scholarly journals Characteristics of Anti-SARS-CoV-2 Antibodies in Recovered COVID-19 Subjects

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 697
Author(s):  
Angela Huynh ◽  
Donald M. Arnold ◽  
James W. Smith ◽  
Jane C. Moore ◽  
Ali Zhang ◽  
...  
Keyword(s):  
Population Level ◽  
Enzyme Linked Immunosorbent Assay ◽  
The Novel ◽  
Rt Pcr ◽  
S Protein ◽  
Viral Neutralization ◽  
Humoral Immune ◽  
Global Pandemic ◽  
Polymerase Chain ◽  
Ig G

Coronavirus Disease 2019 (COVID-19) is a global pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While detection of SARS-CoV-2 by polymerase chain reaction with reverse transcription (RT-PCR) is currently used to diagnose acute COVID-19 infection, serological assays are needed to study the humoral immune response to SARS-CoV-2. Anti-SARS-CoV-2 immunoglobulin (Ig)G/A/M antibodies against spike (S) protein and its receptor-binding domain (RBD) were characterized in recovered subjects who were RT-PCR-positive (n = 153) and RT-PCR-negative (n = 55) using an enzyme-linked immunosorbent assay (ELISA). These antibodies were also further assessed for their ability to neutralize live SARS-CoV-2 virus. Anti-SARS-CoV-2 antibodies were detected in 90.9% of resolved subjects up to 180 days post-symptom onset. Anti-S protein and anti-RBD IgG titers correlated (r = 0.5157 and r = 0.6010, respectively) with viral neutralization. Of the RT-PCR-positive subjects, 22 (14.3%) did not have anti-SARS-CoV-2 antibodies; and of those, 17 had RT-PCR cycle threshold (Ct) values > 27. These high Ct values raise the possibility that these indeterminate results are from individuals who were not infected or had mild infection that failed to elicit an antibody response. This study highlights the importance of serological surveys to determine population-level immunity based on infection numbers as determined by RT-PCR.

scholarly journals Development of a serological assay to identify SARS-CoV-2 antibodies in COVID-19 patients

2020 ◽  
Author(s):  
Angela Huynh ◽  
Donald M Arnold ◽  
John G Kelton ◽  
James W Smith ◽  
Jane C Moore ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Acute Infection ◽  
Genetic Material ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
S Protein ◽  
Global Pandemic ◽  
Triton X ◽  
High Throughput Assay ◽  
Ig G

Coronavirus Disease 2019 (COVID-19) is a global pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While molecular assays are used to detect viral genetic material for the diagnosis of acute infection, reliable serological assays are needed to measure immunity against SARS-CoV-2. In this report, we describe an enzyme-linked immunosorbent assay (ELISA) that detects antibodies against the following SARS-CoV-2 recombinant proteins: the full-length spike (S) protein and the receptor-binding domain (RBD). Our assay is sensitive and specific for immunoglobulin (Ig) G, IgA and IgM anti-S protein and anti-RBD antibodies. Samples were pre-treated with Triton X-100 to inactivate potential virus without affecting antibody detection. Our in-house ELISA performed as well as the commercial EUROIMMUN and Ortho assays for anti-SARS-CoV-2 antibodies. This method provides a high-throughput assay that does not require specialized instrumentation and can be widely used to determine immunity and the dynamic range of antibodies found within SARS-CoV-2.

scholarly journals CT findings of 795 COVID-19 positive cases: a multicenter study in Egypt

2020 ◽  
Vol 51 (1) ◽  
Author(s):  
Youssriah Yahia Sabri ◽  
Mohamed Mohsen Tolba Fawzi ◽  
Eman Zaki Nossair ◽  
Safaa Mohamed El-Mandooh ◽  
Amira Aly Hegazy ◽  
...  
Keyword(s):  
Virus Disease ◽  
Chest Ct ◽  
Imaging Features ◽  
Rt Pcr ◽  
Relevant Research ◽  
Non Invasive ◽  
Ct Findings ◽  
Global Pandemic ◽  
Polymerase Chain ◽  
Ct Studies

