scholarly journals Evaluation of RT-PCR Assay for Routine Laboratory Diagnosis of Rabies in Post Mortem Brain Samples from Different Species of Animals

2012 ◽  
Vol 23 (3) ◽  
pp. 392-396 ◽  
Author(s):  
R. P. Aravindh Babu ◽  
S. Manoharan ◽  
P. Ramadass ◽  
N. D. J. Chandran
Keyword(s):  
Laboratory Diagnosis ◽  
Routine Laboratory ◽  
Post Mortem ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Post Mortem Brain

scholarly journals Comparison of SARS-CoV-2 antigen electrochemiluminescence immunoassay to RT-PCR assay for laboratory diagnosis of COVID-19 in Peshawar

Diagnosis ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bilal Iqbal ◽  
Maria Khan ◽  
Noman Shah ◽  
Mirza Muhammad Dawood ◽  
Valeed Jehanzeb ◽  
...  
Keyword(s):  
Laboratory Diagnosis ◽  
Cross Sectional Study ◽  
Antigen Test ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Cross Sectional ◽  
Viral Loads ◽  
Testing Algorithms ◽  
Frequent Testing ◽  
Antigen Testing

Abstract Objectives Antigen based rapid diagnostic tests possesses a potential to be utilized along with Gold standard methods to detect Covid-19 infection to cope with the demand of testing. The aim of this study was to determine diagnostic accuracy of electrochemiluminescence based automated antigen detection immunoassay comparing with molecular based test RT-PCR (Covid-19). Methods It was a cross-sectional study conducted in RMI Peshawar, from 1st April 2021 till 30th April 2021. The study comprised 170 individuals who were suspected of having Covid-19. Nasopharyngeal samples taken from suspected individuals were analyzed by RT-PCR and automated antigen test (Elecsys SARS-CoV-2 Antigen) simultaneously. The correlation of SARS-CoV-2 antigen with PCR positive and negative cases was analyzed for specificity, sensitivity respectively. Results The ECLIA based Elecsys antigen test (Roche) revealed overall sensitivity 72%, specificity 95% and accuracy of 94.9%. Sensitivity of antigen test progressively declined from 94.3% in Ct <25 to 70.8% in Ct 26–29 and then to 47.2% in Ct 30–35. Conclusions Based on the findings of our study we conclude that automated antigen testing (Elecsys SARS-CoV-2 Antigen) cannot replace molecular based testing like RT PCR. Elecsys SARS-CoV-2 Ag test should be used complementary to RT-PCR in testing algorithms. Frequent testing strategy should be adopted while using automated antigen testing to overcome its limitation in individuals with low viral loads.

scholarly journals Rapid SARS-CoV-2 antigen detection assay in comparison with real-time RT-PCR assay for laboratory diagnosis of COVID-19 in Thailand

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Chutikarn Chaimayo ◽  
Bualan Kaewnaphan ◽  
Nattaya Tanlieng ◽  
Niracha Athipanyasilp ◽  
Rujipas Sirijatuphat ◽  
...  
Keyword(s):  
Real Time ◽  
Sensitivity And Specificity ◽  
False Negative ◽  
Laboratory Diagnosis ◽  
Antigen Detection ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Screening Assay ◽  
The Real ◽  
Pcr Test

