PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (1000775)

Clipboard (0)
None

Related Articles

1.  Urinalysis and Urinary Tract Infection: Update for Clinicians 
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.
doi:10.1155/S1064744901000412
PMCID: PMC1784655  PMID: 11916184
2.  Urinary Tract Infections in Older Women 
JAMA  2014;311(8):844-854.
IMPORTANCE
Asymptomatic bacteriuria and symptomatic urinary tract infections (UTIs) in older women are commonly encountered in outpatient practice.
OBJECTIVE
To review management of asymptomatic bacteriuria and symptomatic UTI and review prevention of recurrent UTIs in older community-dwelling women.
EVIDENCE REVIEW
A search of Ovid (Medline, PsycINFO, Embase) for English-language human studies conducted among adults aged 65 years and older and published in peer-reviewed journals from 1946 to November 20, 2013.
RESULTS
The clinical spectrum of UTIs ranges from asymptomatic bacteriuria, to symptomatic and recurrent UTIs, to sepsis associated with UTI requiring hospitalization. Recent evidence helps differentiate asymptomatic bacteriuria from symptomatic UTI. Asymptomatic bacteriuria is transient in older women, often resolves without any treatment, and is not associated with morbidity or mortality. The diagnosis of symptomatic UTI is made when a patient has both clinical features and laboratory evidence of a urinary infection. Absent other causes, patients presenting with any 2 of the following meet the clinical diagnostic criteria for symptomatic UTI: fever, worsened urinary urgency or frequency, acute dysuria, suprapubic tenderness, or costovertebral angle pain or tenderness. A positive urine culture (≥105 CFU/mL) with no more than 2 uropathogens and pyuria confirms the diagnosis of UTI. Risk factors for recurrent symptomatic UTI include diabetes, functional disability, recent sexual intercourse, prior history of urogynecologic surgery, urinary retention, and urinary incontinence. Testing for UTI is easily performed in the clinic using dipstick tests. When there is a low pretest probability of UTI, a negative dipstick result for leukocyte esterase and nitrites excludes infection. Antibiotics are selected by identifying the uropathogen, knowing local resistance rates, and considering adverse effect profiles. Chronic suppressive antibiotics for 6 to 12 months and vaginal estrogen therapy effectively reduce symptomatic UTI episodes and should be considered in patients with recurrent UTIs.
CONCLUSIONS AND RELEVANCE
Establishing a diagnosis of symptomatic UTI in older women requires careful clinical evaluation with possible laboratory assessment using urinalysis and urine culture. Asymptomatic bacteriuria should be differentiated from symptomatic UTI. Asymptomatic bacteriuria in older women should not be treated.
doi:10.1001/jama.2014.303
PMCID: PMC4194886  PMID: 24570248
3.  Diagnostic accuracy of rapid urine dipstick test to predict urinary tract infection among pregnant women in Felege Hiwot Referral Hospital, Bahir Dar, North West Ethiopia 
BMC Research Notes  2014;7:481.
Background
Untreated bacteriuria during pregnancy has been shown to be associated with low birth-weight and premature delivery. Therefore, routine screening for bacteriuria is advocated. The decision about how to screen pregnant women for bacteriuria has always been a balance between the cost of screening versus the sensitivity and specificity. This study was designed to evaluate the diagnostic accuracy of the rapid dipstick test to predict urinary tract infection in pregnancy against the gold standard urine culture.
Method
A total of 367 mid stream urine samples were collected, inoculated on MacConkey, Manitol salt agar (MSA) and blood agar and incubated aerobically at 37°C for overnight. Specimens were classified as “positive” for urinary tract infection (UTI) if the growth of the pathogen(s) was at a count ≥ 105 colony-forming units per milliliter (cfu/mL) of urine and classified as “negative” with growth of <105 cfu/mL. Urine samples were tested for the presence of nitrite and leukocyte esterase using dipstick rapid test in accordance to the manufacturer’s instructions.
Results
From the total study participants, 37 pregnant women were symptomatic and the remaining 330 pregnant women were asymptomatic. The sensitivity and specificity of dipstick tests of leukocyte esterase was 50% and 89.1% for pregnant women with asymptomatic UTI(ABU) and 71.4% and 86.7% for symptomatic UTI respectively and for nitrite 35.7% and 98.0% for ABU and 57.1% and 96.7% symptomatic UTI.
Conclusion
This study revealed that the use of dipstick leukocyte esterase and nitrite for screening UTI particularly asymptomatic bacteriuria was associated with many false positive and negative results when it was compared against the gold standard culture method. The low sensitivity and positive predictive value of urine dipstick test proved that culture should be used for the diagnosis of UTI.
doi:10.1186/1756-0500-7-481
PMCID: PMC4118157  PMID: 25073620
Dipstick test; Pregnant women; UTI; Asymptomatic bacteriuria
4.  Validating the prediction of lower urinary tract infection in primary care: sensitivity and specificity of urinary dipsticks and clinical scores in women 
Background
Dipsticks are one of the most commonly used near-patient tests in primary care, but few clinical or dipstick algorithms have been rigorously developed.
Aim
To confirm whether previously documented clinical and dipstick variables and algorithms predict laboratory diagnosis of urinary tract infection (UTI).
Design of study
Validation study.
Setting
Primary care.
Method
A total of 434 adult females with suspected lower UTI had bacteriuria assessed using the European Urinalysis Guidelines.
Results
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.
Conclusion
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.
doi:10.3399/bjgp10X514747
PMCID: PMC2894378  PMID: 20594439
algorithms, clinical scoring; diagnosis, urinary tract infection; primary care; urinalysis
5.  Evaluation of dipstick analysis among elderly residents to detect bacteriuria: a cross-sectional study in 32 nursing homes 
BMC Geriatrics  2009;9:32.
