scholarly journals Evaluation of Two Rapid Assays for Detection ofClostridium difficile Toxin A in Stool Specimens

1999 ◽  
Vol 37 (9) ◽  
pp. 3044-3047 ◽  
Author(s):  
Daniel P. Fedorko ◽  
Howard D. Engler ◽  
Elizabeth M. O’Shaughnessy ◽  
Esther C. Williams ◽  
Cynthia J. Reichelderfer ◽  
...  
Keyword(s):  
Predictive Value ◽  
Chart Review ◽  
Laboratory Diagnosis ◽  
Clinical Diagnostics ◽  
Becton Dickinson ◽  
Toxin A ◽  
Ofclostridium Difficile ◽  
Rapid Assays ◽  
Toxigenic Culture ◽  
Stool Specimens

Rapid laboratory diagnosis of Clostridium difficile-associated diarrhea (CDAD) is highly desirable in the setting of hospital cost containment. We tested 654 stool specimens to compare the performance of two assays for rapid detection of toxin A, the Immunocard Toxin A test (Meridian Diagnostics, Inc.) and the Culturette Brand Toxin CD enzyme immunoassay (EIA) (Becton Dickinson Microbiology Systems), with a cytotoxin assay (Cytotoxi Test; Advanced Clinical Diagnostics) and culture on cycloserine-cefoxitin-fructose agar followed by determination of the production of toxins A and B. A chart review was performed for patients whose stool specimens provided positive results on one to three of the assays. With the “gold standard” of all four assays positive or chart review evidence of CDAD, 97 (14.8%) stool specimens were positive by one or more assays and 557 (85.2%) were negative by all methods. Total agreement for all assays was 90.5% (592 of 654). The sensitivity, specificity, positive predictive value, and negative predictive value for toxigenic culture were 94.7, 98.6, 87.1, and 99.5%, respectively, for toxigenic culture; 87.7, 98.6, 86.2, and 98.8%, respectively, for the cytotoxin assay; 71.9, 99.3, 91.1, and 97.3%, respectively, for the Immunocard; and 68.4, 99.1, 88.6, and 96.9%, respectively, for the Culturette EIA. While easy to perform and highly specific, these rapid assays do not appear to be sufficient for accurate diagnosis of CDAD.

scholarly journals Comparison of Culture, Cytotoxin Assay and Two Eia Tests with Clinical Diagnosis ofClostridium difficile-Associated Diarrhea

1994 ◽  
Vol 5 (4) ◽  
pp. 163-167 ◽  
Author(s):  
Marilyn Binning ◽  
Michael A John ◽  
Berend C Schieven ◽  
Thomas W Austin ◽  
Robert Lannigan ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Selective Medium ◽  
Infectious Diarrhea ◽  
Toxin A ◽  
Ofclostridium Difficile ◽  
Clinical Criteria ◽  
Hospital Patients ◽  
Common Etiology ◽  
Stool Specimens ◽  
Single Laboratory

Objective: The most common etiology of infectious diarrhea in hospitalized patients isClostridium difficile. No single laboratory test yields a definitive diagnosis. Four methods were evaluated for their sensitivity and specificity in patients who had clinically definedC difficile-associated diarrhea.Methods: Clinical criteria forC difficile-associated diarrhea were defined. All adult in-hospital patients whose stools were tested forC difficilewere prospectively followed. Stools were examined with culture on a selective medium, a commercial cytotoxicity assay (cta), and two commercially available enzyme immunoassays (eias) for toxin A (Meridian) and toxin AB (cbc).Results: During the study period 235 stool specimens from 185 patients were tested. Fifty-one patients were positive forC difficileor its markers,ctawas most sensitive (80%), whereascbc-eiawas most specific (98%). Differences in the sensitivities ofctaand Meridian-eiawere minor (80% versus 73.3%) and they were equally specific (95.5%).Conclusions: The sensitivity and specificity ofeiafor toxin A is similar to other tests. However, due to rapidity and ease of performance, it may be a more practical test for the diagnosis ofC difficile-associated diarrhea, especially if the cytotoxin assay is not available.

scholarly journals Combination of Culture, Antigen and Toxin Detection, and Cytotoxin Neutralization Assay for OptimalClostridium difficileDiagnostic Testing

