Dipsticks are one of the most commonly used near-patient tests in primary care, but few clinical or dipstick algorithms have been rigorously developed.
To confirm whether previously documented clinical and dipstick variables and algorithms predict laboratory diagnosis of urinary tract infection (UTI).
Design of study
A total of 434 adult females with suspected lower UTI had bacteriuria assessed using the European Urinalysis Guidelines.
Sixty-six per cent of patients had confirmed UTI. The predictive values of nitrite, leucocyte esterase (+ or greater), and blood (haemolysed trace or greater) were confirmed (independent multivariate odds ratios = 5.6, 3.5, and 2.1 respectively). The previously developed dipstick rule — based on presence of nitrite, or both leucocytes and blood — was moderately sensitive (75%) but less specific (66%; positive predictive value [PPV] 81%, negative predictive value [NPV] 57%). Predictive values were improved by varying the cut-off point: NPV was 76% for all three dipstick results being negative; the PPV was 92% for having nitrite and either blood or leucocyte esterase. Urine offensive smell was not found to be predictive in this sample; for a clinical score using the remaining three predictive clinical features (urine cloudiness, dysuria, and nocturia), NPV was 67% for none of the features, and PPV was 82% for three features.
A clinical score is of limited value in increasing diagnostic precision. Dipstick results can modestly improve diagnostic precision but poorly rule out infection. Clinicians need strategies to take account of poor NPVs.
algorithms, clinical scoring; diagnosis, urinary tract infection; primary care; urinalysis
Urinary tract infection (UTI) is one of the most common sources of infection in children under five. Prompt diagnosis and treatment is important to reduce the risk of renal scarring. Rapid, cost-effective, methods of UTI diagnosis are required as an alternative to culture.
We conducted a systematic review to determine the diagnostic accuracy of rapid tests for detecting UTI in children under five years of age.
The evidence supports the use of dipstick positive for both leukocyte esterase and nitrite (pooled LR+ = 28.2, 95% CI: 17.3, 46.0) or microscopy positive for both pyuria and bacteriuria (pooled LR+ = 37.0, 95% CI: 11.0, 125.9) to rule in UTI. Similarly dipstick negative for both LE and nitrite (Pooled LR- = 0.20, 95% CI: 0.16, 0.26) or microscopy negative for both pyuria and bacteriuria (Pooled LR- = 0.11, 95% CI: 0.05, 0.23) can be used to rule out UTI. A test for glucose showed promise in potty-trained children. However, all studies were over 30 years old. Further evaluation of this test may be useful.
Dipstick negative for both LE and nitrite or microscopic analysis negative for both pyuria and bacteriuria of a clean voided urine, bag, or nappy/pad specimen may reasonably be used to rule out UTI. These patients can then reasonably be excluded from further investigation, without the need for confirmatory culture. Similarly, combinations of positive tests could be used to rule in UTI, and trigger further investigation.
Many studies have evaluated the accuracy of dipstick tests as rapid detectors of bacteriuria and urinary tract infections (UTI). The lack of an adequate explanation for the heterogeneity of the dipstick accuracy stimulates an ongoing debate. The objective of the present meta-analysis was to summarise the available evidence on the diagnostic accuracy of the urine dipstick test, taking into account various pre-defined potential sources of heterogeneity.
Literature from 1990 through 1999 was searched in Medline and Embase, and by reference tracking. Selected publications should be concerned with the diagnosis of bacteriuria or urinary tract infections, investigate the use of dipstick tests for nitrites and/or leukocyte esterase, and present empirical data. A checklist was used to assess methodological quality.
70 publications were included. Accuracy of nitrites was high in pregnant women (Diagnostic Odds Ratio = 165) and elderly people (DOR = 108). Positive predictive values were ≥80% in elderly and in family medicine. Accuracy of leukocyte-esterase was high in studies in urology patients (DOR = 276). Sensitivities were highest in family medicine (86%). Negative predictive values were high in both tests in all patient groups and settings, except for in family medicine. The combination of both test results showed an important increase in sensitivity. Accuracy was high in studies in urology patients (DOR = 52), in children (DOR = 46), and if clinical information was present (DOR = 28). Sensitivity was highest in studies carried out in family medicine (90%). Predictive values of combinations of positive test results were low in all other situations.
Overall, this review demonstrates that the urine dipstick test alone seems to be useful in all populations to exclude the presence of infection if the results of both nitrites and leukocyte-esterase are negative. Sensitivities of the combination of both tests vary between 68 and 88% in different patient groups, but positive test results have to be confirmed. Although the combination of positive test results is very sensitive in family practice, the usefulness of the dipstick test alone to rule in infection remains doubtful, even with high pre-test probabilities.
