LUNG ULTRASOUND IN RULING OUT COVID-19 AMONG HEALTHCARE WORKERS IN TWO ITALIAN EMERGENCY DEPARTMENTS: A MULTICENTER STUDY.

Purpose: The high percentage of asymptomatic patients and the non-high sensitivity of real-time reverse transcription-polymerase chain reaction (RT-PCR) test on nasopharyngeal swab cause some healthcare workers to be infected but asymptomatic and a source of spread of the epidemic. This study aimed to verify if the lung ultrasound (LUS) had enough high negative predictive value to rule out coronavirus disease 2019 (COVID-19) among a population of healthcare workers operating in the Emergency Department. Methods: A multicenter prospective observational study was conducted, enrolling healthcare workers among the staff of two Emergency Departments in Northeast Italy. The definitive diagnosis of COVID-19 was established by an adjudication committee, based on the clinical data and RT-PCR on nasopharyngeal swab result. Results: From March 30, 2020, to April 22, 2020, we enrolled 155 cases. The adjudication committee determined two true positives for COVID-19. Twenty-one healthcare workers presented suggestive symptoms (2 true positives and 19 false positives). The nasopharyngeal swab was positive in one case (1 false-negative case). LUS was suggestive for COVID-19 pneumonia in 4 cases (2 false-positive cases). The diagnostic accuracy of LUS was 98.7% (95% CI 95.4%-99.8%). The sensitivity and the specificity of LUS were 100% (95% CI 15.8% -100%) and 98.7% (95% CI 95.4% - 99.8%), respectively. The negative predictive value was 100% (95% CI 100% -100%). Conclusion: LUS has a good enough negative predictive value for ruling out COVID-19 in a population of healthcare workers exposed to COVID-19.

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Role of Covid Antigen in the Diagnosis of Covid Positive in Obstetric Patients

10.53350/pjmhs2115103356 ◽

2021 ◽

Vol 15 (10) ◽

pp. 3356-3358

Author(s):

Ambreen Fatima ◽

Nidda Yaseen ◽

Amna Fareed ◽

Kashif Ali Samin ◽

Shumaela Kanwal ◽

...

Keyword(s):

Nucleic Acid ◽

Early Detection ◽

Negative Predictive Value ◽

Predictive Value ◽

False Negative ◽

Nucleic Acid Amplification ◽

Antigen Test ◽

Rt Pcr ◽

Cross Sectional ◽

Specificity And Sensitivity

Background and Aim: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapid emergence postured significant challenges on the health system in recent years. The early detection of cases is thought to be critical in preventing this pandemic by coronavirus disease (COVID-19), especially important in the obstetrical population due to theirs numerous interactions with another parturient when hospitalized for delivery. Therefore, the present study aimed to assess the COVID antigen test performance in COVID-positive obstetrics patients. Materials and Methods: This cross-sectional study was conducted on 1296 Covid-19 asymptomatic women admitted to the Obstetrics and Gynaecology Department of Muhammad Teaching Hospital & Medical College, Peshawar and Fauji Foundation Hospital, Rawalpindi for the duration of six months from February 2021 to July 2021. Antigen-based test rapid diagnostic test (RDT) was used for screening out COVID-19 positive obstetrics patients or women through nasopharyngeal swabs. Women with negative rapid antigen test results were confirmed with RT-polymers chain reaction test of nucleic acid amplification tests (NAAT). Ethical approval and informed consent were taken from the hospital ethical committee and each individual respectively. All the known positive COVID-19 patients during admission were excluded. SPSS version 24 was used for data analysis. Results: The overall prevalence of rapid antigen-positive tested patients was 13.2% (171/1296). The prevalence of positive tested women through rapid antigen test, Nucleic Acid Amplification Test (NAAT), and RT-PCR were 27 (2.1%), 51 (3.9%), and 93 (7.2%) respectively. Of the total 1296 rapid antigen tests, 27 were positive, and the false-negative confirmed positive by NAAT was 144.Thus the sensitivity of the rapid antigen test was 15.8% and the negative predictive value was 93.7%. Of the total 298 Nucleic Acid Amplification Tested had sensitivity and negative predictive value of 89.6% and 99.06% respectively. RT-PCR was carried out on 972 patients, positive diagnosed cases were 36 while 15 were initially negative and were positive with the test was repeated. The sensitivity and negative predictive value was 71.45% and 95.8% respectively. Conclusion: Our study found that Ag-RDT plays a significant role in SARS-CoV-2 early detection in infected individuals, with high specificity and sensitivity to disease infectious stage, whether symptomatic or asymptomatic, and can be used as a decision supported tool. Early detection of COVID-19 status in women admitted for delivery could benefit neonatal protection care. Keywords: Covid-19; Rapid antigen test; RT-PCR test