Background
Few studies have evaluated dipstick urinalysis for elderly and practically none present confidence intervals. Furthermore, most previous studies combine all bacteria species in a "positive culture". Thus, their evaluation may be inappropriate due to Yule-Simpson's paradox. The aim of this study was to evaluate diagnostic accuracy of dipstick urinalysis for the elderly in nursing homes.
Methods
In this cross-sectional study voided urine specimens were collected from 651 elderly individuals in nursing homes. Dipstick urinalysis for nitrite, leukocyte esterase and urine culture were performed. Sensitivity, specificity, positive and negative predictive values with 95% confidence intervals were calculated. Visual readings were compared to readings with a urine chemistry analyzer.
Results
207/651 (32%) of urine cultures showed growth of a potentially pathogenic bacterium. Combining the two dipsticks improved test characteristics slightly compared to using only one of the dipsticks. When both dipsticks are negative, presence of potentially pathogenic bacteria can be ruled out with a negative predictive value of 88 (84–92)%. Visual and analyzer readings had acceptable agreement.
Conclusion
When investigating for bacteriuria in elderly people at nursing homes we suggest nitrite and leukocyte esterase dipstick be combined. There are no clinically relevant differences between visual and analyzer dipstick readings. When dipstick urinalysis for nitrite and leukocyte esterase are both negative it is unlikely that the urine culture will show growth of potentially pathogenic bacteria and in a patient with an uncomplicated illness further testing is unnecessary.
doi:10.1186/1471-2318-9-32
PMCID: PMC2724370  PMID: 19635163
6.  The urine dipstick test useful to rule out infections. A meta-analysis of the accuracy 
BMC Urology  2004;4:4.
Background
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.
Methods
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.
Results
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.
Conclusions
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.
doi:10.1186/1471-2490-4-4
PMCID: PMC434513  PMID: 15175113
7.  Diagnostic accuracy of UriSed automated urine microscopic sediment analyzer and dipstick parameters in predicting urine culture test results 
Biochemia Medica  2013;23(2):211-217.
Introduction
Urinary tract infection (UTI) is one of the most common types of infection. Currently, diagnosis is primarily based on microbiologic culture, which is time- and labor-consuming. The aim of this study was to assess the diagnostic accuracy of urinalysis results from UriSed (77 Electronica, Budapest, Hungary), an automated microscopic image-based sediment analyzer, in predicting positive urine cultures.
Materials and methods:
We examined a total of 384 urine specimens from hospitalized patients and outpatients attending our hospital on the same day for urinalysis, dipstick tests and semi-quantitative urine culture. The urinalysis results were compared with those of conventional semi-quantitative urine culture.
Results:
Of 384 urinary specimens, 68 were positive for bacteriuria by culture, and were thus considered true positives. Comparison of these results with those obtained from the UriSed analyzer indicated that the analyzer had a specificity of 91.1%, a sensitivity of 47.0%, a positive predictive value (PPV) of 53.3% (95% confidence interval (CI) = 40.8–65.3), and a negative predictive value (NPV) of 88.8% (95% Cl = 85.0–91.8%). The accuracy was 83.3% when the urine leukocyte parameter was used, 76.8% when bacteriuria analysis of urinary sediment was used, and 85.1% when the bacteriuria and leukocyturia parameters were combined. The presence of nitrite was the best indicator of culture positivity (99.3% specificity) but had a negative likelihood ratio of 0.7, indicating that it was not a reliable clinical test.
Conclusions:
Although the specificity of the UriSed analyzer was within acceptable limits, the sensitivity value was low. Thus, UriSed urinalysis results do not accurately predict the outcome of culture.
doi:10.11613/BM.2013.025
PMCID: PMC3900068  PMID: 23894867
urinalysis; bacteriuria; sensitivity; specificity; urinary tract infection
8.  Urinary ATP and visualization of intracellular bacteria: a superior diagnostic marker for recurrent UTI in renal transplant recipients? 
SpringerPlus  2014;3:200.
Renal transplant recipients (RTR) are highly susceptible to urinary tract infections (UTIs) with over 50% of patients having at least one UTI within the first year. Yet it is generally acknowledged that there is considerable insensitivity and inaccuracy in routine urinalysis when screening for UTIs. Thus a large number of transplant patients with genuine urine infections may go undiagnosed and develop chronic recalcitrant infections, which can be associated with graft loss and morbidity. Given a recent study demonstrating ATP is released by urothelial cells in response to bacteria exposure, possibly acting at metabotropic P2Y receptors mediating a proinflammatory response, we have investigated alternative, and possibly more appropriate, urinalysis techniques in a cohort of RTRs.
Mid-stream urine (MSU) samples were collected from 53 outpatient RTRs. Conventional leukocyte esterase and nitrite dipstick tests, and microscopic pyuria counts (in 1 μl), ATP concentration measurements, and identification of intracellular bacteria in shed urothelial cells, were performed on fresh unspun samples and compared to ‘gold-standard’ bacterial culture results.
Of the 53 RTRs, 22% were deemed to have a UTI by ‘gold-standard’ conventional bacteria culture, whereas 87%, 8% and 4% showed evidence of UTIs according to leukocyte esterase dipstick, nitrite dipstick, and a combination of both dipsticks, respectively. Intracellular bacteria were visualized in shed urothelial cells of 44% of RTRs, however only 1 of the 23 RTRs (44%) was deemed to have a UTI by conventional bacteria culture. A significant association of the ‘gold-standard’ test with urinary ATP concentration combined with visualization of intracellular bacteria in shed urothelial cells was determined using the Fisher’s exact test.
