Determination of diagnostic value (validity) leukocyte esterase (urine dipstick strip) in differentiating inflammatory arthritis from bacterial arthritis

Abstract Background: The current diagnostic cornerstone for septic arthritis contains gram stains, bacterial culture, and cell count with a differential of aspirated synovial fluid. Recently, a synovial leukocyte esterase (LE) test has been used for diagnosing septic arthritis. Since this test measures the esterase activity of leukocytes, there is always a dilemma for using this test in patients with inflammatory arthritis. Methods: We collected the synovial fluid specimens as part of the general diagnostic protocol for patients suspected of Juvenile Idiopathic Arthritis (JIA) or Septic Arthritis (SA). Each group included 34 patients. We compared the result of the synovial LE test with the result of the culture of each patient. Results: The mean ages of patients were 64.14 ± 31.27 and 50.88 ± 23.19 months in the JIA group and septic arthritis group, respectively. The LE test results were positive in 30 specimens, trace in 3 and negative in one in the first-time test and were positive in 31 specimens and trace in 3 in the second-time test, while it was negative in all patients with JIA. Hence, the sensitivity of the synovial LE test was 80.8%, the specificity, PPV, and NPV were 78.6, 70.0, 86.8% respectively based on a positive culture. Conclusion: The leukocyte esterase strip test can be used as a rapid, bedside method for diagnosing or excluding bacterial infections in different body fluids. The synovial LE test can be used as an accurate test to rapidly rule in or out an acute articular bacterial infection, even in patients with concurrent inflammatory arthritis.(AU)

Esterasa leucocitaria como prueba diagnóstica eficaz, económica y rápida ante un proceso infeccioso articular de rodilla / Leucocyte esterase as a reliable diagnostic, cost-effective and fast in knee infections

Resumen: Antecedentes: La infección articular es un reto ortopédico por la complejidad diagnóstica y sus efectos devastadores al no tratarse oportunamente. Se cuenta con diversos estudios de diagnóstico: cultivo, VSG, PCR, conteo de leucocitos, entre otros, pero ninguno es preciso, tardan más de 30 minutos en realizarse y requieren una infraestructura compleja. En este estudio se determina la sensibilidad y especificidad de la esterasa leucocitaria para la detección de un proceso infeccioso articular en población mexicana. Material y métodos: de Noviembre de 2015 a Abril de 2016 se obtuvo líquido sinovial de pacientes con diagnóstico de infección articular con o sin implante y sin infección con patología degenerativa de rodilla. Se evaluó la muestra mediante el test de esterasa leucocitaria COMBI-SCREEN 11SYS con lectura colorimétrica a los dos minutos, determinando positivo para infección: dos cruces, el resto de la muestra fue enviado a cultivo. Resultados: Se aplicó el test a 64 muestras de líquido sinovial de rodilla, 19 diagnosticadas con infección articular y 45 sin infección. Se obtuvo una sensibilidad 100%, especificidad 88.24% VPP 68.42% y VPN 100%, índice de concordancia kappa 0.753 mediante el programa IBM SPSS Statistics 22, Python versión 2.7. Conclusiones: La esterasa leucocitaria es una prueba rápida, económica y eficaz para detectar un proceso infeccioso contra un proceso inflamatorio con alta probabilidad de acierto. Este estudio presentó un índice de concordancia kappa de 0.753, demostrando ser reproducible, por lo que se recomienda implementarse en los servicios de urgencias a nivel nacional.