Abstract Background The Coronavirus disease 2019 (COVID-19) pandemic continues to spread across the world. Hence, there is an urgent need for rapid, simple, and accurate tests to diagnose severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Performance characteristics of the rapid SARS-CoV-2 antigen detection test should be evaluated and compared with the gold standard real-time reverse transcription-polymerase chain reaction (RT-PCR) test for diagnosis of COVID-19 cases. Methods The rapid SARS-CoV-2 antigen detection test, Standard™ Q COVID-19 Ag kit (SD Biosensor®, Republic of Korea), was compared with the real-time RT-PCR test, Allplex™ 2019-nCoV Assay (Seegene®, Korea) for detection of SARS-CoV-2 in respiratory specimens. Four hundred fifty-four respiratory samples (mainly nasopharyngeal and throat swabs) were obtained from COVID-19 suspected cases and contact individuals, including pre-operative patients at Siriraj Hospital, Bangkok, Thailand during March–May 2020. Results Of 454 respiratory samples, 60 (13.2%) were positive, and 394 (86.8%) were negative for SARS-CoV-2 RNA by real-time RT-PCR assay. The duration from onset to laboratory test in COVID-19 suspected cases and contact individuals ranged from 0 to 14 days with a median of 3 days. The rapid SARS-CoV-2 antigen detection test’s sensitivity and specificity were 98.33% (95% CI, 91.06–99.96%) and 98.73% (95% CI, 97.06–99.59%), respectively. One false negative test result was from a sample with a high real-time RT-PCR cycle threshold (Ct), while five false positive test results were from specimens of pre-operative patients. Conclusions The rapid assay for SARS-CoV-2 antigen detection showed comparable sensitivity and specificity with the real-time RT-PCR assay. Thus, there is a potential use of this rapid and simple SARS-CoV-2 antigen detection test as a screening assay.

scholarly journals Laboratory diagnosis challenges of Covid-19: a Real-time RT-PCR assay-based survey

2021 ◽  
Vol 19 (1) ◽  
pp. 63-68
Author(s):  
Saiedeh Erfanian ◽  
Danesh javeshghani ◽  
Mohsen Farhang ◽  
Abazar Roustazadeh ◽  
◽  
...  
Keyword(s):  
Real Time ◽  
Laboratory Diagnosis ◽  
Rt Pcr ◽  
Pcr Assay

scholarly journals Multi-site evaluation of the LN34 pan-lyssavirus real-time RT-PCR assay for post-mortem rabies diagnostics

PLoS ONE ◽  
2018 ◽  
Vol 13 (5) ◽  
pp. e0197074 ◽  
Author(s):  
Crystal M. Gigante ◽  
Lisa Dettinger ◽  
James W. Powell ◽  
Melanie Seiders ◽  
Rene Edgar Condori Condori ◽  
...  
Keyword(s):  
Real Time ◽  
Post Mortem ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Site Evaluation

scholarly journals ISOLATION AND DETECTION OF NEWCASTLE DISEASE VIRUS FROM FIELD OUTBREAKS IN BROILER AND LAYER CHICKENS BY REVERSE TRANSCRIPTION–POLYMERASE CHAIN REACTION

2012 ◽  
Vol 8 (2) ◽  
pp. 87-92 ◽  
Author(s):  
MH Haque ◽  
MT Hossain ◽  
MT Islam ◽  
MA Zinnah ◽  
MSR Khan ◽  
...  
Keyword(s):  
Newcastle Disease ◽  
Culture System ◽  
Virus Isolation ◽  
Cloacal Swab ◽  
Post Mortem ◽  
Rt Pcr ◽  
Isolation Rate ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Polymerase Chain