Urinary tract infection (UTI) is the most common non-intestinal infection worldwide. In the developed world, incidence and prevalence of UTI would be similar owing to the relatively short duration of illness experienced by women with ready access to healthcare services. We hypothesize that, in the developing world, factors limiting access to care and those which may increase the likelihood of developing UTI, result in increased morbidity. This difference is reflected in an increased prevalence of UTI in regions where women suffer the effects of UTI for extended periods of time.
This study represents a cross sectional analysis of UTI prevalence in rural western Panama conducted over the course of a 3-day medical mission. All women 18–45 years of age reporting to the medical brigade clinic were tested for UTI by dipstick urinalysis and a brief history regardless of whether they themselves were presenting with a complaint.
UTI was diagnosed clinically by providers in 29.8% of the women tested although only 21.15% of these same women met the evidence-based study criteria. This prevalence of 21.15% is seven times greater than reported by the Panamanian Ministry of Health. When comparing the effectiveness of clinical diagnosis relative to urinalysis by dipstick, a Kappa coefficient revealed only low moderate agreement (0.42; SE 0.0955).
The prevalence of UTI in rural western Panama is greater than would be expected based on prevalence data from either the US or Panamanian Ministry of Health and may represent an opportunity for targeted interventions, including educational programming about UTI prevention.
Acute urinary tract infections (UTI) are one of the most common bacterial infections among women presenting to primary care. However, there is a lack of consensus regarding the optimal reference standard threshold for diagnosing UTI. The objective of this systematic review is to determine the diagnostic accuracy of symptoms and signs in women presenting with suspected UTI, across three different reference standards (102 or 103 or 105 CFU/ml). We also examine the diagnostic value of individual symptoms and signs combined with dipstick test results in terms of clinical decision making.
Searches were performed through PubMed (1966 to April 2010), EMBASE (1973 to April 2010), Cochrane library (1973 to April 2010), Google scholar and reference checking.
Studies that assessed the diagnostic accuracy of symptoms and signs of an uncomplicated UTI using a urine culture from a clean-catch or catherised urine specimen as the reference standard, with a reference standard of at least ≥ 102 CFU/ml were included. Synthesised data from a high quality systematic review were used regarding dipstick results. Studies were combined using a bivariate random effects model.
Sixteen studies incorporating 3,711 patients are included. The weighted prior probability of UTI varies across diagnostic threshold, 65.1% at ≥ 102 CFU/ml; 55.4% at ≥ 103 CFU/ml and 44.8% at ≥ 102 CFU/ml ≥ 105 CFU/ml. Six symptoms are identified as useful diagnostic symptoms when a threshold of ≥ 102 CFU/ml is the reference standard. Presence of dysuria (+LR 1.30 95% CI 1.20-1.41), frequency (+LR 1.10 95% CI 1.04-1.16), hematuria (+LR 1.72 95%CI 1.30-2.27), nocturia (+LR 1.30 95% CI 1.08-1.56) and urgency (+LR 1.22 95% CI 1.11-1.34) all increase the probability of UTI. The presence of vaginal discharge (+LR 0.65 95% CI 0.51-0.83) decreases the probability of UTI. Presence of hematuria has the highest diagnostic utility, raising the post-test probability of UTI to 75.8% at ≥ 102 CFU/ml and 67.4% at ≥ 103 CFU/ml. Probability of UTI increases to 93.3% and 90.1% at ≥ 102 CFU/ml and ≥ 103 CFU/ml respectively when presence of hematuria is combined with a positive dipstick result for nitrites. Subgroup analysis shows improved diagnostic accuracy using lower reference standards ≥ 102 CFU/ml and ≥ 103 CFU/ml.
Individual symptoms and signs have a modest ability to raise the pretest-risk of UTI. Diagnostic accuracy improves considerably when combined with dipstick tests particularly tests for nitrites.
Urinary Tract Infection (UTI) is a common problem in pregnancy due to the morphological and the physiological changes that take place in the genitourinary tract during pregnancy. Screening methods may be useful, because a full bacteriological analysis could be reserved for those patients who are symptomatic or those who have positive screening test results. The exact prevalence of UTI in rural, pregnant women is unknown. The present study was undertaken to estimate the prevalence of UTI in pregnant women and for ascertaining the utility of the Griess Nitrite test and the Urinary Pus Cell Count of ≥5 cells per micro litre test for the screening or the early detection of UTI in them at primary health care clinics. Occurrence of urinary complaints was compared in UTI and non UTI women.
