Symptom‐based diagnosis of urinary tract infection in women: are we over‐prescribing antibiotics?

Background: Current clinical guidelines for the management of symptoms suggesting urinary tract infection recommend empiric antibiotic therapy. Objective: To determine the diagnostic accuracy of urinary tract symptoms for early identification of urinary tract infection (UTI) in sexually active women when culture results are not available. Method: This was a cross‐sectional observational study conducted in a tertiary care hospital between July 2009 and May 2011. Subjects comprised 312 women ≥ 18 year of age who reported to the physician with symptoms suggestive of UTI. A predesigned questionnaire was filled and urine was analysed by microscopic examination and culture. Diagnostic values were calculated against gold standard urine culture results (> 10² CFU/ml) and 95% CIs and likelihood ratios are reported. Results: A total of 312 women were enrolled, as culture was contaminated in 36 only 276 women were included in final analysis. Prevalence of UTI was 46.01% amongst symptomatic women. Urgency (p = 0.001), burning sensation during micturition (p = 0.035), dysuria (p = 0.004), frequency of sexual intercourse > 5 per month (p = 0.010) and pyuria (p = 0.000) were significantly associated with culture positivity. Absence of pyuria emerged as best predictor for ruling out UTI even if the woman had symptoms (sensitivity 93.70%, NPV 91.84%, AUC 77.07%, LR? 0.1). The combination of urgency, burning during micturition and pyuria was the best predictor of UTI in our study (sensitivity 85.83%, PPV 71.71%, AUC 78.48%, LR+ 2.97) Conclusion: Symptoms alone have low accuracy when assessed against the reference standard for diagnosing UTI. Empiric treatment of UTI based on symptoms may expose large number of patients to unnecessary antibiotics. Wet mount microscopy for presence of pyuria as a ‘near patient test’ before starting antibiotics seems a rational approach for management of UTI in symptomatic women.     

An observational study of empirical antibiotics for adult women with uncomplicated UTI in general practice

OBJECTIVES: Women presenting in primary care with symptoms suggestive of uncomplicated urinary tract infection (UTI) are commonly managed without urine culture. We therefore do not know how successful general practitioners (GPs) are at targeting antibiotic treatment to women who would have had a microbiologically confirmed UTI, or at avoiding antibiotics in those who would have had a negative culture, had all patients with a suspected UTI been sampled. We therefore explored the association between antibiotic prescribing and urine culture results when culture was performed in all symptomatic patients. METHODS: GPs in nine general practices in South Wales were asked to submit urine specimens from all women consulting with clinically suspected, uncomplicated UTI. Patients were followed up 2 weeks later by questionnaire. RESULTS AND CONCLUSIONS: One hundred and thirteen adult women with a median age of 54 years were included and 61% received empirical antibiotics. There was very low agreement between the decision to prescribe empirically and subsequent culture result (Kappa = 0.04), with 60% of those prescribed empirical antibiotics subsequently found to have a negative culture, and 25% of those found to have a positive culture not prescribed empirical antibiotics. Current strategies to target empirical antibiotic prescribing in clinically suspected, uncomplicated UTI require review.     

Risk factors for symptomatic urinary tract infection in women with diabetes

OBJECTIVE: Women with diabetes have urinary tract infections (UTIs) more often than women without diabetes. The aim of the present multicenter study was to evaluate which clinical characteristics are associated with the development of a symptomatic UTI during an 18-month follow-up period. RESEARCH DESIGN AND METHODS: Patients with either type 1 or type 2 diabetes who were between 18 and 75 years of age were included. Follow-up results were available for 589 of the 636 women included in this study. All patients were interviewed, their medical history was noted, and at least one uncontaminated urine culture was collected at the moment of study entry. RESULTS: Of the 589 women, 115 (20%) developed a symptomatic UTI, 96 (83%) of whom were prescribed antimicrobial therapy A total of 34 women (14%) with type 1 diabetes developed a UTI. The most important risk factor for these women was sexual intercourse during the week before entry into the study (44% without vs. 53% with sexual intercourse, relative risk [RR] = 3.0, P = 0.01). A total of 81 (23%) women with type 2 diabetes developed a UTI. The most important risk factor for these women was the presence of asymptomatic bacteriuria (ASB) at baseline (25% without vs. 42% with ASB, RR = 1.65, P = 0.04). CONCLUSIONS: Risk factors for developing a UTI are the presence of ASB for women with type 2 diabetes and sexual intercourse during the week before entry into the study for women with type 1 diabetes.     