It is apparent that standard bedside tests for UTIs give variable results and that seemingly quiescent bacteria in urothelial cells are very common in RTRs and may represent a focus of subclinical infection. Furthermore, our results suggest urinary ATP concentration combined with detection of intracellular bacteria in shed urinary epithelial cells may be a sensitive means by which to detect ‘occult’ infection in RTRs.
doi:10.1186/2193-1801-3-200
PMCID: PMC4022969  PMID: 24839587
Intracellular bacteria; IBC; Pyuria; Urinary ATP; Bladder; Acridine orange stain
9.  Developing clinical rules to predict urinary tract infection in primary care settings: sensitivity and specificity of near patient tests (dipsticks) and clinical scores 
Background
Suspected urinary tract infection (UTI) is one of the most common presentations in primary care. Systematic reviews have not documented any adequately powered studies in primary care that assess independent predictors of laboratory diagnosis.
Aim
To estimate independent clinical and dipstick predictors of infection and to develop clinical decision rules.
Design of study
Validation study of clinical and dipstick findings compared with laboratory testing.
Setting
General practices in the south of England.
Method
Laboratory diagnosis of 427 women with suspected UTI was assessed using European urinalysis guidelines. Independent clinical and dipstick predictors of diagnosis were estimated.
Results
UTI was confirmed in 62.5% of women with suspected UTI. Only nitrite, leucocyte esterase (+ or greater), and blood (haemolysed trace or greater) independently predicted diagnosis (adjusted odds ratios 6.36, 4.52, 2.23 respectively). A dipstick decision rule, based on having nitrite, or both leucocytes and blood, was moderately sensitive (77%) and specific (70%); positive predictive value (PPV) was 81% and negative predictive value (NPV) was 65%. Predictive values were improved by varying the cut-off point: NPV was 73% for all three dipstick results being negative, and PPV was 92% for having nitrite and either blood or leucocyte esterase. A clinical decision rule, based on having two of the following: urine cloudiness, offensive smell, and dysuria and/or nocturia of moderate severity, was less sensitive (65%) (specificity 69%; PPV 77%, NPV 54%). NPV was 71% for none of the four clinical features, and the PPV was 84% for three or more features.
Conclusions
Simple decision rules could improve targeting of investigation and treatment. Strategies to use such rules need to take into account limited negative predictive value, which is lower than expected from previous research.
PMCID: PMC1874525  PMID: 16882379
clinical scoring algorithms; diagnosis, urinary tract infection; dipsticks
10.  Leukocyte counts in urine reflect the risk of concomitant sepsis in bacteriuric infants: A retrospective cohort study 
BMC Pediatrics  2007;7:24.
Background
When urine infections are missed in febrile young infants with normal urinalysis, clinicians may worry about the risk – hitherto unverified – of concomitant invasion of blood and cerebrospinal fluid by uropathogens. In this study, we determine the extent of this risk.
Methods
In a retrospective cohort study of febrile 0–89 day old infants evaluated for sepsis in an urban academic pediatric emergency department (1993–1999), we estimated rates of bacteriuric sepsis (urinary tract infections complicated by sepsis) after stratifying infants by urine leukocyte counts higher, or lower than 10 cells/hpf. We compared the global accuracy of leukocytes in urine, leukocytes in peripheral blood, body temperature, and age for predicting bacteruric sepsis. The global accuracy of each test was estimated by calculating the area under its receiver operating characteristic curve (AUC). Chi-square and Fisher exact tests compared count data. Medians for data not normally distributed were compared by the Kruskal-Wallis test.
Results
Two thousand two hundred forty-nine young infants had a normal screening dipstick. None of these developed bacteremia or meningitis despite positive urine culture in 41 (1.8%). Of 1516 additional urine specimens sent for formal urinalysis, 1279 had 0–9 leukocytes/hpf. Urine pathogens were isolated less commonly (6% vs. 76%) and at lower concentrations in infants with few, compared to many urine leukocytes. Urine leukocytes (AUC: 0.94) were the most accurate predictors of bacteruric sepsis. Infants with urinary leukocytes < 10 cells/hpf were significantly less likely (0%; CI:0–0.3%) than those with higher leukocyte counts (5%; CI:2.6–8.7%) to have urinary tract infections complicated by bacteremia (N = 11) or bacterial meningitis (N = 1) – relative risk, 0 (CI:0–0.06) [RR, 0 (CI: 0–0.02), when including infants with negative dipstick]. Bands in peripheral blood had modest value for detecting bacteriuric sepsis (AUC: 0.78). Cases of sepsis without concomitant bacteriuria were comparatively rare (0.8%) and equally common in febrile young infants with low and high concentrations of urine leukocytes.
Conclusion
In young infants evaluated for fever, leukocytes in urine reflect the likelihood of bacteriuric sepsis. Infants with urinary tract infections missed because of few leukocytes in urine are at relatively low risk of invasive bacterial sepsis by pathogens isolated from urine.
doi:10.1186/1471-2431-7-24
PMCID: PMC1906775  PMID: 17567901
11.  Rapid tests and urine sampling techniques for the diagnosis of urinary tract infection (UTI) in children under five years: a systematic review 
BMC Pediatrics  2005;5:4.
Background
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.
Methods
We conducted a systematic review to determine the diagnostic accuracy of rapid tests for detecting UTI in children under five years of age.
Results
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.
Conclusion
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.
doi:10.1186/1471-2431-5-4
PMCID: PMC1084351  PMID: 15811182
12.  Interleukin-6 concentrations in the urine and dipstick analyses were related to bacteriuria but not symptoms in the elderly: a cross sectional study of 421 nursing home residents 
BMC Geriatrics  2014;14:88.
