scholarly journals Longitudinal Monitoring of SARS-CoV-2 IgM and IgG Seropositivity to Detect COVID-19

2020 ◽  
Vol 5 (5) ◽  
pp. 908-920 ◽  
Author(s):  
Raymond T Suhandynata ◽  
Melissa A Hoffman ◽  
Michael J Kelner ◽  
Ronald W McLawhon ◽  
Sharon L Reed ◽  
...  
Keyword(s):  
False Positive Rate ◽  
The United States ◽  
Performance Parameters ◽  
Chain Reaction ◽  
Viral Antibodies ◽  
Positive Rate ◽  
Polymerase Chain ◽  
First Time ◽  
Kinetics Of ◽  
Disease Free

Abstract Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a novel beta-coronavirus that has recently emerged as the cause of the 2019 coronavirus pandemic (COVID-19). Polymerase chain reaction (PCR) based tests are optimal and recommended for the diagnosis of an acute SARS-CoV-2 infection. Serology tests for viral antibodies provide an important tool to diagnose previous exposure to the virus. Here we evaluate the analytical performance parameters of the Diazyme SARS-CoV-2 IgM/IgG serology assays and describe the kinetics of IgM and IgG seroconversion observed in patients with PCR-confirmed COVID-19 who were admitted to our hospital. Methods We validated the performance of the Diazyme assay in 235 presumed SARS-CoV-2 negative subjects to determine specificity. Subsequently, we evaluated the SARS-CoV-2 IgM and IgG seroconversion of 54 PCR-confirmed COVID-19 patients and determined sensitivity of the assay at three different timeframes. Result Sensitivity and specificity for detecting seropositivity at ≥15 days following a positive SARS-CoV-2 PCR result, was 100.0% and 98.7% when assaying for the panel of IgM and IgG. The median time to seropositivity observed for a reactive IgM and IgG result from the date of a positive PCR was 5 days (IQR: 2.75–9 days) and 4 days (IQR: 2.75–6.75 days), respectively. Conclusions Our data demonstrate that the Diazyme IgM/IgG assays are suited for the purpose of detecting SARS-CoV-2 IgG and IgM in patients with suspected SARS-CoV-2 infections. For the first time, we report longitudinal data showing the evolution of seroconversion for both IgG and IgM in a cohort of acutely ill patients in the United States. We also demonstrate a low false positive rate in patients who were presumed to be disease free.

scholarly journals Multi-Platform Comparison of SARS-CoV-2 Serology Assays for the Detection of COVID-19

2020 ◽  
Vol 5 (6) ◽  
pp. 1324-1336 ◽  
Author(s):  
Raymond T Suhandynata ◽  
Melissa A Hoffman ◽  
Michael J Kelner ◽  
Ronald W McLawhon ◽  
Sharon L Reed ◽  
...  
Keyword(s):  
Predictive Value ◽  
False Positive Rate ◽  
Disease Prevalence ◽  
Percentage Agreement ◽  
Chain Reaction ◽  
Acute Infections ◽  
Positive Rate ◽  
Platform Comparison ◽  
Polymerase Chain ◽  
Time Frames

Abstract Background COVID-19 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel beta-coronavirus that is responsible for the 2019 coronavirus pandemic. Acute infections should be diagnosed by polymerase chain reaction (PCR) based tests, but serology tests can demonstrate previous exposure to the virus. Methods We compared the performance of the Diazyme, Roche, and Abbott SARS-CoV-2 serology assays using 179 negative participants to determine negative percentage agreement (NPA) and in 60 SARS-CoV-2 PCR-confirmed positive patients to determine positive percentage agreement (PPA) at 3 different time frames following a positive SARS-CoV-2 PCR result. Results At ≥15 days, the PPA (95% CI) was 100 (86.3–100)% for the Diazyme IgM/IgG panel, 96.0 (79.7–99.9)% for the Roche total Ig assay, and 100 (86.3–100)% for the Abbott IgG assay. The NPA (95% CI) was 98.3 (95.2–99.7)% for the Diazyme IgM/IgG panel, 99.4 (96.9–100)% for the Roche total Ig assay, and 98.9 (96.0–99.9)% for the Abbott IgG assay. When the Roche total Ig assay was combined with either the Diazyme IgM/IgG panel or the Abbott IgG assay, the positive predictive value was 100% while the negative predictive value remained greater than 99%. Conclusions Our data demonstrates that the Diazyme, Roche, and Abbott SARS-CoV-2 serology assays have similar clinical performances. We demonstrated a low false-positive rate across all 3 platforms and observed that false positives observed on the Roche platform are unique compared to those observed on the Diazyme or Abbott assays. Using multiple platforms in tandem increases the PPVs, which is important when screening populations with low disease prevalence.

