Performance criteria for rapid screening methods to detect mycotoxins

2014 ◽  
Vol 7 (4) ◽  
pp. 439-447 ◽  
Author(s):  
C. von Holst ◽  
J. Stroka
Keyword(s):  
False Negative ◽  
Screening Method ◽  
Performance Criterion ◽  
Performance Criteria ◽  
Rapid Screening ◽  
Cost Ratio ◽  
Screening Methods ◽  
Method Performance ◽  
Official Control ◽  
The Impact

The paper describes the validation of screening methods that are used for official control to classify samples into negative and suspect positive samples. The concept is based on the principle that negative samples are considered as compliant, whereas suspect positive samples need to be re-analysed with confirmatory methods. An important performance criterion often used is a maximum value of 5% for the probability of false negative results obtained on samples that contain the analyte at the legal limit. Since the result of analysis is a binary decision, specific validation schemes need to be applied. The paper places emphasis on practical aspects of the calculation of the method performance characteristics, which are required to check whether the methods fulfil the performance criterion. The paper shows that screening methods based on a visual inspection, e.g. a dipstick, require special data treatment. In contrast there are many methods where the classification into negative and suspect positive samples is based on the comparison of a measured response against a cut-off value. This type of methods can be validated with quantitative statistics. The paper also elaborates on the calculation of the rate of false positive results of compliant samples. In addition the impact on the economical aspect of the use of the screening method is estimated, taking into account external factors such as the cost ratio between the screening and the confirmatory method and the occurrence of non-compliant samples in the entire population of the samples.

Toward Harmonization of Performance Criteria for Mycotoxin Screening Methods: The EU Perspective

2016 ◽  
Vol 99 (4) ◽  
pp. 906-913 ◽  
Author(s):  
Veronica M T Lattanzio
Keyword(s):  
Screening Method ◽  
Relevant Information ◽  
Performance Criteria ◽  
Screening Methods ◽  
The European Union ◽  
Fitness For Purpose ◽  
Method Performance ◽  
Practical Applications ◽  
Interlaboratory Validation ◽  
The Impact

Abstract Screening methods are defined as methods that are used to detect the presence of a substance or class of substances at the level of interest. These methods must have the capability of high sample throughput when being used to screen large numbers of samples for potential noncompliant results. Before using a screening method for practical applications, its fitness for the intended purpose needs to be demonstrated. This is normally achieved by conducting a validation study, comparing method performance against predefined criteria. Official guidelines recently established by the European Union for the evaluation of fitness-for-purpose performance parameters of screening methods to be used for the detection of mycotoxins in foods are presented and discussed herein. Practical applications of this evaluation scheme for single- and interlaboratory validation studies, as well as relevant information on screening method performances are reviewed, with emphasis on the impact of mycotoxin contamination in real samples on the fitness-for-purpose of the screening test. Lastly, validation follow-up is discussed in terms of extension of the scope of the method (increasing the range of application in terms of mycotoxin/matrix combinations), method implementation and verification, and evaluation of the method's applicability to modified mycotoxins.

Identification of Streptococcus pyogenes in a Pediatric Outpatient Department: A Practical System Designed for Rapid Results and Resident Teaching

PEDIATRICS ◽  
1974 ◽  
Vol 54 (6) ◽  
pp. 718-723
Author(s):  
Katherine Sprunt ◽  
Dorothea Vail ◽  
Russell S. Asnes
Keyword(s):  
False Positive ◽  
Fluorescent Antibody ◽  
False Negative ◽  
Screening Method ◽  
Rapid Screening ◽  
Resident Teaching ◽  
Antibody Uptake ◽  
Busy Clinic ◽  
Group A ◽  
Laboratory Tool