2013 ◽  
Vol 24 (2) ◽  
pp. 89-92 ◽  
Author(s):  
Michelle J Alfa ◽  
Shadi Sepehri
Keyword(s):  
Diagnostic Algorithm ◽  
Laboratory Diagnosis ◽  
Neutralization Assay ◽  
Confirmatory Test ◽  
Toxin A ◽  
Diagnostic Laboratory ◽  
Toxigenic Culture ◽  
Stool Samples ◽  
Step Algorithm ◽  
One Year

BACKGROUND: There has been a growing interest in developing an appropriate laboratory diagnostic algorithm forClostridium difficile, mainly as a result of increases in both the number and severity of cases ofC difficileinfection in the past decade. AC difficilediagnostic algorithm is necessary because diagnostic kits, mostly for the detection of toxins A and B or glutamate dehydrogenase (GDH) antigen, are not sufficient as stand-alone assays for optimal diagnosis ofC difficileinfection. In addition, conventional reference methods forC difficiledetection (eg, toxigenic culture and cytotoxin neutralization [CTN] assays) are not routinely practiced in diagnostic laboratory settings.OBJECTIVE: To review the four-step algorithm used at Diagnostic Services of Manitoba sites for the laboratory diagnosis of toxigenicC difficile.RESULT: One year of retrospectiveC difficiledata using the proposed algorithm was reported. Of 5695 stool samples tested, 9.1% (n=517) had toxigenicC difficile. Sixty per cent (310 of 517) of toxigenicC difficilestools were detected following the first two steps of the algorithm. CTN confirmation of GDH-positive, toxin A- and B-negative assays resulted in detection of an additional 37.7% (198 of 517) of toxigenicC difficile. Culture of the third specimen, from patients who had two previous negative specimens, detected an additional 2.32% (12 of 517) of toxigenicC difficilesamples.DISCUSSION: Using GDH antigen as the screening and toxin A and B as confirmatory test forC difficile, 85% of specimens were reported negative or positive within 4 h. Without CTN confirmation for GDH antigen and toxin A and B discordant results, 37% (195 of 517) of toxigenicC difficilestools would have been missed. Following the algorithm, culture was needed for only 2.72% of all specimens submitted forC difficiletesting.CONCLUSION: The overview of the data illustrated the significance of each stage of this four-stepC difficilealgorithm and emphasized the value of using CTN assay and culture as parts of an algorithm that ensures accurate diagnosis of toxigenicC difficile.

scholarly journals Evaluation of the Use of Rectal Swabs for Laboratory Diagnosis ofClostridium difficileInfection

2018 ◽  
Vol 56 (7) ◽  
Author(s):  
N. Jazmati ◽  
E. Kirpal ◽  
E. Piepenbrock ◽  
Y. Stelzer ◽  
M. J. G. T. Vehreschild ◽  
...  
Keyword(s):  
Liquid Medium ◽  
Detection Rate ◽  
Laboratory Diagnosis ◽  
Toxin A ◽  
Suitable Alternative ◽  
Content Type ◽  
Toxigenic Culture ◽  
Rectal Swabs ◽  
Stool Samples ◽  
The Impact

ABSTRACTFor the diagnosis ofClostridium difficileinfection (CDI), microbiological testing is almost always accomplished through the analysis of stool specimens. We evaluated the performances of rectal swabs with liquid transport medium (FS) and nylon flocked dry swabs for the detection ofC. difficile. Additionally, the impact on the diagnostic yield of storing swabs at −80°C for up to 3 months was evaluated. Sixty clinical stool samples positive forC. difficileby PCR were used for simulating rectal swabbing. FS and dry swabs were dipped into the stool and tested by PCR directly after swabbing at 1 and 3 months after storage at −80°C. Stool and the liquid medium of FS were additionally tested by a combination of glutamate dehydrogenase antigen (GDH) testing and toxin A/B enzyme immunoassay (EIA), as well as by toxigenic culture (TC). Using dry swabs, the PCR-based detection rate ofC. difficilewas equal to the rate using stool samples (30/30 [100%]), whereas the detection rate in FS was significantly lower (25/30 [83.2%];P= 0.019). The sensitivities of FS for detectingC. difficileby PCR, TC, GDH testing, and toxin A/B EIA were 83.3%, 85.7%, 88%, and 68.9%, respectively. Storage of swabs at −80°C had no impact on the detection rate. FS cannot replace stool samples in the two-step laboratory diagnosis of CDI, as the sensitivities were too low, probably due to diluting effects of the fecal sample in the liquid medium. For simple PCR-based detection ofC. difficile, dry swabs proved to be a suitable alternative to the use of stool samples.