We conducted a study on 300 randomly selected, pregnant women from rural areas. Urine cultures, pus-cell counts and the Griess nitrite test were used for diagnosis of UTI. The screening tests for UTI were evaluated in terms of their sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV) and the percentage of correctly classified.
In the present study, the prevalence of UTI was found to be 29/300 (9.6%, 95% confidence interval 9.57-9.63). The specificities of the two screening tests were comparable (97.05% and 94.47%). Also, the negative predictive values of the two tests were almost similar (97.77% and 96.96%). The percentage of correctly classified by the Griess nitrite test and the urine pus cell count were found to be 95.33% and 92.33% respectively. The proportion of the women with various urinary complaints was significantly higher (P<0.00) in the UTI subjects as compared to that in the non-UTI subjects.
Urine culture remains the gold standard for the detection of asymptomatic bacteriuria. The Nitrite test of uncentrifuged urine was observed to be the best among the screening tests which were evaluated in terms of their efficiency and validity.
UTI; Pregnancy; Rural; Urine Culture; Griess Nitrite test; Screening tests; Urinary Pus cell Test
Urinary tract infection (UTI) is common in children, and may cause serious illness and recurrent symptoms. However, obtaining a urine sample from young children in primary care is challenging and not feasible for large numbers. Evidence regarding the predictive value of symptoms, signs and urinalysis for UTI in young children is urgently needed to help primary care clinicians better identify children who should be investigated for UTI. This paper describes the protocol for the Diagnosis of Urinary Tract infection in Young children (DUTY) study. The overall study aim is to derive and validate a cost-effective clinical algorithm for the diagnosis of UTI in children presenting to primary care acutely unwell.
DUTY is a multicentre, diagnostic and prospective observational study aiming to recruit at least 7,000 children aged before their fifth birthday, being assessed in primary care for any acute, non-traumatic, illness of ≤ 28 days duration. Urine samples will be obtained from eligible consented children, and data collected on medical history and presenting symptoms and signs. Urine samples will be dipstick tested in general practice and sent for microbiological analysis. All children with culture positive urines and a random sample of children with urine culture results in other, non-positive categories will be followed up to record symptom duration and healthcare resource use. A diagnostic algorithm will be constructed and validated and an economic evaluation conducted.
The primary outcome will be a validated diagnostic algorithm using a reference standard of a pure/predominant growth of at least >103, but usually >105 CFU/mL of one, but no more than two uropathogens.
We will use logistic regression to identify the clinical predictors (i.e. demographic, medical history, presenting signs and symptoms and urine dipstick analysis results) most strongly associated with a positive urine culture result. We will then use economic evaluation to compare the cost effectiveness of the candidate prediction rules.
This study will provide novel, clinically important information on the diagnostic features of childhood UTI and the cost effectiveness of a validated prediction rule, to help primary care clinicians improve the efficiency of their diagnostic strategy for UTI in young children.
Urinary Tract Infection; Children; Primary care; Point-of-care-test; Dipstick test; Near-patient testing; Diagnosis; Economic models
Urinary tract infections (UTIs) are a common source of bacterial infection among young febrile children. The diagnosis of UTI is challenging because the clinical presentation is not specific.
To describe clinical predictors to identify young children needing urine culture for evaluation of UTI.
Retrospective cohort study of all children younger than two years of age (719 hospital visits for 545 patients) suspected of having a UTI during a 12-month period. The outcome was UTI, defined as a catheterized urine culture with pure growth of 104 colonies/mL or greater, or suprapubic aspiration culture with 103 colonies/mL or greater. Candidate predictors included demographic, historical and physical examination variables.
The medical records of 545 children younger than two years of age were reviewed. Forty-six per cent were girls. Mean age was 9.1 months (SD 7 months). Four variables were found to predict UTI: absence of another source of fever on examination (odds ratio [OR]=41.6 [95% CI, 8.8 to 197.4]), foul smelling urine (OR=19.7 [95% CI, 5.7 to 68.2]), white blood cell count greater than 15,000/mm3 (OR=4.3 [95% CI, 2.0 to 9.3]), younger than six months old (OR=3.1 [95% CI, 1.3 to 7.1]). The sensitivity of an abnormal urine analysis was 0.77 (95% CI, 0.66 to 0.88) and the specificity was 0.31 (95% CI, 0.2 to 0.42).