The present research work was carried out to isolate and identify Newcastle disease virus (NDV) by using haemagglutination inhibition (HI) test and reverse transcription-polymerase chain reaction (RT-PCR) assay. A total of 160 clinical (blood, tracheal and cloacal swabs) and post-mortem (brain, lung, colon and spleen) samples were collected from chickens of two field outbreaks of Newcastle disease (ND) in 2006, one in a broiler (Cobb-500) farm of Mymensingh district and other one in a layer (Sonali) farm of Gazipur district. All the samples were inoculated onto 10-day-old embryonated chicken eggs through allantoic sac route and in the chicken embryo fibroblasts (CEFs) cell culture. The allantoic fluid (AF) of the dead embryos and the infected culture fluid (ICF) of the CEF were harvested at 48 and 96 hours of post-infection, respectively. The HI and RT-PCR were employed to detect NDV in tissue homogenates of all the clinical and post-mortem samples as well as laboratory samples (AF and ICF). Among the clinical samples, virus isolation rate was found higher from tracheal swab (90%) compared to those of cloacal swab (85%) and serum (65%). On the other hand, among the four different types of post-mortem samples, virus isolation rate was found higher in spleen (100%) compared to those of lungs (80%), colon (60%), and brain (80%) samples. In CEF cell culture system, the rate of virus isolation from all the aforesaid samples was found 100% with the exception of serum samples. The isolation rate of NDV was higher in CEF culture system (93.8%) compared to that of avian embryos (80%). Among the clinical and post-mortem samples, inoculum of only cloacal swab and colon showed HA and HI activities. The anti-NDV hyperimmune serum revealed complete inhibition of the 4 haemagglutination unit of each isolate of viruses isolated from broiler and layer chickens present in the laboratory samples (AF and ICF). The NDV specific primers used in the direct RT-PCR for genome detection of NDV showed equal sensitivity and specificity with the RNA extracted from the clinical, post-mortem and laboratory samples (AF and ICF) as with the genomic RNA of reference NDV. Higher rate of detection of NDV was recorded with RT-PCR assay than HI test. Therefore, the molecular method (RT-PCR) can be introduced for rapid and confirmatory detection of NDV from any form of outbreak of ND in the field level of Bangladesh.DOI = http://dx.doi.org/10.3329/bjvm.v8i2.9618 Bangl. J. Vet. Med. (2010). 8 (2) : 87–92 

scholarly journals Post-Mortem RT-PCR Assay for SARS-CoV-2 RNA in COVID-19 Patients’ Corneal Epithelium, Conjunctival and Nasopharyngeal Swabs

2021 ◽  
Vol 10 (18) ◽  
pp. 4256
Author(s):  
Francesco Aiello ◽  
Marco Ciotti ◽  
Gabriele Gallo Afflitto ◽  
Maria Cristina Rapanotti ◽  
Bartolo Caggiano ◽  
...  
Keyword(s):  
Corneal Epithelium ◽  
Ocular Surface ◽  
Post Mortem ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Ocular Tissues ◽  
Hospital Patients ◽  
The Mean ◽  
Polymerase Chain ◽  
Surface Disturbances

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease has been described to possibly be associated with ocular surface disturbances. However, whether the virus could invade ocular tissues still remains elusive. In the present study, we tried to investigate the post-mortem presence of SARS-CoV-2 RNA in corneal epithelium gathered by patients with an ante-mortem confirmed diagnosis of Coronavirus disease-19 (COVID-19). Cadavers with an ante-mortem confirmed diagnosis of moderate to severe COVID-19 were examined. Clinical and demographic features were retrieved from hospital patients’ notes. For each cadaver, corneal scrapings, conjunctival swabs (CS) and nasopharyngeal swabs (NPS) were collected to perform real-time reverse transcriptase polymerase chain reaction ((RT)-PCR) for SARS-CoV-2. Fourteen consecutive cadavers with an ante-mortem confirmed diagnosis of moderate to severe COVID-19 were examined. The last NPS performed ante-mortem confirmed SARS-CoV-2 infection in 12/14 (85.7%) patients. The mean death-to-swab time (DtS) was 3.15 ± 0.5 (2.10–5.1) h. The post-mortem NPS and CS found positive for SARS-CoV-2 RNA were 9/14 (64.3%) and 3/28 (10.7%), respectively. None of the corneal epithelium scrapes tested positive to RT-PCR for SARS-CoV-2 RNA. These data promote the SARS-CoV-2 as not able to contaminate the post-mortem corneal epithelium, while it can persist in different other structures of the ocular surface (i.e., the conjunctiva). It is reasonable to assume that such a contamination can occur ante-mortem too.

TaqMan PCR assay in the control of RNA normalization in human post-mortem brain tissue

2006 ◽  
Vol 49 (3) ◽  
pp. 276-284 ◽  
Author(s):  
Marta Barrachina ◽  
Esther Castaño ◽  
Isidro Ferrer
Keyword(s):  
Brain Tissue ◽  
Post Mortem ◽  
Pcr Assay ◽  
Post Mortem Brain ◽  
Taqman Pcr
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