scholarly journals Tips for a reduction of false positives in manual RT-PCR diagnostics of SARS-CoV-2

Bionatura ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 1948-1954
Author(s):  
Francisco J. Alvarez ◽  
Mariela Perez-Cardenas ◽  
Marco Gudiño ◽  
Markus P. Tellkamp
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
High Specificity ◽  
False Positives ◽  
Rt Pcr ◽  
Manual Operation ◽  
Laboratory Techniques ◽  
Specificity And Sensitivity ◽  
The World ◽  
Pcr Diagnostics ◽  
Positive Results

RT-PCR is the standard gold technique for testing the presence of RNA of the coronavirus causing Severe Acute Respiratory Syndrome (SARS-CoV-2) due to its high specificity and sensitivity. Despite its general use and reliability, no lab in the world is immune to the generation of false positives. These errors cause a loss of confidence in the technique's power and damage the image of laboratories. More importantly, they can take a toll on tested individuals and have economic, psychological, and health-associated effects. Most false positives are caused during a manual operation inside the laboratory. However, not much has been published about the errors associated with particular laboratory techniques used to detect the virus since the beginning of the actual pandemic. This work precisely reflects on events that occur during manual RT-PCR diagnostics in a COVID-19 laboratory, providing tips for reducing false-positive results.

scholarly journals Assessment of dengue and COVID-19 antibody rapid diagnostic tests cross-reactivity in Indonesia

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Marsha S. Santoso ◽  
Sri Masyeni ◽  
Sotianingsih Haryanto ◽  
Benediktus Yohan ◽  
Martin L. Hibberd ◽  
...  
Keyword(s):  
Diagnostic Tests ◽  
High Specificity ◽  
Cross Reactivity ◽  
Rapid Diagnostic Tests ◽  
Rt Pcr ◽  
Delayed Treatment ◽  
Health Practitioners ◽  
The World ◽  
Laboratory Features ◽  
Positive Results

Abstract Background The coronavirus disease 2019 (COVID-19) pandemic remains ongoing around the world, including in areas where dengue is endemic. Dengue and COVID-19, to some extent, have similar clinical and laboratory features, which can lead to misdiagnosis, delayed treatment and patient’s isolation. The use of rapid diagnostic tests (RDT) is easy and convenient for fast diagnosis, however there may be issues with cross-reactivity with antibodies for other pathogens. Methods We assessed the possibility of cross-reactivity between SARS-CoV-2 and dengue antibodies by: (1) testing five brands of COVID-19 IgG / IgM RDTs on 60 RT-PCR-confirmed dengue samples; (2) testing 95 RT-PCR-confirmed COVID-19 samples on dengue RDT; and (3) testing samples positive for COVID-19 IgG and/or IgM on dengue RDT. Results We observed a high specificity across all five brands of COVID-19 RDTs, ranging from 98.3 to 100%. Out of the confirmed COVID-19 samples, one patient tested positive for dengue IgM only, another tested positive for dengue IgG only. One patient tested positive for dengue IgG, IgM, and NS1, suggesting a co-infection. In COVID-19 IgG and/or IgM samples, 6.3% of COVID-19 IgG-positive samples also tested positive for dengue IgG, while 21.1% of COVID-19 IgM-positive samples also tested positive for dengue IgG. Conclusion Despite the high specificity of the COVID-19 RDT, we observed cross-reactions and false-positive results between dengue and COVID-19. Dengue and COVID-19 co-infection was also found. Health practitioners in dengue endemic areas should be careful when using antibody RDT for the diagnosis of dengue during the COVID-19 pandemic to avoid misdiagnosis.

scholarly journals Performance of Commercially Available Rapid Serological Assays for the Detection of SARS-CoV-2 Antibodies

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1067
Author(s):  
Anwar M. Hashem ◽  
Rowa Y. Alhabbab ◽  
Abdullah Algaissi ◽  
Mohamed A. Alfaleh ◽  
Sharif Hala ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Significant Variation ◽  
High Specificity ◽  
Lateral Flow ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Standard Methods ◽  
Specific Antibodies ◽  
Time Points

The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continues to spread globally. Although several rapid commercial serological assays have been developed, little is known about their performance and accuracy in detecting SARS-CoV-2-specific antibodies in COVID-19 patient samples. Here, we have evaluated the performance of seven commercially available rapid lateral flow immunoassays (LFIA) obtained from different manufacturers, and compared them to in-house developed and validated ELISA assays for the detection of SARS-CoV-2-specific IgM and IgG antibodies in RT-PCR-confirmed COVID-19 patients. While all evaluated LFIA assays showed high specificity, our data showed a significant variation in sensitivity of these assays, which ranged from 0% to 54% for samples collected early during infection (3–7 days post symptoms onset) and from 54% to 88% for samples collected at later time points during infection (8–27 days post symptoms onset). Therefore, we recommend prior evaluation and validation of these assays before being routinely used to detect IgM and IgG in COVID-19 patients. Moreover, our findings suggest the use of LFIA assays in combination with other standard methods, and not as an alternative.