An incremental increase in risk for UTI is associated with younger age (younger than six months), having a white blood cell count higher than 15,000/mm3, parental report of malodorous or foul smelling urine and the absence of an alternative source of fever. In the present patient population, obtaining a urine culture from children with at least one of these clinical predictors would have resulted in missing one UTI (2%), and 111 negative cultures (20%) would have been avoided.
Children; Diagnosis; Urinary tract infection
A positive dipstick urinalysis (i.e., leukocyte esterase test and/or nitrite test) did not reliably detect significant bacteriuria in 479 ambulatory women with suspected uncomplicated urinary tract infection; 18.9% of the urine samples that demonstrated significant bacteriuria would have been rejected by the laboratory based on a negative urinalysis screen.
In an ongoing national study of women to identify risk factors for interstitial cystitis/painful bladder syndrome (IC/PBS), dysuria was identified at onset of IC/PBS in a small majority and evidence for urinary tract infection (UTI) was evaluated.
In women with IC/PBS of ≤12 months duration, symptoms and pertinent laboratory tests at onset were assessed by telephone interview and medical record review.
Of 138 cases, 75 (54%) reported that they started to experience burning or pain on urination at onset of IC/PBS. Of those with urines cultured, 12/35 (34%) with dysuria vs. 1/21 (5%) without dysuria yielded a uropathogen (p=.01). Similarly, microscopic WBC and dipstick nitrites and leukocyte esterase were each significantly more common in urines of those with dysuria than those without. Additionally, 7/75 of those with dysuria vs. 1/62 without dysuria reported chills or fever at onset of IC/PBS. Using various definitions, the prevalence of UTI at onset of IC/PBS, at a minimum, was 16 – 33 % of those with dysuria vs. < 2% of those without dysuria (p ≤ .003).
A slight majority of women with IC/PBS reported dysuria at onset of their IC/PBS symptoms. Available laboratory data suggest dysuria may be a sensitive indicator of UTI at onset of IC/PBS; its specificity is as yet undetermined.
interstitial cystitis; painful bladder syndrome; dysuria; burning on urination; bacteriuria; urinary tract infection
Dysuria is a common presenting complaint of women and urinalysis is a valuable tool in the initial evaluation of this
presentation. Clinicians need to be aware that pyuria is the best determinate of bacteriuria requiring therapy and
that values significant for infection differ depending on the method of analysis. A hemocytometer yields a value of
≥ 10 WBC/ mm3
significant for bacteriuria, while manual microscopy studies show ≥ 8 WBC/high-power field
reliably predicts a positive urine culture. In cases of uncomplicated symptomatic urinary tract infection, a positive
value for nitrites and leukocyte esterase by urine dipstick can be treated without the need for a urine culture. Automated
urinalysis used widely in large volume laboratories provides more sensitive detection of leukocytes and
bacteria in the urine.With automated microscopy, a value of > 2 WBC/hpf is significant pyuria indicative of inflammation
of the urinary tract. In complicated cases such as pregnancy, recurrent infection or renal involvement,
further evaluation is necessary including manual microscopy and urine culture with sensitivities.
Semi-quantitative bacteruria counts (s-QBC) are important in the diagnosis of urinary tract infection (UTI) due to most uropathogens. The prognostic value of s-QBC for diagnosis of UTI due to group B streptococcus (GBS) is unknown. In this study, we assessed the value of s-QBC for differentiating acute GBS UTI from asymptomatic bacteruria (ABU), independent of other potential prognostic indicators.
Medical record review and urinalysis (UA) values for 1593 patients who had urinary GBS isolated (103 to ≥105 CFU/ml) during a four-year period were analyzed using binary logistic regression to determine the predictive values of s-QBC, age, and gender for infection category (acute UTI, ABU) based on the clinical diagnosis.
s-QBC alone had a strong predictive value for infection category but only for ABU. Multivariate logistic regression showed similar predictive power of s-QBC for infection category using age as a co-predictor, which was also independently associated with infection category. Typical s-QBC cut-off values that are commonly used in diagnostic settings had no significant power in predicting infection category. Among other UA measures, proteinuria and hematuria were significantly associated with acute infection.
Together, these data show that s-QBC is not useful in the differential diagnosis of GBS UTI. Among the patients in this study, age was an equally effective prognostic indicator compared to s-QBC for identifying high- and low-risk patients for acute GBS UTI. Collectively, these findings indicate that age-based associations may be equally as useful as s-QBC for predicting infection category in the setting of adult patients with GBS-positive urine cultures.