Abstract Background Corona Virus Disease 2019 (COVID-19) outbreak was officially announced as a global pandemic by the WHO on March 11th 2020. Thorough understanding of CT imaging features of COVID-19 is essential for effective patient management; rationalizing the need for relevant research. The aim of this study was to analyze the chest CT findings of patients with real-time polymerase chain reaction (RT-PCR) proved COVID-19 admitted to four Egyptian hospitals. The recently published RSNA expert consensus statement on reporting COVID-19 chest CT findings was taken into consideration. Results Normal CT “negative for COVID-19” was reported in 26.1% of our RT-PCR proved COVID-19 cases. In descending order of prevalence, imaging findings of the positive CT studies (73.9%) included GGO (69%), consolidation (49.7%), crazy paving (15.4%), and peri-lobular fibrosis (40.6%). These showed a dominantly bilateral (68.2%), peripheral (72.4%), and patchy (64.7%) distribution. Remarkably, thymic hyperplasia was identified in 14.3% of studies. According to the RSNA consensus, CT findings were classified as typical in 68.9%, indeterminate in 3.6%, and atypical in 1.4% of the evaluated CT studies. Conclusion Although COVID-19 cannot be entirely excluded by chest CT, it can be distinguished in more than two-thirds of cases; making CT a widely available, non-invasive, and rapid diagnostic tool.

scholarly journals Evaluation of Sandwich Enzyme-Linked Immunosorbent Assay and Reverse Transcription Polymerase Chain Reaction for the Diagnosis of Foot-and-Mouth Disease

Intervirology ◽  
2021 ◽  
pp. 1-6
Author(s):  
Salman Khan ◽  
Syed Asad Ali Shah ◽  
Syed Muhammad Jamal
Keyword(s):  
Polymerase Chain Reaction ◽  
Viral Genome ◽  
Foot And Mouth Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Kappa Value ◽  
Polymerase Chain ◽  
Pcr Assays ◽  
Level Of Agreement

<b><i>Background:</i></b> Foot-and-mouth disease (FMD) is an infectious and highly contagious disease of cloven-hoofed domestic and wild animals, causing heavy economic losses to the livestock industry. Rapid and reliable diagnosis of the disease is essential for the implementation of effective control measures. This study compared sandwich enzyme-linked immunosorbent assay (S-ELISA) and conventional reverse transcription polymerase chain reaction (RT-PCR) for the diagnosis of FMD. <b><i>Methods:</i></b> A total of 60 epithelial samples from suspected cases of FMD were tested using both S-ELISA and RT-PCR assays. The level of agreement between the assays was assessed by calculating the Kappa value. <b><i>Results:</i></b> S-ELISA detected 38 (63%) samples positive for FMD virus (FMDV). Being predominant, serotype O was detected in 22 (57.9%) of the total samples tested positive, whereas 9 (23.7%) and 7 (18.4%) samples were found positive for serotypes A and Asia-1, respectively. RT-PCR detected viral genome in 51 (85%) of the samples using pan-FMDV primers set, 1F/1R. Thirty-six samples were found positive and 7 negative by both the tests. The level of agreement between the tests was assessed by calculating the Kappa value, which was found to be fair (Kappa value = 0.303 and 95% CI = 0.089; 0.517) and significant (<i>p</i> = 0.009). However, 2 samples, which were found positive on S-ELISA tested negative on RT-PCR. This may be attributed to the presence of nucleotide mismatch(es) in the primer-binding sites that may have resulted in failure of amplification of the viral genome. The serotype-specific RT-PCR assays not only confirmed serotyping results of S-ELISA but were also able to establish serotype in 9 S-ELISA-negative but pan-FMDV RT-PCR-positive samples. <b><i>Conclusions:</i></b> The RT-PCR assay contributes significantly to establishing a quick, sensitive, and definitive diagnosis of FMD in resource-constrained countries. Samples giving negative results in S-ELISA should be tested in RT-PCR for the disease detection and virus typing.

scholarly journals Monitoring Current-Season Spread of Potato virus Y in Potato Fields Using ELISA and Real-Time RT-PCR