Background
Up to half the residents of nursing homes for the elderly have asymptomatic bacteriuria (ABU), which should not be treated with antibiotics. A complementary test to discriminate between symptomatic urinary tract infections (UTI) and ABU is needed, as diagnostic uncertainty is likely to generate significant antibiotic overtreatment. Previous studies indicate that Interleukin-6 (IL-6) in the urine might be suitable as such a test. The aim of this study was to investigate the association between laboratory findings of bacteriuria, IL-6 in the urine, dipstick urinalysis and newly onset symptoms among residents of nursing homes.
Methods
In this cross sectional study, voided urine specimens for culture, urine dipstick and IL-6 analyses were collected from all residents capable of providing a voided urine sample, regardless of the presence of symptoms. Urine specimens and symptom forms were provided from 421 residents of 22 nursing homes. The following new or increased nonspecific symptoms occurring during the previous month were registered; fatigue, restlessness, confusion, aggressiveness, loss of appetite, frequent falls and not being herself/himself, as well as symptoms from the urinary tract; dysuria, urinary urgency and frequency.
Results
Recent onset of nonspecific symptoms was common among elderly residents of nursing homes (85/421). Urine cultures were positive in 32% (135/421), Escherichia coli was by far the most common bacterial finding. Residents without nonspecific symptoms had positive urine cultures as often as those with nonspecific symptoms with a duration of up to one month. Residents with positive urine cultures had higher concentrations of IL-6 in the urine (p < 0.001). However, among residents with positive urine cultures there were no differences in IL-6 concentrations or dipstick findings between those with or without nonspecific symptoms.
Conclusions
Nonspecific symptoms among elderly residents of nursing homes are unlikely to be caused by bacteria in the urine. This study could not establish any clinical value of using dipstick urinalysis or IL-6 in the urine to verify if bacteriuria was linked to nonspecific symptoms.
doi:10.1186/1471-2318-14-88
PMCID: PMC4137105  PMID: 25117748
Interleukin-6; Urinary tract infections; Bacteriuria; Homes for the aged; Nursing homes; Dipstick urinalysis; Diagnostic tests
13.  A Comparative Study of the Triphenyltetrazolium Chloride (Uroscreen) Test and Conventional Methods for the Detection of Bacteriuria 
Canadian Medical Association Journal  1965;92(22):1161-1165.
Acute urinary tract infection may be preceded by and active pyelonephritis may be associated with asymptomatic bacteriuria. Treatment of asymptomatic bacteriuria may prevent or arrest active, chronic pyelonephritis and its sequelae. Consequently, there is a need for a reliable and simple screening procedure to detect asymptomatic bacteriuria in large segments of the population.
The reliability and practicability of tests advocated for the detection of bacteriuria, including the new chemical triphenyltetrazolium chloride (T.T.C.) (Uroscreen) test, were evaluated. Reliability was assessed by correlating results of these tests with bacterial counts of tested urines. Significant bacteriuria is defined as the presence of 100,000 or more organisms per ml. of urine.
The T.T.C. (Uroscreen) test was positive in 92.5% of cases of bacteriuria; there were 7.5% false-negative and 2.8% false-positive results. Bacteria on Gram-stained smear were found in 95.5% of the cases of bacteriuria and in 14.6% of those with non-infected urine; pyuria (more than three leukocytes per high-power field), in 60% of those with bacteriuria and in 15.9% of those with presumably non-infected urine. Bacteria were conspicuous in the urinary sediment in 91.1% of cases of bacteriuria and in 3.7% of presumably non-infected urines.
The T.T.C. (Uroscreen) test fulfilled the criteria for a reliable and simple screening procedure. It should be used concomitantly with other screening tests when the urine is examined routinely.
PMCID: PMC1928330  PMID: 14285304
14.  Bacteriuria amongst Pregnant Women in the Buea Health District, Cameroon: Prevalence, Predictors, Antibiotic Susceptibility Patterns and Diagnosis 
PLoS ONE  2013;8(8):e71086.
Background
Bacteriuria is associated with significant maternal and foetal risks. However, its prevalence is not known in our community.
Objectives
This study was carried out to determine the prevalence and predictors of bacteriuria in pregnant women of the Buea Health District (BHD) as well as the antibiotic sensitivity patterns of bacterial isolates. It also sought to determine the diagnostic performance of the nitrite and leucocyte esterase tests in detecting bacteriuria in these women.
Methods
An observational analytic cross-sectional study was carried out amongst pregnant women attending selected antenatal care centres in Buea. We recruited 102 consenting pregnant women for the study. Demographic and clinical data were collected using structured questionnaires. Clean catch midstream urine was collected from each participant in sterile leak proof containers. Samples were examined biochemically, microscopically and by culture. Significant bacteriuria was defined as the presence of ≥108 bacteria/L of cultured urine. Identification and susceptibility of isolates was performed using API 20E and ATB UR EU (08) (BioMerieux, Marcy l'Etoile, France).
Results
Significant bacteriuria was found in the urine of 24 of the 102 women tested giving a bacteriuria prevalence of 23.5% in pregnant women of the BHD. Asymptomatic bacteriuria was detected in 8(7.8%) of the women. There was no statistically significant predictor of bacteriuria. Escherichia coli were the most isolated (33%) uropathogens and were 100% sensitive to cefixime, cefoxitin and cephalothin. The nitrite and leucocyte esterase tests for determining bacteriuria had sensitivities of 8%, 20.8% and specificities of 98.7% and 80.8% respectively.
