Prevalence of Asymptomatic Bacteriuria in Hospitalized Patients

Subclinical bacteriuria and surgical-site infection in 140 dogs with orthopedic and neurological conditions

Objectives

This study aimed to determine the prevalence, risk factors, and types of bacterial isolates associated with subclinical bacteriuria (SBU) in dogs with reduced mobility; and to explore the influence of SBU on surgical-site infection (SSI) in dogs treated surgically for their conditions.

Animals

We studied 140 client-owned dogs.

Procedure

Medical records of dogs with orthopedic and neurological conditions from 3 academic referral hospitals were reviewed. Dogs receiving antimicrobials or showing lower urinary tract signs were excluded. Using generalized linear models, clinical, procedural, and postoperative variables were evaluated as possible risk factors for SBU and SSI.

Results

The prevalence of SBU and the rate of SSI were 8.5% (12/140) and 10.4% (10/96), respectively. Urine culture was completed in 6 of 12 dogs with SBU, and 3 results were positive (Escherichia coli in 2 dogs and Staphylococcus spp. in 1 dog). Four of the 10 dogs that developed SSI received postoperative antimicrobial therapy. The prevalence of SBU and types of bacterial isolates were similar to those in previous reports. Significant risk factors for developing SBU and its association with SSI were not identified.

Conclusion and clinical relevance

Screening and treating for SBU preoperatively remains controversial.

Correlation of Pyuria and Bacteriuria in Acute Care

BACKGROUND

Pyuria is often used as an import marker in the diagnosis of urinary tract infection. The interpretation of pyuria may be especially important in patients with nonspecific complaints. There is a paucity of data to demonstrate the utility of pyuria alone in the diagnosis of bacteriuria or urinary tract infection. This study aims to further define the relationship of pyuria and positive bacterial growth in urine culture, as well as the diagnostic utility of different urine white blood cell cutoff points.

METHOD

A total of 46,127 patients older than the age of 18 were selected from the inpatient population of HCA Healthcare System Capital Division. Urine microscopy results were stratified by white blood cell count and correlated with positivity of urine culture bacterial growth. The optimal urine white blood cell cutoff was derived based on the receiver operating characteristic curve plot.

RESULTS

Urine microscopy finding of white blood cell 0-5 cell/hpf, 5-10 cell/hpf, 10-25 cell/hpf, and higher than 25 cell/hpf was associated with 25.4%, 28.2%, 33%, and 53.8% rates of bacteriuria, respectively. The receiver operating characteristic curve plot demonstrated that pyuria alone did not provide adequate diagnostic accuracy to predict bacteriuria. The optimal cutoff point for the best combination of sensitivity and specificity was found to be 25 cell/hpf.

CONCLUSION

Pyuria alone provides inadequate diagnostic accuracy for predicting bacteriuria. Urine white blood cell count greater than 25 cell/hpf was found to be the optimal cutoff to detect bacteriuria. The result of this study supports the current guideline recommendation against antibiotic treatment based on urine analysis alone. It also informs future design of randomized controlled trial that investigates interventional strategies for patients with pyuria and nonspecific complaints.

Envisioning Future UTI Diagnostics

Urinary tract infections (UTIs) are among the most common bacterial infections in the United States and are a major driver of antibiotic use - both appropriate and inappropriate - across healthcare settings. UTI treatment has become complex due to antibacterial resistance; one quarter of urinary tract isolates of Escherichia coli in the United States in 2017 were resistant to fluoroquinolones and one third to trimethoprimsulfamethoxazole (1), agents with historically predictable activity against E. coli. As a result, more broad-spectrum antibiotics are being used to treat UTIs, contributing to selection of further antibiotic resistance.