Plant Disease ◽  
2013 ◽  
Vol 97 (5) ◽  
pp. 641-644 ◽  
Author(s):  
Manphool S. Fageria ◽  
Mathuresh Singh ◽  
Upeksha Nanayakkara ◽  
Yvan Pelletier ◽  
Xianzhou Nie ◽  
...  
Keyword(s):  
Real Time ◽  
Potato Virus ◽  
Potato Virus Y ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Current Season ◽  
Seed Market ◽  
Polymerase Chain ◽  
Time Of Harvest

The current-season spread of Potato virus Y (PVY) was investigated in New Brunswick, Canada, in 11 potato fields planted with six different cultivars in 2009 and 2010. In all, 100 plants selected from each field were monitored for current-season PVY infections using enzyme-linked immunosorbent assay (ELISA) and real-time reverse-transcription polymerase chain reaction (RT-PCR) assay. Average PVY incidence in fields increased from 0.6% in 2009 and 2% in 2010 in the leaves to 20.3% in 2009 and 21.9% in 2010 in the tubers at the time of harvest. In individual fields, PVY incidence in tubers reached as high as 37% in 2009 and 39% in 2010 at the time of harvest. Real-time RT-PCR assay detected more samples with PVY from leaves than did ELISA. A higher number of positive samples was also detected with real-time RT-PCR from growing tubers compared with the leaves collected from the same plant at the same sampling time. PVY incidence determined from the growing tubers showed a significant positive correlation with the PVY incidence of tubers after harvest. Preharvest testing provides another option to growers to either top-kill the crop immediately to secure the seed market when the PVY incidence is low or leave the tubers to develop further for table or processing purposes when incidence of PVY is high.

scholarly journals Epidemiology and Control of Congo Fever in Sacrificial Animals of Pakistan

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Hafiz Muhammad Rizwan ◽  
Muhammad Sohail Sajid ◽  
Haider Abbas ◽  
Muhammad Fiaz Qamar ◽  
Qaiser Akram
Keyword(s):  
Tick Control ◽  
Enzyme Linked Immunosorbent Assay ◽  
Many Body ◽  
Rt Pcr ◽  
Body Tissues ◽  
Crimean Congo Haemorrhagic Fever ◽  
Polymerase Chain ◽  
And Control ◽  
Successful Prevention ◽  
Venereal Transmission

The cases and deaths due to Crimean-Congo haemorrhagic fever (CCHF) [49] virus commonly known as Congo virus (fatality rate 15%) have been reported throughout Pakistan from the last five years especially during religious occasion, Eid-ul-Azha. The annual increase in death rates due to CCHF demonstrate the importance of awareness of Congo fever at academia as well as public level. The symptoms of Congo fever which appear one to nine days after tick bite, include sudden high fever, muscle aches, abdominal pain, headache, dizziness, sore eyes, jaundice, mood swings, confusion, aggression, and sensitivity to light. The other signs include sore throat, joint pain, vomiting, diarrhea, hemorrhages, and bleeding from skin and large intestine. The Infection has been reported in many species of wild as well as domestic animals including hares, cattle, sheep, goats, dogs, mice and hedgehogs. At least 31 species of Hyalomma, Boophilus, Rhipicephalus, Dermacentor (Ixodidae: hard ticks) act as vector of CCHF in which transovarial, transstadial and venereal transmission occurs. The virus attacks the immune system of the host and influences the immune cells. The Congo fever virus can be isolated from blood, plasma and many body tissues (kidneys, liver, spleen, lungs, brain and bone marrow). Mice inoculation, enzyme-linked immunosorbent assay (ELISA), reverse transcription polymerase chain reaction (RT-PCR) can be used for detection of the infection. Furthermore, IgM and IgG antibodies against CCHFV can also be detected and quantified. Education of general public, tick control with acaricides, use of anti-CCHFV immunoglobulin, usage of approved repellents to prevent tick bites, wearing neutral-coloured garments, application of a permethrin spray to the clothing, avoiding tall grasses and shrubs, applying sunscreen, avoiding direct contact with the blood or tissues of animals are the factors for successful prevention of the infection.

scholarly journals Identification et caractérisation des isolats d'orbivirus des îles de la Réunion et de la Martinique