Urinary tract infection; Cystitis; Bacteruria; Streptococcus agalactiae; Asymptomatic bacteruria; Urinalysis; Uropathogen
To validate and implement a computer module for the management of uncomplicated urinary tract infections (UTI).
Women age 18 to 64 years, with a previous UTI, voiding symptoms, and absence of complicating features (comorbidities, vaginal discharge, back pain, emesis, and fever/chills).
The computer module was validated against clinician diagnosis and urine culture. Following validation, the module was implemented in the urgent care clinic as a management option for women with suspected UTI; computer-directed therapy (CDT)-eligible women received antibiotic treatment without a clinician examination. Patient satisfaction with the module and return visits for UTI-related complaints were assessed.
In the validation study, 18 of 68 women (26%) were CDT-eligible. Clinicians diagnosed 17/18 CDT-eligible women with uncomplicated UTI. Sixty-seven percent of CDT-eligible women had a positive urine culture. Since implementation, 162 women have accessed the module, and 35% have received CDT. Ninety-eight percent (95% confidence interval: 95% to 100%) found the program easy to use and 95% (89% to 100%) would recommend it to friends/family. Two (4%) CDT-treated women had a return visit to our institution for a UTI-related illness within 2 weeks.
A computer module accurately identifies women with culture-confirmed, uncomplicated UTIs. Patients are highly satisfied with the module.
urinary tract infection; cystitis; computer-assisted therapy; computer-assisted diagnosis; patient satisfaction
Urinary tract infections (UTIs) are associated with significant morbidity. We rely on clinical presentation, urinalysis, and urine culture to diagnose UTI. To differentiate between lower UTI and pyelonephritis, we depend on the clinical presentation. In the extremes of age and in immunocompromised individuals, clinical presentation is often atypical posing a challenge to diagnosis. In the elderly, the high prevalence of asymptomatic bacteriuria is another confounder. We conducted a search of publications to find novel biomarkers to diagnose UTI and to ascertain its severity. We searched PUBMED, MEDLINE and SCOPUS databases for studies pertaining to novel biomarkers and UTI. Two reviewers independently evaluated the methodology of the studies using the STARD (Standards for Reporting of Diagnostic Accuracy) criteria. We have identified procalcitonin as a biomarker to differentiate lower UTI from pyelonephritis in the pediatric age group. Elevated serum procalcitonin levels can result in early and aggressive treatment at the time of presentation. Interleukin 6 has also shown some promise in differentiating between lower UTI and pyelonephritis but needs further validation. Lastly, given the paucity of data in certain subgroups like diabetics, kidney transplant recipients, and individuals with spinal cord injury, further studies should be conducted in these populations to improve diagnostic criteria that will inform clinical management decisions.
urinary tract infection; novel biomarkers
Objective To assess the effectiveness of antibiotic treatment of women with symptoms of urinary tract infection but negative urine dipstick testing.
Design Prospective, double blind, randomised, placebo controlled trial.
Setting Primary care, among a randomly selected group of general practitioners in Christchurch, New Zealand.
Participants 59 women aged 16-50 years presenting with a history of dysuria and frequency in whom a dipstick test of midstream urine was negative for both nitrites and leucocytes. Participants with complicated urinary tract infection were excluded.
Intervention Trimethoprim 300 mg daily for three days or placebo.
Main outcome measures Self reported diary of symptoms for seven days, recording the presence or absence of individual symptoms each day, followed by a structured telephone questionnaire after seven days. The main clinical outcome was resolution of dysuria at three and seven days and median time to resolution. Secondary outcomes were resolution of other symptoms.
Results The median time for resolution of dysuria was three days for trimethoprim compared with five days for placebo (P = 0.002). At day 3, five (24%) of patients in the treatment group had ongoing dysuria compared with 20 (74%) in the placebo group (P = 0.005). This difference persisted until day 7: two patients (10%) in the treatment group v 11 (41%) in the placebo group; P = 0.02). The number needed to treat was 4. The median duration of constitutional symptoms (feverishness, shivers) was reduced by four days.
Conclusions Although a negative dipstick test for leucocytes and nitrites accurately predicted absence of infection when standard microbiological definitions were used (negative predictive value 92%), it did not predict response to antibiotic treatment. Three days' treatment with trimethoprim significantly reduced dysuria in women whose urine dipstick test was negative. These results support the practice of empirical antibiotic use guided by symptoms. Balancing the competing interests of symptom relief and the minimisation of antibiotic use remains a dilemma—further research is needed to determine clinical predictors of response to antibiotics.