Conclusion
Bacteriuria is frequent in pregnant women in the BHD suggesting the need for routine screening by urine culture. Empiric treatment with cefixime should be instituted until results of urine culture and sensitivity are available. Nitrite and leucocyte esterase tests were not sensitive enough to replace urine culture as screening tests.
doi:10.1371/journal.pone.0071086
PMCID: PMC3745459  PMID: 23976983
15.  Evaluation of the Nitrite Test in Screening for Urinary Tract Infection in Febrile Children with Sickle Cell Anaemia in Maiduguri- Nigeria 
Background:
Urinary tract infection is a significant cause of morbidity in children with sickle cell anaemia (SCA). Individuals with SCA have increased risk of urinary tract infection (UTI). Facilities for urine culture may not be available in most rural and even some urban areas in most developing countries like Nigeria. It will therefore be useful to have a simple means of screening such children for UTI with the intent of prompt treatment.
Materials and Methods:
The study will evaluate the usefulness of the nitrite test in detecting UTI in febrile SCA children. This study was carried out in the Department of Paediatrics University of Maiduguri Teaching Hospital and State Specialist Hospital Maiduguri.
Results:
The study consisted of 250 children aged 6 months to 15 years with SCA presenting with fever (temperature ≥ 37. 5°C). Midstream urine specimen was collected from older children and suprapubic bladder aspiration of urine specimen was collected from infants. Samples were subjected to nitrite test, culture and sensitivity.
There was significant bacteriuria in 65 (26+) children with SCA. A positive test for nitrite was obtained in 43 of the 65 (66.2+) children. The nitrite test has a specificity of 93.5+ in detecting bacteriuria, a sensitivity of 66.2+, a positive predictive value of 78.2+ and a negative predictive value of 93.5+. A positive nitrite test was significantly associated with bacteriuria, while a negative test was also significantly associated with an absence of bacteriuria.
Conclusions:
From this study, the nitrite test is useful as a screening test for UTI in SCA children. However in sick children with SCA, microscopy, culture and sensitivity should still be done in spite of a negative nitrite test.
PMCID: PMC3180749  PMID: 21968796
Nitrite; Screening; Urinary tract infection
16.  Leukocyte esterase-nitrite and bioluminescence assays as urine screens. 
Journal of Clinical Microbiology  1985;22(4):531-534.
The 1-min leukocyte esterase (LE)-nitrite test (Chemstrip 9; Biodynamics, Division of Boehringer Mannheim Biochemicals, Indianapolis, Ind.) and a bioluminescence assay (Monolight centrifugation method; Analytical Luminescence Laboratory, Inc., San Diego, Calif.) were tested for their efficacy as urine screens among 453 patients at a tertiary-care teaching hospital. Both methods had the capacity to exclude significant bacteriuria (greater than or equal to 10(5) CFU/ml) when compared with the results of conventional culture methods, with predictive values of 99 and 93%, respectively, for a negative test. Bioluminescence was the more accurate nonculture method used. Sensitivity and specificity values were 97 and 71%, respectively, for bioluminescence, 82 and 60%, respectively, for LE with nitrite, and 72 and 64%, respectively, for LE without nitrite. At reduced levels of bacteriuria less than 10(5) CFU/ml), the sensitivities of LE-nitrite and bioluminescence were decreased but comparable. The addition of protein and blood test results in the Chemstrip 9, along with LE-nitrite as bacteriuria indicators, were unsatisfactory because of the large numbers of false-positive results attributed to protein and blood determinations. LE activity as detected by the LE test was a poor predictor of significant bacteriuria in both male and female patients. The sensitivity (71%) and specificity (57%) of the LE test in male patients were significantly lower than those previously reported and varied with the patient population studied.
PMCID: PMC268461  PMID: 3935662
17.  Optimum Methadone Compliance Testing 
Executive Summary
Objective
The objective of this analysis was to determine the diagnostic utility of oral fluid testing collected with the Intercept oral fluid collection device.
Clinical Need: Target Population and Condition
Opioids (opiates or narcotics) are a class of drugs derived from the opium poppy plant that typically relieve pain and produce a euphoric feeling. Methadone is a long-acting synthetic opioid used to treat opioid dependence and chronic pain. It prevents symptoms of opioid withdrawal, reduces opioid cravings and blocks the euphoric effects of short-acting opioids such as heroin and morphine. Opioid dependence is associated with harms including an increased risk of exposure to Human Immunodeficiency Virus and Hepatitis C as well as other health, social and psychological crises. The goal of methadone treatment is harm reduction. Treatment with methadone for opioid dependence is often a long-term therapy. The Ontario College of Physicians and Surgeons estimates that there are currently 250 physicians qualified to prescribe methadone, and 15,500 people in methadone maintenance programs across Ontario.
Drug testing is a clinical tool whose purpose is to provide objective meaningful information, which will reinforce positive behavioral changes in patients and guide further treatment needs. Such information includes knowledge of whether the patient is taking their methadone as prescribed and reducing or abstaining from using opioid and other drugs of abuse use. The results of drug testing can be used with behavior modification techniques (contingency management techniques) where positive reinforcements such as increased methadone take-home privileges, sustained employment or parole are granted for drug screens negative for opioid use, and negative reinforcement including loss of these privileges for drug screens positive for opioid used.
Body fluids including blood, oral fluid, often referred to as saliva, and urine may contain metabolites and the parent drug of both methadone and drugs of abuse and provide a means for drug testing. Compared with blood which has a widow of detection of several hours, urine has a wider window of detection, approximately 1 to 3 days, and is therefore considered more useful than blood for drug testing. Because of this, and the fact that obtaining a urine specimen is relatively easy, urine drug screening is considered the criterion measure (gold standard) for methadone maintenance monitoring. However, 2 main concerns exist with urine specimens: the possibility of sample tampering by the patient and the necessity for observed urine collection. Urine specimens may be tampered with in 3 ways: dilution, adulteration (contamination) with chemicals, and substitution (patient submits another persons urine specimen). To circumvent sample tampering the supervised collection of urine specimens is a common and recommended practice. However, it has been suggested that this practice may have negative effects including humiliation experienced by patient and staff, and may discourage patients from staying in treatment. Supervised urine specimen collection may also present an operational problem as staff must be available to provide same-sex supervision. Oral fluid testing has been proposed as a replacement for urine because it can be collected easily under direct supervision without infringement of privacy and reduces the likelihood of sample tampering. Generally, the results of oral fluid drug testing are similar to urine drug testing but there are some differences, such as lower concentrations of substances in oral fluid than urine, and some drugs remain detectable for longer periods of time in urine than oral fluid.
