scholarly journals Role of Rapid Antigen Testing in Population-Based SARS-CoV-2 Screening

2021 ◽  
Vol 10 (17) ◽  
pp. 3854
Author(s):  
Vicente Martín-Sánchez ◽  
Tania Fernández-Villa ◽  
Ana Carvajal Urueña ◽  
Ana Rivero Rodríguez ◽  
Sofía Reguero Celada ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Diagnostic Test ◽  
Internal Validity ◽  
High Specificity ◽  
Population Based ◽  
Predictive Values ◽  
Asymptomatic Patients ◽  
Screening Performance ◽  
Antigen Testing

This study evaluates a population-based screening of asymptomatic people, using a rapid antigen diagnostic test (RADT), in areas of high transmission. To detect sources of SARS-CoV-2 infection, nasopharyngeal samples were taken and were tested using RADT. Confirmatory RT-qPCR tests were performed in both positive and negative cases. The internal validity of the RADT, the prevalence of infection, and the positive and negative predictive values (PPV and NPV) were estimated, based on the percentages of confirmed cases with 95% confidence interval. Of the 157,920 people registered, 50,492 participated in the screening; 50,052 were negative, and 440 were positive on the RADT (0.87%). A total of 221 positive RADT samples were reanalysed using RT-qPCR and 214 were confirmed as positive (96.8%; 95% CI: 93.5–98.7%), while 657 out of 660 negative RADT samples were confirmed as RT-qPCR negative (99.5%; 95% CI 98.7–99.9%). The sensitivity obtained was 65.1% (38.4–90.2%) and the specificity was 99.97% (99.94–99.99%). The prevalence of infection was 1.30% (0.95–2.13%). The PPVs were 95.4% (85.9–98.9%) and 97.9% (93.3–99.5%), respectively, while the NPVs were 99.7% (99.4–100%) and 99.2% (98.7–100%), respectively. The high specificity found allow us to report a high screening performance in asymptomatic patients, even in areas where the prevalence of infection was less than 2%.

scholarly journals Accuracy of multiparametric magnetic resonance imaging for detecting extracapsular extension in prostate cancer: a systematic review and meta-analysis

2019 ◽  
Vol 92 (1104) ◽  
pp. 20190480 ◽  
Author(s):  
Fan Zhang ◽  
Chen-Lu Liu ◽  
Qian Chen ◽  
Sheng-Chao Shao ◽  
Shuang-Qing Chen
Keyword(s):  
Prostate Cancer ◽  
Confidence Interval ◽  
Diagnostic Accuracy ◽  
Meta Analysis ◽  
Characteristic Curve ◽  
High Specificity ◽  
Cochrane Library ◽  
Extracapsular Extension ◽  
Predictive Values ◽  
Enhanced Mri

Objective: To evaluate the diagnostic accuracy of multiparametric MRI (mpMRI) for detecting extracapsular extension (ECE) in patients with prostate cancer (PCa). Methods and materials: We searched MEDLINE, PubMed, Embase and the Cochrane library up to December 2018. We included studies that used mpMRI to differentiate ECE from organ-confined PCa with a combination of T2 weighted imaging (T2WI), diffusion-weighted imaging, and dynamic contrast-enhanced MRI. All studies included had pathological diagnosis with radical prostatectomy. Two reviewers independently assessed the methodological quality of included studies by using Quality Assessment of Diagnostic Accuracy Studies 2 tool. We calculated pooled sensitivity, specificity, positive and negative predictive values, diagnostic odds ratios and receiver operating characteristic curve for mpMRI from 2 × 2 tables. Results: A total of 17 studies that comprised 3374 participants were included. The pooled data showed a sensitivity of 0.55 (95% confidence interval 0.43, 0.66]) and specificity of 0.87 (95% confidence interval 0.82, 0.91) for extracapsular extension detection in PCa. Conclusion: First, our meta-analysis shows moderate sensitivity and high specificity for mpMRI to differentiate ECE from organ-confined prostate cancer before surgery. Second, our meta-analysis shows that mpMRI had no significant differences in performance compared with the former meta-analysis with use of T2WI alone or with additional functional MRI. Advances in knowledge: It is the first meta-analysis to evaluate the accuracy of mpMRI in combination of TWI, diffusion-weightedimaging and dynamiccontrast-enhanced-MRI for extracapsular extension detection.

