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Introduction: Urinary tract infections are the most common bacterial infections in pregnancy.Asymptomatic bacteriuria (ASB) refers to the presence of bacteria in the urine of an individualwithout symptoms of urinary tract infection. ASB which occurs in 2-11% of pregnancies is a majorpredisposition to the development of pyelonephritis. Aims and objectives: The aims and objectivesof the study were to: Study the effectiveness of various screening tests: urine microscopy, gramstain, catalase test, leukocyte esterase test and nitrite test and to compare their sensitivity,specificity, positive predictive value and negative predictive value. Materials and Methods: Thestudy included 500 pregnant women attending the outpatient department over 18 months. The urinesamples collected in sterile containers were screened for urine microscopy, gram stain, catalase test,leukocyte esterase test and nitrite test. The samples were processed on CLED (Cysteine lactoseelectrolyte deficient) agar as the standard against which other screening tests are identified.Results: Gram’s stain (89.34%) was the most sensitive of all and the least reliable test was thecatalase test among the methods of screening tests. Conclusion: Urine culture is considered to bethe gold standard in detecting ASB in pregnant women. Gram’s stain of urine is a good screeningtest when compared to other screening methods. Screening for bacteria in all trimesters isnecessary to prevent the dangerous complications associated with ASB.

Asymptomatic bacteriuria leading to urinary tract infection is the most frequently encountered condition in pregnancy, which has been associated with an increased risk of pre-term delivery and low birth weight. Clinically the diagnosis of UTI can be difficult as symptoms are non-specific. Gold standard method for diagnosis of UTI is urine culture. Up to 18 hours are required for bacterial growth on culture media by standard laboratory techniques, which leads to delay in the treatment. In the present study 100 midstream urine samples from asymptomatic pregnant women were collected. Gram staining, Griess Nitrite Test, Triphenyl tetrazolium chloride test (TTC), Catalase test, these four screening tests were performed on the samples and their results were compared with the results of urine culture. Among these 100 samples, the study revealed that 14 pregnant women had significant bacteriuria (1,00,000 or more bacteria/ ml of urine) giving a prevalence of 14%. This study showed that Gram staining has highest sensitivity i.e. 92.85% and TTC has highest specificity i.e. 98.83% for the detection of significant bacteriuria. To conclude if we perform these two tests in combination then we get a sensitivity of 98.97% and specificity of 94.22% which is not 100% but very close to it. Use of these screening tests will help in early diagnosis and initiation of treatment of UTI in pregnant women. Keywords: Asymptomatic bacteriuria, Pregnancy, Screening tests, UTI.

Introduction: Urinary Tract Infection (UTI) is one of the most common bacterial infection encountered in clinical practice. Even though urine culture is considered as the gold standard in detection of bacteriuria, many alternative screening methods like urine microscopy, chemical analysis using dipstick method and Gram’s staining have been evaluated which are more economical and rapid. Hence, this study was undertaken to evaluate various screening methods in the rapid diagnosis of Urinary Tract Infections. Objectives: To evaluate Gram staining of urine, leucocyte esterase and nitrite dipstick test methods in the rapid diagnosis of Urinary Tract Infections. Materials and Methods: All urine samples received at Microbiology laboratory, McGann hospital, attached to Shimoga Institute of Medical Sciences, during study period was subjected to Gram staining, leucocyte esterase and nitrite dip stick test along with culture. Results of these tests were compared to culture results. Sensitivity and specificity of the tests was determined taking culture as standard. Results: A total of 560 urine samples were processed. Culture showed significant bacteriuria in 210 cases. The sensitivity of urine microscopy was 70.9%, leucocyte esterase test was 98% and nitrite test was 74.8%. Whereas the specificity of urine microscopy was 70%, leucocyte esterase test was 79.1% and nitrite test was 98.8%. Similarly, the sensitivity of combined leucocyte esterase and nitrite tests was 90.9% and specifity was 97.4%. Sensitivity and specificity of all the three screening tests combined were 95.7% and 94.8% respectively. Conclusion: Screening tests such as, Urine microscopy by Gram’s staining, Leucocyte esterase and nitrite dipstick test in combination can be used routinely to exclude bacteriuria. Urine culture can be employed only in the screening tests positive cases and in symptomatic cases irrespective of test results, thereby making diagnosis of UTI cost effective and rapid. Keywords: Bact

This paper presents the design and fabrication of an automatic colorimetric sensor for on-site determination of nitrite in aquaculture. The colorimetric analysis of nitrite is based on the API nitrite test kit reagents, and the color intensity of nitrite solution is detected using a low-cost color sensor. The fabricated sensing system uses off-the-shelf components and has a compact housing that makes it low-cost and highly portable. This sensor is capable of detecting nitrite in water up to 5 mg/L. Experimental results showed that the nitrite concentrations estimated by the designed sensor were almost comparable to those obtained with the commercial spectrophotometer. With integrated wireless communications capabilities, it helps farmers to respond promptly to adverse changes in pond water parameters and to minimize losses. The colorimetric sensing platform designed in this paper can be applicable to more chemical analysis by establishing the calculation model according to the absorption spectra of the new reagent solution.

A urine dipstick test used for prompt diagnosis of urinary tract infection (UTI) is a rapid and cost-effective method. The main objective of this study was to compare the efficacy of the urine dipstick test with culture methods in screening for UTIs along with the detection of the blaCTX-M gene in extended spectrum β-lactamase (ESBL)-producing Escherichia coli. A total of 217 mid-stream urine samples were collected from UTI-suspected patients attending Bharatpur Hospital, Chitwan, and tested by dipstick test strip (COMBI-10SL, Germany) prior to the culture. E. coli isolates were identified by standard microbiological procedures and subjected to antimicrobial susceptibility testing by Kirby Bauer disc diffusion method following CLSI guideline. Primary screening of ESBL-producing E. coli isolates was conducted using ceftriaxone, cefotaxime and ceftazidime discs and phenotypically confirmed by combined disk diffusion test. Plasmid DNA of ESBL-producing strains was extracted by phenol-chloroform method and subjected to PCR for detection of the blaCTX-M gene. Out of 217 urine samples, 48 (22.12%) showed significant bacteriuria. Among 46 (21.20%) Gram negative bacteria recovered, the predominant one was E. coli 37 (77.08%) of which 33 (89.19%) were multidrug resistant (MDR). E. coli isolates showed a higher degree of resistance towards cefazolin (62.16%) while 81.08% of the isolates were sensitive towards amikacin followed by nitrofurantoin (70.27%). Among 14 (37.84%) phenotypically confirmed ESBL isolates, only eight (21.62%) isolates carried the blaCTX-M gene. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of urine dipstick test were 43.75%, 77.51%, 35.59% and 82.91%, respectively. Besides, the use of dipstick test strip for screening UTI was associated with many false positive and negative results as compared to the gold standard culture method. Hence, dipstick nitrite test alone should not be used as sole method for screening UTIs.

Objective: The purpose of this study is to evaluate the diagnostic value of nitrite test in comparison with urine culture (U/C) results in patients with Urinary tract infection (UTI) symptoms. Methods: This cross-sectional study was performed on 203 patients with UTI symptoms. Middle urine sample was taken into sterile plastic containers, and simultaneously the urine sample and the nitrite test were done by the use of urine dipstick test. Data were analyzed using SPSS software version 23. Results: The results of the urine culture test indicated that the highest excreted organisms in both sexes were E. coli (58.8%), Candida (17.6%), Klebsiella (8.8%), E. coli (MDR) (5.9%), Pseudomonas (2.9%), Enterococcus (2.9%) and Acinetobacter (2.9%). The results showed that there was a significant correlation between U/C and urine analysis (U/A) test results (P = 0.01), and in U/C positive results, U/A results were significantly positive for UTI. Other findings showed a significant relationship between the results of nitrite one and nitrite two tests (P = 0.001). There was a significant correlation between urinary, and nitrite1 levels (P = 0.04). Also, in this study, the sensitivity and specificity of diagnostic tests for U/A and nitrite 1 and 2 with U/C were calculated as the Golden Standard method. Conclusion: Overall, the results of this study showed that the negative nitrite test and urine dipstick test could be performed in emergency cases to prevent ectopic dysfunction and inadequate diagnosis. Also, it can reduce the unreasonable expenses for U/A.