The Technology Being Reviewed
The Intercept Oral Specimen Collection Device (Ora-Sure Technologies, Bethlehem, PA) consists of an absorbent pad mounted on a plastic stick. The pad is coated with common salts. The absorbent pad is inserted into the mouth and placed between the cheek and gums for 3 minutes on average. The pad absorbs the oral fluid. After 3 minutes (range 2min-5 min) the collection device is removed from the mouth and the absorbent pad is placed in a small vial which contains 0.8mL of pH-balanced preservative, for transportation to a laboratory for analysis. It is recommended that the person undergoing oral fluid drug testing have nothing to eat or drink for a 10- minute period before the oral fluid specimen is collected. This will remove opportunity for adulteration. Likewise, it is recommended that the person be observed for the duration of the collection period to prevent adulteration of the specimen. An average of 0.4 mL of saliva can be collected. The specimen may be stored at 4C to 37C and tested within 21 days of collection (or within 6 weeks if frozen).
The oral fluid specimen must be analyzed in a laboratory setting. There is no point-of-care (POC) oral fluid test kit for drugs of abuse (other than for alcohol). In the laboratory the oral fluid is extracted from the vial after centrifugation and a screening test is completed to eliminate negative specimens. Similar to urinalysis, oral fluid specimens are analyzed first by enzyme immunoassay with positive specimens sent for confirmatory testing. Comparable cut-off values to urinalysis by enzyme immunoassay have been developed for oral fluids
Review Strategy
 
Research Question
What is the diagnostic utility of the Intercept oral specimen device?
Inclusion criteria:
Studies evaluating paired urine and oral fluid specimens from the same individual with the Intercept oral fluid collection device.
The population studied includes drug users.
Exclusion criteria:
Studies testing for marijuana (THC) only.
Outcomes:
Sensitivity and Specificity of oral fluid testing compared to urinalysis for methadone (methadone metabolite), opiates, cocaine, benzodiazepines, and alcohol.
Quality of the Body of Evidence
The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to evaluate the overall quality of the body of evidence (defined as 1 or more studies) supporting the research questions explored in this systematic review. A description of the GRADE system is reported in Appendix 1.
Summary of Findings
A total of 854 potential citations were retrieved. After reviewing titles and abstracts, 2 met the inclusion and exclusion criteria. Two other relevant studies were found after corresponding with the author of the 2 studies retrieved from the literature search. Therefore a total of 4 published studies are included in this analysis. All 4 studies carried out by the same investigator meet the definition of Medical Advisory Secretariat level III (not a-randomized controlled trial with contemporaneous controls) study design. In each of the studies, paired urine and oral fluid specimens where obtained from drug users. Urine collection was not observed in the studies however, laboratory tests for pH and creatinine were used to determine the reliability of the specimen. Urine specimens thought to be diluted and unreliable were removed from the evaluation. Urinalysis was used as the criterion measurement for which to determine the sensitivity and specificity of oral fluid testing by the Intercept oral fluid device for opiates, benzodiazepines, cocaine and marijuana. Alcohol was not tested in any of the 4 studies. From these 4 studies, the following conclusions were drawn:
The evidence indicates that oral fluid testing with the Intercept oral fluid device has better specificity than sensitivity for opiates, benzodiazepines, cocaine and marijuana.
The sensitivity of oral fluids testing with the Intercept oral fluid device seems to be from best to worst: cocaine > benzodiazepines >opiates> marijuana.
The sensitivity and specificity for opiates of the Intercept oral fluid device ranges from 75 to 90% and 97- 100% respectively.
The consequences of opiate false-negatives by oral fluid testing with the Intercept oral fluid device need to be weighed against the disadvantages of urine testing, including invasion of privacy issues and adulteration and substitution of the urine specimen.
The window of detection is narrower for oral fluid drug testing than urinalysis and because of this oral fluid testing may best be applied in situations where there is suspected frequent drug use. When drug use is thought to be less frequent or remote, urinalysis may offer a wider (24-48 hours more than oral fluids) window of detection.
The narrow window of detection for oral fluid testing may mean more frequent testing is needed compared to urinalysis. This may increase the expense for drug testing in general.
POC oral fluid testing is not yet available and may limit the practical utility of this drug testing methodology. POC urinalysis by immunoassay is available.
The possible applications of oral fluid testing may include:
Because of its narrow window of detection compared to urinalysis oral fluid testing may best be used during periods of suspected frequent or recent drug use (within 24 hours of drug testing). This is not to say that oral fluid testing is superior to urinalysis during these time periods.
In situations where an observed urine specimen is difficult to obtain. This may include persons with “shy bladder syndrome” or with other urinary conditions limiting their ability to provide an observed urine specimen.
When the health of the patient would make urine testing unreliable (e,g., renal disease)
As an alternative drug testing method when urine specimen tampering practices are suspected to be affecting the reliability of the urinalysis test.
Possible limiting Factors to Diffusion of Oral Fluid Technology
No oral fluid POC test equivalent to onsite urine dips or POC analyzer reducing immediacy of results for patient care.