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Accuracy of Roche SARS-CoV-2 Rapid Antigen Test in Nasopharyngeal Swab: Clinical Impression Matters

Journal of Biomedical Research & Environmental Sciences ◽

10.37871/jbres1334 ◽

2021 ◽

Vol 2 (10) ◽

pp. 929-938

Author(s):

Khin Phyu Pyar ◽

Khine Khine Su ◽

Kyaw Wunna ◽

Myo Thant ◽

Kaung Myat ◽

...

Keyword(s):

Predictive Value ◽

False Negative ◽

Hospital Setting ◽

Clinical Samples ◽

Nasopharyngeal Swab ◽

Clinical Impression ◽

Antigen Test ◽

Rt Pcr ◽

Ct Value

Background: In COVID-19 pandemic, the diagnosis and treatment must be as early as possible to save the life of each patient. Moreover, screening of asymptomatic carriers, close contacts or healthy subjects must not be delay to prevent transmission to publics. For confirmation of diagnosis of SARS-CoV-2 infection, nasopharyngeal swab must be tested either by real-time Reverse Transcription Polymerase Chain Reaction (RT-PCR) tests or Rapid Antigen Test (RAT). RAT is faster, easier and cheaper; thus, it is suitable for health service in developing country. Objectives: The aim of this study was to assess the diagnostic accuracy of Roche SARS-CoV-2 Rapid Antigen Test (RAT) in diagnosing SARS-CoV-2 infection. Methods: Hospital based exploratory study was done in out-patient department and fever clinic, and molecular laboratory of No. (1) Defence Services General Hospital. Nasopharyngeal swabs were taken, and the Roche SARS- CoV-2 RAT was conducted in parallel with RT-PCR test (reference standard). Results: Among the 932 patients/subjects recruited, RT-PCR was positive in 468 individuals, corresponding to a prevalence of 50.2%. The RAT was positive in 363 patients (60.4%), false positive in 120 patients; it was negative in 569 individuals (39.6%), false negative in 225 patients. The overall sensitivity of the RAT was 51.9% (95% Confidence Interval [CI] 47.29-56.53) and, the specificity was 74.1% (95% CI 69.9-78.07); positive predictive value was 66.9% and negative predictive value was 60.5%. The sensitivity varied with Ct value; 78% in clinical samples with Ct values < 20, 57.5% in those with Ct values between 21 and 25, 41.8% in samples with Ct values between 26 and 30, and, 36.4% in samples with Ct value > 30. Conclusion: The accuracy of the SARS-CoV-2 Roche RAT in diagnosing SARS-CoV-2 infections was inferior to RT-PCR and manufacturer’s data. The sensitivity was with low Cycle threshold values < 20 which were inversely related to the viral load. RAT test should be used in association with clinical impression of physicians. In hospital setting especially in emergency department, the role of RAT should be reconsidered in those patients presenting with anosmia and some cases of dyspnoea, late symptoms in the course of disease, as the RAT results would be false negative. Other errors may arise if the operator for RAT has to handle more than recommended tests per hour especially in the peak of epidemics.

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Scoring System for the Diagnosis of COVID-19

The Open Public Health Journal ◽

10.2174/1874944502013010413 ◽

2020 ◽

Vol 13 (1) ◽

pp. 413-414 ◽

Cited By ~ 1

Author(s):

Mohamed Farouk Allam

Keyword(s):

Scoring System ◽

Clinical Symptoms ◽

False Negative ◽

Nasopharyngeal Swab ◽

Rt Pcr ◽

Pcr Assay ◽

Negative Results ◽

False Negative Results ◽

Symptoms And Signs

Due to the international spread of COVID-19, the difficulty of collecting nasopharyngeal swab specimen from all suspected patients, the costs of RT-PCR and CT, and the false negative results of RT-PCR assay in 41% of COVID-19 patients, a scoring system is needed to classify the suspected patients in order to determine the need for follow-up, home isolation, quarantine or the conduction of further investigations. A scoring system is proposed as a diagnostic tool for suspected patients. It includes Epidemiological Evidence of Exposure, Clinical Symptoms and Signs, and Investigations (if available). This scoring system is simple, could be calculated in a few minutes, and incorporates the main possible data/findings of any patient.