A rapid screening method for identification of clinic patients with pharyngitis who are carrying group A beta-hemolytic streptococci and for teaching residents the values and limitations of the culture-disk approach to identification has been reviewed as developed for a busy clinic and a busy hospital laboratory. Identification of positive cultures in less than 24 hours, using Taxos A disk and specific fluorescent antibody uptake, resulted in 12% apparent false-positive and 3.6% false-negative reports. However, when viewed in the light of the techniques used for verifying results, there were probably 3% false-positive and 3% false-negative reports. The screening method is considered acceptably reliable and practical as a laboratory tool and a resident teaching device.

scholarly journals A study of prevalence of asymptomatic bacteriuria in pregnant women from rural areas attending to Obstetric Department in Akash Hospital, Karnataka, India

2019 ◽  
Vol 8 (7) ◽  
pp. 2845
Author(s):  
Rohini N. S. ◽  
Ravishankar S. N. ◽  
Kala K. ◽  
Rakshith N. R.
Keyword(s):  
Pregnant Women ◽  
Urine Culture ◽  
Screening Method ◽  
Asymptomatic Bacteriuria ◽  
Significant Risk ◽  
Screening Tests ◽  
Rapid Screening ◽  
Screening Methods ◽  
Gram Staining ◽  
In Pregnancy

Background: Asymptomatic bacteriuria (ASB) in pregnancy is a significant risk factor for developing upper urinary tract infection and pyelonephritis which is associated with significant maternal and fetal risks. The aim of this study was to know the prevalence of asymptomatic bacteriuria in pregnancy, to identify the organisms and their antibiotic susceptibility patterns and to formulate a single or combined rapid screening method as an acceptable alternative to urine culture.Methods: A total of 375 pregnant women aged between 18 to 45 years were included in this study. Clean catch mid-stream urine samples were collected. Screening tests done were gram staining of uncentrifuged urine, pus cell count, nitrite test and leukocyte esterase test. Identification of pathogens and antibiotic sensitivity tests were performed as per standard urine culture and sensitivity methods.Results: Out of the 375 pregnant women, 31 (8.4%) had significant bacteriuria. High percentage of women with ASB were primigravidas (51.38%) and in 2nd trimester (43.86%). The most common organism isolated was E.coli (56.14%). In screening tests, gram staining of uncentrifuged urine had a sensitivity of 85.71%. Sensitivity of 71.42% was found in Nitrite and leucocyte esterase tests. However, the combination of these two tests, with either test positive, showed sensitivity and negative predictive value of 90.47% and 99.09% respectively.Conclusions: Early detection and treatment of ASB in pregnancy can prevent complications. ASB can be identified by simple and combined rapid screening methods and urine culture along with antibiogram. Therefore, screening and treatment of ASB may be incorporated as routine antenatal care for safe motherhood and healthy newborn.

Comparison between VIDAS Automatic Enzyme-Linked Fluorescent Immunoassay and Culture Method for Salmonella Recovery from Pork Carcass Sponge Samples

2002 ◽  
Vol 65 (10) ◽  
pp. 1656-1659 ◽  
Author(s):  
KUANG-SHENG YEH ◽  
CHIN-EN TSAI ◽  
SHIH-PING CHEN ◽  
CHAO-WEI LIAO
Keyword(s):  
False Negative ◽  
Screening Method ◽  
Culture Method ◽  
Automated System ◽  
Rapid Screening ◽  
Assay Method ◽  
Intensive Culture ◽  
Negative Results ◽  
False Negative Results ◽  
Potential Alternative

VIDAS Salmonella (VIDAS-SLM) is an automated system that uses the enzyme-linked fluorescent assay method to detect Salmonella species. This study evaluated the efficacy of the VIDAS-SLM method in detecting Salmonella species in pork carcass sponge samples gathered from 10 slaughter plants in Taiwan. Two hundred fifty-seven pork carcass sponge samples were screened by the VIDAS-SLM method and by the culture method in parallel. While 18 sponge samples were found to test positive by both methods, the VIDAS-SLM method detected four additional positive samples for which the culture method failed to recover Salmonella. The specificity of the VIDAS-SLM method was found to be 0.98, and its sensitivity was 1.0, since no false-negative results occurred. Artificially inoculated Salmonella at concentrations as low as 5.0 × 100 CFU/ml was detected in the heat-inactivated sponge sample in the presence or absence of 5.0 × 104 CFU of Citrobacter freundii per ml. Thus, the VIDAS-SLM method is a rapid screening method and a potential alternative to the time- and labor-intensive culture method.