Currently, physicians get reimbursed directly for POC urinalysis. Oral fluid must be analyzed in a lab setting removing physician reimbursement, which is a source of program funding for many methadone clinics.
Small amount of oral fluid specimen obtained; repeat testing on same sample will be difficult.
Reliability of positive oral fluid methadone (parent drug) results may decrease because of possible contamination of oral cavity after ingestion of dose. Therefore high methadone levels may not be indicative of compliance with treatment. Oral fluid does not as yet test for methadone metabolite.
There currently is no licensed provincial laboratory that analyses oral fluid specimens.
Abbreviations
2-ethylidene- 1,5-dimethyl-3,3-diphenylpyrrolidine
enzyme immunoassay
Enzyme Linked Immunosorbent Assay (ELISA),
Enzyme Multiplied Immunoassay Test (EMIT)
Gas chromatography
gas chromatography/mass spectrometry
High-performance liquid chromatography
Limit of Detection
Mass spectrometry
Methadone Maintenance Treatment
Oral fluid testing
Phencyclidine
Point of Care Testing
tetrahydrocannabinol
11-nor-delta-9-tetrhydrocannabinol-9-carboxylic acid
urine drug testing
PMCID: PMC3379523  PMID: 23074492
18.  Home screening for bacteriuria in children with spina bifida and clean intermittent catheterization 
BMC Infectious Diseases  2012;12:264.
Background
Significant bacteriuria (SBU) and urinary tract infections (UTIs) are common in patients with spina bifida and neuropathic detrusor sphincter dysfunction. Laboratory agar plated culture is the gold standard to establish SBU. It has the disadvantage of diagnostic and subsequent therapeutic delay. Leukocyte esterase tests (LETs) and dip slides proved to be useful in the general populations to exclude SBU and UTI. The aim of this study was to evaluate the reliability of LET and dip slide in children with spina bifida without symptoms of UTI. The reliability in children with asymptomatic SBU was not studied before.
Methods
In one hundred and twelve children with spina bifida on clean intermittent catheterization LETs and dip slides were compared with laboratory cultures. Both tests and agar plated cultures were performed on catheterized urine samples. The hypothesis was that the home tests are as accurate as laboratory cultures.
Results
A SBU was found in 45 (40%) of the 112 laboratory cultures. A negative LET excluded SBU (negative predictive value 96%), while a positive LET had a positive predictive value of 72%. The false positive rate was 28%. Dip slide determination of bacterial growth had no added value, other than serving as transport medium.
Conclusions
In spina bifida children, leukocyte esterase testing can be used to exclude significant bacteriuria at home, while dip slide tests have no added value to diagnose or exclude significant bacteriuria.
doi:10.1186/1471-2334-12-264
PMCID: PMC3507913  PMID: 23082909
Bacteriuria; Clean intermittent catheterization; Dip slide; Home testing; Leukocyte esterase test; Spina bifda
19.  Evaluation of reagent strips in detecting asymptomatic bacteriuria in early pregnancy: prospective case series. 
BMJ : British Medical Journal  1998;316(7129):435-437.
OBJECTIVE: To evaluate the performance of reagent test strips in screening pregnant women for asymptomatic bacteriuria at their first visit to an antenatal clinic. DESIGN: Prospective case series. SETTING: Antenatal clinic of a large inner city maternity hospital. SUBJECTS: All women attending for their first antenatal clinic. Patients taking antibiotics for any reason and those with urinary tract symptoms were excluded. INTERVENTION: A midstream urine specimen was divided; half was sent for microscopy and formal bacteriological culture and the other half was tested with a commercial reagent strip test for the presence of blood, protein, nitrite, and leucocyte esterase. MAIN OUTCOME MEASURES: Sensitivity, specificity, and positive and negative predictive values of the reagent strips in diagnosing asymptomatic bacteriuria (defined as 10(5) colony forming units/ml urine). RESULTS: Sensitivity was low, with a maximum of 33% when all four tests were used in combination. Specificity was high, with typical values of 99% or more. Positive predictive value reached a maximum of 69% and negative predictive value was typically 95% or more. CONCLUSION: Urine reagent strips are not sufficiently sensitive to be of use in the screening for asymptomatic bacteriuria and therefore many patients would be missed. In view of the potentially serious sequelae of this condition in pregnant women we recommend that formal bacteriological investigation remain the investigation of choice in this group of patients.
PMCID: PMC2665586  PMID: 9492667
20.  Randomised controlled trial of nitrofurantoin versus placebo in the treatment of uncomplicated urinary tract infection in adult women. 