Objective: To maximize effectiveness, clinical decision-support systems must have access to accurate diagnostic and prescribing information. We measured the accuracy of electronic claims diagnoses and electronic antibiotic prescribing for acute respiratory infections (ARIs) and urinary tract infections (UTIs) in primary care.
Design: A retrospective, cross-sectional study of randomly selected visits to nine clinics in the Brigham and Women's Practice-Based Research Network between 2000 and 2003 with a principal claims diagnosis of an ARI or UTI (N = 827).
Measurements: We compared electronic billing diagnoses and electronic antibiotic prescribing to the gold standard of blinded chart review.
Results: Claims-derived, electronic ARI diagnoses had a sensitivity of 98%, specificity of 96%, and positive predictive value of 96%. Claims-derived, electronic UTI diagnoses had a sensitivity of 100%, specificity of 87%, and positive predictive value of 85%. According to the visit note, physicians prescribed antibiotics in 45% of ARI visits and 73% of UTI visits. Electronic antibiotic prescribing had a sensitivity of 43%, specificity of 93%, positive predictive value of 90%, and simple agreement of 64%. The sensitivity of electronic antibiotic prescribing increased over time from 22% in 2000 to 58% in 2003 (p for trend < 0.0001).
Conclusion: Claims-derived, electronic diagnoses for ARIs and UTIs appear accurate. Although closing, a large gap persists between antibiotic prescribing documented in the visit note and the use of electronic antibiotic prescribing. Barriers to electronic antibiotic prescribing in primary care must be addressed to leverage the potential that computerized decision-support systems offer in reducing costs, improving quality, and improving patient safety.
To determine if urinary symptoms or urinary tract infections (UTI) were associated with sexually transmitted infections (STI) and which history, clinical, and laboratory findings could distinguish these infections in symptomatic women.
A cross sectional sample of 296 sexually-active females aged 14–22 attending a hospital-based teen health center or emergency department were recruited. Genitourinary symptoms, medical and sexual history, and urinalysis results were recorded. STI was defined as a vaginal swab positive for Trichomonas vaginalis or urine nucleic acid amplification test positive for Neisseria gonorrheae or Chlamydia trachomatis. A urine culture with >10,000 colonies of a single pathogen was considered a positive UTI.
In the full sample, prevalence of UTI and STI were 17% and 33%, respectively. Neither urinary symptoms nor UTI was significantly associated with STI. Further analyses are reported for the 154 (51%) with urinary symptoms: Positive urine leukocytes, >1 partner in the last 3 months and history of STI predicted STI. Urinalysis results identified four groups: (1)Normal urinalysis – 67% had no infection; (2)Positive nitrites or protein – 55% had UTI; (3)Positive leukocytes or blood – 62% had STI; and (4)Both nitrites/protein and leukocytes/blood positive – 28% had STI and 65% had UTI. Those without a documented UTI were more likely to have trichomoniasis than those with a UTI, and 65% of those with sterile pyuria had STI, mainly trichomoniasis or gonorrhea.
Adolescent females with urinary symptoms should be tested for both UTI and STIs. Urinalysis results may be helpful to direct initial therapy.
Patients with acute stroke are at risk for pneumonia and urinary tract infection (UTI). Identifying stroke patients at high risk for common infections could enhance timely treatment and improve clinical outcomes. We aimed to identify risk factors associated with the occurrence of pneumonia and UTI during stroke hospitalization.
We analyzed the frequency of pneumonia and UTI and their influence on outcomes during hospitalization in patients diagnosed with ischemic stroke in the California Acute Stroke Prototype Registry (CASPR). Generalized estimating equations were used to identify factors and outcomes independently associated with pneumonia and UTI.
Overall, 663 patients were admitted with acute ischemic stroke at 11 hospitals. Pneumonia occurred in 66 (10%), and UTI in 84 (13%). Older age, atrial fibrillation and congestive heart failure were independently associated with greater risk for developing pneumonia, while a history of dementia was associated with lesser risk. Women and patients with a prior history of cerebrovascular events were significantly more likely to experience a UTI. Both pneumonia and UTI were associated with significantly greater length of stay, but only pneumonia was independently associated with higher inpatient mortality and poorer discharge ambulatory status.
Several factors are associated with an increased risk of developing pneumonia and UTI during ischemic stroke hospitalization. Early identification and treatment of these patients may improve clinical outcomes.