Abstract: Background: The articular infection represents a challenge due to its complexity and its devastating effect when not treated promptly. We have various diagnostic studies: cultures, ESR, CRP, count of leukocytes, among others but none is specific, it takes more than 30 minutes to complete and require complex infrastructure. In this study we determine the sensitivity and specificity of the leukocyte esterase for detection of an infectious process joint in Mexican population. Material and methods: From November 2015 to April 2016 was obtained synovial fluid from patients with diagnosis of knee infection with or without implant and without infection with degenerative pathology of the knee. It assessed the sample through the COMBI-SCREEN 11SYS leukocyte esterase with reading colorimetric test at two minutes determining positive for infection: two crosses, the remainder of the sample was sent to culture. Results: We perform the test in 64 samples of synovial fluid of knee joint 19 diagnosed with infection and 45 without infection. Was obtained a sensitivity 100%, specificity of 88.24%, PPV 68.42% and PNV 100%, kappa index 0.753 using the program IBM SPSS Statistics 22, Python ver. 2.7. Conclusions: Leukocyte esterase is a fast, economical and effective to detect an infectious process against one inflammatory with high probability of success. This study showed an index of concordance 0.753 Kappa, proving to be reproducible so recommend be implemented in the emergency department at the national level.

Validity of leukocyte esterase reagent (LER) strip in diagnosing infectious pleural effusion

Background: Pleural fluid sampling and analysis are essential to confirm an infection. In a resource-limited health care setting or if biochemistries of the aspirated fluid are not available on an emergency basis, urine reagent strips applied to pleural fluid may expedite diagnostic information. Present study was aimed to evaluate the effectiveness of leukocyte esterase reagent (LER) strip in diagnosing infectious pleural effusion and to correlate the reaction of LER strip with various stages of infectious effusions.Methods: A prospective longitudinal study was conducted in the medical ward of Government Mohan Kumaramangalam Medical College Hospital for a period of one year. Pleural effusion patients with associated immuno-compromised conditions like diabetes mellitus, patients on steroids, HIV reactive patients, chronic obstructive lung disease were included for the study. A totalof 84 patients were included for the study. Exploratory thoracocentesis was done with an 8 mm needle and pleural fluid was obtained and sent for cell count and biochemical testing. The pleural fluid was also tested using the leukocyte esterase reagent strip. The results were recorded as 0, 1+, 2+, 3+ based on the density of violet colour.Results: The leukocyte esterase reagent strip test showed totally negative results in all patients with transudative pleural effusion and also in patients with tuberculous pleural effusion, whereas among patients with infectious pleural effusion other than tuberculosis LER strip test showed negative to only 15% of the patients and for remaining it ranged from 1+ to 3+. The validity of leukocyte esterase strip test was tested in comparison with the gold standard culture test. The accuracy of LER strip test was found to be 88.6%, and the sensitivity and specificity was 90.2% and 66.2% respectively.Conclusions: Reagent strips may speed up the bedside diagnosis of infectious effusions. However, where access to standard biochemical pleural fluid analysis is not available this dipstick tests would add value to the management of the patients.

Clinical value of urine heparin-binding protein in the diagnosis of urinary tract infection / 中华检验医学杂志