scholarly journals Transmission of the Citrus Variegated Chlorosis Bacterium Xylella fastidiosa with the Sharpshooter Oncometopia nigricans

Plant Disease ◽  
2002 ◽  
Vol 86 (11) ◽  
pp. 1237-1239 ◽  
Author(s):  
R. H. Brlansky ◽  
V. D. Damsteegt ◽  
J. S. Hartung
Keyword(s):  
United States ◽  
Polymerase Chain Reaction ◽  
Xylella Fastidiosa ◽  
The United States ◽  
Reliable Indicator ◽  
Symptom Development ◽  
Chain Reaction ◽  
Citrus Variegated Chlorosis ◽  
Specific Polymerase Chain Reaction ◽  
Polymerase Chain

Citrus variegated chlorosis (CVC) is an economically important, destructive disease in Brazil and is caused by the bacterium Xylella fastidiosa Wells. The bacterium has been found to be transmitted in Brazil by sharpshooter leafhoppers (Cicadellidae). Sharpshooters are present in most citrus growing areas of the United States. The sharpshooter leafhopper, Oncometopia nigricans Walker, frequently is found feeding on citrus in Florida. This sharpshooter transmits the X. fastidiosa strains that cause Pierce's disease of grape and ragweed stunt. Research was initiated to determine if O. nigricans was capable of vectoring the X. fastidiosa that causes CVC. In 59 different transmission tests, using 1 to 57 insects per test, transmission of the bacterium was observed 12 times (20.3%). Symptom development in the greenhouse was not a reliable indicator of transmission. Transmission was verified by specific polymerase chain reaction-based assays. Individual insects were able to transmit the bacterium. This information on sharpshooter transmission of CVC is needed to assess the threat posed by the CVC disease to the citrus industries in the United States.

scholarly journals Placental Cytomegalovirus Infection

2018 ◽  
Vol 143 (5) ◽  
pp. 639-642 ◽  
Author(s):  
Kaleigh Lindholm ◽  
Mary O'Keefe
Keyword(s):  
The United States ◽  
Late Sequelae ◽  
Chain Reaction ◽  
Fetal Demise ◽  
Live Births ◽  
Delayed Onset ◽  
Viral Culture ◽  
Intracytoplasmic Inclusions ◽  
The Common ◽  
Polymerase Chain

In the United States, cytomegalovirus is the most common congenital viral infection and the number 1 cause of nonhereditary sensorineural hearing loss. The vast majority of infants may be asymptomatic, especially if cytomegalovirus is contracted later in the pregnancy, and some symptoms may have a delayed onset. Therefore, it is important for the pathologist to identify the common histologic findings to help confirm the diagnosis so the child can be followed for late sequelae. Histologic examination of the placenta is important in live births and in cases of intrauterine fetal demise. Chronic lymphoplasmacytic villitis and fibrotic, avascular villi are the most common findings. When present, Cowdry A intranuclear and basophilic intracytoplasmic inclusions are characteristic. Immunohistochemistry for cytomegalovirus can highlight these inclusions as well as the associated eosinophilic debris. In addition, polymerase chain reaction or viral culture on placental or fetal samples can be performed for confirmation.

scholarly journals Estimation of the probability of reinfection with COVID-19 coronavirus by the SEIRUS model