scholarly journals Diagnostic Accuracy and Detection Rate of Glaucoma Screening with Optic Disk Photos, Optical Coherence Tomography Images, and Telemedicine

2021 ◽  
Vol 11 (1) ◽  
pp. 216
Author(s):  
Alfonso Anton ◽  
Karen Nolivos ◽  
Marta Pazos ◽  
Gianluca Fatti ◽  
Miriam Eleonora Ayala ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diagnostic Accuracy ◽  
Detection Rate ◽  
Screening Program ◽  
Rate Sensitivity ◽  
High Specificity ◽  
Population Based ◽  
Optic Disk ◽  
Optical Coherence ◽  
Predictive Values

Purpose: The aim of this study was to evaluate the diagnostic accuracy of optical coherence tomography (OCT) and retinography in the detection of glaucoma through a telemedicine program. Methods: A population-based sample of 4113 persons was randomly selected. The screening examination included a fundus photograph and OCT images. Images were evaluated on a deferred basis. All participants were then invited to a complete glaucoma examination, including gonioscopy, visual field, and dilated fundus examination. The detection rate, sensitivity, specificity, and positive and negative predictive values were calculated. Results: We screened 1006 persons. Of these, 201 (19.9%) were classified as glaucoma suspects; 20.4% were identified only by retinographs, 11.9% only by OCT images, and 46.3% by both. On ophthalmic examination at the hospital (n = 481), confirmed glaucoma was found in 58 (12.1%), probable glaucoma in 76 (15.8%), and ocular hypertension in 10 (2.1%), and no evidence of glaucoma was found in 337 (70.0%). The detection rate for confirmed or probable glaucoma was 9.2%. Sensitivity ranged from 69.4% to 86.2% and specificity from 82.1% to 97.4%, depending on the definition applied. Conclusions: The combination of OCT images and fundus photographs yielded a detection rate of 9.2% in a population-based screening program with moderate sensitivity, high specificity, and predictive values of 84–96%.

Detection of Asymptomatic Deep Vein Thrombosis by Real-Time B-Mode Ultrasonography in Hip Surgery Patients

1992 ◽  
Vol 68 (03) ◽  
pp. 257-260 ◽  
Author(s):  
Giancarlo Agnelli ◽  
Raul Volpato ◽  
Stefano Radicchia ◽  
Franca Veschi ◽  
Paolo Di Filippo ◽  
...  
Keyword(s):  
Deep Vein Thrombosis ◽  
Real Time ◽  
Sensitivity And Specificity ◽  
High Specificity ◽  
Hip Surgery ◽  
Predictive Values ◽  
Vein Thrombosis ◽  
Asymptomatic Patients ◽  
Vein Segment ◽  
Deep Vein

SummaryThe aim of this study was to prospectively evaluate the accuracy of real-time B-mode ultrasonography in the diagnosis of asymptomatic proximal deep vein thrombosis (DVT) in hip surgery patients. Venography was adopted as the gold standard. We studied 100 consecutive patients undergoing hip surgery: 60 patients for hip fracture and 40 patients for elective hip replacement. Bilateral real-time B-mode ultrasonography was performed prior to bilateral venography. The two diagnostic procedures were performed on the same day by different investigators unaware of the assigned prophylatic regimen for DVT Compressibility of the vein segment was adopted as the single criterion for DVT. Venography was performed and judged by radiologists unaware of the ultrasonography results. In 13 limbs venography was either impossible to perform or not adequate for judgement. Ultrasonography and an adequate venography was obtained in 187 limbs. A venography proven DVT was observed in 49 limbs (26.2%) and a proximal DVT in 21 limbs (11.2%). All the patients were asymptomatic for DVT. The sensitivity and specificity of real time B-mode ultrasonography for proximal DVT were 57% (95% confidence interval: C. I. 36–80) and 99% (C. I. 99–100), respectively and the positive and negative predictive values were 93% (C.I. 73–100) and 95% (C.I. 91–97), respectively. The sensitivity and specificity for overall DVT were 25% (C.I. 11–38) and 99% (C.I. 97–100), respectively and the positive and negative predictive values were 92% (C. I. 73–100) and 79% (C.I. 76–85), respectively. Our data indicate that realtime B-mode ultrasonography for its high specificity could make venography unnecessary in patients with positive results. However, because of its low sensitivity it cannot be used for the screening of DVT in asymptomatic patients, nor can it replace venography for outcome measurements in clinical trials on DVT prophylaxis.