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The management of surgical patients in the emergency setting during COVID-19 pandemic: the WSES position paper

World Journal of Emergency Surgery ◽

10.1186/s13017-021-00349-0 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Belinda De Simone ◽

Elie Chouillard ◽

Massimo Sartelli ◽

Walter L. Biffl ◽

Salomone Di Saverio ◽

...

Keyword(s):

Systematic Review ◽

Emergency Surgery ◽

Healthcare Workers ◽

Mass Casualty ◽

Position Paper ◽

Surgical Patients ◽

Nasopharyngeal Swab ◽

Emergency Setting ◽

Open Approach ◽

Rt Pcr

Abstract Background Since the COVID-19 pandemic has occurred, nations showed their unpreparedness to deal with a mass casualty incident of this proportion and severity, which resulted in a tremendous number of deaths even among healthcare workers. The World Society of Emergency Surgery conceived this position paper with the purpose of providing evidence-based recommendations for the management of emergency surgical patients under COVID-19 pandemic for the safety of the patient and healthcare workers. Method A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) through the MEDLINE (PubMed), Embase and SCOPUS databases. Synthesis of evidence, statements and recommendations were developed in accordance with the GRADE methodology. Results Given the limitation of the evidence, the current document represents an effort to join selected high-quality articles and experts’ opinion. Conclusions The aim of this position paper is to provide an exhaustive guidelines to perform emergency surgery in a safe and protected environment for surgical patients and for healthcare workers under COVID-19 and to offer the best management of COVID-19 patients needing for an emergency surgical treatment. We recommend screening for COVID-19 infection at the emergency department all acute surgical patients who are waiting for hospital admission and urgent surgery. The screening work-up provides a RT-PCR nasopharyngeal swab test and a baseline (non-contrast) chest CT or a chest X-ray or a lungs US, depending on skills and availability. If the COVID-19 screening is not completed we recommend keeping the patient in isolation until RT-PCR swab test result is not available, and to manage him/she such as an overt COVID patient. The management of COVID-19 surgical patients is multidisciplinary. If an immediate surgical procedure is mandatory, whether laparoscopic or via open approach, we recommend doing every effort to protect the operating room staff for the safety of the patient.

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Evaluation of SARS-CoV-2 antigen-based rapid diagnostic kits in Pakistan: formulation of COVID-19 national testing strategy

Virology Journal ◽

10.1186/s12985-021-01505-3 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Umar Saeed ◽

Sara Rizwan Uppal ◽

Zahra Zahid Piracha ◽

Azhar Rasheed ◽

Zubair Aftab ◽

...

Keyword(s):

Gold Standard ◽

Injection Drug Users ◽

Drug Users ◽

Diagnostic Testing ◽

False Negative ◽

Cross Sectional Study ◽

Nasopharyngeal Swab ◽

Rt Pcr ◽

Cross Sectional ◽

Negative Results

AbstractRapid diagnosis of SARS-CoV-2 during pandemic enables timely treatment and prevention of COVID-19. Evaluating the accuracy and reliability of rapid diagnostic testing kits is crucial for surveillance and diagnosis of SARS-CoV-2 infections in general population, injection drug users, multi-transfused populations, healthcare workers, prisoners, barbers and other high risk populations. The aim of this study was to evaluate performance and effectiveness of nasopharyngeal swab (NSP) and saliva based rapid antigen detection testing kits in comparison with USFDA approved triple target gold standard real-time polymerase chain reaction. A cross-sectional study was conducted on 33,000 COVID-19 suspected patients. From RT-PCR positive patients, nasopharyngeal swab (NSP) and saliva samples were obtained for evaluation of rapid COVID-19 testing kits (RDT). 100/33,000 (0.3%) of specimens were RT-PCR positive for SARS-CoV-2. Among RT-PCR positive, 62% were males, 34% were females, and 4% were children. The NSP-RDT (Lepu Medical China) analysis revealed 53% reactivity among males, 58% reactivity among females, and 25% reactivity among children. However saliva based RDT (Lepu Medical China) analysis showed 21% reactivity among males and 23% among females, and no reactivity in children. False negative results were significantly more pronounced in saliva based RDT as compared to NSP-RDT. The sensitivity of these NSP-RDT and saliva based RDT were 52% and 21% respectively. The RDTs evaluated in this study showed limited sensitivities in comparison to gold standard RT-PCR, indicating that there is a dire need in Pakistan for development of suitable testing to improve accurate COVID-19 diagnosis in line with national demands.

