture result.

Impact of laboratory-reported urine culture colony counts on the diagnosis and treatment of urinary tract infection for hospitalized patients

Reducing health care-associated urinary tract infection (UTI) is a National Patient Safety Goal. The purpose of this investigation was to establish a colony count threshold to predict clinically significant UTIs that develop in hospitalized patients. A total of 185 cases were reviewed sequentially by 2 physicians. The information extracted included subjective complaints, presence of an indwelling urinary catheter, clinical signs and symptoms, WBC count, urinalysis, and urine culture results. The first reviewer recorded whether the patient was diagnosed and treated for a UTI by the clinician. The second reviewer determined if the patient met National Healthcare Safety Network guidelines for nosocomial UTI. Compared with patients with colony counts less than 100,000 colony-forming units per milliliter (CFU/mL), patients with colony counts 100,000 CFU/mL or more were 73.86 times more likely to have a clinically significant UTI (odds ratio, 73.86; 95% confidence interval, 24.23 ∼ 225.15; P < .0001; c-statistic, 0.859). Reporting positive results only for patients with 100,000 CFU/mL or more would have reduced the number of positive cultures by 38%. These data suggest that reporting colony counts less than 100,000 CFU/mL encourages treatment of non-clinically significant UTIs in hospitalized patients, causing inappropriate antibiotic use.