Objective To dectect urine level of heparin-binding protein(HBP)in screening urinary tract infection(UTI).Methods A case-control study was performed.From June 2016 to December 2016, urine levels of HBP were detected by enzyme linked immunosorbent assay in 119 patients with definite UTI, 18 patients with probable UTI,58 patients with no UTI and 52 normal controls who were enrolled at Fudan University Hua Shan Hospital North.Meanwhile,urine leukocyte esterase test(U-LE)and urine nitrite test (U-NIT)were performed by urine dipstick analyzer.And count of urine WBC(U-WBC)was performed by urine formed elements analyzer.The overall level of each group was compared using Kruskal-Wallis H test. Two independent samples were compared by Mann-Whitney U test.The correlation between U-HBP, U-LE and U-WBC were assessed using Spearman′s rank coefficient.Receiver operating characteristic curves were constructed to illustrate the diagnostic power of U-HBP, U-LE, U-NIT and U-WBC for UTI.Results In definite UTI group,probable UTI group,no UTI group and normal control group,the levels of U-HBP, U-LE,U-NIT and U-WBC were significantly different(H values were 166.73,126.88,47.92 and 144.05, respectively,P<0.05).Areas under the receiver-operating characteristics curves(AUC)of U-HBP, U-LE,U-NIT and U-WBC were 0.948,0.836,0.671 and 0.897 respectively for the diagnosis of UTI.When a cut-off value of 69.20 ng/ml was used in U-HBP, the sensitivity and specificity for detection of definite UTI were 89.9%(107/119)and 89.1%(114/128),respectively.When U-LE at a cut-off value of 4+, the sensitivity was 76.5%(91/119)and specificity was 81.3%(104/128).When U-NIT at a cut-off value of 1+,the sensitivity was 36.1%(43/119)and specificity was 97.7%(125/128).When U-WBC at a cut-off value of 233.6/μl,the sensitivity was 82.4%(98/119)and specificity was 82.8%(106/128). A strong correlation was detected between U-HBP and U-WBC(r=0.896, P<0.05).The correlation between U-HBP and U-LE was also strong(r=0.798, P<0.05).Conclusions Heparin-binding protein in the urine was significantly better in diagnosis of UTI,compared with the other markers.It could probably be acted as an important new biomarker for diagnosis of UTI.

Esterasa leucocitaria como prueba diagnóstica ante un proceso infeccioso articular de rodilla / Leukocyte esterase as a diagnostic tool for an infectious disease of the knee

Resumen: Antecedentes: La infección articular es un reto ortopédico por su complejidad diagnóstica y efectos devastadores al no tratarse oportunamente. Contamos con diversos estudios de diagnóstico: cultivo, VSG, PCR, conteo de leucocitos, entre otros, pero ninguno es preciso, tardan más de 30 minutos en realizarse y requieren de infraestructura compleja. En este estudio determinamos la sensibilidad y especificidad de la esterasa leucocitaria para la detección de un proceso infeccioso articular en población mexicana. Material y métodos: Durante Noviembre de 2015 a Abril de 2016, se obtuvo líquido sinovial de pacientes con diagnóstico de infección articular con o sin implante, y de otros sin infección, con patología degenerativa de rodilla. Se evaluó la muestra mediante el test de esterasa leucocitaria COMBI-SCREEN 11SYS con lectura colorimétrica a los dos minutos; se determinó positivo para infección con dos cruces; el resto de la muestra fue enviado a cultivo. Resultados: Realizamos el test en 64 muestras de líquido sinovial de rodilla, 19 diagnosticadas con infección articular y 45 sin infección. Se obtuvo una sensibilidad de 100%, especificidad de 88.24%, VPP de 68.42% y VPN de 100%; índice de Kappa de .753. Conclusiones: La esterasa leucocitaria es una prueba eficaz para detectar un proceso infeccioso contra uno inflamatorio con alta probabilidad de acierto. Este estudio presentó un índice de concordancia Kappa de 0.753, con lo que demostró ser reproducible, por lo que recomendamos implementarlo en los servicios de urgencias a nivel nacional.

Abstract: Background: Articular infection is an orthopedic challenge due to its difficult diagnosis and devastating results. Various diagnostic studies exist: culture, ESR, CRP, count of leukocytes, among others, but none is specific, they all take more than 30 minutes to complete, and require complex infrastructure. In this study, we determine the sensitivity and specificity of the leukocyte esterase for detection of an infectious process joint in Mexican population. Material and methods: During November 2015 to April 2016, we obtained synovial fluid from two groups of patients: one with a diagnosis of synovial joint infection with or without implant, and the control group, without infection but with degenerative pathology of the knee. We evaluated the sample using the leukocyte esterase test COMBI-SCREEN 11SYS with colorimetric reading at two minutes; two crosses determined positive for infection; the remainder of the sample was sent for culture. Results: We performed the test in 64 samples of synovial fluid, 19 diagnosed with articular infection and 45 without it. We obtained a sensitivity of 100%, specificity of 88.24%, PPV of 68.42%, and NPV of 100%; Kappa index of .753. Conclusions: Leukocyte esterase is an effective test to detect an infectious process against an inflammatory one with a high probability of success. This study presented an index of agreement Kappa of 0.753, proving to be reproducible.

