scholarly journals Reducing False Negative PCR Test for COVID-19

2020 ◽  
Vol 9 (3) ◽  
pp. 408-410
Author(s):  
Fatemeh Bahreini ◽  
Rezvan Najafi ◽  
Razieh Amini ◽  
Salman Khazaei ◽  
Saeid Bashirian
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
False Negative ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Creative Commons ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain ◽  
Pcr Test

As the SARS-CoV-2 (COVID-19) pandemic spreads rapidly, there is need for a diagnostic test with high accuracy to detect infected individuals especially those without symptoms. Real-time polymerase chain reaction (RT-PCR) is a common molecular test for diagnosing SARS-CoV-2. If some factors are not taken into consideration when performing this test, it can have a relatively large number of false negative results. In this article, we discuss important considerations that could lead to false negative test reduction. Key words: • SARS-CoV-2 • COVID-19 • Real time polymerase chain reaction • RT-PCR test • Diagnosis • False negatives • Genetics • Emerging disease   Copyright © 2020 Bahreini et al. Published by Global Health and Education Projects, Inc. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0)which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in this journal, is properly cited.

scholarly journals Perspective of Arguments in Public Health

2021 ◽  
Vol 9 (1) ◽  
pp. 44-45
Author(s):  
Dinesh Kumar
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Respiratory Symptoms ◽  
False Negative ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Negative Report ◽  
Polymerase Chain ◽  
Time Of Admission ◽  
Pcr Test

Recently, an argument was put forth because a symptomatic and positive patient for CoVID-19 turned tested negative after 7 days, so discharged from the hospital. Both at the time of admission and discharge real-time reverse transcriptase Polymerase Chain Reaction (RT-PCR) was done for testing of CoVID-19. Immediately, patient again developed respiratory symptoms and was admitted to hospital again. Amidst of current CoVID-19 pandemic, a question was asked “What is the specificity of the Real Time-Polymerase Chain Reaction (RT-PCR) test for COVID-19?” with an assumption that what if at the time of discharge the disease is present in patient but test turned out to be negative? In response to that a counter statement was posed that “It is the sensitivity that should be asked rather than specificity”. It was based on the implication of primary question that was implying false negative report of the RT-PCR. It means, since patient was discharged with negative result that could be false negative.

scholarly journals A Multiplex Real-Time Polymerase Chain Reaction (TaqMan) Assay for the Simultaneous Detection of Meloidogyne chitwoodi and M. fallax

2006 ◽  
Vol 96 (11) ◽  
pp. 1255-1262 ◽  
Author(s):  
C. Zijlstra ◽  
R. A. Van Hoof
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Real Time Pcr ◽  
False Negative ◽  
Simultaneous Detection ◽  
Chain Reaction ◽  
Meloidogyne Chitwoodi ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain

This study describes a multiplex real-time polymerase chain reaction (PCR) approach for the simultaneous detection of Meloidogyne chitwoodi and M. fallax in a single assay. The approach uses three fluorogenic minor groove binding (MGB) TaqMan probes: one FAM-labeled to detect M. chitwoodi, one VIC-labeled to detect M. fallax, and one NED-labeled to detect the internal amplification control (IAC) to monitor false negative results. One common primer set is used for the amplification of part of the internal transcribed spacer (ITS) region of M. chitwoodi and M. fallax and one primer set for the amplification of the IAC. The test enabled detection of M. chitwoodi and/or M. fallax in DNA samples extracted from batches of juveniles, from single juveniles, and from infected plant material. Compared with current assays to detect M. chitwoodi and M. fallax, the multiplex real-time PCR offers the following advantages: it is faster because the test can simultaneously detect both quarantine species without the need for post-PCR processing; and it is at least 10 times more sensitive than a comparable regular PCR also targeting the ITS sequence. Inclusion of the IAC facilitates the interpretation of the FAM and VIC cycle threshold (Ct) values and can prevent the scoring of false negative results when FAM, VIC, and NED Ct values are high. The test allows precise quantification when only one of the two species is present in the sample. However, experiments with mixtures of genomic DNA of M. chitwoodi and M. fallax revealed that the ability of the multiplex real-time PCR assay to detect small quantities of DNA of one species is reduced when large quantities of DNA of the other species are present.