2009 ◽  
Vol 62 (2-4) ◽  
pp. 149
Author(s):  
D. Vitour ◽  
Corinne Sailleau ◽  
Emmanuel Breard ◽  
Stéphan Zientara
Keyword(s):  
Sequence Analysis ◽  
Clinical Symptoms ◽  
Enzyme Linked Immunosorbent Assay ◽  
La Réunion ◽  
Rt Pcr ◽  
Polymerase Chain ◽  
The One ◽  
Almost All ◽  
Haemorrhagic Disease

At the beginning of 2009, bluetongue (BT)-like clinical symptoms were reported in cattle on the French island of La Réunion (Indian Ocean). One hundred and twenty-three cows were blood tested for the presence of BT and/or epizootic haemorrhagic disease virus (EHDV) ribonucleic acid (RNA) by group specific reverse transcriptase polymerase chain reaction (RT-PCR). EHDV RNA was detected in 111 samples (90.2%), among which five were also positive for BTV RNA. Sequence analysis of EHDV segment 7 revealed that this circulating strain seemed to be similar to the one isolated in 2003 (99.8% nucleotide identity). The determination of the nucleotide sequence of segment 2 is under investigation. The vironeutralization test (VNT), serotype-specific RT-PCR, as well as sequence analysis identified the isolated BTV strain as serotype 2. These data showed that an EHDV outbreak occurred over the last winter in La Réunion, and it was concomitant to circulation of BTV. Epidemic or enzootic features of both these viruses are not yet known. Since this outbreak, molecular and serological tools specific to EHDV have been or are being developed. Three years ago, 30 healthy head of cattle moved from Metropolitan France to the French Martinique Island (Caribbean Basin) and were distributed in four different farms. Animals were sampled (blood and serum) every 10 days until day 30 and tested for BTV infection by the enzyme-linked immunosorbent assay (ELISA) or RT-PCR assays. Unexpectedly, almost all animals became BTV positive within 20 days. Whenever possible, virus isolation on eggs and baby hamster kidney (BHK) cell cultures were performed. Interestingly, seven BT strains belonging to seven distinct serotypes (BTV-2, 9, 10, 17, 18, 22, 24) were isolated. The coding sequence of segments 7, 8, 9 and 10 of these seven serotypes was obtained, as well as a portion of segment 2. The phylogenetic analysis revealed an unprecedented divergence of these strains with other known BTV sequences.

scholarly journals SARS-CoV-2 neutralizing antibodies: Longevity, breadth, and evasion by emerging viral variants

PLoS Medicine ◽  
2021 ◽  
Vol 18 (7) ◽  
pp. e1003656
Author(s):  
Fiona Tea ◽  
Alberto Ospina Stella ◽  
Anupriya Aggarwal ◽  
David Ross Darley ◽  
Deepti Pilli ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Rt Pcr ◽  
Breakthrough Infection ◽  
Nucleocapsid Proteins ◽  
Viral Neutralization ◽  
Polymerase Chain ◽  
Serial Samples ◽  
High Responders ◽  
Neutralization Response ◽  
Selection Of

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) antibody neutralization response and its evasion by emerging viral variants and variant of concern (VOC) are unknown, but critical to understand reinfection risk and breakthrough infection following vaccination. Antibody immunoreactivity against SARS-CoV-2 antigens and Spike variants, inhibition of Spike-driven virus–cell fusion, and infectious SARS-CoV-2 neutralization were characterized in 807 serial samples from 233 reverse transcription polymerase chain reaction (RT-PCR)–confirmed Coronavirus Disease 2019 (COVID-19) individuals with detailed demographics and followed up to 7 months. A broad and sustained polyantigenic immunoreactivity against SARS-CoV-2 Spike, Membrane, and Nucleocapsid proteins, along with high viral neutralization, was associated with COVID-19 severity. A subgroup of “high responders” maintained high neutralizing responses over time, representing ideal convalescent plasma donors. Antibodies generated against SARS-CoV-2 during the first COVID-19 wave had reduced immunoreactivity and neutralization potency to emerging Spike variants and VOC. Accurate monitoring of SARS-CoV-2 antibody responses would be essential for selection of optimal responders and vaccine monitoring and design.

scholarly journals Serological and Molecular Detection of Hepatitis B virus among patients referred to Kurdistan Center for Hepatology and Gastroenterology in Sulaimani City/Kurdistan Region of Iraq

