scholarly journals Multicenter Evaluation of the Clostridium difficileTOX A/B TEST

1998 ◽  
Vol 36 (1) ◽  
pp. 184-190 ◽  
Author(s):  
D. M. Lyerly ◽  
L. M. Neville ◽  
D. T. Evans ◽  
J. Fill ◽  
S. Allen ◽  
...  

Clostridium difficile, the primary cause of nosocomial diarrhea in the United States and many other industrialized countries, is recognized as a major health concern because of its ability to cause severe intestinal disease leading to complications such as relapses and infections due to vancomycin-resistant enterococci. The disease results from two toxins, toxins A and B, produced by this pathogen. In this study, we evaluated the TOX A/B TEST, a new 1-h enzyme immunoassay (EIA) that detects toxins A and B. We compared the test with the tissue culture assay, which is recognized as the “gold standard” forC. difficile testing. Evaluations were performed in-house at TechLab, Inc. (Blacksburg, Va.) and off-site at four clinical laboratories. Of 1,152 specimens tested, 165 were positive by the TOX A/B TEST and tissue culture and 973 were negative by both tests. The sensitivity and specificity were 92.2 and 100%, respectively. The positive and negative predictive values were 100 and 98.6%, respectively, and the correlation of the TOX A/B TEST with tissue culture was 98.8%. When discrepant samples were resolved by culture, the sensitivity and specificity were 93.2 and 98.9%, respectively. The positive and negative predictive values were 100 and 98.8%, respectively, with a correlation of 99.0%. There were no specimens that were positive by the TOX A/B TEST and negative by tissue culture. Fourteen specimens were negative by the TOX A/B TEST but positive by tissue culture. Of these, two were negative by toxigenic culture, five were positive by toxigenic culture, and seven were not available for further testing. There were no indeterminate results, since the test does not have an indeterminant zone. In a separate study, 102 specimens that were positive by tissue culture and the TOX A/B TEST were examined in toxin A-specific EIAs. Two specimens that presumptively contained toxin A-negative, toxin B-positive (toxA−/toxB+) isolates were identified. One specimen was from a patient with a clinical history consistent with C. difficile infection. Isolates obtained from these specimens by selective culture on solid media and in broth tested toxA−/toxB+ when grown in brain heart infusion dialysis flasks, which stimulate in vitro production of both toxins. Our findings show that the TOX A/B TEST is suitable as a diagnostic aid for C. difficile disease because it correlates well with tissue culture and detects isolates that may be missed with toxin A-specific EIAs.

2020 ◽  
Vol 58 (4) ◽  
Author(s):  
Roosa Savolainen ◽  
Juha M. Koskinen ◽  
Silja Mentula ◽  
Janne O. Koskinen ◽  
Suvi-Sirkku Kaukoranta

ABSTRACT The objective of this study was to evaluate a novel automated random-access test, mariPOC CDI (ArcDia Ltd., Finland), for the detection of Clostridioides difficile glutamate dehydrogenase (GDH) and toxins A and B directly from fecal specimens. The mariPOC test was compared with both the GenomEra C. difficile PCR assay (Abacus Diagnostica Oy, Finland) and the TechLab C. diff Quik Chek Complete (Alere Inc.; now Abbot) membrane enzyme immunoassay (MEIA). Culture and the Xpert C. difficile assay (Cepheid Inc., USA) were used to resolve discrepant results. In total, 337 specimens were tested with the mariPOC CDI test and GenomEra PCR. Of these specimens, 157 were also tested with the TechLab MEIA. The sensitivity of the mariPOC test for GDH was slightly lower (95.2%) than that obtained with the TechLab assay (100.0%), but no toxin-positive cases were missed. The sensitivity of the mariPOC test for the detection of toxigenic C. difficile by analyzing toxin expression was better (81.6%) than that of the TechLab assay (71.1%). The analytical specificities for the mariPOC and the TechLab tests were 98.3% and 100.0% for GDH and 100.0% and 99.2% for toxin A/B, respectively. The analytical specificity of the GenomEra method was 100.0%. The mariPOC and TechLab GDH tests and GenomEra PCR had high negative predictive values of 99.3%, 98.3%, and 99.7%, respectively, in excluding infection with toxigenic C. difficile. The mariPOC toxin A/B test and GenomEra PCR had an identical analytical positive predictive value of 100%, providing highly reliable information about toxin expression and the presence of toxin genes, respectively.