scholarly journals Methods of Diagnosis a Preferential Advantage in COVID-19: A Mini Review

2021 ◽  
pp. 173-179
Author(s):  
Neha Saini ◽  
Prem Pandey ◽  
Mandar Shirolkar ◽  
Atul Kulkarni
Keyword(s):  
Polymerase Chain Reaction ◽  
Severe Acute Respiratory Syndrome ◽  
Review Article ◽  
Diagnostic Methods ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Health Crisis ◽  
The World ◽  
Polymerase Chain ◽  
Novel Coronavirus

Humanity is going through never seen before health crisis due to the outbreak of novel coronavirus or Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). There are 24.02 million cases and 0.82 million deaths worldwide as of 26th August 2020 due to deadly infection of COVID-19. The disease has been spreading exponentially (R-naught number: 3) and has challenged even the best healthcare infrastructure in the world. With the progression of the disease, the countries shifted the focus from cure to diagnosis and containment to flatten the curve. The review shows that the disease is spreading exponentially while the resources are still limited. We focus upon the probable vectors of the virus, different diagnostic methods with advantages & limitations, and the way forward. This review article covers the different diagnostic methods with more advantages, limitations, and the future sneak-peek into the forthcoming developments for the diagnostic processes such as RT-PCR (Reverse Transcription Polymerase chain reaction).

scholarly journals Thermal Effect On The Persistence Of SARS-CoV2 Egyptian Isolates As Measured By Quantitative RT-PCR

2020 ◽  
Author(s):  
M.G. Seadawy ◽  
A.F. Gad ◽  
M.F. Elhoseny ◽  
B. ELharty ◽  
M.S. EL Desoky ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Severe Acute Respiratory Syndrome ◽  
Thermal Effect ◽  
Molecular Study ◽  
Virus Inactivation ◽  
Rt Pcr ◽  
Significant Difference ◽  
The World ◽  
Temperature Ranges ◽  
Thermal Stability Of

AbstractCoronavirus pandemic that caused by severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) appeared in China in 2019 then spread all over the world .COVID-19 firstly appeared in Egypt in Feb 2020. Studies on the thermal stability of the virus is crucial proper specimens’ transportation for molecular study. Oropharyngeal swabs were taken from recently infected military people with COVID-19 from Egypt during April 2020. Samples were aliquoted and the thermal stability of the virus was measured using quantitative real Time RT-PCR for samples treated at different temperature ranges from 20 °C to 70 °C for 2,4and 6 hours. Results shown that inactivation of the virus and significant reduction in the ΔCq values begin at 40 °C/4h. Complete virus inactivation and loss of ΔCq values were seen at 50 °C/6h and 60 °C. Tested samples showed no significant difference in thermal stability at any temp/time combinations tested.

Multisystem Inflammatory Syndrome in Infant with Negative SARS-CoV-2 RT-PCR and Antibodies

2021 ◽  
pp. 35-39
Author(s):  
Hanna Sahhar ◽  
Karly Derwitz ◽  
Erica Rubin
Keyword(s):  
Polymerase Chain Reaction ◽  
Severe Acute Respiratory Syndrome ◽  
Early Diagnosis ◽  
World Health ◽  
Rt Pcr ◽  
Chain Reaction ◽  
The World ◽  
Polymerase Chain ◽  
Health Organization ◽  
Inflammatory Syndrome

Since the declaration of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in March 2020 by the World Health Organization (WHO), there has been an emergence of a new syndrome termed multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19. MIS-C is defined by the presence of fever, systemic inflammation and multiorgan dysfunction in association with SARS-CoV-2 infection or COVID-19 exposure. Knowledge of this syndrome’s presentation and pathophysiology is constantly evolving as more cases are reported in the literature. This case identifies a 3-month-old patient who tested negative for SARS-CoV-2 antigen, reverse transcriptase polymerase chain reaction (RT-PCR) and antibodies but qualified for MIS-C diagnosis. To the best of our knowledge and through extensive research at the time of diagnosing and reporting this condition to the healthcare authorities, we report the youngest pediatric patient with MIS-C diagnosis. We document this case to contribute to further understanding the variable manifestations of MIS-C and the importance of early diagnosis and treatment with intravenous immunoglobulin (IVIG).

scholarly journals Serum Proteomic Fingerprints of Adult Patients with Severe Acute Respiratory Syndrome