Objectives: Urine dipstick is the first step laboratory test to diagnose a urinary tract infection (UTI) which is a common infectious disease diagnosed in the laboratories. Early treatment of UTI is very important in order to prevent long-term complications. The gold standard to diagnose UTI is urine culture so there are a number of unnecessary urine culture requests. However, urine culture results are not available earlier than 24-36 hours. Besides, urine culture is expensive and causes time-consuming of treatment. Our aim in this study was to compare urine leukocyte esterase test and nitrite test of urine dipstick with urine culture to determinate the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Methods: Urine culture results and urine dipstick test results of patients who admitted to Selçuk University Hospital between May 2016 and May 2017 were collected retrospectively. The study included 11.169 patients and 3299 of them have positive urine cultures. Results: In total, 3299 (29.5%) patients have positive urine culture. Out of these culture positive samples, positive dipstick results’ ratios for leukocyte esterase and nitrite were 82.8% (n = 2733) and 22.4% (n = 774). Leukocyte esterase had 82.8% sensitivity and 68.1% specificity, with PPVs and NPVs of 52.1% and 90.5%, respectively. Conclusions: The NPVs are found significantly higher than PPVs and it shows that urinary dipstick is more reliable to exclude disease than to diagnose the disease. Clinicians should not order urine culture from all patients without ant clinic signs.

Background Urinary tract infections (UTIs) are one of the most common infections in primary care. Previous research showed that GPs find it challenging to diagnose UTIs and frequently divert from guidelines leading to unwarranted antibiotic prescriptions and inefficient use of diagnostics such as urinary cultures. We hypothesise that management of UTIs during out-of-hours care may be extra challenging due to a higher workload and logistical issues regarding diagnostic work-up and obtaining results. We therefore aimed to study the workload, diagnostic work-up and treatment of UTIs during out-of-hours primary care. Methods We performed a retrospective observational cohort study in which we analysed a full year (2018) of electronic patient records of two large Dutch GP out-of-hours centres. All adult patients with UTI symptoms were included in this study. Descriptive statistics and multivariate regression were used to analyse diagnostics and subsequent management. Results A total of 5657 patients were included (78.9% female, mean age of 54 years), with an average of eight patients per day that contact a GP out-of-hours centre because of UTI symptoms. Urinary dipsticks were used in 87.5% of all patients visiting the out-of-hours centres with UTI symptoms. Strikingly, urinary cultures were only requested in 10.3% of patients in which urinary culture was indicated. Seventy-four percent of the patients received antibiotics. Seventy-nine percent of the patients with a negative nitrite test still received antibiotics. Remarkably, patients at risk of complications because of a UTI, such as men, received fewer antibiotic prescriptions. Conclusions In total, 74% of the patients received antibiotics. 8 out of 10 patients still received an antibiotic prescription in case of a negative nitrite test, and 9 out of 10 patients with an indication did not receive a urine culture. In conclusion, we found that correctly diagnosing UTIs and prescribing antibiotics for UTIs is a challenge that needs major improvement, especially during out-of-hours GP care.

To determine the clinical utility/disutility of canceling urine cultures in elderly patients with a negative dipstick. The cohort included consecutive patients aged ≥ 65 years hospitalized in internal medicine departments with an admission urinalysis and urine culture (January 1, 2014 to December 31, 2016). We calculated the sensitivity of the dipstick (either a trace leukocyte esterase or a positive nitrite test result) to detect patients with bacteriuria, and the decrease in urine cultures resulting from cancelation in patients with a negative dipstick. We reviewed the charts of patients with a positive culture but negative dipstick to determine if they received appropriate antibiotic therapy and if the culture results had clinical utility, defined as changes in antibiotic therapy made according to culture results in a patient who did not respond to initial antibiotic therapy. The sensitivity of the dipstick for bacteriuria was 90.8% (95% CI, 89.6-92.0%). Of the 210 patients with a positive culture but negative dipstick, 132 (62.9%) had a diagnosis clearly outside the urinary tract. Thirty-five patients (16.7%) received inappropriate differential antibiotic therapy. Urine cultures did not have clinical utility and canceling urine cultures in those with a negative dipstick would result in a 41.5% (95% CI, 40.3-42.7%) decrease in urine cultures. We conclude that canceling orders for urine cultures in the elderly patient with a negative dipstick did not have clinical disutility and would decrease inappropriate antibiotic therapy. Extrapolation to other settings is dependent on urinalysis methodology, patient selection, and physician ordering and treatment behaviors.

Aim. To study prevalence and etiological structure of urinary tract infections (UTIs) in pregnant women with type 1 diabetes mellitus, to assess sensitivity of various methods of UTIs detection. Materials and methods. 192 pregnant women with type 1 diabetes mellitus (DM1) were examined. The presence of a urinary infection was assessed by detection of nitrites, leukocyte esterase in general urinalysis and by bacteriological culture with the use of the classical and "DipStrik" express method. Results. UTI has been detected in 57.3%. The frequency is as follows: asymptomatic bacteriuria (> 105 cfu /ml) (ABU) – 35.9% (n=69), acute pyelonephritis – 19.8% (n=38), acute cystitis – 1.6% (n=3). The proportion of low ABU (102-104 cfu/ ml) is 16.1% (n=31). Escherichia coli prevailed in the structure of pathogens of UTI: in ABU – 66.7%, in pyelonephritis – 78.9%. Then goes Enterococcus faecalis : in ABU – 14.5%, in pyelonephritis – 13.2%; and then Klebsiella : in ABU – 7.2%, in pyelonephritis – 5.3%. Other pathogens ( Streptococcus agalactiae, Staphylococcus aureus, Proteus ) were less common. Sensitivity of the nitrite test to detect UTI was 30%; sensitivity of leukocyte esterase detection for low ABU was 22.6%, for ABU – 52.2%, for pyelonephritis –71%. Sensitivity of the express method "DipStrik" with reference to classical bacteriological culture was 98%. Conclusion. The structure of UTI in DM1 differs from that of in pregnant women without DM. In DM1 a "significant" ABU dominates over a low ABU. The share of manifest forms of UTI in DM1 is much higher than in pregnant without DM. In the structure of UTI pathogens in pregnant women with DM1 gram-positive microbes (E. faecalis, S. agalactiae and S. aureus) have a greater proportion compared with pregnant women without DM, in which more than 80% of UTI pathogens are gram-negative (E. coli, K pneumoniae and Proteus) . Cultural methods still remain the gold standard of UTI detection, and especially its asymptomatic forms. Moreover, the "DipStrik" express method of bacteriological culture has sensitivity comparable to the classical culture (in our study 98 %).