1993 ◽  
Vol 1 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Mark B. Reedy ◽  
Patricia J. Sulak ◽  
William B. McCombs III ◽  
Thomas J. Kuehl

Chlamydia trachomatisis the most common reportable sexually transmitted disease (STD) in the United States. In the 1980s, rapid diagnostic tests for chlamydia began to replace more cumbersome tissue culture methods. Current data on rapid antigen detection assays demonstrate acceptable sensitivity, specificity, and predictive values in populations with a high prevalence of chlamydia. Few studies report the performance of these assays in a low-prevalence obstetric and gynecologic (Ob/Gyn) population, This study compares the most commonly used direct fluorescent antibody (DFA) assay (Syva Microtrak) with tissue culture (TC) in a low-prevalence population. Endocervical specimens (775) were tested from women at risk for chlamydia infection, and the prevalence was found to be 7.7%. The DFA assay demonstrated a sensitivity of 80% and a specificity of 97% compared with TC. The positive and negative predictive values were 72% and 98%, respectively. The results of this study indicate that the Syva DFA assay lacks the sensitivity and positive predictive value for routine use in Ob/Gyn populations with a lowprevalence ofC. trachomatis.


2002 ◽  
Vol 14 (3) ◽  
pp. 258-259 ◽  
Author(s):  
Karen W. Post ◽  
B. Helen Jost ◽  
J. Glenn Songer

A commercially available 1-hour enzyme immunoassay (EIA) for detecting the presence of Clostridium difficile toxins A and B was evaluated for use in diagnosis of C. difficile infections in neonatal swine. This test was compared with a tissue culture cytotoxicity assay, which is considered to be the reference standard for the detection of C. difficile toxins. Twenty-seven samples of colonic contents and 23 fecal samples were collected from freshly euthanized neonatal swine with a history of scours. Of the 50 specimens tested, 20 were positive by the EIA test and tissue culture and 24 were negative by both tests, for an overall correlation of 88%. The sensitivity and specificity of the EIA were 91% and 86%, respectively, and the positive and negative predictive values were 84% and 86%, respectively. The EIA test is considered suitable as an aid for the diagnosis of C. difficile enteritis because of the high correlation between EIA results and those of the tissue culture cytotoxicity assay.


2019 ◽  
Author(s):  
Vincent Guilamo-Ramos ◽  
Marco Thimm-Kaiser ◽  
Adam Benzekri ◽  
Donna Futterman

Despite significant progress in the fight against HIV/AIDS in the United States, HIV prevention and treatment disparities among key populations remain a national public health concern. While new HIV diagnoses are increasing among people under age 30—in particular among racial, ethnic, and sexual minority adolescents and young adults (AYA)—dominant prevention and treatment paradigms too often inadequately consider the unique HIV service needs of AYA. To address this gap, we characterize persistent and largely overlooked AYA disparities across the HIV prevention and treatment continuum, identify AYA-specific limitations in extant resources for improving HIV service delivery in the United States, and propose a novel AYA-centered differentiated care framework adapted to the unique ecological and developmental factors shaping engagement, adherence, and retention in HIV services among AYA. Shifting the paradigm for AYA to differentiated HIV care is a promising approach that warrants implementation and evaluation as part of reinforced national efforts to end the HIV epidemic in the United States by 2030.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ahmad Mahran ◽  
Mohammed Khairy ◽  
Reham Elkhateeb ◽  
Abdel Rahman Hegazy ◽  
Ayman Abdelmeged ◽  
...  