Comparison of Colorimetric Monoclonal Enzyme Immunoassay Screening Methods for Detection of Salmonella in Foods

1990 ◽  
Vol 73 (1) ◽  
pp. 43-50
Author(s):  
Michael S Curiale ◽  
Mary Joan Klatt ◽  
Barbara J Robison ◽  
Lisa T Beck
Keyword(s):  
Enzyme Immunoassay ◽  
Magnetic Beads ◽  
False Negative ◽  
Screening Method ◽  
False Negative Rate ◽  
Culture Method ◽  
Food Samples ◽  
Assay Method ◽  
Screening Methods ◽  
Well Assay

Abstract A colorimetric enzyme immunoassay (EIA) method for detection of Salmonella in foods has been compared to the AOAC colorimetric monoclonal EIA screening method (986.35,15th ed.; 46.B21-46.B29, 14th ed.). The assays use the same monoclonal antibodies and have similar reactivity toward Salmonella. However, the new assay uses antibody-coated microtiter wells instead of coated magnetic beads to capture Salmonella antigens. Compared with the bead assay, the coated-well assay format requires significantly less time to complete, and was consistently able to detect lower levels of Salmonella In mixed culture. Compared to the standard AOAC culture method for food samples, the plate assay was as productive. No false negatives were obtained by the immunoassay; the false negative rate was 1.1% by the culture method. The rate of agreement between the 2 methods was 99.1 %. The official final action bead assay method for Salmonella in foods, 986.35, and the same assay for use with low-moisture foods, 987.11, have been modified official first action to use antibody-coated microtiter strip-wells

scholarly journals Exploring the Use of Two Brief Fatigue Screening Tools in Cancer Outpatient Clinics

2021 ◽  
Vol 20 ◽  
pp. 153473542098344
Author(s):  
Elizabeth J. Pearson ◽  
Allison Drosdowsky ◽  
Lara Edbrooke ◽  
Linda Denehy
Keyword(s):  
Rating Scale ◽  
Statistical Tests ◽  
Screening Method ◽  
Numeric Rating Scale ◽  
Outpatient Setting ◽  
Screening Tools ◽  
Outpatient Clinics ◽  
Screening Methods ◽  
Clinically Significant ◽  
The Impact

Purpose: Cancer fatigue guidelines recommend routine fatigue screening, with further assessment for people reporting moderate to severe fatigue. There is neither a gold-standard, nor a broadly accepted screening method, and knowledge about the impact of screening on care processes is limited. This study aimed to explore the feasibility of 2 fatigue screening methods and current clinical practice in cancer outpatient clinics. Methods: Hospital outpatients attending cancer clinics during 1 week completed a five-item survey: a numeric scale for current tiredness, 2 categorical pictorial scales rating tiredness last week and the impact of fatigue (Fatigue Pictogram), screening tool preference and help needed for survey completion. Participant demographics and fatigue documentation by clinical staff for that appointment were extracted from medical records. Analyses used descriptive statistics. Groups were compared using appropriate statistical tests. Results: Over 75% of participants rated their fatigue consistently as mild or significant on both screening tools. Of 1709 eligible outpatients, 533 (31%) completed the survey. Records were audited for 430 (81%) identifiable participants. Over half of the participants reported moderate or severe tiredness either “now” (237, 57%) and/or “last week” (226, 53%). Clinician documentation of fatigue seldom matched self-reports. Fatigue was rated as severe by 103 participants (24%), yet was noted in only 21 (20%) of these individuals’ clinical notes. Both screening tools were equally preferred. Conclusion: The numeric rating scale and Fatigue Pictogram are equally applicable for screening fatigue in cancer outpatient care. There is a high prevalence of clinically significant fatigue in a hospital outpatient setting that is not documented. Adequate care pathways for further management should be established alongside fatigue screening.