Predictive value of Escherichia coli susceptibility in strains causing asymptomatic bacteriuria for women with recurrent symptomatic urinary tract infections receiving prophylaxis

A significant proportion of women develop a recurrence following an initial urinary tract infection (UTI). In women with recurrent UTI, the predictive value of asymptomatic bacteriuria (ASB) for the development of a subsequent UTI has not yet been established and it is not known whether information from an asymptomatic sample is useful in guiding antimicrobial therapy. To address these questions, we used data that originated from the 'Non-antibiotic prophylaxis for recurrent urinary tract infections' (NAPRUTI) study: two randomized controlled trials on the prevention of recurrent UTI in non-hospitalized premenopausal and postmenopausal women (n=445). During 15months of follow-up, no difference was observed in the time to a subsequent UTI between women with and without ASB at baseline (hazard ratio: 1.07, 95% CI 0.80-1.42). The antimicrobial susceptibility and pulsed-field gel-electrophoresis (PFGE) pattern of 50 Escherichia coli strains causing a UTI were compared with those of the ASB strain isolated 1month previously. The predictive values of the susceptibility pattern of the ASB strain, based on resistance prevalence at baseline, were ≥76%, except in the case of nitrofurantoin- and amoxicillin-clavulanic acid-resistance. Asymptomatic and symptomatic isolates had similar PFGE patterns in 70% (35/50) of the patients. In the present study among women with recurrent UTI receiving prophylaxis, ASB was not predictive for the development of a UTI. However, the susceptibility pattern of E. coli strains isolated in the month before a symptomatic E. coli UTI can be used to make informed choices for empirical antibiotic treatment in this patient population.     

Epidemiology, natural history, and management of urinary tract infections in pregnancy

The urinary tract undergoes profound physiologic and anatomic changes during pregnancy that facilitate the development of symptomatic UTIs in women with bacteriuria. Although the adverse effects of asymptomatic bacteriuria on maternal and fetal health continue to be debated, it is clear that asymptomatic bacteriuria is the major risk factor for developing symptomatic UTI and that symptomatic infections are associated with significant maternal and fetal risks. Because the majority of symptomatic UTIs develop in women with bacteriuria earlier in pregnancy, treatment of bacteriuria is undertaken to prevent symptomatic infections. All women should be screened at the first antenatal visit, which is reliably and inexpensively done with a dipstick culture. Short-course therapy is as effective as prolonged therapy and should be followed with a repeat culture to document clearing of the bacteriuria. Failure to eliminate bacteriuria with repeated therapy or recurrence with the same organism is indicative of renal parenchymal infection or a structural abnormality. All women with persistent bacteriuria or recurrent infection should have follow-up cultures and a complete urologic evaluation after delivery.     

Diabetes and the risk of acute urinary tract infection among postmenopausal women

OBJECTIVE: To examine whether the presence of diabetes alters the risk of acute urinary tract infection (UTI) in postmenopausal women. RESEARCH DESIGN AND METHODS: A case-control study of the Group Health Cooperative of Puget Sound (GHC), a staff-model nonprofit health maintenance organization in Washington State, was conducted. Subjects were women aged 55-75 years who had been members of GHC for at least 1 year and who had had an acute symptomatic UTI within the preceding month. Laboratory files were used to identify women with a urine culture that grew > or =10(5) colonies of a urinary pathogen. Medical records were reviewed to confirm the presence of acute, clinically symptomatic UTI. Control subjects were randomly selected from the GHC enrollment file, screened to remove women with recent UTI, and frequency matched to cases by age within 2 years. An interviewer ascertained self-reported clinician-diagnosed diabetes. Diagnosis of diabetes was confirmed by the GHC diabetes registry. A subsample of women underwent measurement of postvoid residual bladder volume (n = 748) and culture of vaginal flora (n = 454). RESULTS: Of the 901 case and 913 control subjects, diabetes was reported in 13.1 and 6.8%, respectively. The health plan diabetes registry confirmed the diagnosis in 92% of women who self-reported the condition. The age-adjusted odds ratio (OR) for UTI in relation to self-reported clinician-diagnosed diabetes was 2.2 (95% CI 1.6-3.0). Adjustment for frequency of sexual intercourse and history of UTI had little effect on this estimate. Compared with nondiabetic women, higher UTI odds were seen in subjects who used oral hypoglycemic agents (OR 2.9 [95% CI 1.7-5.1]) and insulin (2.6 [1.5-4.6]) but not in subjects with untreated diabetes or diabetes treated by lifestyle changes (1.3 [0.7-2.3]). No significant difference was seen in the OR for UTI in diabetic women with disease of shorter duration (<10 years, OR 1.9) or longer duration (> or =10 years, OR 2.6) or in relation to HbA(1c) level. Similar microbiologic pathogens were seen in diabetic and nondiabetic women. No significant differences were seen by diabetes status in mean postvoid residual bladder volume or vaginal flora. CONCLUSIONS: Diabetes under pharmacologic treatment is associated with increased risk of clinically apparent UTI in postmenopausal women.     