Abstract Background The clinical implication of the increased serum progesterone level on the day of HCG administration in assisted reproduction treatment (ART) is still controversial. The current study aimed to compare the predictive value of serum progesterone on day of HCG administration / metaphase II oocyte (P/MII) ratio on IVF/ ICSI outcome to serum progesterone (P) level alone and the ratio of serum progesterone/estradiol level (P/E2) ratio in prediction of pregnancy rates after ART. Material & methods Two hundred patients admitted to the IVF/ICSI program at Minia IVF center in Egypt in the period from October 2016 to May 2018 were included in this study. Serum Progesterone (P) and Estradiol (E2) levels were estimated on the day of HCG administration. The ratio between serum P and the number of MII oocytes (P/MII ratio) was calculated and the predictive values of the three parameters (P, P/E2 ratio and P/MII ratio) in prediction of cycle outcomes were measured. Results P/ MII oocyte ratio was significantly lower in patients who attained clinical pregnancy (n = 97) as compared with those who couldn’t whilst there was no significant difference in P and P/E2 ratio between the two groups. Using a cut off value of 0.125, the sensitivity and specificity of progesterone/ MII ratio in prediction of no pregnancy in IVF/ICSI were 75.7 and 77.1% respectively with the area under The Receiver operating curve (ROC-AUC) = 0.808. The respective values of the ROC-AUC for the P and P/E2 ratio were 0.651 and 0.712 with sensitivity and specificity of 71.2 and 73.5%for P level and of 72.5 and 75.3% for P/E2 ratio. Implantation or clinical pregnancy rates were significantly different between patients with high and low P/MII ratio irrespective of day of embryo transfer (day 3 or 5). Conclusions In patients with normal ovarian response, serum progesterone on day of HCG / MII oocyte ratio can be a useful predictor of pregnancy outcomes and in deciding on freezing of all embryos for later transfer instead of high progesterone level alone.


2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 801-807
Author(s):  
Nathaniel A Young ◽  
Ryan L Lambert ◽  
Angela M Buch ◽  
Christen L Dahl ◽  
Jackson D Harris ◽  
...  

ABSTRACT Introduction Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic compounds used industrially for a wide variety of applications. These PFAS compounds are very stable and persist in the environment. The PFAS contamination is a growing health issue as these compounds have been reported to impact human health and have been detected in both domestic and global water sources. Contaminated water found on military bases poses a potentially serious health concern for active duty military, their families, and the surrounding communities. Previous detection methods for PFAS in contaminated water samples require expensive and time-consuming testing protocols that limit the ability to detect this important global pollutant. The main objective of this work was to develop a novel detection system that utilizes a biological reporter and engineered bacteria as a way to rapidly and efficiently detect PFAS contamination. Materials and Methods The United States Air Force Academy International Genetically Engineered Machine team is genetically engineering Rhodococcus jostii strain RHA1 to contain novel DNA sequences composed of a propane 2-monooxygenase alpha (prmA) promoter and monomeric red fluorescent protein (mRFP). The prmA promoter is activated in the presence of PFAS and transcribes the mRFP reporter. Results The recombinant R. jostii containing the prmA promoter and mRFP reporter respond to exposure of PFAS by activating gene expression of the mRFP. At 100 µM of perfluorooctanoic acid, the mRFP expression was increased 3-fold (qRT-PCR). Rhodococcus jostii without exposure to PFAS compounds had no mRFP expression. Conclusions This novel detection system represents a synthetic biology approach to more efficiently detect PFAS in contaminated samples. With further refinement and modifications, a similar system could be readily deployed in the field around the world to detect this critical pollutant.


2020 ◽  
Vol 12 (1) ◽  
Author(s):  
J. W. Brakel ◽  
T. A. Berendsen ◽  
P. M. C. Callenbach ◽  
J. van der Burgh ◽  
R. J. Hissink ◽  
...  