scholarly journals RAPID LAB SCREENING METHODS FOR WINTER PROTECTION METHODS OF STRAWBERRY

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 655b-655
Author(s):  
J.M. Turner ◽  
K.K. Tanino
Keyword(s):  
Low Temperature ◽  
Cultural Practices ◽  
Screening Method ◽  
Rapid Screening ◽  
Screening Methods ◽  
Temperature Profiles ◽  
Controlled System ◽  
Row Covers ◽  
Rapid Screening Method ◽  
One Year

On average, one year in ten is a true test winter for screening winter hardy plants. Thus, screening of cultural practices under field conditions is often difficult, requiring many years data. In Saskatchewan, the two major winter stresses are low temperature and desiccation. Under controlled lab conditions, a rapid screening method for cultural practices on strawberry (Fragaria × ananassa Duch.) plants was developed. Temperature profiles and survival under various row covers and mulches in this controlled system corresponded well to previous field results. Straw over plastic and snow over plastic row covers conferred the best low temperature protection on these plants.

Patient navigation (PN) for colorectal cancer screening (CRC): Experience in program implementation for underserved neighborhoods of Cleveland, Ohio.

2019 ◽  
Vol 37 (27_suppl) ◽  
pp. 147-147
Author(s):  
Katherine Glass ◽  
Aqeel Seals
Keyword(s):  
Colorectal Cancer ◽  
Program Implementation ◽  
Patient Navigation ◽  
Underserved Populations ◽  
Screening Method ◽  
Screening Methods ◽  
Community Members ◽  
Crc Screening ◽  
The Impact ◽  
Cleveland Ohio

147 Background: Cleveland, Ohio has high rates of colorectal cancer (CRC). 50% of CRC in Cleveland is late stage, and rates of CRC screening in Cleveland are low. Colonoscopy is a screening method for CRC, but barriers exist for the underserved population of Cleveland. The Fecal Immunohistochemical Test (FIT) is a less-costly and non-invasive CRC screening method that has demonstrated increased uptake in CRC screening for underserved populations. Previous literature has demonstrated that Patient Navigation (PN) can increase screening rates in underserved populations through education and assistance to overcome barriers to care. Little, however, has been published about the impact of pairing PN with a program that encourages either colonoscopies or FIT utilization to complete screening. Methods: Community members were educated about both colonoscopies and FIT in a neutral manner. After education, interested participants provided preference for screening type. Participants received follow-up calls from patient navigators. Navigators provided encouragement to complete screening and collected information about barriers. Results: N = 612 patients received PN for CRC. 72% of the population (n = 442) were Black. 47% (n = 290) chose colonoscopy, and n = 322 chose FIT. 44% (n = 263) completed a screening. 19% (n = 55) of those choosing colonoscopy completed screening. 66% (n = 213) choosing FIT completed screening. Women who chose FIT were more likely than men who chose FIT to complete screening (86% vs. 45%, p < 0.001). Barriers to screening included appointment coordination, transportation, and insurance. Conclusions: When offered PN and choice of CRC screening, community members in Cleveland equally chose colonoscopy vs. FIT. Those that chose FIT were more likely to complete screening (p < 0.001). Barriers suggest access and use of healthcare remain challenging for underserved communities. The simplicity of FIT paired with PN may remove barriers for this population and increase screening uptake. More research needs to be done to understand the impact of PN on sustained rate of completion.

scholarly journals Real-Time PCR Method for Detection of Salmonella spp. in Environmental Samples

2017 ◽  
Vol 83 (14) ◽  
Author(s):  
Kuppuswamy N. Kasturi ◽  
Tomas Drgon
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Environmental Samples ◽  
False Negative ◽  
Screening Method ◽  
Reference Method ◽  
Rapid Screening ◽  
Content Type ◽  
Pcr Method ◽  
Group D