Complicated urinary tract infection in patients with benign prostatic hyperplasia

Complicated urinary tract infection (UTI) is a symptomatic urinary infection accompanied by functional or structural abnormalities of the genitourinary tract. Benign prostatic hyperplasia (BPH) is a major cause of lower urinary tract obstruction in male patients, and bladder outlet obstruction (BOO) secondary to BPH can lead to UTIs in men. However, no evidence has clearly shown that UTI in the aging male population is associated with either post-void residual urine or BOO. Screening for the presence of bacteriuria is recommended prior to any procedure manipulating the urinary tract, and imaging studies of the upper urinary tract are recommended to identify underlying abnormalities. Recurrent or persistent UTI in men with BPH is an indication for surgical treatment. Asymptomatic bacteriuria should be screened for and treated before transurethral resection of the prostate (TURP). In addition, antibiotic prophylaxis reduced the risk of UTI in patients undergoing TURP. The choice of specific antimicrobial for prophylaxis should be based on local pathogen prevalence and individual antibiotic susceptibility. Patients with severe systemic infections require hospitalization, and empirical therapy should include an intravenous antimicrobial regimen. Further prospective studies are needed to refine the treatment process for complicated UTI in patients diagnosed with BPH.     

Management of asymptomatic bacteriuria in patients with diabetes mellitus

OBJECTIVE: To review the literature regarding the management of asymptomatic bacteriuria (ASB) in patients with diabetes mellitus. DATA SOURCES: A MEDLINE (1967-June 2003) and bibliographic search of the English-language literature was conducted using the search terms diabetes mellitus, asymptomatic, bacteriuria, and urinary tract infection. DATA SYNTHESIS: ASB occurs in diabetic women more commonly than in non-diabetics and is associated with an increased risk of symptomatic urinary tract infection (UTI) among patients with type 2 diabetes. Symptomatic UTIs tend to follow a more complicated course in diabetics. Despite these independent observations, antimicrobial therapy has not been shown to reduce symptomatic UTIs, pyelonephritis, or hospitalization for UTI. CONCLUSIONS: Available evidence does not support antimicrobial treatment of ASB among patients with diabetes mellitus.     

Intermittent catheterization in the rehabilitation setting: a comparison of clean and sterile technique

OBJECTIVE: To compare the onset of symptomatic urinary tract infection in individuals with spinal cord injury in a rehabilitation setting who are randomized to clean or sterile intermittent catheterization technique. DESIGN: Randomized controlled design. SETTING: Spinal cord rehabilitation units in western Canada. SUBJECTS: Thirty-six patients with cervical spinal cord injuries requiring intermittent catheterization by nursing staff were recruited. None had a previous history of voiding dysfunction or urinary tract infections. Interventions: Subjects were randomized to either clean or sterile intermittent catheterization technique. Protocols for both clean and sterile techniques were standardized and followed by nursing staff and caregivers. MAIN MEASURES: Primary outcome measure was symptomatic urinary tract infection as diagnosed by urine culture > or = 10(5) colony-forming units/mL, pyuria (> or =10 leukocytes on high-power field), and accompanying symptoms. RESULTS: A total of 189 urine specimens from 36 subjects were cultured. Of the 36 subjects, 15 (43%) developed a symptomatic urinary tract infection: 6/16 (37%) from the clean group; 9/20 (45%) from the sterile group (P> 0.05). Mean time to onset for symptomatic urinary tract infection for the clean group was 3.0 (standard deviation (SD) 2.4) weeks and for the sterile group, 3.6 (SD 1.3) weeks (P> 0.05). The most common urinary organisms at onset of symptomatic urinary tract infection were Enterococcus species followed by Klebsiella. CONCLUSION: Clean intermittent catheterization in the rehabilitation setting does not appear to place the patient with spinal cord injury at increased risk for developing symptomatic urinary tract infection, and has significant cost and time saving benefits for the health care system, as well as enhancing the transition for the patient from rehabilitation to community.     