Abstract Introduction Several countries advocate screening for aneurysms of the abdominal aorta (AAA) in selected patients. In the Netherlands, routine screening is currently under review by the National Health Council. In any screening programme, cost-efficiency and accuracy are key. In this study, we evaluate the Aorta Scan (Verathon, Amsterdam, Netherlands), a cost-effective and easy-to-use screening device based on bladder scan technology, which enables untrained personnel to screen for AAA. Methods We subjected 117 patients to an Aorta Scan and compared the results to the gold standard (abdominal ultrasound). We used statistical analysis to determine sensitivity and specificity of the Aorta Scan, as well as the positive and negative predictive values, accuracy, and inter-test agreement (Kappa). Results Sensitivity and specificity were 0.86 and 0.98, respectively. Positive predictive value was 0.98 and negative predictive value was 0.88. Accuracy was determined at 0.92 and the Kappa value was 0.85. When waist–hip circumferences (WHC) of > 115 cm were excluded, sensitivity raised to 0.96, specificity stayed 0.98, positive and negative predictive value were 0.98 and 0.96, respectively, accuracy to 0.97, and Kappa to 0.94. Conclusion Herein, we show that the Aorta Scan is a cost-effective and very accurate screening tool, especially in patients with WHC below 115 cm, which makes it a suitable candidate for implementation into clinical practice, specifically in the setting of screening selected populations for the presence of AAA.


Author(s):  
Kyle L. Alford ◽  
Naresh Kumar

Volatile organic compounds (VOCs) are commonly found in consumer products, including furniture, sealants and paints. Thus, indoor VOCs have become a public health concern, especially in high-income countries (HICs), where people spend most of their time indoors, and indoor and outdoor air exchange is minimal due to a lack of ventilation. VOCs produce high levels of reaction with the airway epithelium and mucosa membrane and is linked with pulmonary diseases. This paper takes a stock of the literature to assess the strength of association (measured by effect size) between VOCs and pulmonary diseases with the focus on asthma and its related symptoms by conducting a meta-analysis. The literature was searched using the PubMed database. A total of 49 studies that measured VOCs or VOC types and pulmonary health outcomes were included in the analysis. The results of these studies were tabulated, and standard effect size of each study was computed. Most studies were conducted in high-income countries, including France (n = 7), Japan (n = 7) and the United States (n = 6). Our analysis suggests that VOCs have a medium-sized effect on pulmonary diseases, including the onset of asthma (effect size (or Cohen’s d) ~0.37; 95% confidence interval (CI) = 0.25–0.49; n = 23) and wheezing (effective size ~0.26; 95% CI = 0.10–0.42; n = 10). The effect size also varied by country, age and disease type. Multiple stakeholders must be engaged in strategies to mitigate and manage VOC exposure and its associated pulmonary disease burden.


2021 ◽  
Vol 13 (11) ◽  
pp. 5985
Author(s):  
Bryan Weichelt ◽  
Jeffrey VanWormer ◽  
Yin Xu ◽  
Chris Kadolph ◽  
Simon Lin

Cardiovascular disease (CVD) is a major public health concern in the United States. In response to the federally sponsored Million Hearts Risk Check Challenge, a team of programmers, software developers, health-information technologists, and clinicians in an integrated healthcare system in Wisconsin collaborated to develop Heart Health MobileTM (HHM), designed to improve awareness of cardiovascular disease risk and promote risk factor control among users. This paper outlines the development processes and highlights key lessons learned for mobile health applications. An agile project management methodology was used to dedicate adequate resources and employ adaptive planning and iterative development processes with a self-organized, cross-functional team. The initial HHM iOS app was developed and tested, and after additional modifications, gamified and HTML 5 versions of the app were released. The development of an iOS app is low in cost and sustainable by a healthcare system. Future app modifications to enhance data security and link self-reported cardiovascular risk assessment data to patient medical records may improve performance, patient relevance, and clinician acceptance of HHM in the primary-care setting. Legal and institutional barriers regarding the capture and analyses of protected health information must be mitigated to fully capture, analyze, and report patient health outcomes for future studies.


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