2006 ◽  
Vol 52 (3) ◽  
pp. 421-429 ◽  
Author(s):  
Ronald TK Pang ◽  
Terence CW Poon ◽  
KC Allen Chan ◽  
Nelson LS Lee ◽  
Rossa WK Chiu ◽  
...  
Keyword(s):  
Viral Load ◽  
Severe Acute Respiratory Syndrome ◽  
Roc Curve ◽  
Serum Proteins ◽  
Early Stage ◽  
High Specificity ◽  
Roc Curves ◽  
Roc Curve Analysis ◽  
Outbreak Period ◽  
Specificity And Sensitivity

Abstract Background: Severe acute respiratory syndrome (SARS) is an emerging infectious disease caused by a new coronavirus strain, SARS-CoV. Specific proteomic patterns might be present in serum in response to the infection and could be useful for early detection of the disease. Methods: Using surface-enhanced laser desorption/ionization (SELDI) ProteinChip technology, we profiled and compared serum proteins of 39 patients with early-stage SARS infection and 39 non-SARS patients who were suspected cases during the SARS outbreak period. Proteomic patterns associated with SARS were identified by bioinformatic and biostatistical analyses. Features of interest were then purified and identified by tandem mass spectrometry. Results: Twenty proteomic features were significantly different between the 2 groups. Fifteen were increased in the SARS group, and 5 were decreased. Their concentrations were correlated with 2 or more clinical and/or biochemical variables. Two were correlated with the SARS-CoV viral load. Hierarchical clustering analysis showed that a majority of the SARS patients (95%) had similar serum proteomic profiles and identified 2 subgroups with poor prognosis. ROC curve analysis identified individual features as potential biomarkers for SARS diagnosis (areas under ROC curves, 0.733–0.995). ROC curve areas were largest for an N-terminal fragment of complement C3c α chain (m/z 28 119) and an internal fragment of fibrinogen α-E chain (m/z 5908). Immunoglobulin κ light chain (m/z 24 505) positively correlated with viral load. Conclusions: Specific proteomic fingerprints in the sera of adult SARS patients could be used to identify SARS cases early during onset with high specificity and sensitivity.

scholarly journals Rapid Creation of a Temporary Isolation Ward for Patients With Severe Acute Respiratory Syndrome in Taiwan

2004 ◽  
Vol 25 (12) ◽  
pp. 1026-1032 ◽  
Author(s):  
Chang-Phone Fung ◽  
Tsorng-Liu Hsieh ◽  
Kuang-Huan Tan ◽  
Chin-Hui Loh ◽  
Jiunn-Sheng Wu ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Infection Control ◽  
Control Measures ◽  
World Health ◽  
Military Hospital ◽  
Rt Pcr ◽  
Medical Centers ◽  
Isolation Ward ◽  
The Impact ◽  
Positive Results

AbstractObjectives:To rapidly establish a temporary isolation ward to handle an unexpected sudden outbreak of severe acute respiratory syndrome (SARS) and to evaluate the implementation of exposure control measures by healthcare workers (HCWs) for SARS patients.Design:Rapid creation of 60 relatively negative pressure isolation rooms for 196 suspected SARS patients transferred from 19 hospitals and daily temperature recordings of 180 volunteer HCWs from 6 medical centers.Setting:A military hospital.Results:Of the 196 patients, 34 (17.3%) met the World Health Organization criteria for probable SARS with positive results of serologic testing for SARS-associated coronavirus (SARS-CoV), reverse transcriptase polymerase chain reaction (RT-PCR) from nasopharyngeal or throat swabs for SARS-CoV, or both. Seventy-four patients had suspected SARS based on unprotected exposure to SARS patients; three of them had positive results on RT-PCR but negative serologic results. The remaining 88 patients did not meet the criteria for a probable or suspected SARS diagnosis. Of the 34 patients with probable SARS, 13 were transferred to medical centers to receive mechanical ventilation due to rapid deterioration of chest x-ray results, and three patients died of SARS despite intensive therapy in medical centers. During the study period, one nurse developed probable SARS due to violation of infection control measures, but there was no evidence of cross-transmission to other HCWs.Conclusions:Despite the use of full personal protection equipment, the facility failed to totally prevent exposures of HCWs to SARS but minimized the risk of nosocomial transmission. Better training and improvements in infection control infrastructure may limit the impact of SARS.

