ABSTRACT
BACKGROUND: Fecal occult blood tests (FOBTs) have been widely used as a means of colorectal cancer screening. Automated FOBTs using immunologic principles have the advantages such as quantitation, high specificity, and high throughput. We evaluated a newly-introduced automated FOBT analyzer, OC-SENSOR neo (OC neo) (Eiken Chemical Co., Japan). METHODS: The precision, linearity, and carry-over rate of OC neo were assessed with specimens prepared in accordance with the guidelines of CLSI. We performed a parallel test between OC neo and OC-SENSOR I (OC I) (Eiken Chemical Co.) using 300 consecutive stool specimens and 60 OC I-positive specimens. The results were analyzed with SPSS version 13.0 (SPSS Inc., USA). RESULTS: The coefficients of variation (CV) of within-run, between-run, and between-day using OCControl L (Eiken Chemical Co.) of ca. 150 ng/mL were 3.5-7.8%, 4.5-8.8% and 4.9-5.0%, respectively. The linear regression coefficient and carry-over rate with the range of 67.8-939.4 ng/mL were 0.9998 (P<0.001), and 0.1%, respectively. Correlation coefficient between OC neo and OC I was R(2)=0.954 (P<0.001) for 60 OC I-positive specimens. The positive and negative interpretations of 300 consecutive specimens by OC neo were completely consistent with those of OC I. CONCLUSIONS: Because OC neo showed an excellent performance and a good correlation with OC I, OC neo warrants to be a reliable quantitative FOBT system for high volume laboratories.
Subject(s)
Humans , Colorectal Neoplasms/diagnosis , Hemoglobins/analysis , Mass Screening/instrumentation , Occult Blood , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
BACKGROUND: Glutaraldehyde is used most commonly as a high-level disinfectant for semicritical patient-care equipments. However, its potential toxicity to healthcare workers and a long exposure time needed to kill mycobacteria can be problematic. Recently, Perasafe(R) (Antec International, UK) has been introduced in the market as a safe and very effective disinfectant. This study was to evaluate the efficacy of Perasafe(R) against not only bacteria and yeast but also mycobacteria and bacterial spores and compare it with glutaraldehyde. MATERIAL AND METHOD: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Mycobacterium tuberculosis, and Bacillus subtilis were used for the test. Perasafe(R) and Cidex(R) were used at the final concentration of 1.62% and 2.25%, respectively; the disinfectants were neutralized by Tween 80 (0.5%) in the mycobacterial test and by lecithin (0.75%) in all other tests. Bacterial suspensions were made in phosphate buffer with or without fetal bovine serum (1%) to simulate dirty or clean conditions, respectively. The disinfectants were tested at 0, 24 and 48 hr of preparation to check stability. An effective disinfectant activity was defined as a 5 log10 reduction in viable counts. RESULTS: E. coli, S. aureus, P. aeruginosa and C albicans were effectively disinfected in less than 5 min by both Perasafe(R) and Cidex(R) and the both disinfectants remained equally effective under the dirty conditions or at 48 hr of preparation. Perasafe(R) was effective in 1 min against B. subtilis spores compared to Cidex(R) which took 30 min for the same activity. M. tuberculosis was effectively disinfected in 10 min by Perasafe(R) and 20 min by Cidex(R). CONCLUSIONS: Perasafe(R) showed greater tuberculocidal and sporicidal activities than Cidex(R), although both disinfectants were equally effective against common bacterial and yeast pathogens. Perasafe(R) may be an outstanding high-level disinfectant for endoscopes and other semicritical medical equipment.