scholarly journals The Performance of Two Rapid Antigen Tests During Population-Level Screening for SARS-CoV-2 Infection

2021 ◽  
Vol 8 ◽  
Author(s):  
Mohammad Alghounaim ◽  
Hamad Bastaki ◽  
Farah Bin Essa ◽  
Hoda Motlagh ◽  
Salman Al-Sabah
Keyword(s):  
Positive Predictive Value ◽  
Prospective Study ◽  
Predictive Value ◽  
Point Of Care ◽  
Population Level ◽  
Lower Sensitivity ◽  
Rt Pcr ◽  
Antigen Tests ◽  
A Prospective Study ◽  
Antigen Testing

Background: SARS-CoV-2 antigen assays offer a rapid mean to diagnose and isolate infected individuals. However, their utility in population-level screening is unknown.Objectives: The performance of two antigen tests in detecting SARS-CoV-2 was assessed among individuals randomly selected in the community.Study Design: A prospective study that performed head-to-head comparison of two SARS-CoV-2 antigen assays. Individuals were recruited during community SARS-CoV-2 screening over 10 working days. Demographic and clinical data were collected. Standard Q COVID-19 Ag test, a point-of-care chromatographic assay, was conducted immediately, and then the sample was transported to the virology laboratory to perform PCR and the LIAISON SARS-CoV-2 Ag chemiluminesence immunoassay.Results: respiratory samples from 991 individuals were collected, and 62 were positive by PCR. Inconclusive PCR results were observed in 19 samples and were excluded. The median age of participants was 40.2 years (IQR 32.3–47.8), and 932 (94%) were males. Most (77.4%) of infections were asymptomatic. The sensitivity and the specificity of the LIAISON assay were 43.3% (95%CI 30.6–56.8) and 99.9% (95%CI 99.3–100). The Standard Q assay had lower sensitivity (30.6%, 95%CI 19.6–43.7) but similar specificity (98.8%, 95%CI, 97.8–99.4). Similarly, the LIAISON assay had higher positive predictive value (96.3%, 95%CI 81–99.9% vs. 63.3%, 95%CI, 43.9–80.1%). Both assays performed better in symptomatic patients and among samples with a low-cycle threshold (Ct < 25).Conclusion: In our setting of random community surveillance, rapid antigen testing of nasopharyngeal swabs by either LIAISON SARS-CoV-2 Ag (DiaSorin) or Standard Q COVID-19 Ag (SD Biosensor) was less sensitive to detecting SARS-CoV-2 than the TaqPath COVID-19 RT-PCR.

scholarly journals Evaluation of saliva molecular point of care for detection of SARS-CoV-2 in ambulatory care

2021 ◽  
Author(s):  
Jerome Le Goff ◽  
Solen Kerneis ◽  
Caroline Elie ◽  
Severine Mercier Delarue ◽  
Nabil Gastli ◽  
...  
Keyword(s):  
Point Of Care ◽  
False Negative ◽  
Lamp Assay ◽  
Rapid Identification ◽  
Ambulatory Setting ◽  
Nasopharyngeal Swab ◽  
Lower Sensitivity ◽  
Rt Pcr ◽  
A Prospective Study ◽  
Antigen Testing

Background: The rapid identification of SARS-CoV-2 infected individuals is a cornerstone in strategies for the control of virus spread. The sensitivity of SARS-CoV-2 RNA detection by RT-PCR is similar in saliva and nasopharyngeal swab. Rapid molecular point-of-care tests in saliva could facilitate, broaden and speed up the diagnosis. Objectives and methods: We conducted a prospective study in two community COVID-19 screening centers to evaluate the performances of a CE-marked RT-LAMP assay (EasyCoV) specifically designed for the detection of SARS-CoV-2 RNA from fresh saliva samples, compared to nasopharyngeal RT-PCR as reference test, saliva RT-PCR and nasopharyngeal antigen testing. Results: Overall, 117 of the 1718 participants (7%) were tested positive with nasopharyngeal RT-PCR. Sensitivities of saliva RT-PCR and nasopharyngeal antigen test were 93% (95% Confidence Interval (95%CI): 86-97) and 85% (95%CI: 77-91), respectively. The sensitivity and specificity of the RT-LAMP assay in saliva were 34% (95%CI: 26-44) and 97% (95%CI: 96-98). The performance was similar in symptomatic and asymptomatic participants and whatever the reference standard considered. Ct values of nasopharyngeal RT-PCR were significantly lower in the 40 true positive subjects with saliva RT-LAMP (Ct 25.9) than in the 48 false negative subjects with saliva RT-LAMP (Ct 28.4) (p=0.028). Conclusion: In the ambulatory setting, the detection of SARS-CoV-2 from crude saliva samples with the RT-LAMP assay had a lower sensitivity than nasopharyngeal RT-PCR, saliva RT-PCR and nasopharyngeal antigen testing.