Introduction: Urinary tract infection (UTI) is the most common serious bacterial infection in young infants. Signs and symptoms are often nonspecific. Objectives: To describe clinical, demographic and laboratory features of UTI in infants ≤ 3 months old. Methods: Cross-sectional study of infants ≤ 3 months old with UTI diagnosed in a pediatric emergency department, for the period 2010-2012. UTI was defined as ≥ 50,000 colony-forming units per milliliter of a single uropathogen isolated from bladder catheterization. Paired urinalysis and urine culture from group culture-positive and group culture-negative were used to determine the sensitivity and specificity of pyuria and nitrite tests in detecting UTI. Results: Of 519 urine cultures collected, UTI was diagnosed in 65 cases (prevalence: 12.5%); with male predominance (77%). The most common etiologies were Escherichia coli (56.9%), Klebsiella pneumoniae (18.5%) and Enterococcus faecalis (7.7%). Frequent clinical manifestations were fever (77.8%), irritability (41.4%) and vomiting (25.4%). The median temperature was 38.7°C. The sensitivity of the nitrite test was 30.8% (95%CI:19.9-43.4%), specificity of 100% (95%CI:99.2-100%). Pyuria ≥ 10,000/mL had a sensitivity of 87.7% (95%CI:77.2-94.5%), specificity of 74.9% (95%CI:70.6 -78.8%). The median peripheral white blood cell count was 13,150/mm3; C-reactive protein levels were normal in 30.5% of cases. Conclusions: The male: female ratio for urinary tract infection was 3.3:1. Non-Escherichia coli etiologies should be considered in empirical treatment. Fever was the main symptom. Positive nitrite is highly suggestive of UTI but has low sensitivity; whereas pyuria ≥ 10,000/mL revealed good sensitivity, but low specificity. Peripheral white blood cell count and C-reactive protein concentration have limited usefulness to suggest UTI. RESUMO Introdução: A infecção do trato urinário (ITU) é um quadro infeccioso grave mais frequente em lactentes jovens, cujos sinais e sintomas são frequentemente inespecíficos. Objetivos: Descrever aspectos clínicos, demográficos e laboratoriais de ITU em lactentes ≤ 3 meses. Métodos: Estudo transversal de ITU diagnosticada em lactentes ≤ 3 meses, em pronto-socorro geral de pediatria, entre 01/01/2010 a 31/12/2012. Diagnóstico de ITU definida como crescimento ≥ 50.000 unidades formadoras de colônia por mililitro de uropatógeno único, colhido por cateterismo vesical. Urina tipo I e urocultura foram pareadas dos grupos cultura-positiva e cultura-negativa para determinar a sensibilidade e especificidade de piúria e teste do nitrito para o diagnóstico de ITU. Resultados: Das 519 uroculturas colhidas, confirmou-se 65 casos de ITU (prevalência: 12,5%), com predomínio em meninos (77%). As etiologias mais frequentes foram Escherichia coli (56,9%), Klebsiella pneumoniae (18,5%) e Enterococcus faecalis (7,7%). Os sintomas mais frequentes foram febre (77,8%), irritabilidade (41,4%) e vômitos (25,4%). A temperatura mediana foi de 38,7°C. A sensibilidade do nitrito positivo foi de 30,8% (IC95%:19,9-43,4%), especificidade de 100% (IC95%:99,2-100%). Piúria ≥ 10.000/mL apresentou sensibilidade de 87,7% (IC95%:77,2-94,5%), especificidade de 74,9% (IC95%:70,6-78,8%). A contagem mediana de leucócitos foi 13.150/mm3. A proteína C reativa foi normal em 30,5% dos casos. Conclusões: A proporção entre meninos e meninas para ITU foi de 3,3:1. Outros agentes além de Escherichia coli devem ser considerados no tratamento empírico. A febre foi a principal queixa. O nitrito positivo é altamente sugestivo de ITU mas tem baixa sensibilidade; enquanto que a piúria ≥ 10.000/mL revelou boa sensibilidade, porém baixa especificidade. Leucograma e proteína C reativa demonstraram pouca utilidade clínica para sugerir ITU.

Leachate monitoring required done periodically to know effectiveness of landfill management. Nitrite levels was one of pollution indicator parameter. Nitrite test using test kit method offers simplicity and concise testing time. This reasearch is propose to determine method validity of nitrite testing with portable colorimeter all at once measuring nitrite on landfill leachate and to construct technical strategies for decrease nitrite content on it. The reasearch be located at Cahaya Kencana landfill in Banjar Districts. Method validity of nitrite testing determined based on calibration curve linierity, aquracy, precision, and method comparation. Nitrite levels on landfill leachate are measuring on check point SP-1, SP-2, SP-3, and SP-4. Technical strategy to decrease nitrite levels arranged uses descriptive method and field survey. Method validity of nitrite test using portable colorimeter on landfill leachate sample declared valid based on determination of calibration curve linierity with correlation coefficient (r) 0,997; aquracy test obtained Recovery (R) 95%; precision test obtained Relative Standard Deviation (RSD) 6,33%; and comparation of testing among method use independent t-test obtained Sig. (2-tailed, α 95%) value 0,968. Nitrite levels as result of measuring on leachate at Cahaya Kencana landfill in Banjar Districts shows that sample on SP-1 check point has exceed quality standard while SP-2, SP-3, dan SP-4 spot are belowed. Technical strategy that recommended are recirculation of leachate to landfill areas, aeration optimalization with added aerator to facultative pond, replace bacterial home with honeycomb biofilter media, and also apply fitoremediation at wetland pond in a way to grow Eceng Gondok (Eichhornia crassipes) plant that could lowered organic pollutant matters.

AIM: This study evaluated using urine dipstick tests with the clean-catch method to screen for urinary tract infection (UTI) in febrile infants under 90 days of age. METHODS: We carried out a comparative diagnostic accuracy study of infants under 90 days old, who were studied for unexplained fever without any source, in the emergency room of a hospital in Madrid from January 2011 to January 2013. We obtained matched samples of urine using two different methods: a clean-catch, standardised stimulation technique and catheterisation collection. The results of the leucocyte esterase test and nitrite test were compared with their urine cultures. RESULTS: We obtained 60 pairs of matched samples. A combined analysis of leukocyte esterase and, or, nitrites yielded a sensitivity of 86% and a specificity of 80% for the diagnosis of UTIs in clean-catch samples. The sensitivity of leukocyte esterase and, or, nitrites in samples obtained by catheterisation were not statistically different to the clean-catch samples (p = 0.592). CONCLUSION: Performing urine dipstick tests using urine samples obtained by the clean-catch method was an accurate screening test for diagnosing UTIs in febrile infants of less than 90 days old. This provided a good alternative to bladder catheterisation when screening for UTIs. Sin financiación 2.265 JCR (2018) Q2, 43/125 Pediatrics 1.031 SJR (2018) Q1, 51/318 Pediatrics, Perinatology and Child Health, 528/2844 Medicine (miscellaneous) No data IDR 2018 UEM

In a primary care study of urinary tract infections (UTIs) performed 2008 in Uppsala County, Sweden, 43% of the patients were culture negative. In order to investigate the background to the observed overdiagnosis of UTI, study invitations were sent to the previously included patients. A total of 256 patients (88% women) approved to participate. Patient charts and recorded laboratory data were reviewed. Two or more of the cardinal symptoms were reported in 53% of the women and in 19% of the men. A dipstick test was performed in 93% of the consultations. The highest positive predicted values in women had a positive nitrite test (95%, 95% CI 87; 99) and dysuria in combination with urgency (81%, 95% CI 72; 88). Seventy-one percent of the women who fulfilled the symptom criteria received an antibiotic prescription directly, 87% of these had a positive culture. The drug of choice was pivmecillinam for women (51%) and quinolones (50%) for men. The treatment duration was too long for the women; 68% were treated for ≥7 days. In conclusion, the adherence to national guidelines/recommendations was inadequate. To reduce the selection of multiresistant bacteria, an improvement of the use of diagnostic criteria/tools and antibiotic drugs in primary care is necessary.