全自动尿液有形成分分析仪细菌检测对尿路感染诊断价值的探讨

目的探讨UF-1000i全自动尿液有形成分分析仪细菌信息对临床尿路感染(UTI)诊断的应用价值。方法收集216例临床疑似尿路感染患者尿液样本,分别采用UF-1000i全自动尿液有形成分分析仪和尿液细菌培养及鉴定,比较两者结果。结果 216例临床诊断为尿路感染患者的UF-1000i全自动尿液有形成分分析仪细菌数量检测阳性率为38.0%(82/216),细菌培养阳性率为31.0%(67/216),两种方法检测结果经统计无显著性差异(P0.05)。UF-1000i全自动尿液有形成分分析仪细菌检测诊断尿路感染的敏感度为69.0%、特异性为82.9%、假阳性率为17.1%、假阴性率为31.0%、阳性预测值为73.2%、阴性预测值为79.8%、诊断符合率为77.3%。结论 UF-1000i全自动尿液有形成分分析仪检测简易、快速,细菌检测有助于及时辅助尿路感染临床诊断,可作为临床筛查的手段。     

Asymptomatic bacteriuria may be considered a complication in women with diabetes. Diabetes Mellitus Women Asymptomatic Bacteriuria Utrecht Study Group

OBJECTIVE: To study the prevalence of and risk factors for asymptomatic bacteriuria (ASB) in women with and without diabetes. RESEARCH DESIGN AND METHODS: A total of 636 nonpregnant women with diabetes (type 1 and type 2) who were 18-75 years of age and had no abnormalities of the urinary tract, and 153 women without diabetes who were visiting the eye and trauma outpatient clinic (control subjects) were included. We defined ASB as the presence of at least 10(5) colony-forming units/ml of 1 or 2 bacterial species in a culture of clean-voided midstream urine from an individual without symptoms of a urinary tract infection (UTI). RESULTS: The prevalence of ASB was 26% in the diabetic women and 6% in the control subjects (P < 0.001). The prevalence of ASB in women with type 1 diabetes was 21%. Risk factors for ASB in type 1 diabetic women included a longer duration of diabetes, peripheral neuropathy, and macroalbuminuria. The prevalence of ASB was 29% in women with type 2 diabetes. Risk factors for ASB in type 2 diabetic women included age, macroalbuminuria, a lower BMI, and a UTI during the previous year. No association was evident between current HbA1c level and the presence of ASB. CONCLUSIONS: The prevalence of ASB is increased in women with diabetes and might be added to the list of diabetic complications in these women.     

Evaluation of the Coral UTI Screen system for rapid automated screening of significant bacteriuria in a regional centralized laboratory

An evaluation of the Coral UTI screen system (Coral Biotechnology, San Diego, CA) compared to urinalysis/urine culture was done to assess its performance for rapidly screening a high volume of urine samples for significant bacteriuria in a regional central microbiology laboratory. A total of 1094 urine samples from ambulatory patients were evaluated. 670 (61.2%) urine samples were negative or positive [178 (16.3%)] by both methods. 217 (19.8%) other samples were UTI screen positive but had either no growth or no uropathogens on culture; 9 of these samples were possibly false negative by culture because of the presence of pyuria, indicating the presence of either a urinary tract infection or another inflammatory process. Another 29 (2.7%) samples had false negative screens because the urine culture was positive, but only 5 of these patients were treated with antibiotics after urine specimen collection. Overall, the Coral UTI screen has a sensitivity of 86.0%, a specificity of 75.5% and a positive and negative predictive value of 45.0% and 95.9% respectively. Routine use of the UTI screen would allow same day reporting of 65% of all urine culture results without having to proceed to culture.     