scholarly journals Evaluation of saliva molecular point of care for detection of SARS-CoV-2 in ambulatory care

2021 ◽  
Author(s):  
Jérôme LeGoff ◽  
Solen Kernéis ◽  
Caroline Elie ◽  
Séverine Mercier Delarue ◽  
Nabil Gastli ◽  
...  
Keyword(s):  
Point Of Care ◽  
False Negative ◽  
Lamp Assay ◽  
Rapid Identification ◽  
Nasopharyngeal Swab ◽  
Lower Sensitivity ◽  
Rt Pcr ◽  
Registration Number ◽  
A Prospective Study ◽  
Antigen Testing

Abstract Background Rapid identification of SARS-Cov-2 infected individuals is a cornerstone for the control of virus spread. The sensitivity of SARS-CoV-2 RNA detection by RT-PCR is similar in saliva and nasopharyngeal swab. Rapid molecular point-of-care tests in saliva could facilitate, broaden and speed up the diagnosis. Methods We conducted a prospective study in two community COVID-19 screening centers to evaluate the performances of a CE-marked RT-LAMP assay (EasyCoV™) designed for the detection of SARS-CoV2 RNA from fresh saliva samples, compared to nasopharyngeal RT-PCR, to saliva RT-PCR and to nasopharyngeal antigen testing. Results Overall, 117 of the 1718 participants (7%) were tested positive with nasopharyngeal RT-PCR. Compared to nasopharyngeal RT-PCR, the sensitivity and specificity of the RT-LAMP assay in saliva were 34% and 97% respectively. The Ct values of nasopharyngeal RT-PCR were significantly lower in the 40 true positive subjects with saliva RT-LAMP (Ct 25.9) than in the 48 false negative subjects with saliva RT-LAMP (Ct 28.4) (p = 0.028). Considering six alternate criteria for reference test, including saliva RT-PCR and nasopharyngeal antigen, the sensitivity of saliva RT-LAMP ranged between 27 and 44%. Conclusion The detection of SARS-CoV-2 from crude saliva samples with a RT-LAMP assay had a lower sensitivity than nasopharyngeal RT-PCR, saliva RT-PCR and nasopharyngeal antigen testing. Registration number : NCT04578509

Sensitivity and positive predictive value of CT, MRI and 123I-MIBG scintigraphy in localizing pheochromocytomas: A prospective study

2006 ◽  
Vol 27 (7) ◽  
pp. 583-587 ◽  
Author(s):  
Franco Lumachi ◽  
Alberto Tregnaghi ◽  
Pietro Zucchetta ◽  
Maria Cristina Marzola ◽  
Diego Cecchin ◽  
...  
Keyword(s):  
Positive Predictive Value ◽  
Prospective Study ◽  
Predictive Value ◽  
Mibg Scintigraphy ◽  
A Prospective Study

scholarly journals Characteristics of children and antigen test performance at a SARS-CoV-2 community testing site

2021 ◽  
Author(s):  
Laura Ford ◽  
Melissa J. Whaley ◽  
Melisa M. Shah ◽  
Phillip P. Salvatore ◽  
Hannah E. Segaloff ◽  
...  
Keyword(s):  
Test Performance ◽  
Point Of Care ◽  
Lower Sensitivity ◽  
Antigen Test ◽  
Rt Pcr ◽  
Culture Methods ◽  
Viral Culture ◽  
Asymptomatic Children ◽  
Testing Site ◽  
Antigen Tests