The urine dipstick is used in combination with other clinical and microbiologic data to diagnose urinary tract infections (UTIs). It is usually ‘first-line’ in diagnosis given the ease of testing, low cost, and ability to use as a point-of-care test. Two components of the dipstick that are utilized in assisting in the diagnosis of UTIs are leukocyte esterase and nitrites. Leukocyte esterase is an enzyme that is released by white blood cells (WBCs) and therefore correlates with pyuria. Some bacteria (such as E. coli) convert urinary nitrates that are routinely present in the urine into nitrite. Therefore, a positive nitrite test on the urine dipstick is suggestive of the presence of these organisms. Importantly, a positive dipstick result only suggests the presence of bacteriuria and does not help in distinguishing between asymptomatic bacteriuria and symptomatic UTI. False positive and false negative dipstick tests are also common, and consideration should be given to the clinical context when interpreting results. When considering the diagnosis of a urinary tract infection, the dipstick result should therefore be used with careful interpretation of symptoms, urine microscopy, and urine culture along with consideration of other potentially confounding diagnoses such as sexually transmitted infections (STI) and vaginosis.

Introduction: Urinary Tract Infection (UTI) is a significant health problem in young women and adolescent females. Microscopic analysis and/or urine culture are costly, labour intensive laboratory-based tests. For many individuals, access and affordability for such care can be difficult specially in India rural settings have limited resources for this. The concept of selfscreening for UTI by urine dipstick bedside method and benefits of adopting it as a regular school health programme is relatively new in our country. Aim: To evaluate the ability of self screening for UTI by urine dipstick method in the adolescent school girls. Materials and Methods: In this cross-sectional study the ability to self screen for UTI in 374 participants, including 184 girls from a rural school and 190 girls together from two urban schools was evaluated. At each school, the participants were educated about UTI and the objectives and methodology of the study. The participants reported to the school (to the investigators) within one hour of collecting first-morning, clean-voided, midstream urine sample in a sterile labelled container. The ability to self-interpret for UTI by the participants using dipstick method was evaluated. The interpretation by the investigator was considered the gold standard. Sensitivity, specificity and predictive values were calculated to assess the ability to self screen for UTI. The association between UTI and contributory factors was calculated using Chi-square tests. Results: The overall self screening ability of the participants for UTI was found to have sensitivity, specificity, positive and negative predictive values of 81.82%, 96.7%, 42.86% and 99.43%, respectively. The UTI was significantly associated with water intake (χ2 =11.196, p

Aim This study analysed the association between a positive nitrite dipstick test and an invasive bacterial infection (IBI) in infants younger than 90 days of age with fever without source (FWS). Methods We performed a secondary analysis of data from a prospective multicentre study of infants up to 90 days of age with FWS undergoing care in 19 paediatric EDs between October 2011 and September 2013. Invasive bacterial infection was defined as a positive blood or cerebrospinal fluid culture. Results The dipstick urinalysis was positive for nitrite or leucocyte esterase in 766 (22.5%) of the 3401 infants we studied, and 270 (35.2%) had a dipstick test that was just positive for nitrite. Overall, 107 were diagnosed with an IBI (3.1%). The IBI prevalence was 2.2% among patients with a normal urine dipstick, 4.4% if they had positive leucocyte esterase test results, 8.3% where the nitrite test was positive and 10.6% when both tests were positive. After multivariate analysis, a positive nitrite test remained an independent risk factor for IBI (odds ratio 2.7, 95% confidence interval 1.4-4.9). Conclusion In infants under 90 days of age with FWS, a positive nitrite urine dipstick test was an independent risk factor for IBI.

BACKGROUND: A recent study in young infants found that different cutoffs maximized the accuracy of the urine white blood cell count in dilute versus concentrated urine samples. We aimed to confirm this finding and to determine its impact on clinical care. METHODS: We conducted a retrospective analysis of data gathered on consecutive children RESULTS: We included 10 078 children. The ability to rule in UTI (as measured by the positive likelihood ratio [LR]) was similar in dilute and concentrated urine for the leukocyte esterase test (11.76 vs 10.71, respectively). The positive LR for urine white blood cell count per high-powered field was higher in dilute urine (9.83 vs 6.12). In contrast, the positive LR for the nitrite test was lower in dilute urine (20.54 vs 47.44). Despite these differences, we found little change in the number of children treated with antibiotics in predictive models that took urine SG into consideration. CONCLUSIONS: Although we found that urine SG influences the accuracy of some components of the urinalysis, its inclusion in the decision-making process had negligible effect on the clinical care of children with UTI.

Background: Urinary tract infection (UTI) is a common bacterial infection causing illness in children. It may be difficult to recognize UTI in children because the presenting symptoms and signs are non-specific, particularly in younger children. In addition, urine collection and interpretation of urine tests in children are not easy, and therefore, it may not always be possible to confirm the diagnosis unequivocally. The study was conducted to evaluate the value of the modified nitrite test in diagnosing urinary tract infection (UTI) in children.Methods: The study included 150 children of both sexes, aged below 5 years, who were examined due to suspicion of UTI. The efficacy of the modified nitrite test to predict culture positivity was studied.Results: Modified nitrite test was positive in 14 out of the 26 culture-positive urine samples (sensitivity 53.85%). The specificity, positive predictive value, and negative predictive value were 96.77%, 77.78%, and 90.91%. The overall diagnostic accuracy was 89.33%.Conclusions: Modified nitrite test is an effective rapid screening test for diagnosing pediatric UTI.

AimsResults of urinalysis are available earlier than urine culture results. If urinalysis can predict results of culture, early decision can be made on treatment and whether urine samples should be cultured. This study sought to compare the performance of urinalysis tests by automated test strip analyser (nitrite and leucocyte esterase) with flow cytometry (bacteria and white cell count) in different subpopulations and types of samples.MethodsConsecutive urine samples (n=2351) from a population with a median age of 45 years, 37.2% men, were tested. Sensitivity, specificity, positive predictive value and negative predictive value (NPV) of the tests were calculated using contingency tables. The gold standard was positive urine culture with cut-off >105 CFU/mL.Results14% of the cultures were positive (95.6% monomicrobial, 74.7% Enterobacteriaceae). Overall, nitrite test was the most specific (98.7%) but the least sensitive (43.2%). Bacteria count was the most sensitive (91.7%) and highly specific (87.5%). In infants ConclusionsOverall, the performance of urinalysis is excellent. Flow cytometry tests performed better than automated test strip analyser in ruling out urine to be cultured.

Urinary tract infections (UTIs) are the most common type of nosocomial infection. Traditionally, the presence of white blood cells and microorganisms in the urine provides objective evidence for UTI diagnosis. Here, we describe the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) to measure the nitrite and nitrate levels in urine and investigate the potential of this method for UTI diagnosis. LC-MS/MS analysis was performed in positive electrospray ionization mode. After adding (15)N-labeled internal standards and derivatizing with 2,3-diaminonaphthalene (DAN), the urinary nitrite content was directly analyzed by LC-MS/MS, whereas the urinary nitrate was first reduced to nitrite before derivatization and LC-MS/MS analysis. The derivatization of nitrite and enzymatic reduction of nitrate were optimized. This method was then applied to 241 healthy subjects and 73 UTI patients. Optimization tests revealed that 1 mL of crude urine required at least 6.25 μmol of DAN to completely derivatize nitrite and 2.5 U of nitrate reductase to completely reduce nitrate to nitrite. Urinary analysis showed that the urinary concentration of nitrite and the nitrite/nitrate ratio were higher in UTI patients than in healthy subjects. Compared with the dipstick-based urinary nitrite test and using LC-MS/MS to determine the nitrite concentration (sensitivity: 23-25%), the nitrite/nitrate ratio was significantly more sensitive (95%) and exhibited a satisfactory specificity (91%) in the screening of UTIs. Taken together, the nitrite/nitrate ratio, which reflects the reducing ability of pathogenic bacteria, could be a better method for the diagnosis of UTIs that is not subject to variations in urine specimen quality.