Screening for haemorrhagic disorders in paediatric patients by means of a questionnaire

2009 ◽  
Vol 29 (S 01) ◽  
pp. S87-S89 ◽  
Author(s):  
I. Music ◽  
M. Novak ◽  
B. Acham-Roschitz ◽  
W. Muntean
Keyword(s):  
Predictive Value ◽  
Laboratory Diagnosis ◽  
Von Willebrand Disease ◽  
Control Group ◽  
Older Children ◽  
Mild Disease ◽  
History Of ◽  
Von Willebrand ◽  
Specific Symptoms ◽  
Infants And Young Children

SummaryAim: In children, screening for haemorrhagic disorders is further complicated by the fact that infants and young children with mild disease in many cases most likely will not have a significant history of easy bruising or bleeding making the efficacy of a questionnaire even more questionable. Patients, methods: We compared the questionnaires of a group of 88 children in whom a haemorrhagic disorder was ruled out by rigorous laboratory investigation to a group of 38 children with mild von Willebrand disease (VWD). Questionnaires about child, mother and father were obtained prior to the laboratory diagnosis on the occasion of routine preoperative screening. Results: 23/38 children with mild VWD showed at least one positive question in the questionnaire, while 21/88 without laboratory signs showed at least one positive question. There was a trend to more specific symptoms in older children. Three or more positive questions were found only in VWD patients, but only in a few of the control group. The question about menstrual bleeding in mothers did not differ significantly. Sensitivity of the questionnaire for a hemostatic disorder was 0.60, while specifity was 0.76. The negative predictive value was 0.82, but the positive predictive value was only 0.52. Conclusions: Our small study shows, that a questionnaire yields good results to exclude a haemostatic disorder, but is not a sensitive tool to identify such a disorder.

scholarly journals Development of an Electronic Algorithm to Identify Inappropriate Antibiotic Prescribing for Pediatric Pharyngitis

2020 ◽  
Vol 41 (S1) ◽  
pp. s188-s189
Author(s):  
Jeffrey Gerber ◽  
Robert Grundmeier ◽  
Keith Hamilton ◽  
Lauri Hicks ◽  
Melinda Neuhauser ◽  
...  
Keyword(s):  
Predictive Value ◽  
Gold Standard ◽  
Antibiotic Stewardship ◽  
Chart Review ◽  
Antibiotic Use ◽  
Audit And Feedback ◽  
Urgent Care ◽  
Antibiotic Prescribing ◽  
Tract Infections ◽  
The Impact

Background: Antibiotic overuse contributes to antibiotic resistance and unnecessary adverse drug effects. Antibiotic stewardship interventions have primarily focused on acute-care settings. Most antibiotic use, however, occurs in outpatients with acute respiratory tract infections such as pharyngitis. The electronic health record (EHR) might provide an effective and efficient tool for outpatient antibiotic stewardship. We aimed to develop and validate an electronic algorithm to identify inappropriate antibiotic use for pediatric outpatients with pharyngitis. Methods: This study was conducted within the Children’s Hospital of Philadelphia (CHOP) Care Network, including 31 pediatric primary care practices and 3 urgent care centers with a shared EHR serving >250,000 children. We used International Classification of Diseases, Tenth Revision (ICD-10) codes to identify encounters for pharyngitis at any CHOP practice from March 15, 2017, to March 14, 2018, excluding those with concurrent infections (eg, otitis media, sinusitis), immunocompromising conditions, or other comorbidities that might influence the need for antibiotics. We randomly selected 450 features for detailed chart abstraction assessing patient demographics as well as practice and prescriber characteristics. Appropriateness of antibiotic use based on chart review served as the gold standard for evaluating the electronic algorithm. Criteria for appropriate use included streptococcal testing, use of penicillin or amoxicillin (absent β-lactam allergy), and a 10-day duration of therapy. Results: In 450 patients, the median age was 8.4 years (IQR, 5.5–9.0) and 54% were women. On chart review, 149 patients (33%) received an antibiotic, of whom 126 had a positive rapid strep result. Thus, based on chart review, 23 subjects (5%) diagnosed with pharyngitis received antibiotics inappropriately. Amoxicillin or penicillin was prescribed for 100 of the 126 children (79%) with a positive rapid strep test. Of the 126 children with a positive test, 114 (90%) received the correct antibiotic: amoxicillin, penicillin, or an appropriate alternative antibiotic due to b-lactam allergy. Duration of treatment was correct for all 126 children. Using the electronic algorithm, the proportion of inappropriate prescribing was 28 of 450 (6%). The test characteristics of the electronic algorithm (compared to gold standard chart review) for identification of inappropriate antibiotic prescribing were sensitivity (99%, 422 of 427); specificity (100%, 23 of 23); positive predictive value (82%, 23 of 28); and negative predictive value (100%, 422 of 422). Conclusions: For children with pharyngitis, an electronic algorithm for identification of inappropriate antibiotic prescribing is highly accurate. Future work should validate this approach in other settings and develop and evaluate the impact of an audit and feedback intervention based on this tool.Funding: NoneDisclosures: None

scholarly journals Development of an Electronic Algorithm to Target Outpatient Antimicrobial Stewardship Efforts for Acute Bronchitis

