scholarly journals COMPARISON OF ANALYTICAL SENSITIVITY AND SPECIFICITY OF REVERSE TRANSCRIPTION LOOP-MEDIATED ISOTHERMAL AMPLIFICATION (RT-LAMP) AND REVERSE TRANSCRIPTION POLYMERASE CHAIN REACTION (RT-PCR) FOR DETECTION OF LOCAL PESTIVIRUS A

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Marc F. Österdahl ◽  
Karla A. Lee ◽  
Mary Ni Lochlainn ◽  
Stuart Wilson ◽  
Sam Douthwaite ◽  
...  

Abstract Background A cost effective and efficient diagnostic tool for COVID-19 as near to the point of care (PoC) as possible would be a game changer in the current pandemic. We tested reverse transcription loop mediated isothermal amplification (RT-LAMP), a method which can produce results in under 30 min, alongside standard methods in a real-life clinical setting. Methods This prospective service improvement project piloted an RT-LAMP method on nasal and pharyngeal swabs on 21 residents of a high dependency care home, with two index COVID-19 cases, and compared it to multiplex tandem reverse transcription polymerase chain reaction (RT-PCR). We recorded vital signs of patients to correlate clinical and laboratory information and calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of a single swab using RT-LAMP compared with the current standard, RT-PCR, as per Standards for Reporting Diagnostic Accuracy Studies (STARD) guidelines. Results The novel method accurately detected 8/10 RT-PCR positive cases and identified a further 3 positive cases. Eight further cases were negative using both methods. Using repeated RT-PCR as a “gold standard”, the sensitivity and specificity of a single novel test were 80 and 73% respectively. PPV was 73% and NPV was 83%. Incorporating retesting of low signal RT-LAMP positives improved the specificity to 100%. We also speculate that hypothermia may be a significant early clinical sign of COVID-19. Conclusions RT-LAMP testing for SARS-CoV-2 was found to be promising, fast and to work equivalently to RT-PCR methods. RT-LAMP has the potential to transform COVID-19 detection, bringing rapid and accurate testing to the PoC. RT-LAMP could be deployed in mobile community testing units, care homes and hospitals to detect disease early and prevent spread.


Biomédica ◽  
2019 ◽  
Vol 39 (2) ◽  
pp. 415-426
Author(s):  
Alfonso Bettin-Martínez ◽  
José Villareal-Camacho ◽  
Guillermo Cervantes-Acosta ◽  
Jorge Acosta-Reyes ◽  
Juliana Barbosa ◽  
...  

Introducción. El virus sincicial respiratorio humano (hRSV) es la causa más frecuente de infección respiratoria aguda de las vías respiratorias inferiores en niños menores de cinco años. El desarrollo de técnicas moleculares para identificarlo es uno de los retos actuales en el campo de la investigación clínica.Objetivo. Evaluar un método de amplificación isotérmica para la detección rápida del hRSV en niños con infección respiratoria aguda.Materiales y métodos. Se extrajo el ARN viral de 304 muestras de hisopado nasal en niños con síntomas de infección respiratoria aguda atendidos en el servicio de urgencias del Hospital de la Universidad del Norte en Barranquilla entre abril del 2016 y julio del 2017. Se evaluó la prueba de amplificación isotérmica mediada por bucle mediante transcriptasa inversa de la proteína de la matriz (M) (Reverse Transcription Loop-Mediated Isothermal Amplification, RT-LAMP) comparada con técnicas moleculares como la reacción en cadena de la polimerasa mediante transcriptasa inversa múltiple anidada (Reverse Transcription-Polymerase Chain Reaction, RT-PCR), la cual se empleó como la prueba estándar, la PCR en tiempo real (quantitative PCR, qPCR) y la RT-LAMP de la proteína L (L) para la detección rápida del virus sincicial respiratorio (VSR), subtipo A y subtipo B.Resultados. La prueba de RT-LAMP (M) tuvo una sensibilidad de 93,59 %, una especificidad de 92,92 % y una concordancia de 0,83 ± 0,036 comparada con la prueba de RT-PCR anidada. El índice kappa del RT-LAMP (M) fue superior, y los valores del RTLAMP (L) y la qPCR concordaron (0,75 ± 0,043 y 0,71 ± 0,045, respectivamente).


