Poor Predictive Ability of Urinalysis and Microscopic Examination to Detect Urinary Tract Infection (original) (raw)
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Bangladesh Journal of Medical Microbiology, 2023
Presence of bacteria in urine along with physical symptoms is referred as UTI. One of the illnesses that still has a high mortality and morbidity rate, even after receiving numerous treatments and numerous antibiotics, is urinary tract infection 1. Because the urinary tract is typically free of bacteria, viruses, fungi, and parasites, infections there lead to urinary tract infections. Renal failure is the most fatal of its complications, according to Mandell et al 2. Bacteriuria refers to the presence of bacteria in the urine, which increases the risk of urinary tract infection. Urine analysis and urine culture should be used to confirm urinary tract infection. If the urine culture obtained by clean catch midstream has more than 100,000 colony units per mL or catheterization method has more than 100 colony units per ml, it is considered positive 2. Urinary infection is diagnosed if the patient has symptoms such as dysuria, urinary frequency, suprapubic pain, burning sensation during micturition with fever 1. Dipstick test like leukocyte
Journal of College of Medical Sciences-Nepal, 2021
Introduction: Urine dipstick is a rapid, cost-effective test used as a marker for quick detection of bacterial Urinary Tract Infection (UTI). Nitrite test depends on the conversion of nitrate to nitrite by the action of Gramnegative bacteria present in urine. The purpose of this study was to determine the sensitivity, specificity, positive predictive value and negative predictive value of Nitrite test in relation to urine culture. Methods: Two hundred fresh uncentrifuged urine samples with suspicion of UTI were collected and tested for nitrite by using urine dipstick strip (COMBI-10SL) prior to the culture. Nitrite was consideredas positive if there was a change in color of dipstick from colorless towards pink within 60 seconds.Quantitative urine culture was performed by using the strips calibrated to deliver 0.02 μL of urine onCystine Lactose Electrolyte Deficient (CLED) agar. All plates were incubated at 37°C and read after 24to 48 hours. Culture was considered as the gold standar...
The clinical laboratory diagnosis of urinary tract infection was compared in two hundred (200) midstream urine samples using bacteria culture and urinary nitrite detection technique. The comparative susceptibility of the isolates to common antibiotics was evaluated using completely randomized design (CRD). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for each antibiotics test was evaluated using standard laboratory procedures. Approximately fifty one percent (101/200) of urine samples that were culture yielded significant bacteriuria (SBU) as compared to (32.59%, 65/200) which had positive nitrite detection. Also eighteen percent (18%, 35/200) of the negative nitrite detection test showed evidence of significant bacteriuria. Significant bacteriuria was significantly associated at p<0.05 with culture isolation technique. A total of nine (9) different bacterial isolates were detected in this study. The isolates and their frequency of occurrence were Escherichia coli 30(29.7%), Pseudomonas aeruginosa 15(14.9%), Klebsiella pneumonia 13(12.8%), Enterococcus faecalis and Citrobacterfreundii 10(9.9), Proteus mirabilis 9(8.9), Staphylococcus aureus 8(7.7%), Serretiamarcesens and Streptococcus specie 3(3.0%).The mean total viable count ranged from 31.50±3.15x10 7 cfuml-1 to 262.5±1.09x10 8 cfuml-1. The antibiotics susceptibility profile reveals a high level of susceptibility of most isolates to Gentamycin(50%), Ciprofloxacin(83%), Tarivid(100%), Augumentin(50%) and Levofloxacin(100%) with mean zone of inhibition ranging from 18.6mm to 20.3mm. However, high resistance profile of hundred percent was observed with nalidixic acid, ampicillin and septrin while reflacin resistant rate was 66.7%. Intermediary susceptibility was observed with streptomycin (50%) and ceporex (66.7%). This study therefore reveals the diagnostic superiority of culture method to urinary nitrite detection technique. In addition, it also reveals Escherichia coli as the most frequently isolated agent of bacteriuria. Furthermore, the study shows a high level of susceptibility of urinary isolates to Gentamycin, Ciprofloxacin Levofloxacin, Augumentin and Tarivid.
