ABSTRACT
OBJECTIVE: Urine culture, the gold standard to confirm the presence of urinary tract infection (UTI), is the most requested assay in the microbiology department. Our objective was to determine the diagnostic yield of the UF-Series cytometer as a screening method for UTI. METHODS: All the urine samples sent to the six Microbiology Laboratories participating in a period of 5 working days were analyzed. We collected demographic variables, apart from those variables related to urine samples: source and sample type (midstream, catheterized or nephrostomy urines), collection with/without boric acid, cytometer parameters (leukocyturia, bacteriuria, bacteria morphology and epithelial cells) and urine culture results. ROC curves were plotted to determine predictive capacity of the cytometer. RESULTS: A sample of 2,468 patients with average age of 53 years were processed (ratio women:men 2:1). Urine culture detected 23% of positive urine samples. The predictor variables of UTI were: morphology of bacilli, bacteriuria ≥21 bacteria/µL, age ≥65 years, samples collected in the emergency service and hospitalization and preserving conditions. With 21 bacteria/µL as a cut-off point, we obtained a sensitivity of 93.3% and 94.5% negative predictive value, then reducing the samples to be cultured by 28.9% with 1.6% false negatives. CONCLUSIONS: We consider that the UF-Series is a valid and accurate tool for the detection of UTI. Therefore, it could be used as screening method in the clinical practice prior to the urine culture, reducing culture requirement by approximately 30%, with a low false negative rate.
Subject(s)
Flow Cytometry/instrumentation , Urinary Tract Infections/diagnosis , Urinary Tract Infections/microbiology , Adult , Aged , Aged, 80 and over , Bacteriuria/microbiology , Bacteriuria/urine , False Positive Reactions , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Prospective Studies , ROC Curve , Reproducibility of Results , Sensitivity and Specificity , Urine/microbiology , Young AdultABSTRACT
The new Sysmex UF-1000i analyzer - which incorporates bacteria morphology distinction - allows to automatically screen samples to be cultured at microbiology laboratories. We have evaluated the feasibility and accuracy of Sysmex UF-1000i to screen urinary tract infections (UTIs). A total amount of 2468 urine samples from six Spanish hospitals were analysed. Demographic and clinical data such as age, gender, source and sample type, preserving conditions, cytometer parameters (bacteria, leucocytes and bacteria morphology) as well as urine culture results (gold standard) were recorded. After applying data mining techniques, the variables of age, bacteria count and rod morphology were defined as predictive variables of UTIs. By using the UF-1000i in combination with a predictive algorithm of three decision rules, we could identify 94·9 and 47·4% positive and negative urine samples, respectively, with a negative predictive value of 97 and only 1·17% diagnostic error. This error was reduced down to 0·4% when contaminated samples were excluded. Our results show that flow cytometry parameters together with age, by means of a predictive algorithm model, can be used to screen UTIs. Its implementation would avoid culturing 38% of urine samples, and therefore, would reduce time to diagnosis with a discrete false negative ratio. SIGNIFICANCE AND IMPACT OF THE STUDY: Fluorescent flow cytometry performance has recently spread for urine screening. However, controversy about cytometer results can be drawn from medical literature. This study shows the diagnosis accuracy of Sysmex UF-1000i analyzer by means of a group of decision rules encompassing both demographic variables (age) and cytometer parameters (bacteria, leucocytes and bacteria morphology). After applying the predictive algorithm, the UF-1000i could optimally identify 95% urinary tract infections with high negative predictive value and low diagnostic error. Implementation of UF-1000i would avoid culturing almost 38% of urine samples, thus reducing time to diagnosis, unnecessary antibiotic treatments and consequently improving cost-effectiveness.
Subject(s)
Bacteria/isolation & purification , Flow Cytometry/methods , Urinalysis/methods , Urinary Tract Infections/diagnosis , Urine/microbiology , Adolescent , Adult , Aged , Aged, 80 and over , Algorithms , Bacterial Load , Child , Child, Preschool , Female , Flow Cytometry/instrumentation , Hospitals , Humans , Infant , Infant, Newborn , Leukocytes , Male , Middle Aged , Urinary Tract Infections/microbiology , Young AdultABSTRACT
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Subject(s)
Humans , Male , Middle Aged , Asthma, Occupational/diagnosis , Bronchial Provocation Tests , Wood/adverse effects , Trees/adverse effects , Quercus/adverse effectsABSTRACT
Otomycosis is a common disease. We try to analyze the causative factors for otomycosis in our environment. Our study includes 451 patients with a presumed diagnosis of otomycosis. The patients were included by ear, nose and throat specialist and general doctors; the diagnosis was confirmed in 24.43% and 16.16% respectively. The most common fungal pathogen found was Aspergillus spp. and Candida sp. The high frecuency of Aspergillus Niger may be because of the diferent ways of gathering samples. The abundance of Candida parapsilosis in the samples that came from general doctors may be because the inadequate treatment with topic antibiotics contributes fungal proliferation. We conclude that the causative factors for otomycosis could be avoided or treated. Treatment with antifungal agents is not enought to ensure complete cure, an furthermore the treatment should be aimed to restore the physiology of the external auditory cannal.
Subject(s)
Mycoses/diagnosis , Otitis/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Mycoses/epidemiology , Otitis/epidemiology , Otitis/microbiology , Retrospective StudiesABSTRACT
La otomicosis es una enfermedad frecuente. Pretendemos dilucidar distintos criterios de esta afección estudiándola en nuestro medio. Se incluyen 451 pacientes con diagnóstico de presunción: otomicosis. Proceden de consultas otorrinolaringológicas y de médicos de familia: sólo se confirma microbiológicamente el diagnóstico en un 24,43% y en un 16,16% respectivamente. Los géneros fúngicos más abundantes son Aspergillus spp. y Candida spp. La frecuencia en la presencia de Aspergillus níger se relaciona con las distintas metodologías en la extracción de las muestras. La abundancia de Candida parapsilosis en muestras procedentes de médicos de familia se considera debida a la proliferación fúngica tras uso inadecuado de antibioterapia tópica. Se concluye que los factores predisponentes para el desarrollo de la otomicosis pueden ser evitables o tratables. Se manifiesta que la utilización de antimicóticos no es suficiente para obtener la curación completa; el tratamiento ha de ir encaminado, además, a restaurar la fisiología del conducto auditivo externo
Otomycosis is a common disease. We try to analyze the causative factors for otomycosis in our environment. Our study includes 451 patients with a presumed diagnosis of otomycosis. The patients were included by ear, nose and throat specialist and general doctors; the diagnosis was confirmed in 24.43% and 16.16% respectively. The most common fungal pathogen found was Aspergillus spp. and Candida sp. The high frecuency of Aspergillus Níger may be because of the diferent ways of gathering samples. The abundance of Candida parapsilosis in the samples that came from general doctors may be because the inadequate treatment with topic antibiotics contributes fungal proliferation. We conclude that the causative factors for otomycosis could be avoided or treated. Treatment with antifungal agents is not enought to ensure complete cure, an furthermore the treatment should be aimed to restore the physiology of the external auditory cannal