scholarly journals The Use of a Mimic to Detect Polymerase Chain Reaction– Inhibitory Factors in Feces Examined for the Presence of Lawsonia Intracellularis

2003 ◽  
Vol 15 (3) ◽  
pp. 268-273 ◽  
Author(s):  
Magdalena Jacobson ◽  
Stina Englund ◽  
András Ballagi-Pordány
Keyword(s):  
Polymerase Chain Reaction ◽  
False Negative ◽  
Clinical Samples ◽  
Lawsonia Intracellularis ◽  
Chain Reaction ◽  
Fecal Samples ◽  
Wild Boars ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain

Lawsonia intracellularis is an intracellular organism that causes proliferative enteritis in pigs. This bacterium is difficult to culture, and antemortem demonstration of the microbe is therefore often performed on fecal samples by polymerase chain reaction (PCR). Polymerase chain reaction is sensitive and specific, but inhibitory factors in feces might cause false-negative results. This article describes the construction and use of an internal standard, a mimic. The mimic is amplified by the same primers as those used for L. intracellularis DNA and thus could indicate false-negative results in clinical samples. The amplicon was clearly visible when as few as 10 mimic molecules were added per amplification reaction and when no inhibitors were present. When fecal samples were spiked with the mimic, the detection limit was 102 molecules per PCR. Sixty clinical samples, 20 from wild boars, 20 from growing pigs with diarrhea, and 20 from pigs without diarrhea, were prepared by a boiling procedure and subjected to PCR together with 103 mimic molecules. Nine samples were positive, of which 7 originated from pigs with diarrhea and 2 from pigs without diarrhea. In 14 samples from wild boars, in 8 samples from pigs without diarrhea, and in 3 samples from pigs with diarrhea, neither the mimic nor the target DNA was visible. This indicated the presence of inhibitors in these samples. It is concluded that the mimic can be used as an internal control in the diagnosis of L. intracellularis to indicate inhibition of PCR.

scholarly journals Deteksi Plasmodium falciparum dengan menggunakan metode real-time polymerase chain reaction di daerah Likupang dan Bitung

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
David C. Tooy ◽  
Janno B. Bernadus ◽  
Angle Sorisi
Keyword(s):  
Polymerase Chain Reaction ◽  
Plasmodium Falciparum ◽  
Real Time ◽  
Real Time Pcr ◽  
18S Rrna ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Negative Results ◽  
Pcr Method ◽  
Polymerase Chain