Background: Performance characteristics of SARS-CoV-2 antigen tests among children are limited despite the need for point-of-care testing in school and childcare settings. We describe children seeking SARS-CoV-2 testing at a community site and compare antigen test performance to real-time reverse transcription-polymerase chain reaction (RT-PCR) and viral culture. Methods: Two anterior nasal specimens were self-collected for BinaxNOW antigen and RT-PCR testing, along with demographics, symptoms, and exposure information from individuals ≥5 years at a community testing site. Viral culture was attempted on residual antigen or RT-PCR positive specimens. Demographic and clinical characteristics, and the performance of SARS-CoV-2 antigen tests, were compared among children (<18 years) and adults. Results: About one in ten included specimens were from children (225/2110); 16.4% (37/225) were RT-PCR positive. Cycle threshold values were similar among RT-PCR positive specimens from children and adults (22.5 vs 21.3, p=0.46) and among specimens from symptomatic and asymptomatic children (22.5 vs 23.2, p=0.39). Sensitivity of antigen test compared to RT-PCR was 73.0% (27/37) among specimens from children and 80.8% (240/297) among specimens from adults; among specimens from children, specificity was 100% (188/188), positive and negative predictive value were 100% (27/27) and 94.9% (188/198) respectively. Virus was isolated from 51.4% (19/37) of RT-PCR positive pediatric specimens; all 19 had positive antigen test results. Conclusions : With lower sensitivity relative to RT-PCR, antigen tests may not diagnose all positive COVID-19 cases; however, antigen testing identified children with live SARS-CoV-2 virus.

scholarly journals The Value of Bacterial Culture During Clean Orthopedic Surgery a Prospective Study of 1,036 Patients

2004 ◽  
Vol 25 (6) ◽  
pp. 512-514 ◽  
Author(s):  
Louis Bernard ◽  
Christophe Sadowski ◽  
Daniel Monin ◽  
Richard Stern ◽  
Blaise Wyssa ◽  
...  
Keyword(s):  
Positive Predictive Value ◽  
Prospective Study ◽  
Negative Predictive Value ◽  
Orthopedic Surgery ◽  
Predictive Value ◽  
Postoperative Infection ◽  
Bacterial Culture ◽  
Bacterial Cultures ◽  
Sensitivity Specificity ◽  
A Prospective Study

AbstractObjective:To determine whether bacterial cultures of the wounds of patients undergoing clean orthopedic surgery would help predict infection.Methods:During 1 year, 1,256 cultures were performed for 1,102 patients who underwent clean orthopedic surgery. Results were analyzed to evaluate their ability to predict postoperative infection.Results:The sensitivity, specificity, positive predictive value, and negative predictive value of the cultures were 38%, 92%, 7%, and 99%, respectively.Conclusions:Cultures performed during clean orthopedic surgery were not useful for predicting postoperative infection.

Comparison between Different Perforator Imaging Modalities for the Anterolateral Thigh Perforator Flap Transfer: A Prospective Study

2020 ◽  
Vol 36 (09) ◽  
pp. 686-693
Author(s):  
Lucas M. Ritschl ◽  
Andreas M. Fichter ◽  
Achim von Bomhard ◽  
Steffen Koerdt ◽  
Victoria Kehl ◽  
...  
Keyword(s):  
Positive Predictive Value ◽  
Prospective Study ◽  
Predictive Value ◽  
Perforator Flap ◽  
Flap Transfer ◽  
Anterolateral Thigh ◽  
American Society ◽  
A Prospective Study ◽  
Patient’S History ◽  
American Society Of Anesthesiologists

Abstract Background Perforator imaging is routinely performed before perforator flap harvest. Hand-held Doppler (hhD) and color duplex ultrasonography (CDU) are currently the most popular radiation-free methods for this purpose that can be applied by the surgeon alone. The aim of this study was to compare the accuracy, reliability, and feasibility of hhD and CDU with indocyanine green angiography (ICGA) in the anterolateral thigh perforator flap (ALTPF). Methods All consecutive ALTPF procedures between May 2017 and April 2018 were included in this prospective study. The perforators were visualized by three investigators independently and randomized, applying hhD, CDU, and ICGA. The presence and the distance to the identified perforator were registered. Further, body mass index (BMI), American Society of Anesthesiologists-status, and the patient's history regarding smoking, alcohol use, and diabetes mellitus were registered alongside gender and age to analyze possible confounders. Results A total of 12 patients were enrolled with a median age of 67 (52–87) years. In total, 30 perforators were detected intraoperatively as well as with the ICGA. The latter visualized the perforators significantly more precisely than hhD and CDU (p < 0.001 and p = 0.001). The sensitivity and positive predictive value were 67 and 62% for hhD, 73 and 64% for CDU, and 100 and 100% for ICGA, respectively. Conclusion According to this study, ICGA visualized perforators more accurately than the standard methods hhD and CDU. Further, it was associated with the highest sensitivity and positive predictive value. ICGA consistently delivered excellent results, whereas hhD and CDU showed variability.

