scholarly journals An Overview of Nucleic Acid Testing for the Novel Coronavirus SARS-CoV-2

2021 ◽  
Vol 7 ◽  
Author(s):  
Huiling Wang ◽  
Gang Li ◽  
Jing Zhao ◽  
Yanjie Li ◽  
Yushu Ai
Keyword(s):  
Nucleic Acid ◽  
Early Diagnosis ◽  
Treatment Plan ◽  
False Negative ◽  
Nucleic Acid Testing ◽  
The Novel ◽  
Negative Results ◽  
Literature Overview ◽  
False Negative Results ◽  
Novel Coronavirus

In this note we analyze the problems in the nucleic acid testing (NAT) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and we also give some suggestions for improving the accuracy of NAT diagnosis. NAT testing is considered to be the diagnostic “gold standard”; at present there are few reviews on NAT for SARS-CoV-2. Moreover, many false-negative results always appear in the procedure of detecting, which has affected early diagnosis of the disease and brought a great challenge to mitigation and containment of the pandemic. In conclusion, comprehensive analyses of serological and imaging findings should be performed to guide the formulation of an accurate clinical diagnosis, treatment plan, and monitoring therapeutic efficacy, in an effort to achieve early diagnosis, containment, and treatment of the disease, thereby effectively reducing progression of the pandemic. This article presents a literature overview of SARS-CoV-2 nucleic acid testing, aiming to provide support for clinicians.

scholarly journals Laboratory markers included in the Corona Score can identify false negative results on COVID-19 RT-PCR in the emergency room

2020 ◽  
Vol 30 (3) ◽  
pp. 357-359
Author(s):  
Roberto Assandri ◽  
Ciro Canetta ◽  
Giovanni Viganò ◽  
Elisabetta Buscarini ◽  
Alessandro Scartabellati ◽  
...  
Keyword(s):  
Emergency Room ◽  
False Negative ◽  
Clinical Syndrome ◽  
The Novel ◽  
Emergency Rooms ◽  
Negative Results ◽  
Emergency Room Patients ◽  
False Negative Results ◽  
Wide Range ◽  
Novel Coronavirus

After December 2019 outbreak in China, the novel Coronavirus infection (COVID-19) has very quickly overflowed worldwide. Infection causes a clinical syndrome encompassing a wide range of clinical features, from asymptomatic or oligosymptomatic course to acute respiratory distress and death. In a very recent work we preliminarily observed that several laboratory tests have been shown as characteristically altered in COVID-19. We aimed to use the Corona score, a validated point-based algorithm to predict the likelihood of COVID-19 infection in patients presenting at the Emergency rooms. This approach combines chest images-relative score and several laboratory parameters to classify emergency room patients. Corona score accuracy was satisfactory, increasing the detection of positive patients’ rate.

scholarly journals Analysis and Prediction of COVID-19 Patients’ False Negative Results for SARS-CoV-2 Detection with Pharyngeal Swab Specimen: A Retrospective Study

2020 ◽  
Author(s):  
Hui Xu ◽  
Li Yan ◽  
Chun (Martin) Qiu ◽  
Bo Jiao ◽  
Yanyan Chen ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Time Window ◽  
Clinical Symptoms ◽  
False Negative ◽  
Ct Imaging ◽  
Nucleic Acid Detection ◽  
False Negatives ◽  
Negative Results ◽  
False Negative Results ◽  
Blood Routine

ABSTRACTBackgroundFalse negative results of SARS-CoV-2 nucleic acid detection pose threats to COVID-19 patients and medical workers alike.ObjectiveTo develop multivariate models to determine clinical characteristics that contribute to false negative results of SARS-CoV-2 nucleic acid detection, and use them to predict false negative results as well as time windows for testing positive.DesignRetrospective Cohort Study (Ethics number of Tongji Hospital: No. IRBID: TJ-20200320)SettingA database of outpatients in Tongji Hospital (University Hospital) from 15 January 2020 to 19 February 2020.Patients1,324 outpatients with COVID-19MeasurementsClinical information on CT imaging reports, blood routine tests, and clinic symptoms were collected. A multivariate logistic regression was used to explain and predict false negative testing results of SARS-CoV-2 detection. A multivariate accelerated failure model was used to analyze and predict delayed time windows for testing positive.ResultsOf the 1,324 outpatients who diagnosed of COVID-19, 633 patients tested positive in their first SARS-CoV-2 nucleic acid test (47.8%), with a mean age of 51 years (SD=14.9); the rest, which had a mean age of 47 years (SD=15.4), tested negative in the first test. “Ground glass opacity” in a CT imaging report was associated with a lower chance of false negatives (aOR, 0.56), and reduced the length of time window for testing positive by 26%. “Consolidation” was associated with a higher chance of false negatives (aOR, 1.57), and extended the length of time window for testing positive by 44%. In blood routine tests, basophils (aOR, 1.28) and eosinophils (aOR, 1.29) were associated with a higher chance of false negatives, and were found to extend the time window for testing positive by 23% and 41%, respectively. Age and gender also affected the significantly.LimitationData were generated in a large single-center study.ConclusionTesting outcome and positive window of SARS-CoV-2 detection for COVID-19 patients were associated with CT imaging results, blood routine tests, and clinical symptoms. Taking into account relevant information in CT imaging reports, blood routine tests, and clinical symptoms helped reduce a false negative testing outcome. The predictive AFT model, what we believe to be one of the first statistical models for predicting time window of SARS-CoV-2 detection, could help clinicians improve the accuracy and efficiency of the diagnosis, and hence, optimizes the timing of nucleic acid detection and alleviates the shortage of nucleic acid detection kits around the world.Primary Funding SourceNone.

scholarly journals Prolonged nucleic acid conversion and false-negative RT-PCR results in Indonesian patients with COVID-19: A case series

2020 ◽  
Author(s):  
Ika Trisnawati ◽  
Riat Al Khair ◽  
Aditya Rifqi Fauzi ◽  
Gunadi
Keyword(s):  
Nucleic Acid ◽  
Male Patient ◽  
False Negative ◽  
Case Series ◽  
Heart Rhythm ◽  
X Rays ◽  
Rt Pcr ◽  
Negative Results ◽  
False Negative Results ◽  
Heart Rhythm Disorders

Abstract Background: Prolonged nucleic acid conversion and false-negative results of real-time reverse transcription polymerase chain reaction (RT-PCR) might occur in some patients with COVID-19 rather than recurrence of infection. Here, we reported four cases of COVID-19 with prolonged nucleic acid conversion and false-negative results of RT-PCR in our institution.Case presentation: Case 1: A 36-year-old-male patient complained of coughing up phlegm one week before admission. His chest X-rays showed mild pneumonia in the right lung. His swab test was confirmed positive for SARS-Cov-2. Besides the last two consecutive negative results, he also had negative results of RT-PCR twice (the 6th and 8th tests) from a total of 11 swab tests. Case 2: A 54-year-old-male patient complained of shortness of breath that worsened with activity. He had a comorbidity of diabetes. His chest X-rays showed inhomogeneous opacity on bilateral paracardial and lateral aspects. His swab test was confirmed positive for SARS-Cov-2. Besides the last two consecutive negative results, he also had negative results of RT-PCR once (the 5th test) from a total of 8 swab tests. Case 3: A 47-year-old man presented with complaints of fever, cough, sore throat, and diarrhea. He had comorbidities of asthma and heart rhythm disorders. His chest X-rays showed bilateral pneumonia. His swab test was confirmed positive for SARS-Cov-2. Besides the last two consecutive negative results, he also showed negative results of RT-PCR twice (the 4th and 6th tests) from a total of 11 swab tests. Case 4: A 56-year-old-female complained of lethargy and diarrhea. She has a history of hyperthyroidism. His chest X-rays showed bilateral pneumonia. She was confirmed positive for SARS-Cov-2. Besides the last two consecutive negative results, she also had negative results of RT-PCR twice (the 2nd and 10th tests) from a total of 14 swab tests.Conclusions: Our cases further confirmed the occurrence of prolonged nucleic acid conversion and the possibility of false negative results of RT-PCR in patients with COVID-19 instead of recurrence of infection. These findings might have an implication on the management of patients with COVID-19 who have already clinically and radiologically recovered, particularly related to subsequent spreading of the infection in the community.

scholarly journals Conjunctival polymerase chain reaction-tests of 2019 novel coronavirus in patients in Shenyang,China

2020 ◽  
Author(s):  
Li Xu ◽  
Xinyue Zhang ◽  
Wei Song ◽  
Baijun Sun ◽  
Jinping Mu ◽  
...  
Keyword(s):  
Clinical Features ◽  
Clinical Symptoms ◽  
False Negative ◽  
Suspected Case ◽  
Negative Results ◽  
False Negative Results ◽  
Laboratory Results ◽  
Polymerase Chain ◽  
Novel Coronavirus ◽  
Negative Detection

Abstract Background We report the laboratory results of conjunctival PCR-tests and some clinical features of these patients infected with COVID-19 in shenyang China.Methods We collected conjunctival samples of the patients to do the laboratory tests by PCR.Medical observed patients were enrolled if they had clinical symptoms. Then we analysed the PCR results and clinical features in order to find some relationships.Results The study include 14 confirmly diagnosed cases ,16 suspected cases and some medical observed patients.1 of the identified case coverted from suspected case.22 medical observed cases were removed because none of them converted to identified cases.1 of the suspected converted to identified case recently.All the conjunctival results of PCR-test were negative.Discussion The reasons of the negative detection results of PCR in conjunctival swabs were discussed.Conclusion Conjunctiva may be a transmission way of COVID-19.And ocular conjunctival swabs could be a diagnostic method for identifying the infection of COVID-19.Emphasis on the false-negative results is vital.

Evaluating real-time PCR for the quantification of distinct pathogens and indicator organisms in environmental samples

2004 ◽  
Vol 50 (1) ◽  
pp. 263-270 ◽  
Author(s):  
M. Lebuhn ◽  
M. Effenberger ◽  
G. Garcés ◽  
A. Gronauer ◽  
P.A. Wilderer
Keyword(s):  
Nucleic Acid ◽  
Real Time ◽  
Real Time Pcr ◽  
Environmental Samples ◽  
False Negative ◽  
Indicator Organisms ◽  
Negative Results ◽  
False Negative Results ◽  
Methodological Bias ◽  
Reliable Quantification

We evaluated quantitative real-time PCR (qPCR) and RTqPCR (for RNA species) for their ability to quantify microorganisms and viruses in problematic environmental samples such as cattle manure, digester material, wastewater and soil. Important developments included a standard spiking approach which compensated for methodological bias and allowed sample-to-sample comparison and reliable quantification. Programme CeTe was developed to calculate endogenous concentrations of target organisms (nucleic acid copies) for each sample separately from the generated standard curves. The approach also permitted assessment of the detection limit of the complete method, including extraction. It varied from sample to sample, due to different extraction efficiencies and variable co-extraction of PCR inhibitors. False negative results were thereby avoided. By using this approach we were able to optimise a DNA extraction protocol from the different tested sample types. Protocols for the extraction of RNA species from environmental samples were also optimised. DNA was (almost) not degraded after lethal shock (autoclaving) in the sterile environment. In contrast, the parallel selective cultivation and qPCR results for various microbial parameters from an anaerobic digester chain suggested that DNA from decaying organisms was readily recycled in metabolically active environments. It may, therefore, be used to determine viable organisms in samples exhibiting substantial metabolic turnover. It is proposed that our standard spiking approach, including data evaluation by the program CeTe, should be considered in future standardisation and norms for the quantification of nucleic acid containing organisms in environmental and product samples.

scholarly journals Development of an Immunochromatographic Test for Rapid Serodiagnosis of Human Pythiosis

2009 ◽  
Vol 16 (4) ◽  
pp. 506-509 ◽  
Author(s):  
Theerapong Krajaejun ◽  
Srisurat Imkhieo ◽  
Akarin Intaramat ◽  
Kavi Ratanabanangkoon
Keyword(s):  
Early Diagnosis ◽  
Serological Test ◽  
False Negative ◽  
Turnaround Time ◽  
Immunochromatographic Test ◽  
Pythium Insidiosum ◽  
Negative Results ◽  
False Negative Results ◽  
Gold Conjugate ◽  
Life Threatening

ABSTRACT Human pythiosis is an emerging and life-threatening infectious disease caused by the fungus-like organism Pythium insidiosum. High rates of morbidity and mortality for patients with pythiosis are exacerbated by the lack of early diagnosis and an effective treatment. Here, we developed and evaluated an immunochromatographic test (ICT) for the diagnosis of human pythiosis, in comparison to a standard serological test of immunodiffusion (ID). Culture filtrate antigen of P. insidiosum was used to detect human anti-P. insidiosum antibody. Sheep anti-human immunoglobulin G-colloidal gold conjugate was used to generate an ICT signal. Thirty-three sera from patients with vascular (n = 27), ocular (n = 4), and cutaneous (n = 2) pythiosis and 181 control sera from healthy blood donors (n = 100), as well as patients with a variety of infectious (n = 56) and noninfectious (n = 25) diseases, were included in the test evaluation. The turnaround time for generating a result by the ICT was less than 30 min, while that for ID was ∼24 h. Based on the results for all sera of pythiosis patients and the control groups, the ICT showed 88% sensitivity and 100% specificity and ID showed 61% sensitivity and 100% specificity. By both tests, false-negative results for sera from all ocular pythiosis patients were obtained. In addition, the ID test yielded false-negative results for sera from eight patients with vascular pythiosis and one patient with cutaneous pythiosis. It was concluded that the ICT is a rapid, user-friendly, and reliable serological test for the early diagnosis of vascular and cutaneous pythiosis.