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COVID-19 serological testing for Healthcare Workers in Lombardy, Italy

European Journal of Public Health ◽

10.1093/eurpub/ckaa165.351 ◽

2020 ◽

Vol 30 (Supplement_5) ◽

Author(s):

G Del Castillo ◽

A Castrofino ◽

F Grosso ◽

A Barone ◽

L Crottogini ◽

...

Keyword(s):

Healthcare Workers ◽

Geographical Area ◽

Healthcare Facility ◽

Nasopharyngeal Swab ◽

Infection Prevalence ◽

Serological Testing ◽

Prevention Policy ◽

Rt Pcr ◽

Serological Tests ◽

Screening Process

Abstract Issue COVID-19 pandemic began in Italy on February 20th, 2020. Since the beginning of the emergency Healthcare Workers' (HCWs) involvement was prominent, mainly due to direct assistance to COVID-19 patients. Therefore, we implemented a prevention policy for HCW screening through serological and RT-PCR testing. Description of the problem HCW screening for SARS-CoV-2 infection is essential for prevention and control of the pandemic. Lombardy's Healthcare authorities settled a screening process for HCWs divided into three steps: 1) body temperature assessment at the beginning and the end of work shift, if fever > 37.5 °C was present the HCW was sent back home and a nasopharyngeal swab was performed; 2) progressive recruitment for serological testing; 3) on those positive to IgG a nasopharyngeal swab was performed and tested for viral RNA by RT-PCR. Results Among 79185 HCW tested, 9589 (12%) were positive on serological IgG testing. Of the 9589 positive a nasopharyngeal swab was performed on 6884. Of these 358 (5%) tested positive and the remaining 6526 (95%) negative to RT-PCR. We calculated a Positive Predictive Value of 5.2%. The rate of positive serological tests for each Healthcare facility varied between 0% and 78%. Five percent of all facilities, belonging to Brescia, Bergamo and Cremona area, reported a positivity rate higher than 40% in HCWs. A second cluster (18% of all facilities), involving the same geographical area, reported a rate between 20% and 40%, whereas the remaining facilities (76%) of the region a rate <20%. Lessons Serological IgG testing can be, if followed by immediate nasopharyngeal swab testing, a valid screening intervention on asymptomatic HCWs especially in a high infection prevalence setting. Key messages Serological IgG testing can be, if followed by immediate nasopharyngeal swab testing, a valid screening intervention on asymptomatic HCWs. Infection prevention in HCW may benefit from a screening campaign especially in high prevalence settings.

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Evaluation of the Carba NP Test for Rapid Detection of Carbapenemase-Producing Enterobacteriaceae and Pseudomonas aeruginosa

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00878-13 ◽

2013 ◽

Vol 57 (9) ◽

pp. 4578-4580 ◽

Cited By ~ 147

Author(s):

Nathalie Tijet ◽

David Boyd ◽

Samir N. Patel ◽

Michael R. Mulvey ◽

Roberto G. Melano

Keyword(s):

Pseudomonas Aeruginosa ◽

Positive Predictive Value ◽

Negative Predictive Value ◽

Predictive Value ◽

Rapid Detection ◽

False Negative ◽

Bacterial Extract ◽

Content Type ◽

Negative Results ◽

False Negative Results

ABSTRACTThe Carba NP test was evaluated against a panel of 244 carbapenemase- and non-carbapenemase-producingEnterobacteriaceaeandPseudomonas aeruginosaisolates. We confirmed the 100% specificity and positive predictive value of the test, but the sensitivity and negative predictive value were 72.5% and 69.2%, respectively, and increased to 80% and 77.3%, respectively, using a more concentrated bacterial extract. False-negative results were associated with mucoid strains or linked to enzymes with low carbapenemase activity, particularly OXA-48-like, which has emerged globally in enterobacteria.

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Response to BNT162b2 mRNA COVID-19 vaccine among healthcare workers in Italy: a 3-month follow-up

Internal and Emergency Medicine ◽

10.1007/s11739-021-02857-y ◽

2021 ◽

Author(s):

Domenico Ponticelli ◽

Fabiana Madotto ◽

Sara Conti ◽

Ippazio C. Antonazzo ◽

Andrea Vitale ◽

...