scholarly journals Basal Follicle-Stimulating Hormone and Peak Gonadotropin Levels after Gonadotropin-Releasing Hormone Infusion Show High Diagnostic Accuracy in Boys with Suspicion of Hypogonadotropic Hypogonadism

2010 ◽  
Vol 95 (6) ◽  
pp. 2811-2818 ◽  
Author(s):  
Romina P. Grinspon ◽  
María Gabriela Ropelato ◽  
Silvia Gottlieb ◽  
Ana Keselman ◽  
Alicia Martínez ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Diagnostic Accuracy ◽  
De Novo ◽  
Hypogonadotropic Hypogonadism ◽  
High Specificity ◽  
Diagnostic Efficiency ◽  
Infusion Test ◽  
Predictive Values ◽  
Constitutional Delay ◽  
Gnrh Infusion

Abstract Context: Differential diagnosis between hypogonadotropic hypogonadism (HH) and constitutional delay of puberty in boys is challenging. Most tests use an acute GnRH stimulus, allowing only the release of previously synthesized gonadotropins. A constant GnRH infusion, inducing de novo gonadotropin synthesis, may allow a better discrimination. Objective: We evaluated the diagnostic accuracy of basal and peak gonadotropins after GnRH infusion, measured by ultrasensitive assays, to confirm the diagnosis in boys with suspected HH. Design and Setting: We conducted a validation study following Standards for Reporting of Diagnostic Accuracy criteria at a tertiary public hospital. Patients and Methods: A GnRH iv infusion test was performed in 32 boys. LH and FSH were determined by immunofluorometric assay at 0–120 min. Diagnosis Ascertainment: The following diagnoses were ascertained: complete HH (n = 19; testes < 4 ml at 18 yr), partial HH (n = 6; testes enlargement remained arrested for ≥1 yr or did not reach 15 ml), and constitutional delay of puberty (n = 7; testes ≥ 15 ml at 18 yr). Main Outcome Measures: Sensitivity, specificity, positive and negative predictive values, and diagnostic efficiency were assessed. Results: Basal FSH less than 1.2 IU/liter confirmed HH with specificity of 1.00 (95% confidence interval = 0.59–1.00), rendering GnRH infusion unnecessary. In patients with basal FSH of at least 1.2 IU/liter, the coexistence of peak FSH less than 4.6 IU/liter and peak LH less than 5.8 IU/liter after GnRH infusion had high specificity (1.00; 95% confidence interval = 0.59–1.00) and diagnostic efficiency (76.9%) for HH. Conclusions: Basal FSH less than 1.2 IU/liter confirms HH, which precludes from further testing, reducing patient discomfort and healthcare system costs. In patients with basal FSH of at least 1.2 IU/liter, a GnRH infusion test has a high diagnostic efficiency.

scholarly journals Diagnostic Performance between Histidine-Rich Protein 2 (HRP-2), a Rapid Malaria Diagnostic Test and Microscopic-Based Staining Techniques for Diagnosis of Malaria

2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Jean Baptiste Niyibizi ◽  
Emmanuel Kamana Gatera
Keyword(s):  
Diagnostic Test ◽  
Rapid Diagnostic Test ◽  
Health Centre ◽  
Malaria Diagnosis ◽  
High Specificity ◽  
Cross Sectional Study ◽  
Diagnostic Challenge ◽  
Cross Sectional ◽  
Predictive Values ◽  
Study Participants