A diagnostic algorithm for detection of urinary tract infections in hospitalized patients with bacteriuria: The "Triple F" approach supported by Procalcitonin and paired blood and urine cultures

For acute medicine physicians, distinguishing between asymptomatic bacteriuria (ABU) and clinically relevant urinary tract infections (UTI) is challenging, resulting in overtreatment of ABU and under-recognition of urinary-source bacteraemia without genitourinary symptoms (USB). We conducted a retrospective analysis of ED encounters in a university hospital between October 2013 and September 2018 who met the following inclusion criteria: Suspected UTI with simultaneous collection of paired urinary cultures and blood cultures (PUB) and determination of Procalcitonin (PCT). We sought to develop a simple algorithm based on clinical signs and PCT for the management of suspected UTI. Individual patient presentations were retrospectively evaluated by a clinical "triple F" algorithm (F1 ="fever", F2 ="failure", F3 ="focus") supported by PCT and PUB. We identified 183 ED patients meeting the inclusion criteria. We introduced the term UTI with systemic involvement (SUTI) with three degrees of diagnostic certainty: bacteremic UTI (24.0%; 44/183), probable SUTI (14.2%; 26/183) and possible SUTI (27.9%; 51/183). In bacteremic UTI, half of patients (54.5%; 24/44) presented without genitourinary symptoms. Discordant bacteraemia was diagnosed in 16 patients (24.6% of all bacteremic patients). An alternative focus was identified in 67 patients, five patients presented with S. aureus bacteremia. 62 patients were diagnosed with possible UTI (n = 20) or ABU (n = 42). Using the proposed "triple F" algorithm, dichotomised PCT of < 0.25 pg/ml had a negative predictive value of 88.7% and 96.2% for bacteraemia und accordant bacteraemia respectively. The application of the algorithm to our cohort could have resulted in 33.3% reduction of BCs. Using the diagnostic categories "possible" or "probable" SUTI as a trigger for initiation of antimicrobial treatment would have reduced or streamlined antimicrobial use in 30.6% and 58.5% of cases, respectively. In conclusion, the "3F" algorithm supported by PCT and PUB is a promising diagnostic and antimicrobial stewardship tool.

Targeting Asymptomatic Bacteriuria in Antimicrobial Stewardship: the Role of the Microbiology Laboratory

This minireview focuses on the microbiologic evaluation of patients with asymptomatic bacteriuria, as well as indications for antibiotic treatment. Asymptomatic bacteriuria is defined as two consecutive voided specimens (preferably within 2 weeks) with the same bacterial species, isolated in quantitative counts of ≥10⁵ CFU/ml in women, including pregnant women; a single voided urine specimen with one bacterial species isolated in a quantitative count ≥10⁵ CFU/ml in men; and a single catheterized urine specimen with one or more bacterial species isolated in a quantitative count of ≥10⁵ CFU/ml in either women or men (or ≥10² CFU/ml of a single bacterial species from a single catheterized urine specimen). Any urine specimen with ≥10⁴ CFU/ml group B Streptococcus is significant for asymptomatic bacteriuria in a pregnant woman. Asymptomatic bacteriuria occurs, irrespective of pyuria, in the absence of signs or symptoms of a urinary tract infection. The two groups with the best evidence of adverse outcomes in the setting of untreated asymptomatic bacteriuria include pregnant women and patients who undergo urologic procedures with risk of mucosal injury. Screening and treatment of asymptomatic bacteriuria is not recommended in the following patient populations: pediatric patients, healthy nonpregnant women, older patients in the inpatient or outpatient setting, diabetic patients, patients with an indwelling urethral catheter, patients with impaired voiding following spinal cord injury, patients undergoing nonurologic surgeries, and nonrenal solid-organ transplant recipients. Renal transplant recipients beyond 1 month posttransplant should not undergo screening and treatment for asymptomatic bacteriuria. There is insufficient evidence to recommend for or against screening of renal transplant recipients within 1 month, patients with high-risk neutropenia, or patients with indwelling catheters at the time of catheter removal. Unwarranted antibiotics place patients at increased risk of adverse effects (including Clostridioides difficile diarrhea) and contribute to antibiotic resistance. Methods to reduce unnecessary screening for and treatment of asymptomatic bacteriuria aid in antibiotic stewardship.

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.