Asymptomatic Bacteriuriain Pregnant Women: Screening Bya Simple Method and Treatment with Single Dose Antimicrobial Therapy

The term asymptomatic bacteriuria in pregnancy indicates persistent actively multiplying bacteria within the urinary tract without showing any symptom in pregnancy. A total of 500 pregnant women were screened for the incidence of asymptomatic bacteriuria by comparing the reliability of urine dip stick evaluation for nitrites and leukocyte esterase activity with that of urine culture in diagnosing asymptomaticbacteriuria. The efficacy of single dose antimicrobial therapy (2 g of Cephalexin or 3 g of Amoxycillin) was evaluated for eradicating asymptomatic bacteriuria. The incidence was found to be 9.2% among the 500 cases in the study group. The dip stick screening could detect the bacteriuric patients correctly in 89.1% of cases. Single dose therapy cured 76.1% of asymptomatic bacteriuria patients. Amoxycillin was found to be more effective when compared to Cephalexin as a single dose antimicrobial therapy.

EVALUATION OF LEUKOCYTE ESTERASE REAGENT STRIPS TEST IN THE DIAGNOSIS OF SPONTANEOUS BACTERIAL PERITONITIS IN CHILDREN WITH CIRRHOSIS / Avaliação de tiras reagentes de teste de esterase de leucócitos no diagnóstico de peritonite bacteriana espontânea em crianças com cirrose

BackgroundSpontaneous bacterial peritonitis is defined as an ascetic fluid infection without an evident intra-abdominal surgically treatable source. Spontaneous bacterial peritonitis is one of the severe complications in patients with cirrhosis and ascites. Without early antibiotic treatment, this complication is associated with high mortality rate; therefore, early diagnosis and treatment of spontaneous bacterial peritonitis is necessary for survival. Leukocyte esterase reagent can rapidly diagnose the spontaneous bacterial peritonitis.ObjectiveThis study aimed to find out the diagnostic accuracy of leukocyte esterase dipstick test for the diagnosis of spontaneous bacterial peritonitis.MethodsA single centered hospital-based cross-sectional study was conducted during July 2013 to August 2014 on children with cirrhotic liver disease and ascites who were admitted in the Department of Pediatric Gastroenterology in Nemazee Hospital affiliated to Shiraz University of Medical Sciences (Iran). All patients underwent abdominal paracentesis, and the ascitic fluid was processed for cell count, leukocyte esterase reagent strip test (Combiscreen SL10) and culture. Spontaneous bacterial peritonitis was defined as having a polymorphonuclear count (PMN ≥250/m3) in ascitic fluid. Sensitivity, specificity, positive predictive value and negative predictive value of leukocyte esterase test were calculated according to the formula.ResultsTotally, 150 ascitic fluid sample of cirrhotic male patients (53.2%) and their mean age (4.33±1.88 years) were analyzed. Biliary atresia (n=44, 29.4%) and idiopathic neonatal hepatitis (n=29, 19.3%) were the most frequent etiology of cirrhosis. Also, abdominal pain (68.6%) and distension (64%) were the most common presenting complaint. Of all cases, 41patients (27.35%) were diagnosed to have spontaneous bacterial peritonitis (PMN ≥250/mm3). Sensitivity and specificity of leukocyte esterase reagent test according to PMNs ≥250mm3 were 87.80% and 91.74%, also on ascitic fluid culture results were 88.23% and 77.44%. Positive predictive value and negative predictive value of this test in PMNs ≥250mm3 were 80% and 95.23% and in cases with positive culture 33.33% and 98.09% were obtained, respectively. Efficiency of leukocyte esterase reagent test in diagnosing spontaneous bacterial peritonitis, according to PMNs ≥250mm3 and culture results were 90.66% and 78.66%.ConclusionThe leukocyte esterase strip test may be used as rapid test for diagnosis of spontaneous bacterial peritonitis due to its high diagnostic validity.