scholarly journals Clinicopathological evaluation of acute appendicitis and the role of ultrasound in diagnosis: a prospective study

2019 ◽  
Vol 6 (5) ◽  
pp. 1471
Author(s):  
Tony Mathew ◽  
Amit Shivshankar Ammanagi
Keyword(s):  
Acute Appendicitis ◽  
Positive Predictive Value ◽  
Prospective Study ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Scoring System ◽  
Lower Abdominal Pain ◽  
Negative Appendicectomy ◽  
A Prospective Study

Background: Acute appendicitis is the most common acute surgical condition of the abdomen. Delay in treatment of acute appendicitis causes lot of complication. Study was done with the objective to study the clinical and pathological presentations of acute appendicitis, to evaluate the role of ultrasound in early diagnosis of acute appendicitis and to reduce negative appendicectomy in patients.Methods: This is a prospective study done on 100 patients with acute right lower abdominal pain clinically presumed to be of appendicular origin. A thorough history, clinical examination and ultrasound scan, was done for all cases. All ultrasound positive cases were subjected to surgery and some negative cases were also taken for surgery based on clinical suspicion. The ultrasound diagnosis was compared with clinical findings, operative findings and histopathological examination reports.Results: The overall accuracy of clinical diagnosis (Alvarado scoring system) with histopathology findings was 72%. The overall sensitivity and specificity was 70.3% and 81.3% respectively and positive predictive value of was 95.2% whereas the negative predictive value was 34.2%. The overall accuracy of ultrasound with histopathology report was 93%, with a sensitivity of 96.4%, specificity of 75%, and a positive predictive value of 95% and a negative predictive value of 80%. Negative appendicectomy rate was 8.82% in females and 3.63% in males.Conclusions: The Alvarado scoring system combined with ultrasound can therefore be used as a cheap and inexpensive way of confirming acute appendicitis thus reducing negative appendicectomy rate.

scholarly journals The Use of Active Melioidosis Detect TM in Early Diagnosis of Melioidosis in Hospital Tengku Ampuan Afzan and Hospital Sultanah Nur Zahirah

2020 ◽  
Vol 18 (2) ◽  
Author(s):  
Wan Nurliyana Wan Ramli
Keyword(s):  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Sensitivity And Specificity ◽  
Predictive Value ◽  
Point Of Care ◽  
Rapid Test ◽  
High Specificity ◽  
Culture Method ◽  
Lower Sensitivity ◽  
Spot Urine

Introduction: Melioidosis is endemic in Malaysia and an important cause of sepsis. Current gold standard for diagnosis is by culture method,but its long procedure will delay the treatment leading to hospital-related mortality.Thus,a good rapid test is needed to reduce its mortality burden. Recently, Active Melioidosis Detect (AMD) have been shown to be useful. Objectives: (1)To measure the sensitivity and specificity of AMD. (2)To study the sensitivity and specificity of early morning urine AMD compared to spot urine AMD. Materials and method: A prospective crosssectional study of clinically suspected melioidosis patients in HTAA and HSNZ from April until December 2018. Blood and urine samples were tested with AMD. Test results were analysed for sensitivity, specificity,positive predictive value and negative predictive value. Results: A total of 89 patients were included in this study.The mean age is 52 years old, and 56.3% were male gender.64% of patients have diabetes mellitus.11 patients have positive blood culture for Bukholderia pseudomallei, 4 of them were tested positive for AMD.3 of them presented with septic shock (3.4%), however none died.The sensitivity of the AMD was 36.4% ([95% CI 12.4 to 68.4]) and the specificity was 66.7% ( [95% CI 46.0 to 82.8]) in all samples, with positive predictive value of 30.7% and negative predictive value of 72%.Blood samples have lower sensitivity of 9.1% ([95% CI 4.8 to 42.9]) with high specificity of 100% ([95% CI 84.5 to 100]). Urine spot samples have higher sensitivity compared to serum and morning urine, with 36.4% ([95%CI 12.4 to 68.4]) and specificity of 88.9% ([95% CI 69.7 to 97.1]). Conclusion: From this pilot study, this test requires further evaluation before incorporating as point of care assay.

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