尿液流水线分析系统联合显微镜检对尿路感染的诊断价值

目的探讨Sysmex UC-3500尿干化学分析仪(简称UC-3500)与UF-5000尿沉渣分析仪(简称UF-5000)的相关参数联合尿沉渣显微镜检在诊断尿路感染(UTI)中的应用价值。方法对该院2021年2—3月1 036例患者的清洁中段尿进行尿干化学分析、流式尿沉渣分析及尿离心显微镜检,另送尿培养鉴定,以尿培养结果作为"金标准",分析尿中性粒细胞酯酶(LEU)、白细胞计数(WBC)、细菌计数(BACT)3项指标联合显微镜检诊断UTI的灵敏度、特异度、符合率。结果 1 036例尿标本中299例(28.86%)尿培养阳性,其中革兰阳性菌162例,革兰阴性菌108例,革兰染色不定的细菌仪器7例(阴道加德纳菌),真菌21例。仪器LEU+WBC+BACT 3项指标联合、显微镜检以及显微镜检联合仪器UTI报警诊断UTI的曲线下面积(AUC)分别为0.635、0.698和0.761;将显微镜检联合UF-5000的仪器UTI报警后,其诊断UTI的符合率由72.18%升高至79.90%。UF-5000的细菌革兰染色分型对革兰阴性菌的符合率(78.82%)高于革兰阳性菌的符合率(47.06%)。类酵...     

住院患者尿路感染筛查中尿有形成分分析的价值

目的评价尿有形成分分析在住院患者尿路感染(UTI)筛查中的应用价值。方法对2018年4月-2018年10月于大连大学附属中山医院住院疑似尿路感染的患者清洁中段尿标本497例进行尿有形成分分析、尿定量细菌培养及菌种鉴定。结果尿有形成分分析仪检测白细胞数和细菌数的阈值为白细胞数64个/μL和细菌数880.6个/μL,以该阈值筛检住院患者尿路感染,其敏感度分别为80.00%和85.19%,特异度分别为79.28%和87.39%。白细胞计数和细菌计数ROC曲线下面积分别为0.860和0.917。结论UF-1000i尿有形成分分析仪中白细胞和细菌计数可作为临床尿路感染快速筛检的辅助实验诊断方法。     

Pathogenesis of urinary tract infections: an update

The pathogenesis of uncomplicated urinary tract infection (UTI) is complex and influenced by many host biological and behavioural factors and by properties of the infecting uropathogens. Most uncomplicated UTIs in women are not associated with underlying functional or anatomical abnormalities of the urinary tract, whereas sexual intercourse, spermicide use, a history of recurrent UTI and recent antimicrobial chemotherapy are important risk factors. A maternal history of UTI and young age at first UTI, as well as sexual intercourse and spermicide use, are risk factors for recurrent UTI in young women. In some young healthy women, especially those with 'low UTI risk' behaviour, features of pelvic anatomy appear to be associated with UTI risk. In postmenopausal women, anatomical and functional characteristics of the genitourinary tract are more strongly associated with UTI risk than in younger women. A genetic predisposition to recurrent UTI is suggested by the association of recurrent UTI in certain age groups with the ABH blood group non-secretor phenotype, a maternal history of UTI and early age at onset of UTI. Virulence determinants of uropathogens are much more important in the normal host than in the host who has a functional or anatomical abnormality of the genitourinary tract.     

Mass spectrometric measurement of urinary kynurenine-to-tryptophan ratio in children with and without urinary tract infection