ContextoA peritonite bacteriana espontânea é definida como uma infecção do fluido ascítico sem evidente origem intra-abdominal cirurgicamente tratável. A peritonite bacteriana espontânea é uma das complicações graves em pacientes com cirrose e ascite. Sem tratamento antibiótico precoce, esta complicação é associada com alta taxa de mortalidade. Portanto, o diagnóstico precoce e tratamento de peritonite bacteriana espontânea são necessários para a sobrevivência. O reagente de esterase de leucócitos pode rapidamente diagnosticar a peritonite bacteriana espontânea.ObjetivoEste estudo teve como objetivo descobrir a acurácia diagnóstica do teste com tiras de esterase de leucócitos para o diagnóstico de peritonite bacteriana espontânea.MétodosUm estudo transversal hospitalar unicêntrico foi realizado entre julho de 2013 e agosto de 2014 em crianças com cirrose hepática e ascite que foram admitidas no Departamento de Gastroenterologia Pediátrica no Hospital de Nemazee afiliado à Universidade de Ciencias Médicas de Shiraz (Irã). Todos os pacientes foram submetidos a paracentese abdominal, e o líquido ascítico foi processado para contagem de células, teste de tira de reagente de esterase de leucócitos (Combiscreen SL10) e cultura. Peritonite bacteriana espontânea foi definida como tendo uma contagem de polimorfonucleares (PMN ≥250/m3) no líquido ascítico. Sensibilidade, especificidade, valor preditivo positivo negativo do teste de esterase de leucócitos foram calculados de acordo com a fórmula.ResultadosForam analisados um total de 150 amostras de líquido ascítico de pacientes cirróticos; (53,2%) eram do sexo masculino e sua média de idade (4,33±1,88 anos). A atresia biliar (n=44, 29,4%) e hepatite neonatal idiopática (n=29, 19,3%) foram as etiologias mais frequentes de cirrose. Além disso, dor abdominal (68,6%) e distensão (64%) foram as queixas mais comuns de apresentação. De todos os casos, 41 (27,35%) foram diagnosticados com peritonite bacteriana espontânea (PMN ≥250/mm3). A sensibilidade e especificidade do teste de reagente de esterase de leucócitos segundo PMN ≥250mm3 foi de 87,80% e 91,74% e, para os resultados de cultura de líquido ascítico, de 88,23% e 77,44%. Valor preditivo positivo e valor preditivo negativo do teste em PMN ≥250mm3 foi de 80% e 95,23% e em casos com cultura positiva 33,33% e 98,09%, respectivamente. A eficiência do teste de reagente esterase de leucócitos no diagnóstico de peritonite bacteriana espontânea, de acordo com resultados de ≥250mm3 e cultura PMN, foi de 90,66% e 78,66%.ConclusãoO teste de tiras de esterase de leucócitos pode ser usado como um teste rápido para diagnóstico de peritonite bacteriana espontânea, devido a sua alta validade diagnóstica.

Influence of Vaginal Discharge on Dry Chemistry Determination of Leukocyte Esterase in Female Urine / 现代检验医学杂志