Abstract: Malaria is one of the most important parasitic disease which is caused by Plasmodium spp. There are approximately 1,2 billion people in the world with high risk of getting malaria. Plasmodium falciparum (P. falciparum) is the cause of tropical malaria or falciparum malaria, and is responsible for most of the mortality rate. Currently, real-time polymerase chain reaction (RT-PCR) is being studied as an alterative of conventional malarian examination. Mangold et al reported that RT-PCR have 94.1% sensitivity and 100% specificity compared to microscopic examination in detecting P. falciparum. The aim of this research is to detect the presence of P. falciparum using RT-PCR in Likupang and Bitung region. This research were using descriptive design to find out the capability of real-time PCR method to detect P. falciparum in Likupang dan Bitung region. The researcher have examined 71 samples which are fulfill the research sample’s criteria. Postive results of P. falciparum found in 18 samples (25,3%) and negative results in 53 samples (74,6%) of total 71 samples with using RT-PCR. No positive results were found in samples from Likupang. There are positive result of P. falciparum in samples from Bitung. It is concluded that RT-PCR method can detect the presence of P. falciparum from the samples obtained from Likupang and Bitung based on the presence of its DNA. This detection efford is done by using 18S rRNA as target gene and ajust specific temperature on the RT-PCR instrument.Keywords: Plasmodium falciparum, Real-time Polymerase Chain Reaction (PCR), DetectionAbstrak: Malaria merupakan salah satu penyakit penting yang disebabkan oleh parasit Plasmodium spp. Kira-kira 1,2 miliar penduduk dunia memiliki risiko tinggi untuk mendapat malaria. Di Indonesia sendiri, terdapat 343.527 kasus terkonfirmasi dan 45 kematian karena malaria. Plasmodium falciparum (P. Falciparum) merupakan penyebab dari malaria tropika atau malaria falsiparum, dan bertanggung jawab atas sebagian besar angka mortalitas. Saat ini Real-Time Polymerase Chain Reaction (RT-PCR) telah banyak diteliti sebagai alternatif dari pemeriksaan malaria. Mangold dkk melaporkan bahwa real-time PCR memiliki nilai sensitivitas 94,1% dan nilai spesifisitas 100% terhadap pemeriksaan mikroskopis dalam mendeteksi P. falciparum. Penelitian bertujuan untuk mendeteksi P. falciparum dengan menggunakan RT-PCR di daerah Likupang dan Bitung. Penelitian ini menggunakan rancangan penelitian deskriptif untuk mengetahui kemampuan metode real-time PCR dalam mendeteksi P. falciparum di daerah Likupang dan Bitung. Tujuan penelitian ini ialah untuk mendeteksi keberadaan P. falciparum dengan menggunakan metode real-time PCR di daerah Likupang dan Bitung. Peneliti memeriksa 71 sampel darah yang memenuhi kriteria sampel penelitian. Hasil positif P. falciparum ditemukan pada 18 sampel (25,3 %) dan hasil negatif pada 53 sampel (74,6 %) dari total 71 sampel dengan menggunakan RT-PCR. Tidak ditemukannya hasil positif P. falciparum pada sampel dari Likupang. Ditemukan hasil positif P. falciparum pada sampel dari Bitung. Simpulan: Metode RT-PCR dapat mendeteksi P. falciparum berdasarkan keberadaan DNA-nya pada sampel yang diperoleh dari daerah Likupang dan Bitung. Deteksi ini berhasil dilakukan dengan menggunakan 18S rRNA sebagai gen target dan pengaturan suhu tertentu pada instrument RT-PCR.Kata kunci: P. falciparum, Real-time Polymerase Chain Reaction (PCR), Detection

scholarly journals Real-Time Polymerase chain reaction trends in COVID-19 patients

2020 ◽  
Vol 37 (1) ◽  
Author(s):  
Dr Sana Abbas ◽  
Aisha Rafique ◽  
Dr Beenish Abbas ◽  
Dr Rashid Iqbal
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Tertiary Care ◽  
False Negative ◽  
Polymerase Chain Reaction Test ◽  
Upper Respiratory Tract ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Asymptomatic Patients ◽  
Polymerase Chain

Objective: To assess trends of real-time Polymerase Chain Reaction test in Coronavirus infected Patients. Methods: This cross-sectional analytical study was conducted at Tertiary Care Institute, Rawalpindi from March 2020 to June 2020. All patients confirmed COVID positive by real-time Polymerase Chain Reaction (PCR) with recent travel history, close contact with known diagnosed patients and had symptoms of fever or upper respiratory tract with body aches. Nasopharyngeal swabs were taken and results generated within 48 hours. Positive PCR was admission criteria follow up was carried out at 7th and 8th day, with negative PCR were discharged. However, those who had persistent positive PCR on the 8th day were tested again on 11th and 12th day. Those with persistent positive results beyond 12th day were shifted to specialized quarantine centres. Results: A total of three hundred and ninety-two patients with mild to moderate illness, PCR positive for COVID 19 were included study with age range 9 - 45 and mean 33.22±7.98 years. A total of 8 (2%) patients were females and 384(98%) males. The duration of the negative test result was Mean ± Std. Deviation 9.05±2.00 with 7 – 8 days 152(38.8%)in and 11 – 12 days in 160(40.8%). PCR results on Day 7 and 8 were negative in 144(36.7%) patients whereas positive in 248(63.3%). PCR results on Day 11 and 12 were negative in 312(79.6%) patients whereas positive in 80 (20.4%). Conclusion: To conclude Real-Time Polymerase Chain Reaction (rT-PCR) inclines to give false negative results additionally can stay positive in asymptomatic patients for moderately longer-term. Hence decision to discharge ought to be intricately adjusted between RT-PCR, clinical judgement, radiological examinations, and biochemical assays. doi: https://doi.org/10.12669/pjms.37.1.3000 How to cite this:Abbas S, Rafique A, Abbas B, Iqbal R. Real-Time Polymerase chain reaction trends in COVID-19 patients. Pak J Med Sci. 2021;37(1):180-184. doi: https://doi.org/10.12669/pjms.37.1.3000 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Development of a Polymerase Chain Reaction Assay for Detection of Burkholderia mallei, a Potent Biological Warfare Agent

