scholarly journals SARS-CoV-2 seroprevalence and detection fraction in Utah urban populations from a probability-based sample

2020 ◽  
Author(s):  
Matthew H. Samore ◽  
Adam Looney ◽  
Brian Orleans ◽  
Tom Greene ◽  
Nathan Seegert ◽  
...  
Keyword(s):  
Urban Areas ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Igg Antibody ◽  
Community Based ◽  
Urban Populations ◽  
Multi Stage ◽  
Case Count ◽  
Chemiluminescent Microparticle Immunoassay ◽  
Polymerase Chain

ABSTRACTThis project’s aim was to generate an unbiased estimate of the incidence of SARS-CoV-2 infection in four urban counties in Utah. A multi-stage sampling design was employed to randomly select community-representative participants 12 years and over. Between May 4 and June 30, 2020, surveys were completed and sera drawn from 8,108 individuals belonging to 5,125 households. A qualitative chemiluminescent microparticle immunoassay was used to detect the presence of IgG antibody to SARS-CoV-2. The overall prevalence of IgG antibody to SARS-CoV-2 was estimated at 0.8%. The estimated seroprevalence-to-case count ratio was 2.4, corresponding to a detection fraction of 42%. Only 0.2% of individuals who had a nasopharyngeal swab collected were reverse transcription polymerase chain reaction (RT-PCR) positive. The prevalence of antibodies to SARS-CoV-2 in Utah urban areas between May and June was low and the prevalence of positive RT-PCR even lower. The detection fraction for COVID-19 in Utah was comparatively high.Article SummaryProbability-based sampling provides an effective method for robust estimates of community-based SARS-CoV-2 seroprevalence and detection fraction among urban populations in Utah.

scholarly journals Regional Difference in Seroprevalence of SARS-CoV-2 in Tokyo: Results from the community point-of-care antibody testing

2020 ◽  
Author(s):  
Morihito Takita ◽  
Tomoko Matsumura ◽  
Kana Yamamoto ◽  
Erika Yamashita ◽  
Kazutaka Hosoda ◽  
...  
Keyword(s):  
Regional Difference ◽  
Point Of Care ◽  
Herd Immunity ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Community Based ◽  
Entire Cohort ◽  
Control And Prevention ◽  
Specific Igg ◽  
Polymerase Chain

AbstractThe serosurvey is an alternative way to know the magnitude of the population infected by coronavirus disease 2019 (COVID-19) since the expansion of capacity of the polymerase chain reaction (PCR) to detect the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was delayed. We herein report seroprevalence of COVID-19 accessed in the two community clinics in Tokyo. The point-of-care immunodiagnostic test was implemented to detect the SARS-CoV-2 specific IgG antibody in the peripheral capillary blood. The overall positive percentage of SARS-CoV-2 IgG antibody is 3.83% (95% confidence interval: 2.76-5.16) for the entire cohort (n =1,071). The central Tokyo of 23 special wards exhibited a significantly higher prevalence compared to the other area of Tokyo (p =0.02, 4.68% [95%CI: 3.08-6.79] versus 1.83 [0.68-3.95] in central and suburban Tokyo, respectively). The seroprevalence of the cohort surveyed in this study is low for herd immunity, which suggests the need for robust disease control and prevention. A community-based approach, rather than state or prefectural levels, is of importance to figure out profiles of the SARS-COV-2 outbreak.

scholarly journals Inappropriate Nasopharyngeal Sampling for SARS-CoV-2 Detection Is a Relevant Cause of False-Negative Reports

2020 ◽  
Vol 163 (3) ◽  
pp. 459-461 ◽  
Author(s):  
Antonio Piras ◽  
Davide Rizzo ◽  
Sergio Uzzau ◽  
Giacomo De Riu ◽  
Salvatore Rubino ◽  
...  
Keyword(s):  
Nasal Obstruction ◽  
Negative Impact ◽  
Present Report ◽  
False Negative ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Radiologic Findings ◽  
Negative Findings ◽  
Current Outbreak ◽  
Polymerase Chain