2020 ◽  
Author(s):  
Victor Alexander Okhuese
Keyword(s):  
Recovery Rate ◽  
Death Rate ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Chain Reaction ◽  
Health Community ◽  
Polymerase Chain ◽  
Model Equations ◽  
Disease Free ◽  
Pcr Test

AbstractWith sensitivity of the Polymerase Chain Reaction (PCR) test used to detect the presence of the virus in the human host, the global health community has been able to record a great number of recovered population. Therefore, in a bid to answer a burning question of reinfection in the recovered class, the model equations which exhibits the disease-free equilibrium (E0) state for COVID-19 coronavirus was developed in this study and was discovered to both exist as well as satisfy the criteria for a locally or globally asymptotic stability with a basic reproductive number R0 = 0 for and endemic situation. Hence, there is a chance of no secondary reinfections from the recovered population as the rate of incidence of the recovered population vanishes, that is, B = 0.Furthermore, numerical simulations were carried to complement the analytical results in investigating the effect of the implementation of quarantine and observatory procedures has on the projection of the further spread of the virus globally. Result shows that the proportion of infected population in the absence of curative vaccination will continue to grow globally meanwhile the recovery rate will continue slowly which therefore means that the ratio of infection to recovery rate will determine the death rate that is recorded globally and most significant for this study is the rate of reinfection by the recovered population which will decline to zero over time as the virus is cleared clinically from the system of the recovered class.

scholarly journals Longest reported case of symptomatic COVID-19 reporting positive for over 230 days in an immunocompromised patient in the United States

2021 ◽  
Vol 9 ◽  
pp. 2050313X2110400
Author(s):  
Bilal Chaudhry ◽  
Lidiya Didenko ◽  
Maaria Chaudhry ◽  
Andrew Malek ◽  
Kirill Alekseyev
Keyword(s):  
Risk Factors ◽  
Polymerase Chain Reaction ◽  
Immunocompromised Patient ◽  
The United States ◽  
Immunocompromised Patients ◽  
Chain Reaction ◽  
Viral Shedding ◽  
Time Period ◽  
Increased Risk ◽  
Polymerase Chain

Coronavirus 2019 (COVID-19) pneumonia was first noted in Wuhan, China. Since the start of the pandemic, there have been millions of cases diagnosed. The average time from onset of symptoms to testing negative SARS-CoV-2 via reverse transcription polymerase chain reaction is roughly 25 days. In patients who continually test positive for COVID-19, it is essential to determine precisely which risk factors contribute to the increase in viral shedding duration. We present a case about a 62-year-old man who has persistently tested positive for COVID-19 for more than 230 days. We followed his treatment course, in which he had been hospitalized multiple times since the onset of symptoms back in April 2020. We have determined that patients with immunosuppression, especially those taking corticosteroids, are at increased risk of prolonged viral shedding. It is essential to continually monitor these immunocompromised patients as they required a greater time period in order to have an appropriate immune response in which antibodies are created.

scholarly journals Epidemiology of Blackberry yellow vein associated virus

Plant Disease ◽  
2013 ◽  
Vol 97 (10) ◽  
pp. 1352-1357 ◽  
Author(s):  
Bindu Poudel ◽  
William M. Wintermantel ◽  
Arturo A. Cortez ◽  
Thien Ho ◽  
Archana Khadgi ◽  
...  
Keyword(s):  
The United States ◽  
Yellow Vein ◽  
Chain Reaction ◽  
Efficient Detection ◽  
Blackberry Yellow Vein Disease ◽  
Polymerase Chain ◽  
Multiple Levels ◽  
And Control ◽  
Trialeurodes Abutilonea ◽  
Vein Disease

Blackberry yellow vein disease is one of the most important diseases of blackberry in the United States. Several viruses are found associated with the symptomology but Blackberry yellow vein associated virus (BYVaV) appears to be the most prevalent of all, leading to the need for a better understanding of its epidemiology. Efficient detection protocols were developed using end-point and quantitative reverse-transcription polymerase chain reaction. A multi-state survey was performed on wild and cultivated blackberry to assess the geographical distribution of the virus. Two whitefly species, Trialeurodes abutilonea and T. vaporariorum, were identified as vectors and 25 plant species were tested as potential BYVaV hosts. The information obtained in this study can be used at multiple levels to better understand and control blackberry yellow vein disease.