Malaria presents a diagnostic challenge in most tropical countries such as Rwanda. Microscopy remains the gold standard for diagnosing malaria, but it is labor intensive and depends upon the skill of the examiner. Malaria rapid diagnostic tests (RDTs) have been developed as an easy, convenient alternative to microscopy. This cross-sectional study was conducted at Rukara Health Center which is located in Eastern Province, Kayonza district, Rwanda. One hundred and fifty suspected cases of malaria, who attended Rukara Health Centre, during the period, from 21st June to 30th July 2018, were included in this study. HRP-2 RDTs (CareStart™ Malaria HRP-2 (Access Bio, Inc., Somerset, New Jersey, USA)), for malaria were performed. Thick smears were prepared and Giemsa-stained as recommended; then slides were observed under microscopy and reported quantitatively; RDTs were reported qualitatively (positive or negative). Both RDTs and thick smear results were recorded on data collection sheet. This study included a total of 150 study participants, 87 (58%) females and 63 (42%) males. The patients included in the study did not receive any antimalarial drug. The mean age of the study participants was 31.6 ± 12.4 with the majority of participants being between 25 and 44 years and the minority being above 65 years. The sensitivity of RDT (HRP-2) was calculated and found to be 95.0%, whereas the sensitivity of Giemsa microscopy was 100%. The specificity of RDT (HRP-2) was calculated and found to be 59.2%, whereas the specificity of Giemsa microscopy was 100%. Negative and positive predictive values of RDT are 85.4% and 82.7%, respectively. Negative and positive predictive values of Giemsa microscopy were both 100%. According to the results of the current study, the sensitivity, specificity, and both positive and negative predictive values of Giemsa microscopy are higher than those of histidine-rich protein 2-based rapid diagnostic test for malaria. The results obtained in histidine-rich protein 2-based rapid diagnostic test for malaria parasites should be confirmed with tests with high specificity. Further studies should determine the most appropriate type of rapid diagnostic test of malaria diagnosis to be used in combination with Giemsa microscopy. In addition, sensitivity and specificity of RDT (HRP-2) and Giemsa microscopy should be assessed against molecular biology techniques.

scholarly journals Five Antigen Tests for SARS-CoV-2: Virus Viability Matters

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 684
Author(s):  
Miroslav Homza ◽  
Hana Zelena ◽  
Jaroslav Janosek ◽  
Hana Tomaskova ◽  
Eduard Jezo ◽  
...  
Keyword(s):  
False Negative ◽  
Antigen Test ◽  
Rt Pcr ◽  
False Negatives ◽  
Predictive Values ◽  
Asymptomatic Patients ◽  
High Prevalence ◽  
Antigen Tests ◽  
Antigen Testing ◽  
Excellent Tool

Antigen testing for SARS-CoV-2 (AGT) is generally considered inferior to RT-PCR testing in terms of sensitivity. However, little is known about the infectiousness of RT-PCR positive patients who pass undetected by AGT. In a screening setting for mildly symptomatic or asymptomatic patients with high COVID-19 prevalence (30–40%), 1141 patients were tested using one of five AGTs and RT-PCR. Where the results differed, virus viability in the samples was tested on cell culture (CV-1 cells). The test battery included AGTs by JOYSBIO, Assure Tech, SD Biosensor, VivaChek Biotech and NDFOS. Sensitivities of the ATGs compared to RT-PCR ranged from 42% to 76%. The best test yielded a 76% sensitivity, 97% specificity, 92% positive, and 89% negative predictive values, respectively. However, in the best performing ATG tests, almost 90% of samples with “false negative” AGT results contained no viable virus. Corrected on the virus viability, sensitivities grew to 81%–97% and, with one exception, the tests yielded high specificities >96%. Performance characteristics of the best test after adjustment were 96% sensitivity, 97% specificity, 92% positive, and 99% negative predictive values (high prevalence population). We, therefore, believe that virus viability should be considered when assessing the AGT performance. Also, our results indicate that a well-performing antigen test could in a high-prevalence setting serve as an excellent tool for identifying patients shedding viable virus. We also propose that the high proportion of RT-PCR-positive samples containing no viable virus in the group of “false negatives” of the antigen test should be further investigated with the aim of possibly preventing needless isolation of such patients.

scholarly journals Severity of infection and seasonal variation of non-typhoid Salmonella occurrence in humans

2006 ◽  
Vol 135 (1) ◽  
pp. 93-99 ◽  
Author(s):  
K. O. GRADEL ◽  
C. DETHLEFSEN ◽  
H. C. SCHØNHEYDER ◽  
T. EJLERTSEN ◽  
H. T. SØRENSEN ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Confidence Interval ◽  
Regression Model ◽  
Population Based ◽  
Severe Gastroenteritis ◽  
Periodic Regression ◽  
Patient Groups

Non-typhoid Salmonella infections may present as severe gastroenteritis necessitating hospitalization and some patients become septic with bacteraemia. We hypothesized that the seasonal variation of non-typhoid Salmonella occurrence in humans diminishes with increased severity of infection. We examined the seasonal variation of non-typhoid Salmonella infections in three patient groups with differing severity of infection: outpatients treated for gastroenteritis (n=1490); in-patients treated for gastroenteritis (n=492); and in-patients treated for bacteraemia (n=113). The study was population-based and included all non-typhoid Salmonella patients in a Danish county from 1994 to 2003. A periodic regression model was used to compute the peak-to-trough ratio for the three patient groups. The peak-to-trough ratios were 4·3 [95% confidence interval (CI) 3·6–5·0] for outpatients with gastroenteritis, 3·2 (95% CI 2·4–4·2) for in-patients with gastroenteritis, and 1·6 (95% CI 1·0–2·8) for in-patients with bacteraemia. We conclude that the role of seasonal variation diminishes with increased severity of non-typhoid Salmonella infection.