ABSTRACT The methods currently used for detecting Salmonella in environmental samples require 2 days to produce results and have limited sensitivity. Here, we describe the development and validation of a real-time PCR Salmonella screening method that produces results in 18 to 24 h. Primers and probes specific to the gene invA, group D, and Salmonella enterica serovar Enteritidis organisms were designed and evaluated for inclusivity and exclusivity using a panel of 329 Salmonella isolates representing 126 serovars and 22 non-Salmonella organisms. The invA- and group D-specific sets identified all the isolates accurately. The PCR method had 100% inclusivity and detected 1 to 2 copies of Salmonella DNA per reaction. Primers specific for Salmonella-differentiating fragment 1 (Sdf-1) in conjunction with the group D set had 100% inclusivity for 32 S. Enteritidis isolates and 100% exclusivity for the 297 non-Enteritidis Salmonella isolates. Single-laboratory validation performed on 1,741 environmental samples demonstrated that the PCR method detected 55% more positives than the Vitek immunodiagnostic assay system (VIDAS) method. The PCR results correlated well with the culture results, and the method did not report any false-negative results. The receiver operating characteristic (ROC) analysis documented excellent agreement between the results from the culture and PCR methods (area under the curve, 0.90; 95% confidence interval of 0.76 to 1.0) confirming the validity of the PCR method. IMPORTANCE This validated PCR method detects 55% more positives for Salmonella in half the time required for the reference method, VIDAS. The validated PCR method will help to strengthen public health efforts through rapid screening of Salmonella spp. in environmental samples.

scholarly journals Comparative Evaluation of Ligation-Mediated PCR and Spoligotyping as Screening Methods for Genotyping ofMycobacterium tuberculosis Strains

1999 ◽  
Vol 37 (10) ◽  
pp. 3118-3123 ◽  
Author(s):  
Stefano Bonora ◽  
M. Cristina Gutierrez ◽  
Giovanni Di Perri ◽  
Francesca Brunello ◽  
Benedetta Allegranzi ◽  
...  
Keyword(s):  
Comparative Evaluation ◽  
Screening Method ◽  
Rflp Analysis ◽  
Step Test ◽  
Screening Tests ◽  
Rapid Screening ◽  
Screening Methods ◽  
Typing Method ◽  
Low Prevalence ◽  
Discriminatory Index

Spoligotyping has been suggested as a screening test in multistep genotyping of Mycobacterium tuberculosis strains. Relying on restriction fragment length polymorphism (RFLP) analysis with IS6110 (IS6110 RFLP analysis) as a “gold standard,” we performed a comparative evaluation of spoligotyping and ligation-mediated PCR (LMPCR), a recently described PCR-based typing method, as rapid screening tests for fingerprinting of 158 M. tuberculosis strains collected in Verona, Italy. LMPCR seemed to be comparable to spoligotyping in terms both of feasibility with rapidly extracted DNA and of generation of software-analyzable images. Moreover, LMPCR grouped considerably fewer strains than spoligotyping (38 versus 67%) and was found to reduce the cluster overestimation rate (26.3 versus 58%) and to give a better discriminatory index (0.992 versus 0.970) compared to spoligotyping. In our geographical region, where there was no evidence of clustered strains carrying fewer than six IS6110 copies, LMPCR was found to be more discriminatory than spoligotyping. We also evaluated two models of three-step typing strategies, involving the use of spoligotyping and LMPCR as screening methods and IS6110 RFLP analysis as a further supporting test. LMPCR proved to be a more effective first-step test than spoligotyping, significantly reducing the need for subtyping. LMPCR should be considered an alternative to spoligotyping as a rapid screening method for M. tuberculosis fingerprinting, particularly in areas with a low prevalence of M. tuberculosis strains carrying few copies of IS6110.

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