scholarly journals Detection of Toxoplasma gondii in a free-ranging giant anteater

2017 ◽  
Vol 47 (8) ◽  
Author(s):  
Thais Oliveira Morgado ◽  
Francielle Cristina Kagueyama ◽  
Janaina Marcela Assunção Rosa ◽  
Melissa Debesa Belizário ◽  
Richard de Campos Pacheco ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Agglutination Test ◽  
Zoonotic Infection ◽  
Chronic Infections ◽  
Chain Reaction ◽  
Positive Serology ◽  
Modified Agglutination Test ◽  
Polymerase Chain ◽  
Free Ranging ◽  
First Time

ABSTRACT: Toxoplasmosis is caused by Toxoplasma gondii, an obligatory intracellular protozoan, which establishes acute and chronic infections in birds and mammals, including humans. This note reports, for the first time, the detection and sequencing of DNA from T. gondii in the peripheral blood of a young free range giant anteater (Myrmecophaga tridactyla). For the diagnosis, the following methods were used: polymerase chain reaction (PCR) and positive serology (1:800) by means of the modified agglutination test (MAT). Since this species may be consumed by humans and predated by wild felids, its importance is emphasized as a probable source of zoonotic infection, in addition to its possible participation in the infection enzootic cycle. Although, parasitemia has been confirmed in this specimen, it presented no clinical sign of infection.

Norwalk-like Virus Sequences Detected by Reverse Transcription-Polymerase Chain Reaction in Mineral Waters Imported into or Bottled in Switzerland

2000 ◽  
Vol 63 (11) ◽  
pp. 1576-1582 ◽  
Author(s):  
CHRISTIAN BEURET ◽  
DOROTHE KOHLER ◽  
THOMAS LÜTHI
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcription ◽  
Carbonic Acid ◽  
Point Mutations ◽  
Chemical Properties ◽  
The United States ◽  
Mineral Waters ◽  
Nucleotide Sequence Analysis ◽  
Chain Reaction ◽  
Polymerase Chain

Norwalk-like viruses (NLVs) is a genus belonging to the Caliciviridae. NLVs are transmitted by the fecal-oral and the aerosol route and are the most common cause of outbreaks of nonbacterial gastroenteritis. NLVs are responsible for an estimated 67% of all illnesses caused by known foodborne pathogens and for 96% of nonbacterial gastroenteritis in the United States. Many outbreaks could be associated with the consumption of primarily or secondarily contaminated foods. To our knowledge, no epidemic arising from contaminated mineral water has been reported. We investigated the presence of NLV sequences in 63 mineral waters of 29 different brands that were imported into or bottled in Switzerland. NLV sequences were detected in 21 mineral waters by reverse transcription-seminested polymerase chain reaction. Specimens of two NLV genogroups (gg), gg I and gg II, were randomly present in the contaminated samples. The presence of NLV sequences could not be correlated either with bottle characteristics or with chemical properties like mineralization, pH, or the presence of carbonic acid. Nucleotide sequence analysis of 12 NLV-positive samples revealed several point mutations. All isolated NLV gg I strains have a similarity of 70 to 87% with the common Desert Shield virus (UO4469), and all isolated NLV gg II strains have a similarity of 89 to 93% with the Camberwell virus (U46500). Possible reasons for the presence of NLV sequences in mineral waters are discussed.

Detection of a few DNA copies by real-time electrochemical polymerase chain reaction

The Analyst ◽  
2017 ◽  
Vol 142 (18) ◽  
pp. 3432-3440 ◽  
Author(s):  
M. Moreau ◽  
S. Delile ◽  
A. Sharma ◽  
C. Fave ◽  
A. Perrier ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Current Work ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
First Time ◽  
Accurate Quantification

In the current work, accurate quantification over 10 to 108 DNA copies has been successfully achieved for the first time by real-time electrochemical PCR.

Sign in / Sign up

Export Citation Format

Share Document