Urine culture is the gold standard in the diagnosis of a Urinary Tract Infection (UTI). More simple tests are often used instead of urine cultures. To compare the sensitivity and specificity of the urine nitrite test and gram staining with urine culture, a cross-sectional study was conducted at RSUP H Adam Malik, from February to July 2017, with participants recruited by consecutive sampling. The data collected were sample characteristics, clinical manifestations, causal organisms, nitrite test, gram staining and urine culture results. The data were analysed using Fisher’s exact test with p < 0.05. A total of 60 samples were included. The organism encountered was Escherichia coli. The most frequent clinical manifestation was fever, exhibited by 37 children with UTIs. The sensitivity and specificity of the nitrate test were 64.8% and 86.9%, respectively, while the sensitivity and specificity of gram staining were 94.5% and 100%, respectively. Gram staining is a good alternative test for diagnosing UTIs, but nitrite testing still needs further research.

Objective The aim of this study was to identify predictive factors for bacteremia conveniently and quickly among outpatients diagnosed with pyelonephritis. Patients All patients who were diagnosed with pyelonephritis at the outpatient clinic in the Department of General Medicine of Juntendo University Hospital from April 1, 2008, to June 30, 2015, were enrolled. Patients from whom blood cultures had not been taken were excluded. Methods Clinical information was extracted from medical charts. Factors potentially predictive of bacteremia were analyzed using a t-test and Fisher's exact test, followed by a multivariable logistic regression model analysis. Results Blood cultures were drawn from 116 patients, and 25 (22%) presented with bacteremia. A multivariate analysis with the age, chills, platelet count and urine nitrite test results revealed that older age, positive urinary nitrite test results and chills tended to be associated with bacteremia, respectively. [older age: unit odds ratio (OR) 1.02, p=0.052, 95% confidence interval (CI) 1.00-1.05, positive urinary nitrite test findings: OR 2.5, p=0.092, 95% CI 0.86-7.7, chills: OR 2.5, p=0.096, 95% CI 0.84-7.65]. The area under the receiver operating characteristic (ROC) curve of this model was 0.77. Regardless of age, positive urinary nitrite test findings were significantly associated with bacteremia (OR 3.1, p=0.033, 95% CI 1.1-9.2), and chills tended to be associated with bacteremia (OR 2.7, p=0.07, 95% CI 0.93-7.9) The area under the ROC curve of this model was 0.75. Conclusion Bacteremia should be considered in pyelonephritis patients with rapidly assessable factors in outpatient clinic. In particular, a model including a urinary nitrite test has the potential to aid in the prediction of bacteremia.

Objective To investigate whether the urine dipstick screening test can be used to predict urine culture results. Methods A retrospective study conducted between January and December 2014 based on data from 8,587 patients with a medical order for urine dipstick test, urine sediment analysis and urine culture. Sensitivity, specificity, positive and negative predictive values were determined and ROC curve analysis was performed. Results The percentage of positive cultures was 17.5%. Nitrite had 28% sensitivity and 99% specificity, with positive and negative predictive values of 89% and 87%, respectively. Leukocyte esterase had 79% sensitivity and 84% specificity, with positive and negative predictive values of 51% and 95%, respectively. The combination of positive nitrite or positive leukocyte esterase tests had 85% sensitivity and 84% specificity, with positive and negative predictive values of 53% and 96%, respectively. Positive urinary sediment (more than ten leukocytes per microliter) had 92% sensitivity and 71% specificity, with positive and negative predictive values of 40% and 98%, respectively. The combination of nitrite positive test and positive urinary sediment had 82% sensitivity and 99% specificity, with positive and negative predictive values of 91% and 98%, respectively. The combination of nitrite or leukocyte esterase positive tests and positive urinary sediment had the highest sensitivity (94%) and specificity (84%), with positive and negative predictive values of 58% and 99%, respectively. Based on ROC curve analysis, the best indicator of positive urine culture was the combination of positives leukocyte esterase or nitrite tests and positive urinary sediment, followed by positives leukocyte and nitrite tests, positive urinary sediment alone, positive leukocyte esterase test alone, positive nitrite test alone and finally association of positives nitrite and urinary sediment (AUC: 0.845, 0.844, 0.817, 0.814, 0.635 and 0.626, respectively). Conclusion A negative urine culture can be predicted by negative dipstick test results. Therefore, this test may be a reliable predictor of negative urine culture. RESUMO Objetivo Verificar se a triagem de urina por fitas reativas é capaz de predizer a cultura de urina. Métodos Estudo retrospectivo realizado entre janeiro e dezembro de 2014 com 8.587 pacientes, com solicitação médica de triagem de urina (fita), sedimento urinário e cultura de urina. Foram analisados sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo e curva ROC. Resultados Foram positivas 17,5% das culturas. O nitrito apresentou sensibilidade de 28% e especificidade de 99%. O valor preditivo positivo foi de 89% e o valor preditivo negativo de 87%. Esterase apresentou sensibilidade de 79% e especificidade de 84%. Valor preditivo positivo e valor preditivo negativo foram de 51% e 95%, respectivamente. A combinação de nitrito ou esterase positivos apresentou sensibilidade de 85% e especificidade de 84%. Valor preditivo positivo e valor preditivo negativo foram, respectivamente, 53% e 96%. O sedimento positivo (mais de dez leucócitos por microlitro) apresentou sensibilidade de 92% e especificidade de 71%. O valor preditivo positivo foi 40% e o negativo, 98%. A combinação de nitrito e sedimento urinário positivos apresentou sensibilidade de 82% e especificidade de 99%. Os valores preditivos positivo e negativo foram 91% e 98%, respectivamente. Para o nitrito ou esterase positivos mais os leucócitos positivos, a sensibilidade foi de 94% e a especificidade de 84%. O valor preditivo positivo foi de 58% e o negativo foi de 99%. Com base na curva ROC, o melhor indicador de urocultura positiva foi a associação entre a esterase ou nitrito positivos na fita mais os leucócitos positivos no sedimento, seguido por nitrito e esterase positivos, sedimento urinário positivo isolado, esterase positiva isolada, nitrito positivo isolado e, finalmente, pela associação entre nitrito e sedimento urinário positivos (AUC: 0,845, 0,844, 0,817, 0,814, 0,635 e 0,626, respectivamente). Conclusão Uma urocultura negativa pode ser prevista com resultados negativos na fita. Portanto, este teste pode ser um preditor confiável de urocultura negativa.

Point-of-care (POC-) testen worden in de nabijheid van patiënten gebruikt om snel een diagnose te stellen. Een bekend voorbeeld is de bloedglucosemeter waarmee de bloedsuikerwaarde van een diabetespatiënt kan worden gemeten. POC-testen worden steeds meer gebruikt in verpleeg-en verzorgingshuizen. Om een juiste diagnose te kunnen stellen is het van belang dat de testen adequaat worden gebruikt. Uit verkennend onderzoek van het RIVM blijkt dat veel specifieke kwaliteits- en veiligheidsaspecten gerelateerd aan het gebruik van POC-testen in de meeste verpleeg- en verzorgingshuizen wel goed zijn geregeld, maar dat voor enkele aspecten nog onvoldoende aandacht is Bevindingen In de meeste verpleeg- en verzorgingshuizen wordt aandacht besteed aan hygiëne, patiëntidentificatie, onderhoud van POC-meters en omgang met bloedof urinemonsters. Onvoldoende aandacht is er voor trainingen en opfriscursussen voor het gebruik van POC-testen. Tevens wordt er niet in alle huizen gebruik gemaakt van protocollen of handleidingen of worden kwaliteitscontroles uitgevoerd bij ontvangst van testmaterialen en vlak voordat ze worden gebruikt. Bijna een kwart van de verpleeghuizen heeft aangegeven geen eindverantwoordelijke voor het gebruik van een POC-test te hebben aangewezen. Aanbevelingen Om de kwaliteit van zorg verder te verbeteren en risico's op gebruiksfouten met POC-testen in verpleeg- en verzorgingshuizen te verminderen, is het aan te bevelen om een eindverantwoordelijke persoon aan te wijzen voor het beheer en gebruik van POC-testen. Vervolgens is het aan te bevelen om periodiek trainingen en opfriscursussen te organiseren en deelname te registreren. Daarnaast is het van belang protocollen of handleidingen op te stellen voor het gebruik van POC-testen. Ook zijn kwaliteitscontroles gewenst bij ontvangst van testmaterialen en vlak voordat ze worden gebruikt.