Reverse transcriptase polymerase chain reaction (RT-PCR) detection of SARS-CoV-2 mRNA on nasopharyngeal swab is the standard for diagnosing active COVID-19 disease in asymptomatic cases and in symptomatic patients without the typical radiologic findings. For the present COVID-19 outbreak in Italy, we describe 4 symptomatic patients with negative RT-PCR results at the first nasopharyngeal swab, which became positive when collected a few hours later by an otolaryngologist. All the patients showed nasal obstruction. The present report suggests that inadequate nasopharyngeal sampling performed by untrained operators in the presence of nasal obstruction can be a relevant case of false-negative findings at RT-PCR, with a clear negative impact on the efforts to contain the current outbreak.

scholarly journals Effectivity Analysis of SARS-CoV-2 Nasopharyngeal Swab Rapid Testing Kits in Pakistan: A Scenario of Inadequate COVID-19 Diagnosis

2021 ◽  
Author(s):  
Umar Saeed ◽  
Sara Rizwan Uppal ◽  
Zahra Zahid Piracha ◽  
Aftab Ahmad Khan ◽  
Azhar Rasheed ◽  
...  
Keyword(s):  
Gold Standard ◽  
Rapid Detection ◽  
International Health ◽  
Time Frame ◽  
Cross Sectional Study ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Cross Sectional ◽  
International Health Organizations ◽  
Polymerase Chain

Abstract COVID-19 pandemic has urged the need of rapid detection of SARS-CoV-2 in limited time frame. To cope with current, COVID-19 expanding scenario, accurate diagnosis of SARS-CoV-2 should be ensured by both national and international health organizations. Sporadic marketing of SARS-CoV-2 rapid detection kits raises questions regarding quality control and assurance. To aim of this study was to examine the effectiveness of SARS-CoV-2 nasopharyngeal swab based rapid detection kits, in comparison to gold standard USFDA approved triple target real-time polymerase chain reaction. A cross-sectional study of 1500 suspected COVID-19 patients was conducted. 100 RT-PCR confirmed patients nasopharyngeal swabs were evaluated for RDT. The COVID-19/SARS-CoV-2 NSP based RDT analysis showed 78% reactivity. Among RT-PCR confirmed negative subjects, 49.3% showed false positivity. The positive predictive analysis revealed 67.82% values, while the negative predictive vales of were 64.40%. The NSP RDTs showed limited sensitivities and specificities compared to gold standard RT-PCR. Accurate surveillance of COVID-19 is dependent upon authentic and validated SARS-CoV-2 detection nation-wide, which needs to be monitored by higher authorities. This study is critical for designing adequate measures by several COVID-19 strategic organizations to prevent future viral epidemics.

scholarly journals SARS-CoV-2 show no infectivity at later stages in a prolonged COVID-19 patient despite positivity in RNA testing

2021 ◽  
Author(s):  
Xiu-Feng Wan ◽  
Cynthia Y Tang ◽  
Detlef Ritter ◽  
Yang Wang ◽  
Tao Li ◽  
...  
Keyword(s):  
Large Scale ◽  
Disease Onset ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Virus Growth ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Asymptomatic Patients ◽  
Hospitalization Period ◽  
Polymerase Chain

Inpatient COVID-19 cases present enormous costs to patients and health systems. Many hospitalized patients may still test COVID-19 positive, even after resolution of symptoms. Thus, a pressing concern for clinicians is the safety of discharging these asymptomatic patients if they have any remaining infectivity. This case report explores the viral viability in a patient with persistent COVID-19 over the course of a two-month hospitalization. Positive nasopharyngeal swab samples, analyzed by quantitative reverse transcription polymerase chain reactions (qRT-PCR), were collected and isolated in the laboratory, and infectious doses were analyzed throughout the hospitalization period. The patient experienced waning symptoms by hospital day 40 and had no viable virus growth in the laboratory by hospital day 41, suggesting no risk of infectivity, despite positive RT-PCR results, which prolonged his hospital stay. Notably, this case showed infectivity for at least 24 days from disease onset, which is longer than the discontinuation of transmission-based precautions recommendation by CDC. Thus, our findings suggest that the timeline for discontinuing transmission-based precautions may need to be extended for patients with prolonged illness. Additional large-scale studies are needed to draw definitive conclusions on the appropriate clinical management for these patients.