Infection; hospitalization; stroke; pneumonia; UTI
There is no evidence surrounding the benefits, effects or clinical outcomes treating asymptomatic urinary tract colonisation. A series of 558 patients undergoing elective admission for orthopaedic surgery were recruited prior to surgery and were screened for urinary tract infection (UTI). Patients had their urine dipstick tested and positive samples were sent for culture and microscopy. Patients with a positive urine culture were treated with antibiotics prior to surgery; 85% of dipsticks tested were positive, while only 7% of the urine samples were culture positive. Over 36% of patients with a pre-operative UTI show some form of post-operative delayed wound healing or confirmed infection versus 16% in the other subgroup giving a relative risk of wound complications of 2:1 (p < 0.02). We have established that patients who present to pre-admission with urinary tract colonisation are a high risk subgroup for wound infection post-operatively.
Urinary tract infections (UTIs) are commonly suspected in residents of long-term care (LTC) facilities, and it has been common practice to prescribe antibiotics to these patients, even when they are asymptomatic. This approach, however, often does more harm than good, leading to increased rates of adverse drug effects and more recurrent infections with drug-resistant bacteria. It also does not improve genitourinary symptoms (eg, polyuria or malodorous urine) or lead to improved mortality rates; thus, distinguishing UTIs from asymptomatic bacteriuria is imperative in the LTC setting. This article provides a comprehensive overview of UTI in the LTC setting, outlining the epidemiology, risk factors and pathophysiology, microbiology, diagnosis, laboratory assessment, and management of symptomatic UTI.
Objective To assess the cost effectiveness of different management strategies for urinary tract infections.
Design Cost effectiveness analysis alongside a randomised controlled trial with a one month follow-up.
Setting Primary care.
Participants 309 non-pregnant adult women aged 18-70 presenting with suspected urinary tract infection.
Interventions Patients were randomised to five basic management approaches: empirical antibiotics, empirical delayed (by 48 hours) antibiotics, or targeted antibiotics based on either a high symptom score (two or more of urine cloudiness, smell, nocturia, dysuria), dipstick results (nitrite or leucocytes and blood), or receipt of a positive result on midstream urine analysis.
Main outcome measure Duration of symptoms and cost of care.
Results Management with targeted antibiotics with midstream urine analysis was more costly over the period of one month. Costs for the midstream urine analysis and dipstick management groups were £37 and £35, respectively; these compared with £31 for immediate antibiotics. Cost effectiveness acceptability curves suggested that if avoiding a day of moderately bad symptoms was valued at less than £10, then immediate antibiotics is likely to be the most cost effective strategy. For values over £10, targeted antibiotics with dipstick testing becomes the most cost effective strategy, though because of the uncertainty we can never be more than 70% certain that this strategy truly is the most cost effective.
Conclusion Dipstick testing with targeted antibiotics is likely to be cost effective if the value of saving a day of moderately bad symptoms is £10 or more, but caution is required given the considerable uncertainty surrounding the estimates.
The results of a study of a screening test for urinary tract infection (UTI) in infants under 18 months is reported. Two hundred and forty three urine specimens were tested in the laboratory using AMES Multistix 8SG reagent strips read by photometer. The strips included three potential markers for urinary tract infection: leucocyte esterase, nitrite, and protein. The predictive value of a positive result (PPV) was low. The predictive value of negative test (NPV) when combining the screen of leucocyte esterase, nitrite, and protein was 99.4% with no difference between boys and girls. The test for leucocyte esterase had a 97.6% negative predictive value. An examination of the results by age confirms the good NPV in all age groups. Paediatricians should find Multistix 8SG strips a useful aid in the diagnosis of urinary tract infection in infants, and that costly culture of samples with negative strip tests can be avoided.
Objective To assess the impact of different management strategies in urinary tract infections.
Design Randomised controlled trial.
Setting Primary care.
Participants 309 non-pregnant women aged 18-70 presenting with suspected urinary tract infection.
Intervention Patients were randomised to five management approaches: empirical antibiotics; empirical delayed (by 48 hours) antibiotics; or targeted antibiotics based on a symptom score (two or more of urine cloudiness, urine smell, nocturia, or dysuria), a dipstick result (nitrite or both leucocytes and blood), or a positive result on midstream urine analysis. Self help advice was controlled in each group.
Main outcome measures Symptom severity (days 2 to 4) and duration, and use of antibiotics.
