Cutoff values for bacteria and leukocytes for urine sediment analyzer FUS200 in culture-positive urinary-tract infections.
OBJECTIVE
The microscopic analysis of urine is essential for the diagnosis of patients with urinary tract infections. Quantitative urine culture is the 'gold standard' method for definitive diagnosis of urinary-tract infections, but it is labor-intensive, time consuming, and does not provide the same-day results. The aim of this study was to evaluate the analytical and diagnostic performance of the FUS200 (Changchun Dirui Industry, China), a new urine sedimentation analyzer in comparison to urine culture as the reference method.


METHODS
We evaluated 1000 urine samples, submitted for culture and urine analysis with a preliminary diagnosis of urinary-tract infection. Cut-off values for the FUS200 were determined by comparing the results with urine cultures. The cut-off values by the receiver operating characteristic (ROC) curve technique, sensitivity, and specificity were calculated for bacteria and white blood cells (WBCs).


RESULTS
Among the 1000 urine specimens submitted for culture, 637 cultures (63.7%) were negative, and 363 were (36.3%) positive. The best cut-off values obtained from ROC analysis were 16/μL for bacteriuria (sensitivity: 82.3%, specificity: 58%), and 34/μL for WBCs (sensitivity: 72.3%, specificity: 65.2%). The area under the curve (AUC) for the bacteria and WBCs count were 0.71 (95% CI: 0.67-0.74) and, 0.72 (95% CI: 0.69-0.76) respectively.


CONCLUSIONS
The most important requirement of a rapid diagnostic screening test is sensitivity, and, in this perspective, an unsatisfactory sensitivity by using bacteria recognition and quantification performed by the FUS200 analyzer has been observed. After further technical improvements in particle recognition and laboratory personnel training, the FUS200 might show better results.
Department of Clinical Biochemistry, Training and Research Hospital , Kayseri , Turkey.
Derya
D
Kocer
Fatma M
FM
Sarıguzel
Cıgdem
C
Karakukcu
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D058491:Bacterial Load; D001437:Bacteriuria / Q000276:immunology / Q000382:microbiology / Q000652:urine*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007958:Leukocyte Count; D007962:Leukocytes / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012016:Reference Values; D012189:Retrospective Studies; D016482:Urinalysis / Q000295:instrumentation*; D055815:Young Adult
FUS200; analytic performance; urinalysis; urine culture