2015 ◽  
Vol 84 (3) ◽  
pp. 215-223
Author(s):  
Shuixian Yang ◽  
Kai-Yu Wang ◽  
Zexiao Yang

Grass carp reovirus (GCRV) has been assigned to a newly established Aquareovirus genus in the family of Reoviridae which leads to haemorrhagic disease and extremely high mortality rate in grass carp. In this study, comparison was made between the novel one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) and the reverse transcription polymerase chain reaction (RT-PCR) for detection of grass carp reovirus. The result indicated that RT-LAMP had × 10 higher sensitivity comparable to RT-PCR. The specificity of the two methods for GCRV detection were both developed successfully by other three aquatic viruses. In the field trial, both RT-PCR and RT-LAMP methods were applied to detect the samples from different infected organs and tissues. The result demonstrated that RT-LAMP had a high accuracy to confirm the diagnosis as well as the RT-PCR. This study showed that the RT-LAMP, compared to the RT-PCR, was simple, time-saving, convenient, but required specificity primers and possibly generated false positive product. Its products, unlike RT-PCR, could not be direcly used in further molecular research after purification. Thus RT-LAMP might be an optimal diagnostic method for rapid and preliminary diagnosis of GCRV infection in resource-limited setting situation.


2021 ◽  
Vol 19 (2) ◽  
pp. 147-151
Author(s):  
M. Kunchev ◽  
V. Belcheva ◽  
E. Grigorov

Q fever, which is caused by Coxiella burnetii, a small, pleomorphic intracellular bacterium, is the most widespread zoonosis in the world. The chronic form of the disease can lead to disability and death. Rapid diagnosis of Q fever is needed in order that effective treatment can be initiated. The conventional retrospective diagnosis of Q fever, based on serology, is useless for the treatment of afflicted patients. Thus, molecular methods have been created to close the diagnostic gap between the onset of the disease and the presence of specific antibodies in serum. A polymerase chain reaction is a suitable and reliable method with high sensitivity and specificity, but it requires expensive equipment and post-amplification protocol. Loop-mediated isothermal amplification (LAMP) is an isothermal technique, conducted at constant temperature that can amplify a negligible amount of DNA to more than 109 copies within one hour, using special primers and polymerase. We have tested the sensitivity and specificity of LAMP in the detection of C. burnetii. The mean positive rate of LAMP and polymerase chain reaction in patients was 100% and 74%, respectively. LAMP reacted negatively with non-C. burnetii pathogens and non-infected blood samples. We conclude that LAMP is a sensitive and specific technique for the detection of C. burnetii and has advantages over serological methods and PCR that make it attractive for diagnosing Q fever in countries around the world.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247618
Author(s):  
Yuta Mikami ◽  
Kazumasa Fuwa ◽  
Eriko Arima ◽  
Yasuo Suda ◽  
Itaru Yanagihara ◽  
...  

Introduction A simple and rapid diagnosis of Ureaplasma spp. is required for the choice of the appropriate antibiotic. However, an ideal detection method has not been available. This study examines the efficacy of the loop-mediated isothermal amplification (LAMP) assay, which provides rapid and sensitive results, to detect Ureaplasma spp. in respiratory tract samples of preterm infants. Methods The study included preterm infants born before 32 weeks of gestation admitted Kagoshima City Hospital from June 2018 to March 2020. Nasopharyngeal swabs and/or tracheal aspirates were obtained in the first seven postnatal days. One hundred sixty-seven nasopharyngeal swabs and 101 tracheal aspirates were analyzed by LAMP, culture, and quantitative real-time polymerase chain reaction. Results All 167 infants had a median (range) gestational age of 28.7 weeks (22.3–30.9) and birthweight 1030g (322–1828). One hundred sixty-seven nasopharyngeal swabs and 101 tracheal aspirates were obtained. In the results of nasopharyngeal swabs, the sensitivity and specificity of LAMP were 73.9% (17/23) and 97.2% (140/144), whereas those of quantitative real-time polymerase chain reaction were 73.9% (17/23) and 95.8% (138/144), compared to culture. In the results of tracheal aspirates, the sensitivity and specificity of LAMP were 89.5% (17/19) and 92.7% (76/82), whereas those of quantitative real-time polymerase chain reaction were 89.5% (17/19) and 93.9% (77/82), compared to culture. Conclusions The LAMP assay showed similar sensitivity and specificity with quantitative real-time polymerase chain reaction in the respiratory tracts of preterm infants including extremely preterm infants during the immediate postnatal period. Therefore, the LAMP is a practical alternative for the early detection so that appropriate antibiotics can be administered for preventing BPD.


2021 ◽  
Vol 8 ◽  
Author(s):  
Kate Hole ◽  
Charles Nfon ◽  
Luis L. