Validity of urinalysis and microscopy for detecting urinary tract infection in the emergency department

Albuminuria Is Affected by Urinary Tract Infection: A Comparison between Biochemical Quantitative Method and Automatic Urine Chemistry Analyzer UC-3500

The automated urine reagent strip test is a cost-effective tool for detecting albuminuria in patients. However, prior research has not investigated how urinary tract infections (UTIs) affect the test's accuracy. Therefore, this study aims to assess the impact of UTIs on albuminuria diagnosis using both the biochemical quantitative method and the test strip method of the Fully Automatic Urine Chemistry Analyzer, UC-3500 (Sysmex, Kobe, Japan). From March to December 2019, we prospectively collected midstream urine from adult female UTI patients before and after one week of cephalexin treatment. The urine samples were subjected to culture, routine urinalysis, and albuminuria diagnosis using the biochemical quantitative method and UC-3500. Albuminuria was defined as a urine albumin to creatinine ratio (UACR) ≥ 30 mg/g in the biochemical quantitative method. The results were compared between the two methods. Among fifty-four female patients (average age: 50.5 ± 4.4 years) with UTIs, 24 (44.44%) had transient albuminuria. The quantitative UACR significantly decreased after one week of antibiotic treatment (median: 53 mg/g to 9 mg/g; median difference: -0.54, p < 0.0001). UC-3500 exhibited a higher false positive rate for diagnosing albuminuria during UTIs (42%) compared to after treatment (19%). Its agreement with the biochemical quantitative method was moderate during UTI (κ = 0.49, 95% confidence interval [CI]: 0.24-0.73) and good after treatment (κ = 0.65, 95% CI: 0.45-0.86). UC-3500's accuracy in diagnosing albuminuria is influenced by UTIs, leading to either transient albuminuria or a false positive reaction of the test strip. UTI should be excluded or treated before its application in albuminuria screening.

Urinary tract infections: a review of the current diagnostics landscape

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

Poor glycemic control and associated factors among patients with type 2 diabetes mellitus: a cross-sectional study

Glycemic control is of paramount importance in care and management for patients with type 2 diabetes mellitus (T2DM). Poor glycemic control is a major health problem that greatly contributes to the development of diabetes related complications. This study aims to assess the prevalence of poor glycemic control and associated factors among outpatients with T2DM attending diabetes clinic at Amana Regional Referral Hospital in Dar-es-salaam, Tanzania from December 2021 to September 2022. A face to face interviewer semi-structured questionnaire was administered during data collection. Binary logistic regression under multivariable analysis was used to determine the independent predictors of poor glycemic control. A total of 248 patients with T2DM were included in the analysis with mean age of 59.8 ± 12.1 years. The mean fasting blood glucose was 166.9 ± 60.8 mg/dL. The prevalence of poor glycemic control was 66.1% (fasting blood glucose > 130 mg/dL or < 70 mg/dL). Failure to adhere to regular follow-up (AOR = 7.53, 95% CI = 2.34-19.73, p < 0.001) and alcoholism (AOR = 4.71, 95% CI = 1.08-20.59, p = 0.040) were the independent predictors of poor glycemic control. The prevalence of poor glycemic control observed in this study was significantly high. Emphasis should be placed on ensuring that patients have regular follow-up for their diabetes clinics and they should also continue modifying some of lifestyle behaviors including refraining from alcoholism, this can help them to have good glycemic control.

Evaluation of haem dipstick pad, urine protein, urine pH and urine protein:creatinine ratio results as a marker of bacteriuria in dogs and cats with inactive urine sediment

OBJECTIVES

Evaluation of haem dipstick pad, urine protein, urine pH and urine protein:creatinine ratio results as a marker of bacteriuria in dogs and cats with inactive urine sediment.

MATERIALS AND METHODS

Cats and dogs with contemporaneous urine dipstick, microscopic sediment analysis and microbiological culture and sensitivity results over a four-year period (2016 to 2020) were retrospectively identified. Dogs and cats with active urine sediments (at least five erythrocytes and/or five leukocytes per high-power field) and/or spermaturia were excluded. Association between urine pH, haem dipstick result, protein dipstick result and urine protein:creatinine ratio with bacteriuria were evaluated using binary logistic regression analysis. Likelihood ratios for bacteriuria were calculated at different diagnostic thresholds.

RESULTS

A total of 668 and 169 dog and cat urine samples were included. Of these, 166 dogs (25%) had a positive urine culture, whilst only 29 cats (17%) had a positive urine culture. In dogs and cats, any positive haem dipstick result was significantly associated with bacteriuria, although only a ≥4+ haem positive result in dogs was associated with a small increase in the likelihood of a positive urine culture, and positive likelihood ratios did not support the use of haem dipstick results as a screening test for bacteriuria in cats. pH, urine protein:creatinine ratio and protein dipstick results were not associated with bacteriuria.

CLINICAL SIGNIFICANCE

Our findings provide proof of concept that haem dipstick pad results in dogs with inactive sediment and without spermaturia might be useful as a screening test for bacteriuria, although further studies are required to confirm these findings.

Utility of Wrist-Wearable Data for Assessing Pain, Sleep, and Anxiety Outcomes After Traumatic Stress Exposure

Importance

Adverse posttraumatic neuropsychiatric sequelae after traumatic stress exposure are common and have higher incidence among socioeconomically disadvantaged populations. Pain, depression, avoidance of trauma reminders, reexperiencing trauma, anxiety, hyperarousal, sleep disruption, and nightmares have been reported. Wrist-wearable devices with accelerometers capable of assessing 24-hour rest-activity characteristics are prevalent and may have utility in measuring these outcomes.

Objective

To evaluate whether wrist-wearable devices can provide useful biomarkers for recovery after traumatic stress exposure.

Design, Setting, and Participants

Data were analyzed from a diverse cohort of individuals seen in the emergency department after experiencing a traumatic stress exposure, as part of the Advancing Understanding of Recovery After Trauma (AURORA) study. Participants recruited from 27 emergency departments wore wrist-wearable devices for 8 weeks, beginning in the emergency department, and completed serial assessments of neuropsychiatric symptoms. A total of 19 019 patients were screened. Of these, 3040 patients met study criteria, provided informed consent, and completed baseline assessments. A total of 2021 provided data from wrist-wearable devices, completed the 8-week assessment, and were included in this analysis. The data were randomly divided into 2 equal parts (n = 1010) for biomarker identification and validation. Data were collected from September 2017 to January 2020, and data were analyzed from May 2020 to November 2022.

Exposures

Participants were recruited for the study after experiencing a traumatic stress exposure (most commonly motor vehicle collision).

Main Outcomes and Measures

Rest-activity characteristics were derived and validated from wrist-wearable devices associated with specific self-reported symptom domains at a point in time and changes in symptom severity over time.

Results

Of 2021 included patients, 1257 (62.2%) were female, and the mean (SD) age was 35.8 (13.0) years. Eight wrist-wearable device biomarkers for symptoms of adverse posttraumatic neuropsychiatric sequelae exceeded significance thresholds in the derivation cohort. One of these, reduced 24-hour activity variance, was associated with greater pain severity (r = -0.14; 95% CI, -0.20 to -0.07). Changes in 6 rest-activity measures were associated with changes in pain over time, and changes in the number of transitions between sleep and wake over time were associated with changes in pain, sleep, and anxiety. Simple cutoffs for these biomarkers identified individuals with good recovery for pain (positive predictive value [PPV], 0.85; 95% CI, 0.82-0.88), sleep (PPV, 0.63; 95% CI, 0.59-0.67, and anxiety (PPV, 0.76; 95% CI, 0.72-0.80) with high predictive value.

Conclusions and Relevance

These findings suggest that wrist-wearable device biomarkers may have utility as screening tools for pain, sleep, and anxiety symptom outcomes after trauma exposure in high-risk populations.

Nomogram for predicting risk factors of fever in patients with negative preoperative urine culture after retrograde intrarenal surgery

PURPOSE

To determine the risk factors for postoperative fever after retrograde intrarenal surgery (RIRS) in patients with negative preoperative urine culture (UC), and to establish a nomogram for predicting postoperative fever based on these risk factors.

METHODS

This study collected 322 patients with negative UC who received RIRS at the First Affiliated Hospital of Anhui Medical University from March 2019 to May 2022. The study population was divided into a fever group and a non-fever group. The risk factors of postoperative fever were determined by univariate and multivariate logistic regression analyses, and a nomogram was established. The nomogram was evaluated in terms of differentiation, calibration, and clinical practicability.

RESULTS

In this study, 47 (14.6%) patients developed a fever after surgery. Multivariate logistic regression analysis showed that for patients with negative preoperative urine culture, urinary leucocyte esterase (P = 0.005), operative time (P = 0.019), and intraoperative hypotension (P = 0.028) were independent risk factors of postoperative fever, and a nomogram was constructed according to the above variables. The area under the curve (AUC) calculated by receiver operating characteristic (ROC) analysis was 0.807 (95% CI 0.739-0.876), indicating good discrimination. The calibration curves showed good consistency, and the clinical decision curve analysis (DCA) showed the clinical applicability of the model.

CONCLUSIONS

For patients with negative preoperative urine culture, urine leukocyte esterase, operative time, and intraoperative hypotension are independent risk factors of postoperative fever. The new nomogram can better assess the risk of infection in patients with negative UC after RIRS.

Point-of-Care Biosensing of Urinary Tract Infections Employing Optoplasmonic Surfaces Embedded with Metal Nanotwins

We report the synthesis of gold nanotwins (Au NTs) on a solid and transparent glass substrate which in turn has been employed for the selective optoplasmonic detection of Escherichia coli (EC) bacteria in human urine for the point-of-care diagnosis of urinary tract infections (UTIs). As compared to the single nanoparticle systems (Au NPs), the Au NTs show an enriched localized surface plasmon resonance (LSPR) due to the enhancement of the electric field under electromagnetic irradiation, e.g., photon, which helps in improving the limits of detection. For this purpose, initially a simple glass surface has been coated with Au NPs, with the help of the linker 3-aminopropyl-triethoxysilane - APTES. The surface has been linked further with another Au NP with the help of the 1,10-alkane-dithiol linker with two thiol ends, which eventually leads to the development of the optoplasmonic surface with Au NTs and an enhanced LSPR response. Subsequently, the EC specific aptamer has been chemically immobilized on the surface of Au NTs with the blocking of free sites via bovine serum albumin (BSA). Remarkably, Raman spectroscopy unfolds a 7-fold increase in the peak intensities with the Au NTs on the glass surface as compared to the surface coated with isolated Au NPs. The enhancement in the LSPR response of glass substrates coated with Au NTs and the EC specific aptamer has been further utilized for the selective and sensitive detection of UTIs. The results have been verified with the help of UV-visible spectroscopy to establish the utility of the proposed sensing methodology. An extensive interference study with other bacterial species unveils the selectivity and specificity of the proposed optoplasmonic sensors toward EC with a detection range of 5 × 10³ to 10⁷ CFU/mL. Intuitively, the method is more versatile in a sense that the sensor can be made specific to any other pathogens by simply changing the design of the aptamer. Finally, a low-cost, portable, and point-of-care optoplasmonic transduction setup is designed with a laser light illumination source, a sample holder, and a sensitive photodetector for the detection of UTIs in human urine.

Prevalence, aetiology, antimicrobial susceptibility testing, and predictors of urinary tract infection among neonates with clinical sepsis: a cross-sectional study

Background

Urinary tract infection (UTI) is the most common and life-threatening bacterial infection among neonates. This study aimed to determine the prevalence, aetiology, and susceptible antimicrobial agents among neonates with UTI.

Methods

This was a cross-sectional analytical hospital-based study that included 152 neonates with clinical sepsis who were admitted at Dodoma regional referral hospital from January to June 2020. Bacterial growth of 1 × 103 colony forming units/mL of a single uropathogen was used to define the presence of UTI. Statistical analysis was performed using SPSS version 23.0 and multivariate analysis was used to determine the predicting factors of UTI. P <0.05 was regarded statistically significant.

Results

The prevalence of UTI was 18.4% (28/152). Klebsiella pneumoniae 64.3% (18/28) and Enterobacter spp. 35.7% (10/28) were the bacterial agents isolated. The bacterial isolates were 90%, and 60% sensitive to ciprofloxacin and amikacin, respectively. Low Apgar score (AOR = 12.76, 95% CI = 4.17–39.06, p<0.001), prolonged labour (AOR = 5.36, 95% CI = 1.28–22.52, p = 0.022), positive urine nitrite test (AOR = 26.67, 95% CI = 7.75–91.70, p<0.001), and positive leucocyte esterase test (AOR = 6.64, 95% CI = 1.47–29.97, p = 0.014) were potential predictors of UTI.

Conclusion

The prevalence of UTI confirmed by urine culture among neonates that were included in the present study indicates that this problem is common in the population where the study was conducted. Klebsiella pneumoniae and Enterobacter spp. were the uropathogens which were isolated. Ciprofloxacin, nitrofurantoin, and amikacin were sensitive to the isolated uropathogens.

Influence of gender on the performance of urine dipstick and automated urinalysis in the diagnosis of urinary tract infections at the emergency department

BACKGROUND

Urinary tract infections (UTIs) are frequently encountered at the Emergency Department (ED). Given the anatomical differences between men and women, we aimed to clarify differences in the diagnostic performance of urinary parameters at the ED.

METHODS

A cohort study of adults presenting at the ED with fever and/or clinical suspected UTI. Performance of urine dipstick (UD) and automated urinalysis (UF-1000i) were analysed for the total study population and men and women separately. We focused on 1) UTI diagnosis and 2) positive urine culture (UC, ≥10⁵ CFU/ml) as outcome.

RESULTS

In 360 of 917 cases (39.3%) UTI was established (men/women 35.1%/43.6%). Diagnostic accuracy of UD was around 10% lower in women compared to men. Median automated leucocyte and bacterial count were higher in women compared to men. Diagnostic performance by receiver operating analysis was 0.851 for leucocytes (men/women 0.879/0.817) and 0.850 for bacteria (men/women 0.898/0.791). At 90% sensitivity, cut-off values of leucocyte count (men 60/µL, women 43/µL), and bacterial count (men 75/µL, women 139/µL) showed performance differences in favour of men. In both men and women, diagnostic performance using specified cut-off values was not different between normal and non-normal bladder evacuation. UC was positive in 327 cases (men/women 149/178), as with UTI diagnosis, diagnostic values in men outperformed women.

CONCLUSIONS

Overall diagnostic accuracy of urinary parameters for diagnosing UTI is higher in men. The described differences in cut-off values for leukocyte and bacterial counts for diagnosing UTI necessitates gender-specific cut-off values, probably reflecting the influence of anatomical and urogenital differences.

Bacteriuria resistance patterns and the suitability of urinalysis as an initial diagnostic tool in a post-antibiotic era

AIMS

Urinalysis is used as a first-line investigation throughout healthcare to indicate bacteriuria and guide treatment of potential urinary tract infections. In light of rising bacterial multi-resistance, we aim to analyse its diagnostic accuracy, determine its usefulness in a present-day setting and evaluate current antibiotic resistance patterns across a Trust population.

METHODS

A retrospective case series of 712 paired urinalysis and urine culture results was obtained over a 1-month period. Sensitivity, specificity and diagnostic accuracy were calculated, and resistance profiles of commonly used Trust antibiotics assessed using statistical analysis.

RESULTS

A high false negative rate of nitrites on urinalysis, with sensitivity of 38.4%, was found. Leucocyte sensitivity was 87.6% and specificity 39.7%, with no improvement in diagnostic accuracy seen when combining both. Positive urine culture growth demonstrated a substantial resistance pattern to trimethoprim of 48%, compounded by a statistically significant correlation with gentamicin resistance (p < 0.0001).

CONCLUSION

Our study has highlighted a reduced accuracy of urinalysis compared with previous literature, questioning its usefulness in the real world. We have consolidated growing published trends doubting the efficacy of trimethoprim, revealing co-existing resistance patterns between commonly used antibiotics. This will have implications for future antibiotic-prescribing protocols and requires further research to ensure guidelines are progressive in consciously managing this growing concern in modern-day healthcare.

Which patient should start empirical antibiotic treatment in urinary tract infection in emergency departments?

OBJECTIVES:

This study aims to determine the factors that would lead the doctors in EDs to a more the accurate diagnosis of urinary tract infection (UTI) and the correct initiation of empirical antibiotherapy in the emergency room and reduce the use of unnecessary antibiotherapy.

METHODS:

This study is a prospective observational study from a single-center, investigating patients with an age of 18 years and older who presented to the emergency department (ED) with the symptoms of UTI between January and May 2018. The guiding parameters to establish a UTI diagnosis and start an empirical antibiotherapy were investigated between the negative (Group 1) and positive (>10³ colonies) (Group 2) groups, as a result of urine culture in terms of urine culture.

RESULTS:

Our study included a total of 108 patients (59 women and 49 men). The average age was 47.11 ± 14.97. Age and gender were similar among the groups and not a discriminating factor in the diagnosis of UTI. High Charlson Comorbidity Index score, history of chronic kidney failure and cerebrovascular disease, leukocyte esterase, nitrite positivity, and leukocyte cluster presence were higher in Group 2. We suggest that these parameters might be predictive values to detect bacterial growth in urine culture. Empirical antibiotherapy was started in 48.4% of the patients in Group 1 and 95.7% of the patients in Group 2.

CONCLUSIONS:

In EDs, admission complaints of the patients and physical examination findings do not always result in the diagnosis of UTI. Our study showed that UTI diagnosis could be made more accurately using leukocyte esterase, nitrite positivity, the presence of leukocyte clusters, and the Charlson Comorbidity Index score. We also suggest that regional antibiotic resistance should be considered before starting empirical antibiotherapy.

Can urine dipstick test be an alternative to detect urinary tract infection in limited resource setting? - A validity study from Bangalore, India

Background

Diagnosis of urinary tract infection (UTI) can be challenging as symptoms are nonspecific. The gold standard for the diagnosis of urine culture is not easily available in resource constrained settings. Hence, the need for affordable point of care diagnostic test could be an inexpensive alternative for urine culture or microscopy. The objective of the study was to validate the urine dipstick test to detect UTI in a resource constrained primary care setting.

Methods

A diagnostic accuracy study was conducted in a health center in an urban slum by Bangalore Baptist Hospital. We included 136 patients suspected to have UTI. Patients were asked to give urine samples for urine dipstick analysis, urine microscopy, and urine culture and validity of the dipstick was analyzed.

Results

A total of 136 patients fulfilling the inclusion criteria were recruited. Nitrite had higher specificity than leukocyte esterase (95% vs. 73%). Positive predictive value for nitrite and leukocyte was 84% and 51%, respectively. A combination of fever, dysuria along with lower abdominal pain had higher specificity (92%). Most common organism that was isolated was E. coli (56%) followed by S. aureus (13%). E. coli was susceptible to nitrofurontoin.

Conclusion

Urine dipstick could be used as a simple diagnostic test in a limited resource setting for a rapid diagnosis and initiation of empirical antibiotic therapy. Urine dipstick for nitrite has a good specificity.

Reconsideration of urine culture for the diagnosis of acute pyelonephritis in children: a new challenging method for diagnosing acute pyelonephritis

Acute pyelonephritis (APN) should be detected and treated as soon as possible to reduce the risk of the development of acquired renal scarring. However, in the medical field, urine culture results are not available or considered when the prompt discrimination of APN is necessary and empirical treatment is started. Furthermore, urine culture cannot discriminate APN among children with febrile urinary tract infection (UTI) (pyelitis, lower UTI with other fever focus). Therefore, the usefulness of urine culture for diagnostic purposes is small and the sampling procedure is invasive. Congenital hypoplastic kidney is the most common cause of chronic kidney injury in children. Thus, it is desirable that a main target be detected as early as possible when imaging studies are performed in children with APN. However, if APN does not recur, no medical or surgical treatment or imaging studies would be needed because the acquired renal scar would not progress further. Therefore, the long-term prognosis of APN in young children, particularly infants, depends on the number of recurrent APN, not other febrile UTI. New methods that enable prompt, practical, and comfortable APN diagnosis in children are needed as alternatives to urinary catheterization for urine culture sampling.

Diagnosis of urinary tract infection in older persons in the emergency department: To pee or not to pee, that is the question

Doreen is a 79-year-old woman referred by her general practitioner to the ED for intravenous antibiotics for a urinary tract infection (UTI). She lives in a residential aged care facility (RACF) and staff report malodourous and cloudy urine. She denies dysuria or frequency. On examination Doreen is frail with vital signs of: temperature 37.7°C, pulse 87 bpm, blood pressure 130/70; there is no suprapubic or flank tenderness. Do you perform a dipstick test on Doreen’s urine for a suspected UTI?

The Emergency Department Diagnosis and Management of Urinary Tract Infection

Urinary tract infection (UTI) is a common infection seen in the emergency department. The spectrum of UTI includes simple versus complicated infection and lower versus upper UTI. No one history or examination finding is definitive for diagnosis. Testing often includes urinalysis and/or urine dipstick, and several pitfalls may occur in interpretation. Urine cultures should be obtained in complicated or upper UTIs but not simple and lower tract UTIs, unless a patient is pregnant. Imaging often is not required. Most patients with simple cystitis and pyelonephritis are treated as outpatients. A variety of potentially dangerous conditions may mimic UTI and pyelonephritis.

Antinatriuretic phenomena seen in children with acute pyelonephritis may be related to the activation of intrarenal RAAS

We investigated whether antinatriuretic phenomena [decreases in urinary sodium (uNa) and fractional excretion of sodium (FENa)] seen in children with acute pyelonephritis (APN) are associated with the renin-angiotensin-aldosterone system (RAAS).We examined 114 children experiencing their first episode of febrile urinary tract infection (fUTI) consecutively admitted to our hospital from July 2012 to June 2014. Blood tests [C-reactive protein, white blood cell count, erythrocyte sedimentation rate, and aldosterone (Aldo)] and urine tests [uNa, urine potassium (uK) and FENa] were performed upon admission. All enrolled children underwent a 99m-dimercaptosuccinic acid renal scanning (DMSA) at admission. Areas with cortical defects (AreaCD) and uptake counts (UptakeCD) on their DMSA scans were calculated. Data were compared between children with positive DMSA results (APN), lower urinary tract infection (L-UTI), and controls; and between children with high and low Aldo levels.uNa, uNa/K, and FENa negatively correlated with AreaCD%, UptakeCD, and Aldo; were significantly lower in APN patients than in LUTIs and controls regardless of Aldo level; were lower in the high Aldo group than in the low Aldo group. However, there is no difference in AreaCD% and UptakeCD between APN children with the high and low Aldo level.Decreases in uNa, uNa/K, and FENa in children with APN may result from an antinatriuretic effect of RAAS and be related to the activation of the intrarenal RAAS.

Atypical Presentation of IgA Nephropathy Mimicking Acute Pyelonephritis

Background

IgA glomerulonephritis may present with hematuria, flank pain, and fever. This clinical presentation may be easily confused with acute pyelonephritis.

Case Report

We present the case of a 25-year-old female with a typical clinical presentation for acute pyelonephritis (high fever, left flank pain, left costovertebral angle tenderness, hematuria, elevated inflammatory markers, and a hypoenhancing region in the left kidney on contrast-enhanced computed tomography). However, urine and blood cultures were both negative, the serum creatinine was elevated, and the urinalysis revealed significant proteinuria and dysmorphic red blood cells. A kidney biopsy confirmed a diagnosis of IgA nephropathy. She was treated with a combination of lisinopril and methylprednisolone, with good response.

Conclusion

Gross hematuria, especially in the absence of pyuria or bacteriuria, should raise the suspicion for underlying IgA nephropathy, even if the rest of the clinical presentation is typical for a urinary tract infection. The presence of significant proteinuria, red blood cell casts, and dysmorphic red blood cells are useful clues suggesting glomerular disease.

Diagnosis and treatment of urinary tract infections across age groups

Urinary tract infections are the most common outpatient infections, but predicting the probability of urinary tract infections through symptoms and test results can be complex. The most diagnostic symptoms of urinary tract infections include change in frequency, dysuria, urgency, and presence or absence of vaginal discharge, but urinary tract infections may present differently in older women. Dipstick urinalysis is popular for its availability and usefulness, but results must be interpreted in context of the patient's pretest probability based on symptoms and characteristics. In patients with a high probability of urinary tract infection based on symptoms, negative dipstick urinalysis does not rule out urinary tract infection. Nitrites are likely more sensitive and specific than other dipstick components for urinary tract infection, particularly in the elderly. Positive dipstick testing is likely specific for asymptomatic bacteriuria in pregnancy, but urine culture is still the test of choice. Microscopic urinalysis is likely comparable to dipstick urinalysis as a screening test. Bacteriuria is more specific and sensitive than pyuria for detecting urinary tract infection, even in older women and during pregnancy. Pyuria is commonly found in the absence of infection, particularly in older adults with lower urinary tract symptoms such as incontinence. Positive testing may increase the probability of urinary tract infection, but initiation of treatment should take into account risk of urinary tract infection based on symptoms as well. In cases in which the probability of urinary tract infection is moderate or unclear, urine culture should be performed. Urine culture is the gold standard for detection of urinary tract infection. However, asymptomatic bacteriuria is common, particularly in older women, and should not be treated with antibiotics. Conversely, in symptomatic women, even growth as low as 10² colony-forming unit/mL could reflect infection. Resistance is increasing to fluoroquinolones, beta-lactams, and trimethoprim-sulfamethoxazole. Most uropathogens still display good sensitivity to nitrofurantoin. First-line treatments for urinary tract infection include nitrofurantoin, fosfomycin, and trimethoprim-sulfamethoxazole (when resistance levels are <20%). These antibiotics have minimal collateral damage and resistance. In pregnancy, beta-lactams, nitrofurantoin, fosfomycin, and trimethoprim-sulfamethoxazole can be appropriate treatments. Interpreting the probability of urinary tract infection based on symptoms and testing allows for greater accuracy in diagnosis of urinary tract infection, decreasing overtreatment and encouraging antimicrobial stewardship.

High Prevalence of Sterile Pyuria in the Setting of Sexually Transmitted Infection in Women Presenting to an Emergency Department

Introduction

The clinical presentations for sexually transmitted infections (STI) and urinary tract infections (UTI) often overlap, and symptoms of dysuria and urinary frequency/urgency occur with both STIs and UTIs. Abnormal urinalysis (UA) findings and pyuria are common in both UTIs and STIs, and confirmatory urine cultures are not available to emergency clinicians to aid in decision-making regarding prescribing antibiotics for UTIs. The objective of this study was to determine the frequency of sterile pyuria in women with confirmed STIs, as well as whether the absolute number of leukocytes on microscopy or nitrite on urine dipstick correlated with positive urine cultures in patients with confirmed STIs. We also sought to determine how many patients with STIs were inappropriately prescribed a UTI antibiotic.

Methods

We performed a retrospective chart review of patients aged 18–50 who had a urinalysis and pelvic examination in the emergency department (including cervical cultures), and tested positive for Neisseria gonorrhoeae, Chlamydia trachomatis, and/or Trichomonas vaginalis. Descriptive statistics were obtained for all variables, and associations between various findings were sought using the Fisher’s exact test for categorical variables. We calculated comparison of proportions using the N-1 chi-squared analysis.

Results

A total of 1,052 female patients tested positive for Neisseria gonorrhoeae, Chlamydia trachomatis, and/or Trichomonas vaginalis and were entered into the database. The prevalence of pyuria in all cases was 394/1,052, 37% (95% confidence interval [CI] [0.34–0.40]). Of the cases with pyuria, 293/394, 74% (95% CI [0.70–0.78]) had sterile pyuria with negative urine cultures. The prevalence of positive urine cultures in our study population was 101/1,052, 9.6% (95% CI [0.08–0.11]). Culture positive urines had a mean of 34 leukocytes per high-power field, and culture negative urines had a mean of 24 leukocytes per high-power field, with a difference of 10, (95% CI [3.46–16.15]), which was statistically significant (p=0.003). Only 123 cases tested positive for nitrite on the urinalysis dipstick; 50/123, 41% (95% CI [0.32–0.49]) had positive urine cultures, and 73/123, 59% (95% CI [0.51–0.68]) had negative urine cultures. Nitrite-positive urines were actually 18% more likely to be associated with negative urine cultures in the setting of positive STI cases, (95% CI [4.95–30.42], p=0.0048). Antibiotics were prescribed for 295 patients with suspected UTI. Of these, 195/295, 66% (95% CI [0.61–0.71]) had negative urine cultures, and 100/295, 34% (0.33, 95% CI [0.28–0.39]) had positive urine cultures. Chi-square analysis yielded a difference of these proportions of 32% (95% CI [23.92–39.62], p<0.0001).

Conclusion

This study demonstrated that in female patients with STIs who have pyuria, there is a high prevalence of sterile pyuria. Our results suggest that reliance on pyuria or positive nitrite for the decision to add antimicrobial therapy empirically for a presumed urinary tract infection in cases in which an STI is confirmed or highly suspected is likely to result in substantial over-treatment.

Is There Any Relation between Ultrasonographic Estimation of Urinary Retention and Lower Urinary Tract Infection in Women?

A study was conducted to determine whether ultrasonographic detection of urinary retention is associated with clinically suspected lower urinary tract infection (UTI). During a 6-month period (January-June 2007), women aged >16 years who presented to the emergency department of Queen Elizabeth Hospital with clinical symptoms of lower UTI were enrolled. Totally 187 patients participated and completed the study. The mean age was 50.8 ± 21.5 years. Sixty-eight (36.4%) had positive urine culture while 119 (63.6%) were negative. Defining a significant residual urine volume of greater than 50 ml had low sensitivity (17.7%) and high specificity (100%) for the detection of UTI. However, when taking into account those of smaller residual urine volume (less than 50 ml), overall 37.6% of the patients with UTI had detectable residual urine in the bladder and no significant residual urine was detected in all culture-negative patients.

Discrimination of culture negative pyelonephritis in children with suspected febrile urinary tract infection and negative urine culture results

BACKGROUND

We investigated whether the C-reactive protein (CRP) level, urine electrolytes, and urine sodium-potassium ratio (uNa/K) could be useful markers for discriminating children with culture negative pyelonephritis (CNP) from children with suspected febrile urinary tract infection (fUTI) and negative urine culture results.

METHODS

We examined 264 children experiencing their first fUTI consecutively admitted to our hospital between January 2011 and October 2014. Blood tests (CRP, white blood cell count [WBC], erythrocyte sedimentation rate [ESR], electrolytes) and urine tests (urine protein to creatinine ratio [uProt/Cr], electrolytes, uNa/K) were performed upon admission. All children with fUTI underwent 99m-dimercaptosuccinic acid (DMSA) scanning at admission. Data were compared between children with acute pyelonephritis (APN), CNP, lower UTI and controls. Using multiple logistic regression analysis (MLRA), the ability of these parameters to predict a cortical defect on DMSA scan (APN and CNP) was analyzed.

RESULTS

The laboratory findings of CNP children were similar with those of APN children except uProt/cr. The CRP level, WBC count, and ESR were higher in children with CNP, while uNa and uNa/K were lower than in children with lower UTI and control. By MLRA, CRP levels and uNa/K were the most relevant factors for predicting a cortical defect on DMSA scan (P = 0.002, <0.001, respectively).

CONCLUSION

We conclude that the combination of CRP or WBC and uNa/K are useful for discriminating children with CNP from children with suspected fUTI and negative urine culture results.

Performance of the dipstick screening test as a predictor of negative urine culture

Objective

To investigate whether the urine dipstick screening test can be used to predict urine culture results.

Methods

A retrospective study conducted between January and December 2014 based on data from 8,587 patients with a medical order for urine dipstick test, urine sediment analysis and urine culture. Sensitivity, specificity, positive and negative predictive values were determined and ROC curve analysis was performed.

Results

The percentage of positive cultures was 17.5%. Nitrite had 28% sensitivity and 99% specificity, with positive and negative predictive values of 89% and 87%, respectively. Leukocyte esterase had 79% sensitivity and 84% specificity, with positive and negative predictive values of 51% and 95%, respectively. The combination of positive nitrite or positive leukocyte esterase tests had 85% sensitivity and 84% specificity, with positive and negative predictive values of 53% and 96%, respectively. Positive urinary sediment (more than ten leukocytes per microliter) had 92% sensitivity and 71% specificity, with positive and negative predictive values of 40% and 98%, respectively. The combination of nitrite positive test and positive urinary sediment had 82% sensitivity and 99% specificity, with positive and negative predictive values of 91% and 98%, respectively. The combination of nitrite or leukocyte esterase positive tests and positive urinary sediment had the highest sensitivity (94%) and specificity (84%), with positive and negative predictive values of 58% and 99%, respectively. Based on ROC curve analysis, the best indicator of positive urine culture was the combination of positives leukocyte esterase or nitrite tests and positive urinary sediment, followed by positives leukocyte and nitrite tests, positive urinary sediment alone, positive leukocyte esterase test alone, positive nitrite test alone and finally association of positives nitrite and urinary sediment (AUC: 0.845, 0.844, 0.817, 0.814, 0.635 and 0.626, respectively).

Conclusion

A negative urine culture can be predicted by negative dipstick test results. Therefore, this test may be a reliable predictor of negative urine culture.

Prediction of Cortical Defect Using C-Reactive Protein and Urine Sodium to Potassium Ratio in Infants with Febrile Urinary Tract Infection

PURPOSE

We investigated whether C-reactive protein (CRP) levels, urine protein-creatinine ratio (uProt/Cr), and urine electrolytes can be useful for discriminating acute pyelonephritis (APN) from other febrile illnesses or the presence of a cortical defect on 99mTc dimercaptosuccinic acid (DMSA) scanning (true APN) from its absence in infants with febrile urinary tract infection (UTI).

MATERIALS AND METHODS

We examined 150 infants experiencing their first febrile UTI and 100 controls with other febrile illnesses consecutively admitted to our hospital from January 2010 to December 2012. Blood (CRP, electrolytes, Cr) and urine tests [uProt/Cr, electrolytes, and sodium-potassium ratio (uNa/K)] were performed upon admission. All infants with UTI underwent DMSA scans during admission. All data were compared between infants with UTI and controls and between infants with or without a cortical defect on DMSA scans. Using multiple logistic regression analysis, the ability of the parameters to predict true APN was analyzed.

RESULTS

CRP levels and uProt/Cr were significantly higher in infants with true APN than in controls. uNa levels and uNa/K were significantly lower in infants with true APN than in controls. CRP levels and uNa/K were relevant factors for predicting true APN. The method using CRP levels, u-Prot/Cr, u-Na levels, and uNa/K had a sensitivity of 94%, specificity of 65%, positive predictive value of 60%, and negative predictive value of 95% for predicting true APN.

CONCLUSION

We conclude that these parameters are useful for discriminating APN from other febrile illnesses or discriminating true APN in infants with febrile UTI.

History and physical examination plus laboratory testing for the diagnosis of adult female urinary tract infection

BACKGROUND

Emergency physicians often encounter females presenting with symptoms suggestive of urinary tract infections (UTIs). The diagnostic accuracy of history, physical examination, and bedside laboratory tests for female UTIs in emergency departments (EDs) have not been quantitatively described.

OBJECTIVES

This was a systematic review to determine the utility of history and physical examination (H&P) and urinalysis in diagnosing uncomplicated female UTI in the ED.

METHODS

The medical literature was searched from January 1965 through October 2012 in PUBMED and EMBASE using the following criteria: Patients were females greater than 18 years of age in the ED suspected of having UTIs. Interventions were H&P and urinalysis used to diagnose a UTI. The comparator was UTI confirmed by a positive urine culture. The outcome was operating characteristics of the interventions in diagnosing a UTI. Study quality was assessed using Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS-2). Sensitivity, specificity, and likelihood ratios (LRs) were calculated using Meta-DiSc.

RESULTS

Four studies (pooled n = 948) were included with UTI prevalence ranging from 40% to 60%. H&P variables all had positive LRs (+LR, range = 0.8 to 2.2) and negative LRs (-LR, range = 0.7 to 1.0) that are insufficient to significantly alter pretest probability of UTI. Only a positive nitrite reaction (+LR = 7.5 to 24.5) was useful to rule in a UTI. To rule out UTI, only a negative leukocyte esterase (LE; -LR = 0.2) or blood reaction on urine dipstick (-LR = 0.2) were significantly accurate. Increasing pyuria directly correlated with +LR, and moderate pyuria (urine white blood cells [uWBC] > 50 colony-forming units [CFUs]/ml) and moderate bacteruria were good predictors of UTI (+LR = 6.4 and 15.0, respectively).

CONCLUSIONS

No single H&P finding can accurately rule in or rule out UTI in symptomatic women. Urinalysis with a positive nitrite or moderate pyuria and/or bacteruria are accurate predictors of a UTI. If the pretest probability of UTI is sufficiently low, a negative urinalysis can accurately rule out the diagnosis.

Overactive bladder: achieving a differential diagnosis from other lower urinary tract conditions

Overactive bladder (OAB) is a debilitating condition characterised by an urgent need to urinate (urgency), often with urinary frequency and, in some cases, urgency incontinence and nocturnal frequency. Patients often adopt complex adaptive behaviours to cope with their symptoms as OAB can compromise all dimensions of a patient's quality of life. Most OAB patients present initially to their primary care physician. Diagnosis is based on presenting symptomatology and does not require any invasive tests. Direct questioning about symptoms is important in achieving a differential diagnosis. The most common condition to be considered when working towards a differential diagnosis is a urinary tract infection (UTI). However, some physicians have expressed concerns about identifying the small number of cases where bladder cancer is a potential underlying aetiology for the symptoms of OAB. In this review, we examine the prevalence and patient profiles for these bladder conditions and their presenting symptomatology. We also review tests that may be recommended to exclude a diagnosis of UTI or bladder cancer and present a diagnostic algorithm suitable for office-based primary care practice.