Shortest Unique Representative Hidden Markov Model (SurHMM) for Detecting Protein Toxins, Virulence Factors and Antibiotic Resistance Genes

2021 ◽  
Author(s):  
Gary Xie ◽  
Jeanne M Fair
Keyword(s):  
Markov Model ◽  
Hidden Markov Model ◽  
Hidden Markov ◽  
Sequence Similarity ◽  
Antibiotic Resistance Genes ◽  
High Specificity ◽  
False Positives ◽  
Bacterial Toxin ◽  
Specificity And Sensitivity ◽  
Next Generation Sequencing Ngs

Abstract Objective: Currently, next generation sequencing (NGS) is widely used to decode potential novel or variant pathogens both in emergent outbreaks and in routine clinical practice. However, the efficient identification of novel or diverged pathogenomic compositions remains a big challenge. It is especially true for short DNA sequence fragments from NGS, since sequence similarity searching is vulnerable to false negatives or false positives, as mismatching or matching with unrelated proteins. Therefore, this study aimed to establish a bioinformatics approach that can generate unique motif sequences for profiling searching, resulting in high specificity and sensitivity. Results: In this study, we introduced a shortest unique representative hidden Markov model (HMM) approach to identify bacterial toxin, virulence factor (VF), and antimicrobial resistance (AR) in short sequence reads. We first construct unique representative domain sequences of toxin genes, VFs, and ARs to avoid potential false positives, and then to use HMM models to accurately identify potential toxin, VF, and AR fragments. The benchmark shows this approach can achieve relatively high specificity and sensitivity if the appropriate cutoff value is applied.

scholarly journals The current scenario of Covid-19 in Chittagong Metropolitan area, Bangladesh: A survey Study

2021 ◽  
Vol 4 (3) ◽  
pp. 01-03
Author(s):  
Shahidul Islam ◽  
Farhana Hoque ◽  
Moushume Chowdhury
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Oxygen Supply ◽  
Age Groups ◽  
Survey Study ◽  
Rt Pcr ◽  
Cross Sectional ◽  
The World ◽  
Current Scenario ◽  
Full Swing ◽  
Breathing Problem

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has induced a sense of panic around the world as the disease is highly contagious and has been spreading in full swing. This study was aimed to investigate SARS-CoV-2 associated epidemiology and clinical outcomes in Bangladesh in order to understand the future course of COVID-19 pandemic and develop prevention approaches. A cross-sectional retrospective interview based study was conducted on RT-PCR confirmed COVID-19 patients admitted in Chattagram Maa O Shishu General Hospital Chittagong, Bangladesh and who recovered four weeks prior to the interview date. Of the total 500 patients, 7% patient are asymptomatic where as for the symptoms associated with COVID-19 fever (85%) and cough (70%) were the most prominent among cases. Our study has revealed that among the age groups, the 40-70 showed the highest infection rate (74.7%) and in terms of gender, the prevalence of Covid-19 infection in males (65%) was 2 times more than that in females (35%). Diabetes was found about (40%) and Hypertension was found (42%), so diabetic and hypertesive patient are more affected. The most used drug is Enoxaparin sodium, Methylprednisolone Na Succinate, Montelucast, fexofenadinb, Doxycyclline, Doxofylline, zinc, vitamin-C, D and about 60% patient need oxygen supply. The most complication after recovery is weak -fatigue, cough & breathing problem.

scholarly journals Clinical characteristics of 57 patients infected with COVID-19 in Baodi area of Tianjin, China

2020 ◽  
Author(s):  
Yingchao Zhang ◽  
Zhentao Lin ◽  
Lijing Wang ◽  
Shuxiang Shan
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Real Time ◽  
Clinical Characteristics ◽  
Laboratory Data ◽  
Chest Tightness ◽  
Rt Pcr ◽  
Pharyngeal Swab ◽  
Radiological Features ◽  
Negative Results ◽  
Positive Results

Abstract BackgroundCoronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading worldwide.ObjectiveTo study the clinical characteristics of COVID-19, we included 57 real-time RT-PCR confirmed patients in Baodi area of Tianjin, China, admitted to hospital from 31 January 2020 and 22 February 2020.MethodsEpidemiological, demographic, clinical, and radiological features and laboratory data were analyzed. Patients were confirmed by real-time RT-PCR with pharyngeal swab and/or sputum samples. Some patients that presented positive results with sputum samples yielded negative results with multiple swab tests, suggesting sputum samples RT-PCR tests may be a more reliable means of positively diagnosing infected individuals.ResultsOf the 57 patients studied, three were mild and 54 were moderate in severity. None of the patients infected traveled to Wuhan indicating all studied cases were infected by human to human transmission. The most common symptoms at onset of illness were included fever (86%), cough (29.8%), myalgia or fatigue (14%), chest tightness (5.3%), sore throat (5.3%), and diarrhea (5.3%).ConclusionCompared with patients of COVID-19 in Wuhan, the symptoms of patients in Baodi area of Tianjin province are relatively mild.

Sign in / Sign up

Export Citation Format

Share Document