Objective The present study is to investigate the influence of vaginal discharge on dry chemistry determination of leukocyte esterase in female urine.Methods Collected 20 and 30 normal vaginal discharge samples.Which humoral routine test degree were Ⅰ and Ⅱ correspondingly,and then analyze leukocyte esterase and squamous epithelial cells in these normal vaginal discharge samples.Collected normal vaginal discharge samples again and isolate the vaginal squamous epithelial cells from those normal vaginal discharge samples.Made two concentration of squamous epithelial cell suspension liquid (20/μl and 60/μl)and added these liquid.To normal female urine and analyze the drying chemical leukocyte esterase in those urine. Cleaned the vulva of those patients with normal leukocyte counts in urine sediment determination,whose dry chemical deter-mination of leukocyte esterase was strong positive,perform the routine urine test with her middle urine.Results The results of the determination of leukocyte esterase in normal vaginal discharge samples were 66.7% positive.And there were ~squamous epithelial cells in all samples (microscopy).No significant difference was observed in the examination of dry chem-istry leukocyte esterase among the normal female urine group,low (20/μl)and high (60/μl)concentrations of squamous epi-thelial cell urine group (P >0.05).The counts of squamous epithelial cells and the rate of positive and intensity of dry chem-ical leukocyte esterase in the middle of second urine were significantly lower than before,and the differences are statistically significant (P <0.05).But there was no significant difference for leukocytes counts.Conclusion Urine squamous epithelial cells had no influence on the detection of leukocyte esterase by dry chemistry.However,the leukocyte esterase in the vaginal discharge greatly influenced the examination of the leukocyte esterase in urine.

Study of preliminary screening value of urinary sediment method and urine dry chemical method in diagnosing urinary tract infection / 国际检验医学杂志

Objective To evaluate the preliminary screening value of bacterium(BACT),leukocyte count(WBC)detected by the UF-1000i urine sediment analyzer and nitrite(NIT)and leukocyte esterase(LEU)detected by the urine dry chemical dipstick analy-zer in diagnosing urinary tract infection(UTI).Methods A total of 346 inpatients or outpatients with suspected UTI in our hospital from July 2012 to June 2013 were performed the midstream urine culture.Among them,91 positive cases as the experimental group and 255 negative cases as the control group were simultaneously performed the urine dry chemical analysis and the urinary sediment analysis.The performance of the various indexes in screening UTI was evaluated with the bacterial culture results as the golden standard.Results The positive rates of NIT,LEU,WBC,BACT,NIT+LEU and WBC+BACT in the experimental group were significantly higher than those in the control group with the statistical differences between the two groups(P <0.05).The areas un-der the ROC curve for diagnosing UTI in NIT,LEU,WBC,BACT,NIT+LEU and WBC+BACT were 0.602,0.664,0.715, 0.770,0.713 and 0.760 respectively,95%CI was 0.530-0.675,0.603-0.725,0.655 -0.775,0.716 -0.824,0.651 -0.774 and 0.704-0.817 respectively;their sensitivity for diagnosing UTI was 0.26,0.86,0.79,0.74,0.86 and 0.85 respectively;The speci-ficity was 0.94,0.47,0.47,0.51,0.46 and 0.33 respectively;The positive likelihood ratio was 4.48,1.62,1.51,1.49,1.58 and 1.27 respectively;The negative likelihood ratio was 0.78,0.30,0.44,0.52,0.31 and 0.46 respectively;The positive predictive value was 0.62, 0.37,0.35,0.35,0.36 and 0.31 respectively;The negative predictive value was 0.78,0.90,0.86,0.84,0.90 and 0.86 respectively.Conclu-sion In the rapid screening of UTI,the indexes of NIT,LEU,WBC and BACT all have the higher negative predictive values.

Evaluation of the reagent test strips and microscopic examination of urine in the diagnosis of urinary tract infection in sows / Precisão da tira reagente e do exame microscópico da urina no diagnóstico de infecções do trato urinário em porcas