scholarly journals Detection of SARS-CoV-2 by real time Reverse Transcriptase-Polymerase Chain Reaction assay in pleural effusion

2021 ◽  
pp. 201
Author(s):  
Keyword(s):  
Polymerase Chain Reaction ◽  
Pleural Effusion ◽  
Reverse Transcriptase ◽  
Pleural Fluid ◽  
Interstitial Pneumonia ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Pleural Involvement

SARS-CoV-2 (severe acute respiratory syndrome-coronavirus-2) is a novel coronavirus identified for the first time in Wuhan (China) in 2019, responsible of the current pandemic infection known as Coronavirus-19 disease (COVID-19). Wide range of clinical presentation of COVD -19 has been observed, from asymptomatic carriers to ARDS. The common signs and symptoms of SARS-CoV-2 infection include fever, fatigue, dry cough, and dyspnoea; the severity of the disease is due to the impairment of the respiratory function. The radiological findings include a large variety of lesions; bilateral interstitial pneumonia is the most concerning presentation of COVID-19. Pleural involvement has been described in a minority of cases: pleural thickening had been observed in 32% of cases whereas pleural effusion is uncommon being described in only 5%. Furthermore, pleural involvement has been significantly associated with a worse prognosis. Coronavirus 2 (SARS-CoV-2), beyond the nasopharyngeal swab, has been detected in other samples; up to now, data about RT-PCR specific results in the pleural fluid of patients suffering from coronavirus disease 2019 5 (COVID-19) are very limited. The current gold standard for diagnosis is nucleic acid detection by real time Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) in nasopharyngeal swab. In this report, a case of a positive RT-PCR for Sars-Cov-2 in the pleura fluid and in the naso- pharyngeal swab of a patient affected by bilateral interstitial pneumonia and severe respiratory failure is described. As the presence of SARS-Cov-2 in the pleural fluid seems to be associated to a poor prognosis, physicians should carry out the specific RT-PCR assay both in the nasopharyngeal swab and in the pleural sample also when the fluid amount is very scarce and not recognizable in the chest X ray. Furthermore, the analysis of multiple samples allows to increase the test reliability.

scholarly journals False-Negative Nasopharyngeal Swab RT-PCR Assays in Typical COVID-19: Role of Ultra-low-dose Chest CT and Bronchoscopy in Diagnosis

2020 ◽  
Author(s):  
Marco Marando ◽  
Adriana Tamburello ◽  
Pietro Gianella
Keyword(s):  
Low Dose ◽  
False Negative ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Oral Swab ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain ◽  
Pcr Assays

On 11 March 2020, the WHO declared COVID-19 a pandemic and global health emergency. We describe the clinical features and role of ultra-low-dose chest computed tomography (CT) and bronchoscopy in the diagnosis of coronavirus disease (COVID-19). In our patient, who was highly suggestive clinically and radiologically for COVID-19, we had two false-negative results for nasopharyngeal and oral swab reverse-transcriptase polymerase chain reaction (RT-PCR) assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Eventually, we confirmed the diagnosis using bronchoscopy and bronchoalveolar lavage (BAL).

scholarly journals High Resolution CHEST CT(HRCT) Evaluation in Patients Hospitalized with COVID-19 Infection

2020 ◽  
Author(s):  
Maulin Patel ◽  
Junad Chowdhury ◽  
Matthew Zheng ◽  
Osheen Abramian ◽  
Steven Verga ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
High Resolution ◽  
Diagnostic Accuracy ◽  
Reverse Transcriptase ◽  
Retrospective Analysis ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Bottom Line ◽  
Polymerase Chain