Comparison of Urine Culture and Urine Dipstick Analysis in Diagnosis of Urinary Tract Infection
Urine dipstick is a useful and commonly used test because of its rapidity and low cost; however its diagnostic accuracy is debatable. This research was carried out to determine sensitivity, specificity and positive and negative predictive values of Nitrite (NIT) and Leukocyte Esterase (LE) testing in relation to urine culture. This research was conducted on 100 hospitalized patients with clinical signs and symptoms compatible with urinary tract infections (UTI). Urine culture and dipstick tests were carried out on urine samples of all patients. Urinalysis LE and NIT studies were performed in fresh and uncentrifuged urine by using a manual urine analyzer (rapignost, Co. Marburg, Germany). The urine culture was considered as gold standard. Urine cultures were positive in 75 (75%) patients. Dipstick tests of urine were positive in 79(79%) patients. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Dipstick test were 76%, 12%, 72% and 14% respectively. Although dipstick test of LE and NIT can avoid a large part of the cost incurred by urine culture, any method of urine screen (LE and NIT) shouldn't be substituted for a urine culture in the symptomatic patients in childhood.
Examination results of leukocytes and nitrites in the early detection of Urinary Tract Infection
2015 International Conference on Computer, Control, Informatics and its Applications (IC3INA), 2015
A general issue for clinical medicine is whether to treat asymptomatic patients who present with bacteria in their urine. Because of increasing antimicrobial resistance, it is important not to treat patients with asymptomatic bacteriuria unless there is evidence of potential benefit. For this purpose, a urinalysis dipstick reagent color acquisition is important, mainly for leukocytes esterase and nitrites reagent which can be an indicator for early detection of Urinary Tract Infection (UTI). Smartphone camera can be used to help people interpreting reagent colors, rather than using expensive instrument that can only be used by professionals. To accomplish that goal a system that can interpret reagent colors and can be installed on smartphone is needed. One of the main issue in developing this system is what color space and method are used, so the values extracted can represent color in the dipstick for further process to obtain reliable result. Reagent detection and acquisition system uses CIELab color space and Stepwise Linear Interpolation based method to measure the level of leukocytes esterase and nitrites reagent in urine. Experimental result proves that Stepwise Linear Interpolation can determine reagent level of nitrite and leukocytes. But, black white calibration can't representing light calibration so data master can't be applied. And in some situation, a further experiment is needed for producing reliable method for determining reagent level which are not represented in the color chart.
International Journal of Pediatrics and Adolescent Medicine, 2016
Background and objectives: To evaluate whether initial urinalysis (UA) and urinary nitrite results can be used as a proxy for choosing empiric antibiotic therapy. Materials and methods: A retrospective study was conducted in an urban inner city community hospital in New York City (NYU Woodhull Medical Center). We reviewed the charts of patients seen in the Emergency Department and Pediatric Clinic who had a diagnosis of urinary tract infection (UTI) during a 3 year time period (January 2010eDecember 2012). Statistical analysis was performed using SPSS 20.0 statistical software. Results: Between January 2010 and December 2012, a total of 378 patients had a diagnosis of UTI. Seventy-five (19.8%) were males and 203 (80.2%) were females. Of the 378 patients with a diagnosis of UTI, the most common isolated pathogen was Escherichia coli, which was detected in 283 (74.9%) isolates. Other bacteria included Klebsiella spp 30 (7.9%), Proteus 21 (5.6%), Enterococcus 14 (3.7%), and others 30 (7.9%). The resistance rate was higher in the nitrite positive group for the following antibiotics: TMP/SMX and ampicillin with or without sulbactam. No significant correlation was found with the remaining studied antibiotics. No significant correlation was found between leukoesterase and the resistance patterns in all of the studied antibiotics, except cefazolin. Conclusion: Urinary nitrite results are not helpful in choosing an initial antibiotic to treat a UTI.