BackgroundIndoleamine-2,3-dioxygenase (IDO) catalyzes the first step of tryptophan (Trp) catabolism, yielding kynurenine (Kyn) metabolites. The kynurenine-to-tryptophan (K/T) ratio is used as a surrogate for biological IDO enzyme activity. IDO expression is increased during Escherichia coli urinary tract infection (UTI). Thus, our objective was to develop a method for measurement of Kyn/Trp ratio in human blood and urine and evaluate its use as a biomarker of UTI.MethodsA mass spectrometric method was developed to measure Trp and Kyn in serum and urine specimens. The method was applied to clinical urine specimens from symptomatic pediatric patients with laboratory-confirmed UTI or other acute conditions and from healthy controls.ResultsThe liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was linear to 500 μmol/L for both Trp and Kyn. Imprecision ranged from 5 to 15% for Trp and 6–20% for Kyn. Analytical recoveries of Trp and Kyn ranged from 96 to 119% in serum and 90–97% in urine. No correlation was found between the K/T ratio and circulating IDO mass (r = 0.110) in serum. Urinary Kyn and Trp in the pediatric test cohort demonstrated elevations in the K/T ratio in symptomatic patients with UTI (median 13.08) and without UTI (median 14.38) compared to healthy controls (median 4.93; p < 0.001 for both comparisons). No significant difference in K/T ratio was noted between symptomatic patients with and without UTI (p = 0.84).ConclusionsMeasurement of Trp and Kyn by LC-MS/MS is accurate and precise in serum and urine specimens. While urinary K/T ratio is not a specific biomarker for UTI, it may represent a general indicator of a systemic inflammatory process.     

Urinary tract infection in patients with lower urinary tract dysfunction

Lower urinary tract dysfunction (LUTD) is becoming more common in aging societies worldwide. In patients with LUTD, the risk of urinary tract infection (UTI) rises due to several distinct mechanisms, including easy bacterial access to the urinary tract, impaired bacterial washout, and an impaired innate defense system. The pathophysiology of LUTD varies depending on whether it is neurogenic or non-neurogenic, as well as by gender; therefore, the etiology and characteristics of UTI differ according to the type of LUTD. Patients with neurogenic LUTD, especially those with spinal cord injury, have a high risk of febrile UTI, and strict bladder management is required to prevent UTI. Clean intermittent catheterization with or without appropriate pharmacological therapy is also strongly recommended for patients with neurogenic LUTD at risk of febrile UTI, unable to void, or with high post-void residual volume. In contrast, both male and female patients with non-neurogenic LUTD have a lower risk of symptomatic UTI. There is insufficient evidence for non-neurogenic LUTD regarding the association between symptomatic UTI but not asymptomatic bacteriuria and LUTD severity, including the presence of post-void residual volume, or whether therapeutic intervention for LUTS reduces the incidence of UTI, particularly in male patients. In this narrative review, we aimed to highlight the pathogenesis, epidemiology, and management of UTI in patients with LUTD.     

Symptomatic Lower Urinary Tract Infection Induced by Cooling of the Feet: A Controlled Experimental Trial

We conducted an open, non-randomized experimental study as a first step to find out whether cooling of the feet may cause symptomatic lower urinary tract infection (UTI) in cystitis-prone women. Twenty-nine healthy women, aged 19–68 (mean 42.5) years, who had had three or more symptomatic episodes of UTI during the previous 12 months were included. They registered symptoms and carried out a strip urinalysis at each urination during a control period of 72 hours. Their lower legs and feet were then immersed in increasingly cold water for 30 minutes. Another 72-hour period of registration followed. Six subjects developed acute distal urinary symptoms at a mean of 55 (95% confidence interval 50 to 61) hours after the cooling, compared with none in the control period. Five of the six had bacteriologically verified lower UTI (P = 0.03 v. the control period). Cooling of the feet seems to provoke symptomatic lower UTI in cystitis-prone women.     

Symptomatic lower urinary tract infection induced by cooling of the feet. A controlled experimental trial.

We conducted an open, non-randomized experimental study as a first step to find out whether cooling of the feet may cause symptomatic lower urinary tract infection (UTI) in cystitis-prone women. Twenty-nine healthy women, aged 19-68 (mean 42.5) years, who had had three or more symptomatic episodes of UTI during the previous 12 months were included. They registered symptoms and carried out a strip urinalysis at each urination during a control period of 72 hours. Their lower legs and feet were then immersed in increasingly cold water for 30 minutes. Another 72-hour period of registration followed. Six subjects developed acute distal urinary symptoms at a mean of 55 (95% confidence interval 50 to 61) hours after the cooling, compared with none in the control period. Five of the six had bacteriologically verified lower UTI (P = 0.03 v. the control period). Cooling of the feet seems to provoke symptomatic lower UTI in cystitis-prone women.