Background: Urinary tract infection (UTI) is one of the most common bacterial infections, annually affecting 150 million people worldwide. The highest prevalence of UTI in the overall elderly population. However, practical problems have occurred in urine sampling in diaper-wearing elderly people. Our aim is to develop a new type of the in-vitro diagnostic devices based on “cotton”, which allows us to detect the nitrite concentrations in urine (i.e., biomarker for urinary tract infection). The combination of cotton-based diagnostic device and a smartphone-based image analysis would help the healthcare people early diagnose urinalysis-based diseases such as UTI, and improve the life quality in elderly populations around the world. Methods: Our diagnostic device integrated into diaper is made up with three primary parts: a test pad, a flow channel made by hydrophobic and hydrophilic cotton and plastic packaging substrates. The smartphone-based image analysis (a specific APP) solved recording issues including variances in either light or focal distance. The mean value was calculated and analyzed based on 8-bit grayscale using ImageJ software and defined as 255– [experiment zone intensity]. Results: The nitrite test color changes from colorless to purple, correlating positively to concentration (from 0.156 to 5 µM) in both test paper only and test pad integrated with diaper and the mean value is calculated and analyzed. Conclusions: Since this device is inexpensive, portable, simple, structurally integrating with diapers and functionally integrated with the smartphone-based application, it would have a wild range potential of becoming a commercially viable diagnostic system, in particular, for the daily healthcare of elderly people.

Background : Urinary tract infection (UTI) is a major global public health issue. The gold standard for diagnosing UTI is urine culture. This is however labour intensive and time consuming. Many prescribers therefore rely on urinalysis in diagnosing UTI. This study sought to evaluate the performance of some parameters of urinalysis as predictors of urine culture positivity. The common causative agents and their antibiotic susceptibility patterns were also determined. Methods : A cross sectional study was carried out at the University of Cape Coast Hospital from July 2017 – December 2017 among out-patients. The performance characteristics of leukocyte esterase (3+) and nitrite reactions were estimated and compared with urine culture. Antimicrobial susceptibility tests were done using disc diffusion technique described by Kirby-Bauer. Results : Prevalence of UTI in this study was 30.0% (64/213). The most prevalent pathogen was E. coli (20, 31.2%), followed by S. saprophyticus (9, 14.1%). Most of the bacteria (52, 94.5%) were sensitive to amikacin, followed by ciprofloxacin (42, 76.3%). The most sensitive (94.4%) of the parameters was pus cells [>5 white blood cells (WBC) per high power field (HPF)] and the least sensitive was the nitrite test (21.0%). The leukocyte esterase test showed the highest accuracy of 91.1%. Conclusion : The study supports the recommendation of the use of oral ciprofloxacin as the first line treatment of uncomplicated UTI by the Ghana Standard Treatment Guidelines (2017). Funding : No funding was provided for this study. Keywords : urine tract infection, urinalysis, uropathogens, Cape Coast

Background Urinary tract infection (UTI) is a common disease in children. Approximately 3-5% of girls and 1 % of boys develop a UTI. In children, prompt treatment is essential because UTI may be a risk factor for developing renal insufficiency or end stage renal disease. Howevet; prompt treatment depends on having a rapid diagnosis. Urine dipstick testis a useful and commonly used because it is low cost and gives rapid results, compared to urine cultures for diagnosing UTis. However, the diagnostic accuracy of the urine dipstick test is debatable. Objective To compare urine dipstick test (leukocyte esterase, nitrite, and combined leukocyte es terase and nitrite) to urine culture for diagnosing UTis. Methods A diagnostic study was held in H. Adam Malik Hospital from May to June 2010. There were 70 children aged 2 to 14 years and recruited by consecutive sampling. Two midstream urine specimens were collected from subjects after cleaning the external urethral orifice. The first specimen was used for urine dipstick testing for leukocyte esterase and nitrite. The second urine specimen was cultured in the laboratory. Urinalysis for leukocyte esterase and nitrite studies were performed with fresh and uncentrifuged urine. Leukocyte esteras e and nitrite caused a change in dipstick color apparent within 2 minutes. Urinalyses were considered to be positive for UTI if either leukocyte esterase or nitrite were positive. The results of urine culture were used as the golden standard. Results The sensitivities of leukocyte esterase and nitrate tests were 90 .5% and 73.8%, respectively. However, the sensitivity for combined leukocyte esterase and nitrite test was 96.4%. Nitrite test was more specific (60.7%) than the leukocyte esterase test (39.3%). The specificity of both tests taken together was 64.3% . For leukocyte esterase alone, nitrate alone, and the two combined the positive predictive values (PPV) were 69.1 %, 73.8%, and 64.3.%, respectively, and the negative predictive values (NPV) were 73.3%, 60.7%, and 96.4%, respectively. Conclusion Urine dipstick test for leukocyte esterase and nitrite combined may be a good alternative diagnostic test for UTis in children than leukocyte esterase or nitrite by themselves in areas with limited resources.

Background:Diagnostic urinary tract infection (UTI) studies have primarily been performed among female patients.Aim:To create a diagnostic algorithm for male general practice patients suspected of UTI.Design and setting:Surveillance study in the Dutch Sentinel General Practice Network.Method:Clinical information and dipstick results were collected from 603 patients. Algorithm-predicted care was compared with care as usual in terms of sensitivity (antibiotic recommended when UTI was confirmed) and specificity (no antibiotic recommended when no UTI was observed).Results:Complete information was available from 490/603 (81 %) males, of whom 66 % (321/490) had a UTI. A diagnostic algorithm recommending antimicrobial prescription in the case of a positive nitrite test or a positive leukocyte esterase test in males aged >= 60 years, had a positive predictive value (PPV) of 83 % (95 % confidence interval [CI] = 78 to 87) and a negative predictive value (NPV) of 60 % (95 % CI = 52 to 66), respectively (area under the ROC curve: 0.78, 95 % CI = 0.74 to 0.82). When both dipstick results were positive in males aged >= 60 years, PPV increased to 90 % (95 % CI = 83 to 94), whereas NPV was highest in males >= 60 years with negative dipstick results (71 %, 95 % CI = 59 to 81). Sensitivity and specificity of predicted UTI care and usual care did not differ (75 % versus 79 %, P = 0.30, and 70 % versus 63 %, P = 0.17, respectively).Conclusion:UTI care provided to Dutch male GP patients is as accurate as predicted care from a diagnostic algorithm. The studied clinical information and dipstick tests are useful for ruling in UTI in males, but have limited value in ruling out this diagnosis.

Urinary tract infection is one of the most frequently seen medical complications in pregnancy. UTI in pregnancy is an important concern, as it possesses risk of complications such as acute and chronic pyelonephritis, toxaemia, anaemia, hypertension, intrauterine growth retardation and increased perinatal mortality. The detection of bacteriuria allows an approach to be made for the prevention of chronic urinary disease in the community and to avoid complications in pregnancy at an early stage. OBJECTIVES: (1) To study the prevalence of bacterial pathogens causing urinary tract infection among pregnant women; (2) To evaluate the sensitivity of the screening test with culture. MATERIALS AND METHODS: A total of 500 samples were investigated from pregnant women aged between 18 to 35 years, with varying gravida and from all three trimesters were included in a period of one year i.e., from January to December 2011. The samples were collected aseptically from women attending the antenatal clinic at the Khaja Banda Nawaz Hospital, Gulbarga. Urine was collected in the sterile urine container. Both macroscopic and microscopic examination was done. Screening tests like Griess Nitrite test and TTC tests were done. Culture was done by standard loop technique. RESULTS: The prevalence rate of UTI in pregnancy was 10.40% i.e., with significant bacteriuria (1,00,000 or more bacterial count/ ml of urine) by Kass concept. The incidence of bacteriuria increased along with age and rising parity. Incidence was similar during all three trimesters. Gram’s staining, TTC and Griess nitrite gave 88.46%, 73.07% and 57.69% respectively correlate with culture positive bacteriurics. CONCLUSIONS: UTI, the most commonly seen complications in pregnancy was 10.4%. Early treatment of bacteriuria not only averts the occurrence of other complications, but also diminishes the risk of premature and perinatal mortality.

Actinobaculum schaalii is a new species that has so far been isolated from human blood, urine and pus. Its importance has probably been underestimated and other Actinobaculum spp. may also have been underdiagnosed. This retrospective study comprises all known cases of A. schaalii infections identified since 2004 in the canton of Neuchâtel (170 000 inhabitants), Switzerland. Strains were cultivated and isolated in the bacteriology laboratory using its routine procedure. Identification included a Rapid ID 32 A strip (bioMérieux) and 16S rRNA gene sequencing. Twenty-one positive samples were found in 19 patients (11 male, 8 female) of all ages (range 16–91 years): 10 from urine (50%), six from blood (30%), one from both blood and urine (5%), and three from pus (15%). Thirteen out of 17 (76%) cases with either blood or urine specimens had underlying genitourinary tract pathologies. When urine cultures were positive for A. schaalii, leucocytes were found in all samples (10/10, 100%) but all nitrite tests were negative (10/10, 100%). The onset of appropriate treatment was delayed due to the diminished sensitivity of A. schaalii to the antibiotics commonly used for UTIs (i.e. ciprofloxacin and trimethoprim/sulfamethoxazole) and to the delay in microbiological diagnosis. A. schaalii should specifically be searched in all cases of leukocyturia with a negative nitrite test but with Gram-positive rods in the Gram stain, in patients with underlying genitourinary tract pathology, instead of dismissing these findings as clinically irrelevant colonization by coryneform bacteria. This infection may be much more common than previously thought.

The diagnostic performance of six methods for bacteriuria testing has been studied in 781 urine specimens obtained in primary health care, using conventional culture as reference method. The cut-off limits for classification of test results into positive and negative have been optimized with respect to diagnostic performance in primary health care. With optimized tests the following diagnostic efficiencies were obtained: 1) Bacterial ATP, 0.94; 2) Bacterial count in sediment, 0.93; 3) Nitrite test, 0,92; 4) Dipslide test, 0,92; 5) White cell count in sediment; 0,87; 6) Granulocyte esterase test; 0.83. The diagnostic performance was also studied for all combinations of two tests. The highest diagnostic efficiency (0.96) was obtained by combining the ATP and dipslide tests. High diagnostic efficiencies can be obtained by a rapid primary test, using other tests for follow-up testing of specimens with intermediate or uninterpretable primary results. The most promising results were obtained by using ATP as the primary test, with follow-up testing of specimens with 3–25 nmol/l of ATP (12 per cent of the specimens). Follow-up testing by conventional culture resulted in overall diagnostic efficiency of 0.98. By performing the nitrite test on specimens with intermediary ATP-results, 81 per cent of the patients with UTI can be classified without culture. Only patients with intermediary ATP and negative nitrite results (10 per cent of the total number) will have to wait for final diagnosis based on conventional culture. Some alternative strategies to combine available methods are discussed in detail. Major advantages of the ATP test are that the test can be performed while the patients are waiting; it provides a numerical and objective result, and, in contrast to culture, it is not influenced by adhesion of bacteria to somatic cells.

As part of the search for a satisfactory screening test for bacteriuria suitable for mass detection, a comparison has been made of the tests that might be useful (Uroscreen, T.T.C. test, nitrite-nitrate incubation test, catalase test, and microscopy of urine for bacteriuria and pyuria) and of quantitative urine culture, which have been carried out in parallel. The results have been compared with the earlier published results obtained by the respective methods. None of the above screening tests has been found to fulfil the demands that should be placed on a test designed for mass detection. As regards the Uroscreen, T.T.C., and nitrite-nitrate incubation tests and microscopy of the urine for bacteriuria, their sensitivity was good but their specificity unacceptably low. Microscopy for pyuria and the catalase test showed too low sensitivity and specificity. The nitrite test was the only test with acceptable specificity but its sensitivity was too low to render it acceptable as the only screening method for mass detection. Various types of simplified urine-culture methods and Schersten's glucose method remain to be evaluated.

Consumption of nitrate and nitrite is associated with a variety of health outcomes. Commercially available test strips that allow semi-quantitative estimation of these contaminants in drinking water are inexpensive relative to laboratory testing, and are simple to use. To examine the accuracy of a nitrate/nitrite test strip, we recruited Washington State residents to estimate levels of these contaminants in their tap water using these strips, and simultaneously provide a tap water sample for laboratory analysis. Paired results were available from 102 homes. On the basis of laboratory assay, nitrate levels as nitrogen ranged from no nitrate (27%) to 40.5 mg/l (median 0.4 mg/l). Spearman's correlation coefficient between test strip- and laboratory-measured nitrate indicated moderate precision overall (r=0.72). Correlation was similar for homes inside and outside city/town limits, but differed by primary source of water for the purveyor indicated by residents (r=0.72 for groundwater and r=0.34 for surface water). Seven (7%) participants reported difficulty in distinguishing colors (contaminant levels) when using the test strip; and among the samples with nitrate, the laboratory assay indicated higher nitrate levels than the test strip for 81%. Nitrite was not detected by laboratory assay; in comparison, five (5%) subjects reported any nitrite according to the test strip. Nitrate/nitrite test strips may be useful in some epidemiologic studies, but should be used with caution, preferably as a screening tool or when laboratory assays are not feasible.

The aim of this study was to determine whether hyperbilirubinemia affects the association between a positive urine nitrite test and a positive urine culture.We conducted an institutional review board-approved, retrospective review of 12 months of patient data, compiling information for patients having urinalysis, urine culture, and total serum bilirubin. Patients were divided into 3 groups according to total serum bilirubin: less than 1.5 mg/dL, 1.5 to 3.0 mg/dL, and greater than 3.0 mg/dL. The point estimates and 95% confidence intervals of the sensitivity, specificity, false-positive proportion (proportion of false positive to all positive tests), and other test characteristics of urine nitrite as an indicator of urinary tract infection were calculated and tested for trend as a function of the 3 total serum bilirubin ranges.Three thousand one hundred seventy-four patients met our study criteria. Specificity of the nitrite test decreased as a function of increasing total serum bilirubin (0.974, 0.966, and 0.855 for the 3 total bilirubin levels, respectively) with a significant trend (P.0001). There was no significant trend in comparable sensitivity values (0.380, 0.417, and 0.241, respectively) with P = .55. The false-positive proportion also increased as a function of total serum bilirubin (17.5%, 17.3%, and 72.0%) with P.0001. Thus, if a patient's total serum bilirubin was elevated to the point of jaundice (3.0 mg/dL), it was approximately 4 times more likely that a positive urine nitrite test would be a "false positive" (ie, nitrite-positive/culture-negative) compared with those with normal serum bilirubin levels.Specificity of the urine nitrite test for urinary tract infection decreases as a function of increasing serum bilirubin. Most patients with hyperbilirubinemia and a positive nitrite test in our sample did not have an associated urinary tract infection.

Purpose Some urinary tract pathogens are capable of reducing nitrates to nitrites, including Escherichia coli, Klebsiella, Proteus, and Serratia. A urinalysis (UA) is commonly performed in patients with symptoms of a urinary tract infection (UTI) in order to detect the presence of nitrites in the urine. The objectives of this study were: 1) to assess the predictive value of the nitrite test in distinguishing nitrate-reducing pathogens from non-reducing pathogens; 2) to determine whether the results of the nitrite test can predict the susceptibility of the urine pathogen to several common antibiotics. Methods A retrospective cross-sectional chart review identified inpatients who had a UA and a positive urine culture (UC). Patients were divided into nitrite-positive and -negative groups based on UA results. Urine pathogens were identified by culture and antibiotic susceptibilities and were compared within the groups. Results Eighty-six UAs were included. A nitrite-positive UA had a 90.6% positive predictive value in identifying a nitrite-producing pathogen. A nitrite-negative UA had a negative predictive value of 33.3% in identifying a non-nitrite producing pathogen. There was no difference in the antibiotic susceptibility for ampicillin, gatifloxacin, and trimethoprim/sulfamethoxazole between the groups. Conclusions A nitrite-positive result indicates a high likelihood of the presence of a nitrite-producing organism. However, a negative nitrite test is a poor predictor of the absence of nitrite-producing pathogens. Therefore, patients with a positive nitrite test on UA can be treated empirically for a nitrite-producing organism until confirmatory laboratory studies can be completed. A nitrite-negative UA is not useful in ruling out a nitrate-reducing organism.

In their article which appears in this issue of Pediatric Nephrology, Dr. S. Swerkersson and co-workers claim that as many as one in every five infants with a true episode of urinary tract infection (UTI) will be missed with the commonly used cut-off level of ≥10(5) colony forming units (CFU)/mL. This controversial finding is supported by the results of seven previous studies including a total of 1587 children. Dr. E.H. Kass, who in the 1950s suggested the presently used cut-off level, knew at the time that it excluded a number of patients with a true infection. Later studies in adult patients also showed that up to 46–49% of women with a likely diagnosis of cystitis had low bacterial counts. These findings can, if true, improve our understanding of cases of unexplained postinfectious renal scarring. Children with low bacterial counts during an acute infectious episode have a significant risk of receiving delayed or even no antimicrobial treatment. The results of scientific studies are also confounded if 20 % of the subjects with a true infection are wrongly included in a control group diagnosed as having no UTI due to low bacterial counts. This problem cannot be easily solved by lowering the cut-off level and generally accepting that any bacterial count signifies a Btrue^ infection as this approach will drastically reduce the specificity of the culture result. Instead, as many as possible urine samples for culture should be collected from babies, infants and small children with a suprapubic bladder puncture, or a catheterised sample. In such samples bacterial counts as low as 103 CFU/mL are generally regarded as significant. In many cases, however, the only possibility is a Bclean catch^ or bag sample. In these situations, the treating physician needs to take all relevant clinical and laboratory parameters into account and if clinically important data support the diagnosis of a UTI not disregard this diagnosis based only on low bacterial counts. C-reactive protein or procalcitonin can, in a febrile child, help the physician differentiate between a febrile bacterial UTI and a viral infection. A positive nitrite test provides, albeit with a low sensitivity, strong support for a UTI diagnosis.

Aims: Urine dipstick analysis is a quick, cheap and a useful test in predicting Urinary Tract Infection (UTI) in hospitalized patients. Our aim is to evaluate the reliability (sensitivity) of urine dipstick analysis against urine culture in the diagnosis of UTI. Materials and Methods: Patients admitted to our hospital suspected of having UTI, with positive urine cultures were included in this study from a 2-year period (January 2011 to December 2012). Dipstick urinalysis was done using multistix 10 SG (Siemens) and clinitek advantus analyzer. The sensitivity of dipstick nitrites, leukocyte esterase and blood in these culture-positive UTI patients was calculated retrospectively. Results: Urine dipstick analysis of 635 urine culture-positive patients was studied. The sensitivity of nitrite alone and leukocyte esterase alone were 23.31% and 48.5%, respectively. The sensitivity of blood alone in positive urine culture was 63.94%, which was the highest sensitivity for a single screening test. The presence of leukocyte esterase and/or blood increased the sensitivity to 72.28%. The sensitivity was found to be the highest when nitrite, leukocyte and blood were considered together. Conclusions: Nitrite test and leukocyte esterase test when used individually is not reliable to rule out UTI. Hence, symptomatic UTI patients with negative dipstick assay should be subjected to urine culture for a proper management.

Background:Urinary tract infections (UTIs) are common bacterial infections dominated by lower UTI in women (LUTIW). Symptoms only are insufficient for diagnosis and accordingly, near patient diagnostic tests confidently confirming significant bacteriuria are desirable. The nitrite test (NIT) has low sensitivity, while bacterial and leukocyte counts disjunctively paired in urine sediment microscopy (SED) have high sensitivity. Similar symptomatic cure rates are found post antibiotic vs. placebo therapy in patients with negative cultures. Consequently, prescription on symptoms only implies unnecessary antibiotic therapy.Aims:to evaluate the diagnostic outcomes of NIT, SED and NIT disjunctively paired with SED (NIT+SED) vs. urine culture, with special focus on bladder incubation time (BIT), and to assess if NIT+SED can reduce unnecessary antibiotic therapy.Methods:A diagnostic, primary care, multicentre study including 1070 women with symptoms suggestive of lower UTI.Results:Significant bacteriuria was found in 77%. The BIT highly influenced the diagnostic outcomes and the optimal duration was 􀀂4h with sensitivity of 66, 90 and 95% for NIT, SED and NIT+SED, respectively. SED performed only in NIT negative specimens could reduce unnecessary antibiotics by 10% vs. prescription on symptoms only. The number needed to test with SED to reduce one unnecessary antibiotic course was five patients at BIT ≥4h and six patients at ≤3h or overall.Conclusion:The BIT highly influences the diagnostic outcomes with the highest accuracy of NIT+SED. Diagnosis of LUTIW with NIT+SED can reduce unnecessary antibiotic therapy and subsequently decrease antimicrobial resistance.Trial registration:The Swedish Medical Product Agency 1995 03 01:151:01783/94.

To assess bacterial aetiology, antimicrobial susceptibility and efficacy of empirical treatment in uncomplicated urinary tract infections and to evaluate the dipstick as a diagnostic tool.Prospective study.Clinical microbiology laboratory and 17 general practice clinics in Telemark County, Norway.A total of 184 female patients between 15 and 65 years of age with symptoms of uncomplicated urinary tract infection.Results from dipstick testing (leucocyte esterase and nitrite), bacterial culture, susceptibility patterns and efficacy of empirical antibacterial therapy on symptoms.Significant bacteruria was detected in 140 (76%) of the 184 urines. The leukocyte esterase test was of little help in predicting culture-positive UTI. A positive nitrite test accurately predicted culture-positivity, while a negative result was ambiguous. The most common bacterium, E. coli, was found in 112 (80%) of the 140 positive urines and was predominantly sensitive to ciprofloxacin (100%), mecillinam (94%), nitrofurantoin (97%), trimethoprim (88%), and sulphonamide (81%), and to a lesser extent to ampicillin (72%). In 18 patients the causative bacterium was resistant to the therapeutic agent used; 7 of these returned to their GP with persisting symptoms while in 11 symptoms resolved without further treatment.The study confirms E. coli as the predominant cause of uncomplicated UTI. Since in the majority of cases the bacterium found was susceptible to the locally preferred antimicrobials and the patients' symptoms were cured, empiric therapy is found to be an effective practice in the study area and, by inference, in others with similar antimicrobial susceptibility patterns.