The diagnosis of the urinary tract infection (UTI) in sows is usually performed by using reagent test strips, since it is a fast and practical method, and capable of being done at the farm. The microscopic examination of the urine is rarely used at the farm since it is a more time consuming and difficult technique. However, there are no studies on the accuracy of those two techniques for the UTI diagnosis on this species. This study aims to assess the accuracy of the reagent test strip and the urine microscopic examination in the diagnosis of ITU in sows, comparing them with the bacteriological examination of urine. In order to select the sows for this study, a chemical reagent test strip was carried out previously and a total of 139 sows were selected, 66 sows of which showed positivity to nitrite in the reagent test strip and 73 without nitrituria. Then, the next day, a new sample collection for performing a complete urinalysis was carried out from those 139 sows, which included physical, chemical, microscopic and microbiological examination of these urine samples. The results revealed that the nitrite test of the reagent strip showed 100% of specificity and 93% of sensitivity. The specificity of the microscopic examination for bacteriuria was 82% and the sensitivity was 100%. The UTI diagnosis by using reagent strips and/or the urine sediment test is reliable if compared to the urine bacteriological examination, which makes possible the rapid diagnosis of UTI in sows at the farm.

O diagnóstico de infecção do trato urinário (ITU) em porcas geralmente é feito com o auxílio de tiras reagentes, por ser um método rápido, prático e passível de ser realizado na própria granja. O exame microscópico da urina raramente é utilizado em granjas por ser uma técnica mais demorada e trabalhosa. No entanto, não existem estudos sobre a precisão destas duas técnicas no diagnóstico de ITU nesta espécie. O objetivo deste estudo foi avaliar a precisão da tira reagente e do exame microscópico da urina no diagnóstico de ITU em porcas, comparando-os com o exame bacteriológico da urina. Para selecionar as porcas que iriam compor o estudo foi realizado um exame químico prévio com tira reagente, do qual foram selecionadas 139 porcas, 66 positivas para nitrito na tira reagente e 73 negativas. No dia seguinte foi realizada uma nova coleta de urina destas 139 porcas para realização da urinálise completa, que incluiu os exames físico, químico, microscópico e microbiológico destas amostras de urina. Os resultados demonstraram que a prova de nitrito da tira reagente apresentou 100% de especificidade e 93% de sensibilidade. A especificidade do exame microscópico para bacteriúria foi de 82% e a sensibilidade de 100%. O diagnóstico de ITU com o uso de tiras reagentes e/ou com exame microscópico da urina é confiável, quando comparado com o exame bacteriológico da urina, o que torna possível o diagnóstico rápido de ITU em porcas na granja.

The Comparison of Microscopic Urine Sediment, Nitrite, and Leukocyte Esterase Tests for Bacteriuria / 감염과화학요법

BACKGROUND: Although bacteriologic culture remains the gold standard for detecting bactriuria, leukocyte esterase, nitrite and urine microscopy are also widely used. However, it is not uncommon to be presented with a discrepancy between these tests. METHODS: We performed leukocyte esterase and nitrite tests by urine reagent strip testing (Combur 10 Test, Roche, Germany), microscopic urinalysis, and by bacteriologic urine culture on 290 persons. RESULTS: The number of pathogens and non-pathogens were 51 (17.6%) and 87 (30.0%) respectively. The number of cases in which no microorganism was isolated (NMI group) was 152 (52.4%). The concordance rate between leukocyte esterase and microscopic leukocytes (leukocyturia) was 70.7%. The sensitivities and specificities of leukocyte esterase, microscopic leukocyte and microscopic bacteria were 72.5%/61.8%, 76.5%/44.1 % and 80.4%/92.1% respectively, and their positive predictive values and negative predictive values were 24% (62.3%)/69.1% (89.7%), 21.3% (53.6%)/62.6% (88.8%) and 51.9% (84.8%)/66.4% (95.3%), respectively. Although the nitrite test showed higher positive rates in the pathogen groups (37.2%) than in the non-pathogen group (2.2%) and NMI group (1.3%), this was only marginally significant. CONCLUSION: The microscopic estimation of bacteria is more a predictable marker of bacteriuria, rather than leukocyte esterase, nitrite, and microscopic leukocytes, in urine.