2016 ◽  
Vol 66 (5) ◽  
pp. 458 ◽  
Author(s):  
Vijai Pal ◽  
Sandeep Singh ◽  
Arvind Kumar Tiwari ◽  
Y.K. Jaiswal ◽  
G.P. Rai
Keyword(s):  
Polymerase Chain Reaction ◽  
Tap Water ◽  
False Negative ◽  
Burkholderia Mallei ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain ◽  
Rapid Tool

Burkholderia mallei is the etiological agent of glanders, primarily a disease of equines. B. mallei is closely related to B. pseudomallei, the causative agent of melioidosis. Therefore, detection of B. mallei and its differentiation from B. pseudomallei, has always been troublesome. In present investigation, a B. mallei specific DNA sequence was identified by performing BLASTn search using ~3000 ORFs of B. mallei NCTC 10229. A polymerase chain reaction (PCR) assay with internal amplification control (IAC) was developed for detection of B. mallei and its differentiation from B. pseudomallei. The PCR assay could amplify a specific 224-bp fragment from all the six B. mallei strains used in the study, whereas other closely related organisms were tested negative. The detection limit of the assay was found to be 10 pg of purified DNA of B. mallei. Incorporation of IAC in the assay makes the results reliable as false negative results which may arise due to presence of PCR inhibitors, can be avoided. For validation, the assay was tested on tap water, Bengal gram and grass artificially spiked with B. mallei. The developed assay can be used as a simple and rapid tool for detection of B. mallei.

False-negative Chlamydia polymerase chain reaction result caused by a cryptic plasmid-deficient Chlamydia trachomatis strain in Australia

Sexual Health ◽  
2019 ◽  
Vol 16 (4) ◽  
pp. 394 ◽  
Author(s):  
Emma L. Sweeney ◽  
Cheryl Bletchly ◽  
Rita Gupta ◽  
David M. Whiley
Keyword(s):  
Polymerase Chain Reaction ◽  
Chlamydia Trachomatis ◽  
False Negative ◽  
Cryptic Plasmid ◽  
Chain Reaction ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain ◽  
Primer Sets ◽  
Pcr Targeting

Background The 7.5-kb chlamydial cryptic plasmid remains a widely used sequence target for Chlamydia trachomatis nucleic acid amplification tests, but sequence variation in this plasmid, particularly a previously reported 377-bp deletion, can cause false-negative results. Here we report the presence in Australia of a C. trachomatis strain lacking the cryptic plasmid. Methods: A rectal swab from a male in his 50s provided a positive result for C. trachomatis using the Roche Cobas 4800 test, but a negative result in our confirmatory in-house polymerase chain reaction (PCR) method targeting the chlamydial cryptic plasmid. This result was unexpected given our in-house PCR assay targeted a region of sequence outside the recognised 377-bp deletion. To further investigate this discrepancy, the sample was retested using a second in-house PCR targeting a chromosomal (ompA) gene as well as six primer sets flanking various regions of the cryptic plasmid. Results: The sample provided positive results in the second in-house method, confirming the presence of C. trachomatis DNA. All other primer sets targeting the cryptic plasmid failed to amplify, indicating a lack of the chlamydial cryptic plasmid in this sample. Conclusions: The recognition of a plasmid-deficient strain of C. trachomatis within Australia highlights further limitations of using the chlamydial cryptic plasmid for C. trachomatis diagnostics and re-emphasises the benefits of using multitarget assays to avoid false-negative results.

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