Background: Urinary tract infection common bacterial disease with all age group causing lower to complicated UTI leading to life threatening condition urosepsis. Urine culture is gold standard however urine dipstick test can help in early detection of UTI by avoiding the complication of UTI. The study aims to compare the diagnostic accuracy of rapid nitrate dip stick test with urine culture and identify the common uropathogens and their antimicrobial susceptibility pattern. Materials and Methods: Clean catch mid stream urine samples from suspected cases of UTI were evaluated by rapid nitrate dip stick and culture. The culture isolates were identified and antimicrobial susceptibility test was performed following Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Total of 202 urine specimens evaluated, out of which 46(22.77%) were positive for rapid nitrate dip stick test, but 42(20.79%) were culture positive. Among the culture positives, nitrate test was positive in 29(69.04%). Gram-negative bacilli were predominant (95.25%), Escherichia coli (21) being most frequent isolate followed by Enterobacter (6), Klebsiella (5) and Acinetobacter (3). The GNB were mostly susceptible to imipenam (75%), amikacin (62.5%) and cotrimoxazole 45%. The overall sensitivity, specificity, positive and negative predictive values of nitrite test in relation to culture were calculated to be 69.04%, 89.4%, 63.0% and 91.6%, respectively but the value of pyuria in relation to culture was 36%, 60%, 68% and 55%, respectively. Conclusion: The study reveals that the rapid nitrate dip stick test can be used in conjunction with urine culture for diagnosis of UTI but cannot replace it entirely.
Evaluation of urinalysis parameters to predict urinary-tract infection
Brazilian Journal of Infectious Diseases, 2007
We evaluated the performance of automated-flow cytometry, urinalysis dipsticks and microscopic urine sediment analysis as predictors of urinary tract infection. Urine cultures were used as a reference method for comparison. Six-hundred-seventy-five urine samples from hospitalized and not hospitalized patients attended at Hospital Mãe de Deus, Porto Alegre, in south Brazil, were included in the study. Among the individual measures analyzed, intense bacteriuria in the microscopic analysis of urinary sediment gave an accuracy of 92.9%. A combination between intense bacteriuria (microscopic analysis) and >20 leukocytes per µL of urine (flow cytometry) gave a higher accuracy (97.3%). We conclude that though it is laborious, microscopic urinalysis is a good analytical tool. Taken together with flow cytometry and dipsticks, we obtained a clinically-acceptable prediction of urinary-tract infection.
Journal of the College of Physicians and Surgeons Pakistan Jcpsp, 2015
Methodology: Three hundred fresh uncentrifuged urine samples with suspicion of UTI, were collected and tested for LE and NIT by using (COMBI-10SL, UK) strip. Nitrite was considered as positive if there was a change in color of dipstick from colorless towards pink within 60 seconds. Leukocyte esterase was considered as positive if there was a change in color from off-white towards purple within 2 minutes. Quantitative urine culture was performed by using the strips calibrated to deliver 0.02 ul of urine on Cystine Lactose Electrolyte Deficient (CLED) medium agar. All plates were incubated at 37°C and read after 24 and 48 hours. Culture was considered as gold standard to evaluate the performance of dipstick test. Results: Out of 300 samples, 136 were culture positive and 164 were culture negative. Out of 136 positive culture results, 103 were dipstick positive and 33 were negative. Sensitivity, specificity, positive predictive value and negative predictive value of both nitrite and leukocyte esterase were 75.74%, 68.90%, 66.66% and 77.40% respectively considering culture as gold standard. Conclusion: Dipstick test for the detection of leukocyte esterase and nitrite in urine are sensitive and specific and can be used reliably for the detection of UTI in resource limited setup.