Results Patients had 3.5 days of moderately bad symptoms if they took antibiotics immediately. There were no significant differences in duration or severity of symptoms (mean frequency of symptoms on a 0 to 6 scale: immediate antibiotics 2.15, midstream urine 2.08, dipstick 1.74, symptom score 1.77, delayed antibiotics 2.11; likelihood ratio test for the five groups P=0.177). There were differences in antibiotic use (immediate antibiotics 97%, midstream urine 81%, dipstick 80%, symptom score 90%, delayed antibiotics 77%; P=0.011) and in sending midstream urine samples (immediate antibiotics 23%, midstream urine 89%, dipstick 36%, symptom score 33%, delayed antibiotics 15%; P<0.001). Patients who waited at least 48 hours to start taking antibiotics reconsulted less (hazard ratio 0.57 (95% confidence interval 0.36 to 0.89), P=0.014) but on average had symptoms for 37% longer than those taking immediate antibiotics (incident rate ratio 1.37 (1.11 to 1.68), P=0.003), particularly the midstream urine group (73% longer, 22% to 140%; none of the other groups had more than 22% longer duration).
Conclusion All management strategies achieve similar symptom control. There is no advantage in routinely sending midstream urine samples for testing, and antibiotics targeted with dipstick tests with a delayed prescription as backup, or empirical delayed prescription, can help to reduce antibiotic use.
Study registration National Research Register N0484094184 ISRCTN: 03525333.
Urinary tract infection (UTI) is the most common bacterial infection in women in general and in postmenopausal women in particular. Two groups of elderly women with recurrent UTI should be differentiated regarding age and general status: healthy, young postmenopausal women aged 50 to 70 years who are neither institutionalized or catheterized and elderly institutionalized women with or without a catheter. Bacteriuria occurs more often in elderly functionally impaired women, but in general it is asymptomatic. However, the risk factors associated with recurrent UTI in elderly women are not widely described. In a multivariate analysis it was found that urinary incontinence, a history of UTI before menopause, and nonsecretor status were strongly associated with recurrent UTI in young postmenopausal women. Another study described the incidence and risk factors of acute cystitis among nondiabetic and diabetic postmenopausal women. Independent predictors of infection included insulin-treated patients and a lifetime history of urinary infection. Borderline associations included a history of vaginal estrogen cream use in the past month, kidney stones, and asymptomatic bacteriuria at baseline. Another important factor in postmenopausal women is the potential role that estrogen deficiency plays in the development of bacteriuria. There are at least two studies showing a beneficial effect of estrogen in the management of recurrent bacteriuria in elderly women. One of these studies showed that vaginal estrogen cream reduced vaginal pH from 5.5±0.7 to 3.6±1.0, restored lactobacillus, and decreased new episodes of UTI. Another study reported similar results using an estriol vaginal ring. However, contradictory results are found in the literature. For example, additional studies found that the use of estriol-containing vaginal pessaries was less effective than oral nitrofurantoin macrocrystals in preventing UTI in postmenopausal women. Two other studies also did not find any benefit in the reduction of UTI by oral estrogen therapy. Unfortunately, the use of estrogen in preventing UTI in postmenopausal women remains questionable. New strategies have been researched for reducing the use of antibiotics in the prevention and treatment of UTI. Two of them are probiotics and cranberry juice or capsules. Although several studies regarding probiotics and cranberry juice or capsules have reported a reduction of episodes of UTI, there is no conclusive evidence that they are useful in the prevention of UTI in postmenopausal women. As for the optimal drug, dosage, and length of treatment for UTI in the elderly, there are no studies comparing these data with the treatment for young women.
Bacteriuria elderly women; Postmenopausal women; Urinary tract infections
The treatment of urinary tract infections (UTIs) continues to evolve as common uropathogens increasingly become resistant to previously active antimicrobial agents. In addition, bacterial isolates, which were once considered to be either colonizers or contaminants, have emerged as true pathogens, likely related to the more complex array of settings where health care is now delivered. Even though the reliability of many antimicrobial agents has become less predictable, the fluoroquinolone group of agents has remained a frequent, if not the most often prescribed, antimicrobial therapy for almost all types of UTIs. Levofloxacin has taken its position at the top of the list as one of the most regularly administered fluoroquinolone agents given to patients with a suspected or proven UTI. The authors review the clinical experience of the use of levofloxacin over the past decade and suggest that the use of levofloxacin for the treatment of UTIs, although still fairly dependable, is perhaps not the best use of this important antimicrobial agent.
fluoroquinolone; antimicrobial agent; UTI; resistance