The Comparison of Microscopic Urine Sediment, Nitrite, and Leukocyte Esterase Tests for Bacteriuria / 감염과화학요법

BACKGROUND: Although bacteriologic culture remains the gold standard for detecting bactriuria, leukocyte esterase, nitrite and urine microscopy are also widely used. However, it is not uncommon to be presented with a discrepancy between these tests. METHODS: We performed leukocyte esterase and nitrite tests by urine reagent strip testing (Combur 10 Test, Roche, Germany), microscopic urinalysis, and by bacteriologic urine culture on 290 persons. RESULTS: The number of pathogens and non-pathogens were 51 (17.6%) and 87 (30.0%) respectively. The number of cases in which no microorganism was isolated (NMI group) was 152 (52.4%). The concordance rate between leukocyte esterase and microscopic leukocytes (leukocyturia) was 70.7%. The sensitivities and specificities of leukocyte esterase, microscopic leukocyte and microscopic bacteria were 72.5%/61.8%, 76.5%/44.1 % and 80.4%/92.1% respectively, and their positive predictive values and negative predictive values were 24% (62.3%)/69.1% (89.7%), 21.3% (53.6%)/62.6% (88.8%) and 51.9% (84.8%)/66.4% (95.3%), respectively. Although the nitrite test showed higher positive rates in the pathogen groups (37.2%) than in the non-pathogen group (2.2%) and NMI group (1.3%), this was only marginally significant. CONCLUSION: The microscopic estimation of bacteria is more a predictable marker of bacteriuria, rather than leukocyte esterase, nitrite, and microscopic leukocytes, in urine.

Cytocentrifuge Gram stain method and urine dipstick test as a screening test of bacteriuria / 대한임상병리학회지

BACKGROUND: Rapid detection of bacteriuria is desirable for diagnosis and treatment of urinary tract infections. The aim of this study was to assess the usefulness of the cytocentrifuge Gram stain, uncentrifuged Gram stain, and urinary nitrite, leukocyte esterase to determine the exclusion of urine culture. METHODS: A cytocentrifuge Gram stain procedure and urine dipstick test were performed to screen for bacteriuria using 155 random fresh urine specimens submitted for routine culture. The authors compared the results of the cytocentrifuge Gram stain, urinary nitrite, leukocyte esterase and multiapplication of three tests with the results of culture. Result: Compared with positive urine culture(>105CFU/mL), cytocentrifuge Gram stain had a good negative predictive value(96.0%) and sensitivity(89.1%). The urinary nitrite and leukocyte esterase test had very low sensitivity(27.0%, 45.9%), respectively. The multiapplication of cytocentrifuge Gram stain, urinary nitrite and leukocyte esterase had a excellent negative predictive value(98.9%) and sensitivity(97.3%), and agree with urine culture positive(36/37 cases, 97.3%). CONCLUSION: Multiapplication of urinary cytocentrifuge Gram stain, nitrite and leukocyte esterase test is a useful screening test for the rapid exclusion of bacteriuria and provides rapid morphologic information about suspected pathogens in cases with positive urine culture.

Leukocyte esterase activity, gram stain, cell count and glucose concentration in intra-amniotic infection

Intraamniotic infection, a common cause of maternal and prenatal morbidity and mortality, is a challenging problem for the obstetrician. This study aims to determine the value of leukocyte esterase activity, grams stain, cell count, and glucose concentration of the amniotic fluid in the diagnosis of intraamniotic infection. Of the 53 subjects,. 35 had intact bag of water and 18 with premature rupture of membranes. In the group with intact bag of water, leukocyte esterase test, Grams stain and quantitative glucose of 84%, 80% and 88% respectively, whereas cell count and quantitative glucose were sensitive at 64% and 90% respectively. In the group with premature rupture membranes, leukocyte esterase test and qualitative glucose had specificities of 81% and 67% respectively, whereas Grams stain, cell count and quantitative glucose had sensitivities of 56% 83% and 100% respectively.