2020 ◽  
Vol 41 (S1) ◽  
pp. s32-s32
Author(s):  
Ebbing Lautenbach ◽  
Keith Hamilton ◽  
Robert Grundmeier ◽  
Melinda Neuhauser ◽  
Lauri Hicks ◽  
...  
Keyword(s):  
Antimicrobial Stewardship ◽  
Predictive Value ◽  
Gold Standard ◽  
Chart Review ◽  
Acute Bronchitis ◽  
Antibiotic Use ◽  
Antibiotic Prescribing ◽  
Diagnostic Codes ◽  
Icd 10 ◽  
The Impact

Background: Antibiotic resistance has increased at alarming rates, driven predominantly by antibiotic overuse. Although most antibiotic use occurs in outpatients, antimicrobial stewardship programs have primarily focused on inpatient settings. A major challenge for outpatient stewardship is the lack of accurate and accessible electronic data to target interventions. We sought to develop and validate an electronic algorithm to identify inappropriate antibiotic use for outpatients with acute bronchitis. Methods: This study was conducted within the University of Pennsylvania Health System (UPHS). We used ICD-10 diagnostic codes to identify encounters for acute bronchitis at any outpatient UPHS practice between March 15, 2017, and March 14, 2018. Exclusion criteria included underlying immunocompromising condition, other comorbidity influencing the need for antibiotics (eg, emphysema), or ICD-10 code at the same visit for a concurrent infection (eg, sinusitis). We randomly selected 300 (150 from academic practices and 150 from nonacademic practices) eligible subjects for detailed chart abstraction that assessed patient demographics and practice and prescriber characteristics. Appropriateness of antibiotic use based on chart review served as the gold standard for assessment of the electronic algorithm. Because antibiotic use is not indicated for this study population, appropriateness was assessed based upon whether an antibiotic was prescribed or not. Results: Of 300 subjects, median age was 61 years (interquartile range, 50–68), 62% were women, 74% were seen in internal medicine (vs family medicine) practices, and 75% were seen by a physician (vs an advanced practice provider). On chart review, 167 (56%) subjects received an antibiotic. Of these subjects, 1 had documented concern for pertussis and 4 had excluding conditions for which there were no ICD-10 codes. One received an antibiotic prescription for a planned dental procedure. Thus, based on chart review, 161 (54%) subjects received antibiotics inappropriately. Using the electronic algorithm based on diagnostic codes, underlying and concurrent conditions, and prescribing data, the number of subjects with inappropriate prescribing was 170 (56%) because 3 subjects had antibiotic prescribing not noted based on chart review. The test characteristics of the electronic algorithm (compared to gold standard chart review) for identification of inappropriate antibiotic prescribing were the following: sensitivity, 100% (161 of 161); specificity, 94% (130 of 139); positive predictive value, 95% (161 of 170); and negative predictive value, 100% (130 of 130). Conclusions: For outpatients with acute bronchitis, an electronic algorithm for identification of inappropriate antibiotic prescribing is highly accurate. This algorithm could be used to efficiently assess prescribing among practices and individual clinicians. The impact of interventions based on this algorithm should be tested in future studies.Funding: NoneDisclosures: None

scholarly journals Natural Language Processing Performance for the Identification of Venous Thromboembolism in an Integrated Healthcare System

2021 ◽  
Vol 27 ◽  
pp. 107602962110131
Author(s):  
Bela Woller ◽  
Austin Daw ◽  
Valerie Aston ◽  
Jim Lloyd ◽  
Greg Snow ◽  
...  
Keyword(s):  
Natural Language Processing ◽  
Venous Thromboembolism ◽  
Natural Language ◽  
Medical Record ◽  
Electronic Medical Record ◽  
Ct Angiography ◽  
Language Processing ◽  
Predictive Value ◽  
Chart Review ◽  
Imaging Studies