BACKGROUND: Urinary tract infections (UTIs) are very common and have been treated with apparent success with antimicrobials for many years. However, there is a paucity of placebo-controlled clinical trials. AIM: To measure the symptomatic and bacteriological short-term effect of nitrofurantoin treatment versus placebo, in the treatment of uncomplicated UTI in adult non-pregnant women. DESIGN OF STUDY: Randomised placebo-controlled trial in general practice. SETTING: Non-pregnant women, aged between 15 and 54 years old, consulting a general practitioner for symtoms suggestive of uncomplicated lower UTI and with pyuria (positive for leucocyte esterase test). METHOD: A dipslide was inoculated in first-void midstream urine and sent for examinion. The patients were randomised to receive nitrofurantoin 100 mg or placebo four times daily for three days. After three, seven, and 14 days a new dipslide was inoculated and symptoms of UTI were checked or improvement of symptoms and bacteriuria. RESULTS: Of 166 women consulting with symptoms suggestive for UTI, 78 had pyuia and agreed to participate in the study (the clinically suspected UTI group); of these, 40 received nitrofurantoin and 38 received placebo. The result for combined symptomatic improvement and cure after three days was 27/35 in the nitrofurantoin group and 19/35 in the placebo group (c2 with Yates' correction P = 0.008; number needed to treat [NNT] = 4.4, 95% confidence interval [CI] = 2.3 to 79). After seven days, combined improvement and cure was observed in 30/34 and 17/33 respectively (P = 0.003, NNT = 2.7, 95% CI = 1.8 to 6.0). At inclusion, 56 women had bacteriuria of > or = 10(5) CFU/ml (the bacteriologically proven UTI group). Of these, 29 received nitrofurantoin and 27 received placebo. After three days the bacteriological cure was 21/26 in the treatment group, compared with 5/25 in the placebo group (P < 0.001; NNT = 1.6, 95% CI= 1.2 to 2.6). After seven days the bacteriological cure rate was 17/23 in the intervention group and 9/22 in the placebo group (P = 0.05, NNT = 3, 95% CI = 1.7 to 17). CONCLUSION: In women with bacteriologically proven UTI, nitrofurantoin was significantly more effective than placebo in achieving bacteriological cure and symptomatic relief in just three days; this was still present after seven days. In patients with clinically suspected UTI the symptomatic effect was statistically significant after
PMCID: PMC1314413  PMID: 12236276
21.  Use of urinary gram stain for detection of urinary tract infection in childhood. 
In this study, urinary culture, urinary Gram stain, and four tests within the urinalysis, leukocyte esterase, nitrite, microscopyfor bacteria, and microscopyforpyuria, were examined in 100 children with symptoms suggesting urinary tract infection. Our purpose was to determine the validity of the urinary Gram stain compared with a combination of pyuria plus Gram stain and overall urinalysis (positiveness of nitrite, leukocyte esterase, microscopy for bacteria, or microscopy for white blood cell). Of 100 children, aged two days to 15 years, 70 (70 percent) had a positive urinary culture: 40 girls (57 percent) and 30 boys (43 percent). Escherichia coli was the most common isolated agent. The sensitivity and specificity of the urinary Gram stain were 80 percent and 83 percent, and that of the combination of pyuria plus Gram stain 42 percent and 90 percent, and that of the overall urinalysis 74 percent and 3.5 percent respectively. Our findings revealed that neither method of urine screen should substitute for a urine culture in the symptomatic patients in childhood.
PMCID: PMC2588732  PMID: 12230312
22.  Disappointing dipstick screening for urinary tract infection in hospital inpatients. 
Journal of Clinical Pathology  1998;51(6):471-472.
AIM: To compare the performance of leucocyte esterase and nitrite dipstick tests with microscopic examination and culture of first morning urines (n = 420) of hospital inpatients. RESULTS: The sensitivity, specificity, and negative predictive value of the leucocyte esterase test for the cutoff of > 10 WBC/microliter were 57%, 94%, and 68%, respectively. For > 5 WBC per high power field (HPF) these variables were 84%, 90%, and 93%. For > 10(5) colony counts/ml, the sensitivity of the nitrite test was 27%, specificity 94%, and negative predictive value 87%. When either leucocyte esterase or nitrite positivity was accepted as a marker of urinary tract infection, the sensitivity was 78%, specificity 75%, and negative predictive value 94%, and there were 22% false negative results. Semiquantitative microscopic estimation of bacteria per HPF yielded 40% false positives. CONCLUSIONS: Leucocyte esterase and nitrite dipstick tests are not suitable for screening for urinary tract infections.
PMCID: PMC500752  PMID: 9771448
23.  Can the Griess Nitrite Test and a Urinary Pus Cell Count of ≥5 Cells Per Micro Litre of Urine in Pregnant Women be Used for the Screening or the Early Detection of Urinary Tract Infections in Rural India? 
Objectives
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.
Method
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.
Results
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.
Conclusion
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.
doi:10.7860/JCDR/2012/4565.2547
PMCID: PMC3527784  PMID: 23285444
UTI; Pregnancy; Rural; Urine Culture; Griess Nitrite test; Screening tests; Urinary Pus cell Test
24.  Validation of a method for the rapid diagnosis of urinary tract infection suitable for use in general practice. 
A combination of reagent strip testing and examining urine appearance can be used to screen out noninfected cases before urine specimens are sent to the laboratory. A validation of this method was carried out in a microbiology laboratory using 970 specimens received over a three-week period. When the tests for nitrite, blood and protein on N-Multistix reagent strips (Ames) were all negative in a clear urine then the predictive value for the absence of bacteriuria was 98.5%. Positive strip tests in a turbid urine detected 80.1% of infections. On the basis of these findings it is recommended that general practitioners test the urine samples of all patients with suspected urinary tract infections by this method and only send to the laboratory those specimens with positive findings. Using this method the routine laboratory workload involved in testing urine specimens would be reduced by 40%, instant results would be available in the general practitioner's surgery and the patient would receive immediate and appropriate treatment.
PMCID: PMC1371380  PMID: 2271259
25.  Laboratory evaluation of leukocyte esterase and nitrite tests for the detection of bacteriuria. 
Journal of Clinical Microbiology  1985;21(5):840-842.
We compared the sensitivity, specificity, and predictive values of the 1-min leukocyte esterase test and the test for urinary nitrite alone and in combination as screening tests for bacteriuria in over 5,000 clinical urine specimens. The leukocyte esterase-nitrite combination had a sensitivity of 79.2%, a specificity of 81%, and a negative predictive value of a negative test of 94.5% for specimens with greater than or equal to 10(5) CFU/ml. Although the sensitivity of this test was too low to allow its use as the only screening test for bacteriuria, it may serve as a useful adjunct to culturing and other urine-processing systems in the microbiology laboratory.
PMCID: PMC271794  PMID: 3998118

Results 1-25 (1000775)