Keyword(s):

Healthcare Workers ◽

Future Research ◽

Nasopharyngeal Swab ◽

Special Focus ◽

Rt Pcr ◽

Vaccine Response ◽

Serology Testing ◽

Effectiveness Data

AbstractThis study investigated the response to BNT162b2 mRNA COVID-19 vaccine among healthcare workers (HCWs) in an Italian teaching hospital. 444 participants were surveyed with either multiple RT-PCR assays for detection of SARS-CoV-2 nucleic acid in nasopharyngeal swabs or serology testing for the research of virus-specific immunoglobulins. Adverse events following immunization (AEFI) were reported. Two weeks after the first dose anti-SARS-CoV-2 antibodies exceeded reactivity cut-off in 82.5% the participants. Four HCWs tested positive at nasopharyngeal swab after 3 months. More than three-quarters reported AEFIs. Our findings offer an insight regarding the vaccine response after 3 months from its administration, with a special focus on effectiveness data, as well as the type and number of AEFIs complained by HCW recipients. The presented study may serve as reference for future research which will be necessary to explore the long-term safety of this vaccine, especially in population at high risk for infection, such as HCWs.

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COVID-19 Thrombosis: Understanding the Negative Predictive Value in a Pandemic

Blood ◽

10.1182/blood-2020-142127 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 5-5

Author(s):

Talat Almukhtar ◽

Julio Hajdenberg ◽

Gurjot Garcha

Keyword(s):

Negative Predictive Value ◽

Predictive Value ◽

Conflicts Of Interest ◽

False Negative ◽

Hospitalized Patients ◽

Radiographic Examination ◽

Icu Patients ◽

Proinflammatory Mediators ◽

Cortical Edema ◽

Thrombotic Complications

A test's negative predictive value-the probability that a negative result is a true negative result-is dependent on the prevalence of the condition. The present pandemic circumstances present us with unique challenges. False negatives in current testing methodology are to be expected.[1] Thus, a rigorous and contextual interpretation of a negative test result is necessary. Blood hypercoagulability and the risk of thrombosis are well documented in cases of the novel SARS-CoV-2 coronavirus (COVID-19) pandemic.[2] The systemic inflammatory response is associated with endothelial upregulation of proinflammatory mediators that lead to in situ thrombi, as well as a generalized disseminated intravascular coagulation. As many as 31% of ICU patients with COVID-19 have been reported to have thrombotic complications. More specifically, cerebral thrombotic complications confined to the arterial bed have been well described.[3, 4]. The case described shows that milder forms of coronavirus infection may lead to other types of critical and unusual thrombotic complications. An otherwise healthy 47-year-old Caucasian woman developed fever and respiratory signs and symptoms consistent with a possible case of COVID-19 infection in late March of 2020. Interstitial opacities were seen on radiographic examination. Two COVID-19 PCR nasopharyngeal tests were negative, and she recovered at home over the following 2 weeks. Three weeks later, she developed headaches, expressive aphasia, and a generalized tonic-clonic seizure. The patient was treated for a possible ischemic stroke with alteplase thrombolysis at a local hospital. After subsequent transfer and evaluation, a diagnosis of a left transverse and sigmoid sinus thrombosis with adjacent cortical edema was made. On review of her history, the patient denied taking any form of hormonal contraception, and did not have personal, or family history indicative of thrombophilia. She recovered fully after anticoagulation with enoxaparin and subsequent dabigatran. Prior to discharge a COVID-19, IgG antibody test was reported as positive. Decontextualized and overly simplistic interpretation of COVID-19 negative tests amidst a pandemic is problematic. In addition to the obvious infection control issues associated with the resulting lack of isolation and contract tracing, it may deprive some patients of the opportunity to receive antithrombotic therapy. Prophylactic and therapeutic regimens for hospitalized patients are in evolution, and have been associated with improved clinical outcomes.[5] We are aware that the role of anticoagulation in outpatient cases is not well studied, but we believe it deserves proper investigation. References: West, C.P., V.M. Montori, and P. Sampathkumar,COVID-19 Testing: The Threat of False Negative Results.Mayo Clin Proc, 2020.Thachil, J., et al.,ISTH interim guidance on recognition and management of coagulopathy inCOVID-19.J Thromb Haemost, 2020.18(5): p. 1023-1026.Oxley, T.J., et al.,Large-Vessel Stroke as a Presenting Feature of Covid-19 in the Young.N Engl J Med, 2020.Klok, F.A., et al.,Confirmation of the high cumulative incidence of thrombotic complications incritically ill ICU patients with COVID-19: An updated analysis.Thromb Res, 2020.Paranjpe, I., et al.,Association of Treatment Dose Anticoagulation with In-Hospital SurvivalAmong Hospitalized Patients with COVID-19.J Am Coll Cardiol, 2020. Disclosures No relevant conflicts of interest to declare.

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

Otolaryngology ◽

10.1177/0194599820931793 ◽

2020 ◽

Vol 163 (3) ◽

pp. 459-461 ◽

Cited By ~ 12

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.

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