Real-time identification of venous thromboembolism (VTE), defined as deep vein thrombosis (DVT) and pulmonary embolism (PE), can inform a healthcare organization’s understanding of these events and be used to improve care. In a former publication, we reported the performance of an electronic medical record (EMR) interrogation tool that employs natural language processing (NLP) of imaging studies for the diagnosis of venous thromboembolism. Because we transitioned from the legacy electronic medical record to the Cerner product, iCentra, we now report the operating characteristics of the NLP EMR interrogation tool in the new EMR environment. Two hundred randomly selected patient encounters for which the imaging report assessed by NLP that revealed VTE was present were reviewed. These included one hundred imaging studies for which PE was identified. These included computed tomography pulmonary angiography—CTPA, ventilation perfusion—V/Q scan, and CT angiography of the chest/ abdomen/pelvis. One hundred randomly selected comprehensive ultrasound (CUS) that identified DVT were also obtained. For comparison, one hundred patient encounters in which PE was suspected and imaging was negative for PE (CTPA or V/Q) and 100 cases of suspected DVT with negative CUS as reported by NLP were also selected. Manual chart review of the 400 charts was performed and we report the sensitivity, specificity, positive and negative predictive values of NLP compared with manual chart review. NLP and manual review agreed on the presence of PE in 99 of 100 cases, the presence of DVT in 96 of 100 cases, the absence of PE in 99 of 100 cases and the absence of DVT in all 100 cases. When compared with manual chart review, NLP interrogation of CUS, CTPA, CT angiography of the chest, and V/Q scan yielded a sensitivity = 93.3%, specificity = 99.6%, positive predictive value = 97.1%, and negative predictive value = 99%.

scholarly journals The predictive value of psychological assessment of candidates for gastric bypass: A medical chart review

2010 ◽  
Vol 24 (2) ◽  
Author(s):  
Nathalie Aubert ◽  
Isabelle Lyon-Pagès ◽  
Isabelle Carrard ◽  
Michel Suter ◽  
Friedrich Stiefel ◽  
...  
Keyword(s):  
Gastric Bypass ◽  
Psychological Assessment ◽  
Predictive Value ◽  
Chart Review ◽  
Medical Chart ◽  
Medical Chart Review

scholarly journals Methods for Molecular Surveillance of Influenza Used in Macedonia

PRILOZI ◽  
2014 ◽  
Vol 35 (2) ◽  
pp. 25-30
Author(s):  
Golubinka Bosevska ◽  
Elizabeta Janceska ◽  
Gordana Kuzmanovska ◽  
Vladimir Mikik ◽  
Nikola Panovski
Keyword(s):  
Influenza Virus ◽  
Predictive Value ◽  
Influenza A ◽  
Rna Extraction ◽  
Influenza Virus Infection ◽  
Laboratory Diagnosis ◽  
Influenza Viruses ◽  
Rt Pcr ◽  
Two Samples ◽  
Nose And Throat

AbstractThe aim: To present and compare different Nucleic Acid Testing assays used for laboratory diagnosis of influenza virus infection in our country.Materials and methods: Respiratory samples used were nose and throat swabs. The RNA extraction was performed with a QIAamp viral RNA kit. During the season 2009–2010 the first 25 samples were tested with: conventional gel-based RT-PCR and CDC rtRT-PCR using published specific matrix and HA gene primers and probes for influenza virus typing and subtyping.Results: Of 25 samples tested with conventional RT-PCR7(28%) were positive for influenza A, but negative for A/H1seasonal and A/H3. Retested with rtRT-PCR 9(36%) were positive for influenza A, 8(32%) were positive for A/H1pdm and 1(4%) was A/H3. Two samples positive with rtRT-PCR for influenza A were negative with RT-PCR. The sensitivity of the RT-PCR in comparison with rtRT-PCR is 100% and the specificity is 88.89%. Positive predictive value for RT-PCR is 77.78%, and negative predictive value is 100%. RT-PCR is a four-step and rtRT-PCR a one-step procedure. The turn-around time of RT-PCR is 6 hours and for rtRT-PCR it is 2 hours.Discussion and conclusion: For surveillance purposes nose and throat swabs are the more easy and practical to collect. It was proved that RT-PCR is too laborious, multi-step and time-consuming. The sensitivity of both assays is equal. The specificity of rtRT-PCR is higher. NAT assays for detection of influenza viruses have become an integral component of the surveillance programme in our country. They provide a fast, accurate and sensitive detection of influenza.

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