AbstractIntroductionCurrently the main diagnostic modality for COVID-19 (Coronavirus disease-2019) is reverse transcriptase polymerase chain reaction (RT-PCR) via nasopharyngeal swab which has high false negative rates. We evaluated the performance of high-resolution computed tomography (HRCT) imaging in the diagnosis of suspected COVID-19 infection compared to RT-PCR nasopharyngeal swab alone in patients hospitalized for suspected COVID-19 infection.MethodsThis was a retrospective analysis of 324 consecutive patients admitted to Temple University Hospital. All hospitalized patients who had RT-PCR testing and HRCT were included in the study. HRCTs were classified as Category 1, 2 or 3. Patients were then divided into four groups based on HRCT category and RT-PCR swab results for analysis.ResultsThe average age of patients was 59.4 (±15.2) years and 123 (38.9%) were female. Predominant ethnicity was African American 148 (46.11%). 161 patients tested positive by RT-PCR, while 41 tested positive by HRCT. 167 (52.02%) had category 1 scan, 63 (19.63%) had category 2 scan and 91 (28.35%) had category 3 HRCT scans. There was substantial agreement between our radiologists for HRCT classification (κ = 0.64). Sensitivity and specificity of HRCT classification system was 77.6 and 73.7 respectively. Ferritin, LDH, AST and ALT were higher in Group 1 and D-dimers levels was higher in Group 3; differences however were not statistically significant.ConclusionDue to its high infectivity and asymptomatic transmission, until a highly sensitive and specific COVID-19 test is developed, HRCT should be incorporated into the assessment of patients who are hospitalized with suspected COVID-19.Key PointsKey QuestionCan High Resolution CT chest (HRCT) improve diagnostic accuracy of current Nasopharyngeal swab in suspected COVID-19 patients?Bottom LineIn this retrospective analysis, our novel HRCT classification identified 20% of all COVID-19 patients who had negative nasopharyngeal reverse transcriptase polymerase chain reaction (RT-PCR) tests but had HRCT findings consistent with COVID-19 pneumonia. These patients were ruled out for other infections and laboratory markers were similar to other RT-PCR positive patientsWhy Read onOur new HRCT classification when combined with RT-PCR can improve diagnostic accuracy while promptly improving triaging in COVID-19 patients.

scholarly journals Symptoms COVID 19 Positive Vapers Compared to COVID 19 Positive Non-vapers

2022 ◽  
Vol 13 ◽  
pp. 215013192110626
Author(s):  
David D. McFadden ◽  
Shari L. Bornstein ◽  
Robert Vassallo ◽  
Bradley R. Salonen ◽  
Mohammed Nadir Bhuiyan ◽  
...  
Keyword(s):  
Nasopharyngeal Swab ◽  
Symptom Experience ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Age And Gender ◽  
Robust Variance ◽  
Polymerase Chain ◽  
And Gender ◽  
Variance Estimates ◽  
The Impact

Objectives: The purpose of the present study was to assess and describe the severity of symptoms reported by Covid-19 positive patients who vaped (smoked e-cigarettes) when compared to those who did not vape or smoke at the time of the diagnosis of Covid-19. Methods: Patients from this study are from a well-characterized patient cohort collected at Mayo Clinic between March 1, 2020 and February 28, 2021; with confirmed COVID-19 diagnosis defined as a positive result on reverse-transcriptase–polymerase-chain-reaction (RT-PCR) assays from nasopharyngeal swab specimens. Among the 1734 eligible patients, 289 patients reported current vaping. The cohort of vapers (N = 289) was age and gender matched to 1445 covid-19 positive patients who did not vape. The data analyzed included: date of birth, gender, ethnicity, race, marital status, as well as lifestyle history such as vaping and smoking and reported covid-19 symptoms experienced. Results: A logistic regression analysis was performed separately for each symptom using generalized estimating equations (GEE) with robust variance estimates in order to account for the 1:5 age, sex, and race matched set study design. Patients who vaped and developed Covid-19 infection were more likely to have chest pain or tightness (16% vs 10%, vapers vs non vapers, P = .005), chills (25% vs 19%, vapers vs non vapers, P = .0016), myalgia (39% vs 32%, vapers vs non vapers, P = .004), headaches (49% vs 41% vapers vs non vapers, P = .026), anosmia/dysgeusia (37% vs 30%, vapers vs non vapers, P = .009), nausea/vomiting/abdominal pain (16% vs 10%, vapers vs non vapers, P = .003), diarrhea (16% vs 10%, vapers vs non vapers, P = .004), and non-severe light-headedness (16% vs 9%, vapers vs non vapers, P < .001). Conclusion: Vapers experience higher frequency of covid-19 related symptoms when compared with age and gender matched non-vapers. Further work should examine the impact vaping has on post-covid symptom experience.