scholarly journals The dark side of SARS-CoV-2 rapid antigen testing: screening asymptomatic patients

2021 ◽  
Author(s):  
Giorgia Caruana ◽  
Laure-Line Lebrun ◽  
Oriane Aebischer ◽  
Onya Opota ◽  
Luis Urbano ◽  
...  
Keyword(s):  
Hospital Admissions ◽  
Screening Method ◽  
Dark Side ◽  
Pcr Analysis ◽  
Rt Pcr ◽  
Asymptomatic Patients ◽  
Antigen Tests ◽  
Outpatient Settings ◽  
Antigen Testing

AbstractMost of the reports describing SARS-CoV-2 rapid antigen tests (RATs) performances derive from COVID-19 symptomatic subjects in outpatient settings during periods of highest incidence of infections and high rates of hospital admissions. Here we investigated the role of RATs in an Emergency Department, as a screening tool before admission for COVID-19 asymptomatic patients. Each patient was screened with two simultaneous nasopharyngeal swabs: one immediately analyzed at the bedside using RAT and the other sent to the laboratory for RT-PCR analysis. A total of 116 patients were screened at hospital admission in a 250-bed community hospital in Morges (EHC), Switzerland. With a disease prevalence of 6% based on RT-PCR results, RAT detected only two out of seven RT-PCR positive patients (sensitivity 28.6%) and delivered two false positive results (specificity 98.2%), thus resulting not fiable enough to be used as a screening method in this clinical scenario.

scholarly journals Evaluation of the role of fundus fluorescein angiography and spectral domain-optical coherence tomography in choroidal neo-vascularization: a hospital-based study

2022 ◽  
Author(s):  
Amit Singh ◽  
Reyaz Ahmed Untoo ◽  
Ourfa Ashraf Wani ◽  
Wasim Rashid
Keyword(s):  
Optical Coherence Tomography ◽  
Confidence Interval ◽  
Diagnostic Accuracy ◽  
Fluorescein Angiography ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Fundus Fluorescein Angiography ◽  
Predictive Values ◽  
Sd Oct

Background: The study was conducted to evaluate the role of fundus fluorescein angiography (FFA) and spectral domain-optical coherence tomography (SD-OCT) in choroidal neo-vascularisation (CNV).Methods: This was a hospital based prospective study carried out in the post-graduate department of ophthalmology, SKIMS medical college, Bemina, Srinagar, Jammu and Kashmir. All patients diagnosed with CNV fulfilling the criteria during the study period w.e.f. October 2018 to March 2020 were enrolled. Visual acuity and pinhole test using Snellen’s chart for literate and E chart for illiterate patient, slit lamp biomicroscope for anterior segment examination, ophthalmoscopy, including stereoscopic examination of the posterior pole, 90D examination of the fundus, Intra-ocular pressure measurement, FFA and SD-OCT was done in these patients.Results: Diagnostic accuracy of OCT was observed with a sensitivity 79.1% (95% confidence interval (CI): 67.3-90.7), specificity 84.3% (95% CI: 74.5-92.9), positive and negative predictive values 78.7% and 85.4%, respectively, (95% CI: 65.5-95.6) and (74.8-93.4) and diagnostic accuracy of FFA was observed with a sensitivity 81.4% (95% confidence interval (CI): 70.6-93.5), specificity 82.31% (95% CI: 71.9-89.3), positive and negative predictive values 79.9% and 83.7%, respectively, (95% CI: 68.8-92.9) and (70.3-91.2).Conclusions: FFA is the gold standard procedure for screening ARMD and detection of dry ARMD, but OCT is more specific diagnostic tool in detecting early subretinal neovascular membrane and also to assess the extent, location and activity of the neovascular membranes. This study concludes that SDOCT is highly sensitive for identifying AMD, CNV, and CNV activity and due to its non-invasive nature with no adverse effects and less time consuming can be used as 1st line of diagnostic modality and FFA be reserved for cases where SD-OCT is not helpful.

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