2020 ◽  
Vol 4 (2) ◽  
pp. 117
Author(s):  
Raz Sirwan Abdulla ◽  
Salih Ahmed Hama
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hbv Dna ◽  
Molecular Techniques ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
B Virus ◽  
Polymerase Chain ◽  
Pcr Techniques ◽  
Positive Results

Hepatitis B virus infection is caused by the hepatitis B virus, a major global health problem. This infection can lead to chronic conditions, followed by cirrhosis and hepatocellular carcinoma (HCC). The current study was aimed to detect HBV using serological and molecular techniques. During 2019, 300 blood samples were collected from Kurdistan Center for Hepatology and Gastroenterology in Sulaimani city. Enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR) techniques were used for the detection of HBsAg and HBV DNA, respectively. Obtained results were revealed that 92 out of 300 tested patients (30.66%) seropositive for HBsAg. Among 92 seropositive patients, 53 were shown positive results for HBV DNA by RT-PCR. Dental clinic visiting and dialysis were among the important risk factors for HBV transmission. The vast majority of positive results were among males. Smokers showed relatively high rates of positive results. One-third of the referred patients who had liver complaints were positive for HBsAg. More than half of the seropositive patients showed RT-PCR positive results. It was concluded that the molecular method (RT-PCR) is more sensitive and gives a more accurate result than serology (ELISA). Therefore, it can be used as a diagnostic tool for HBV detection.

scholarly journals An atypical case: RT-PCR-negative, sero-positive covid-19 patient

Pneumologia ◽  
2020 ◽  
Vol 69 (2) ◽  
pp. 107-114
Author(s):  
William Suriady ◽  
Andika Chandra Putra ◽  
Wiwien Heru Wiyono ◽  
Mohammad Fahmi Alatas ◽  
Bettia Bermawi ◽  
...  
Keyword(s):  
False Negative ◽  
Severe Pneumonia ◽  
World Health ◽  
Diagnostic Process ◽  
The Novel ◽  
Rt Pcr ◽  
Atypical Case ◽  
Polymerase Chain ◽  
Novel Coronavirus ◽  
Health Organization

Abstract The novel coronavirus disease-2019 (COVID-19), caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), has become a public health emergency of international concern. The first confirmed COVID-19 case in Indonesia was announced on 2 March 2020, and later on, 11,192 confirmed cases were reported as of 3 May. The World Health Organization has stated that performing a real-time reverse transcription–polymerase chain reaction (RT-PCR) specific for SARS-CoV-2 on specimens from the upper and the lower respiratory tracts, especially nasopharyngeal and oropharyngeal swabs, is the standard diagnostic procedure for COVID-19. In Indonesia, we also use other diagnostic tests, such as rapid antibody tests specific for SARS-CoV-2. Herein, we report an atypical case of COVID-19 and describe the diagnostic process, the clinical course, with progression to severe pneumonia on Week 3 of illness and the case management. We also try to highlight the possibility of false-negative RT-PCR tests.

scholarly journals Seeing beyond a Dilated Proventriculus: Diagnostic Tools for Proventricular Dilatation Disease in Psittacine Birds

Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3558
Author(s):  
Jeann Leal de Araújo ◽  
Raquel Rubia Rech
Keyword(s):  
Molecular Techniques ◽  
Diagnostic Tools ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Postmortem Diagnosis ◽  
Concise Review ◽  
Life Threatening ◽  
Polymerase Chain ◽  
Proventricular Dilatation Disease ◽  
Diagnostic Outcomes

Proventricular dilatation disease (PDD) is a life-threatening neurological disease caused by parrot bornaviruses (PaBVs) that affects several species worldwide. PDD can be clinically manifested as either a central nervous system condition or a gastrointestinal condition if the nerves and ganglia of the gastrointestinal tract are compromised. We intend to provide a concise review for veterinary clinicians and diagnosticians with focus on the main tools available for PDD diagnosis, including gross and histopathology, immunohistochemistry, molecular techniques and serology. We suggest that a combination of different strategies can increase the success of diagnostic outcomes, as tools such as reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) can be implemented for identification of bornaviral infections in live patients, and gross pathology, histopathology, immunohistochemistry and RT-PCR can provide reliable results for postmortem diagnosis of PDD.

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