scholarly journals Impact of false negative results of RT-PCR test for SARS-CoV-2 in COVID-19 case count as applied to Mexico

2020 ◽  
Author(s):  
Isaac J. Núñez ◽  
Pablo F. Belaunzarán-Zamudio ◽  
Yanink Caro-Vega
Keyword(s):  
False Negative ◽  
Open Data ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Negative Results ◽  
Case Count ◽  
False Negative Results ◽  
True Number ◽  
High Prevalence ◽  
Polymerase Chain

Underestimation of the number of cases during the COVID-19 pandemic has been a constant concern worldwide. Case confirmation is based on identification of SARS-CoV-2 RNA using real time polymerase chain reaction (RT-PCR) in clinical samples. However, these tests have suboptimal sensitivity, especially during the early and late course of infection. Using open data, we estimated that among 1 343 730 people tested in Mexico since February 27th, there were 838 377 (95% CL 734 605 - 1 057 164) cases, compared with 604 376 considering only positive tests. ICU admissions and deaths were around 16% and 9% higher than reported. Thus, we show that accounting for the sensitivity of SARS-Cov-2 RT-PCR diagnostic tests is a simple way to improve estimations for the true number of COVID-19 cases in tested people, particularly in high-prevalence populations. This could aid to better inform public health measures and reopening policies.

scholarly journals Long-term effects of coronavirus disease 2019 on the cardiovascular system, CV COVID registry: A structured summary of a study protocol

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0255263
Author(s):  
Victor Arévalos ◽  
Luis Ortega-Paz ◽  
Diego Fernandez-Rodríguez ◽  
Víctor Alfonso Jiménez-Díaz ◽  
Jordi Bañeras Rius ◽  
...  
Keyword(s):  
Primary Outcome ◽  
Cardiovascular Outcomes ◽  
Clinical Event ◽  
Nasopharyngeal Swab ◽  
Long Term Effects ◽  
Rt Pcr ◽  
Heart Failure Hospitalization ◽  
Chain Reaction ◽  
Polymerase Chain

Background Patients presenting with the coronavirus-2019 disease (COVID-19) may have a high risk of cardiovascular adverse events, including death from cardiovascular causes. The long-term cardiovascular outcomes of these patients are entirely unknown. We aim to perform a registry of patients who have undergone a diagnostic nasopharyngeal swab for SARS-CoV-2 and to determine their long-term cardiovascular outcomes. Study and design This is a multicenter, observational, retrospective registry to be conducted at 17 centers in Spain and Italy (ClinicalTrials.gov number: NCT04359927). Consecutive patients older than 18 years, who underwent a real-time reverse transcriptase-polymerase chain reaction (RT-PCR) for SARS-CoV2 in the participating institutions, will be included since March 2020, to August 2020. Patients will be classified into two groups, according to the results of the RT-PCR: COVID-19 positive or negative. The primary outcome will be cardiovascular mortality at 1 year. The secondary outcomes will be acute myocardial infarction, stroke, heart failure hospitalization, pulmonary embolism, and serious cardiac arrhythmias, at 1 year. Outcomes will be compared between the two groups. Events will be adjudicated by an independent clinical event committee. Conclusion The results of this registry will contribute to a better understanding of the long-term cardiovascular implications of the COVID19.

Sign in / Sign up

Export Citation Format

Share Document