scholarly journals Conjunctival polymerase chain reaction-tests of 2019 novel coronavirus in patients in Shenyang, China

2020 ◽  
Author(s):  
Li Xu ◽  
Xinyue Zhang ◽  
Wei Song ◽  
Baijun Sun ◽  
Jinping Mu ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Randomized Study ◽  
False Negative ◽  
Suspected Case ◽  
Cross Sectional ◽  
Negative Results ◽  
False Negative Results ◽  
Imported Cases ◽  
Novel Coronavirus ◽  
Pcr Test

AbstractPurposeThe 2019 novel coronavirus(COVID-19) mainly transmitted by person-to-person through inhalation of respiratory droplets. We report the laboratory results of conjunctival PCR-tests and some clinical features of these patients in shenyang China.DesignThis is a cross-sectional non-randomized studySubjectsThe study include 14 confirmly diagnosed cases, 16 suspected cases and some medical observed patients.MethodsAll patients with diagnosed and suspected COVID-19 were admitted to a designated hospital in Shenyang, China. We collected conjunctival samples of these patients to do the laboratory tests by real time RT-PCR. Medical observed patients were enrolled if they had clinical symptoms. Then we analysed the PCR results and clinical data from eletronic medical records in order to find some relationships.Main Outcome MeasuresClinical condition and PCR results. of conjunctival swabs compared with other specimensResultsOne of the identified case coverted from suspected case without typical clinical symptoms. Twenty-two medical observed cases were removed because none of them converted to identified cases. One of the suspected converted to identified case recently. The included cases in our study are imported cases with less underlying diseases and the severity of their infection was relatively moderate. All the conjunctival results of PCR-test were negative. Two cases had typical clinical symptoms but were finally confirmed by repeated pharynxswabtests.ConclusionConjunctiva may be a transmission way of COVID-19. And ocular conjunctival swabs in combination with PCR test could be a non-invasive, convenient and feasible diagnostic method for identifying the infection of COVID-19. Emphasis on the false-negative results is vital.

New Diagnostic Possibilities for Neonatal Sepsis

2018 ◽  
Vol 35 (06) ◽  
pp. 575-577 ◽  
Author(s):  
Chryssoula Tzialla ◽  
Cristian Achille ◽  
Lina Bollani ◽  
Mauro Stronati ◽  
Alessandro Borghesi ◽  
...  
Keyword(s):  
Blood Culture ◽  
Early Diagnosis ◽  
Neonatal Sepsis ◽  
False Negative ◽  
Clinical Applications ◽  
Morbidity And Mortality ◽  
Negative Results ◽  
False Negative Results ◽  
Novel Biomarkers ◽  
Diagnostic Approaches

AbstractProgress in neonatal care has decrease morbidity and mortality due to neonatal sepsis (NS). Although diagnosis of sepsis continues to rely on blood culture, this method is too slow and limited by false-negative results. There are numerous sepsis biomarkers that have been evaluated for the early diagnosis of NS, but, to date, there is no single ideal biomarker, though novel biomarkers are becoming more sophisticated and specific in their clinical applications. This review provides an overview of the current diagnostic approaches available or under development for diagnosing NS.

scholarly journals Inhibition monitoring in veterinary molecular testing

2019 ◽  
Vol 32 (6) ◽  
pp. 758-766 ◽  
Author(s):  
Lifang Yan ◽  
Kathy L. Toohey-Kurth ◽  
Beate M. Crossley ◽  
Jianfa Bai ◽  
Amy L. Glaser ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Internal Control ◽  
Control Strategies ◽  
False Negative ◽  
Internal Controls ◽  
Molecular Testing ◽  
Acid Extraction ◽  
Negative Results ◽  
False Negative Results ◽  
Laboratory Technology

Many of the sample matrices typically used for veterinary molecular testing contain inhibitory factors that can potentially reduce analytic sensitivity or produce false-negative results by masking the signal produced by the nucleic acid target. Inclusion of internal controls in PCR-based assays is a valuable strategy not only for monitoring for PCR inhibitors, but also for monitoring nucleic acid extraction efficiency, and for identifying technology errors that may interfere with the ability of an assay to detect the intended target. The Laboratory Technology Committee of the American Association of Veterinary Laboratory Diagnosticians reviewed the different types of internal controls related to monitoring inhibition of PCR-based assays, and provides information here to encourage veterinary diagnostic laboratories to incorporate PCR internal control strategies as a routine quality management component of their molecular testing.

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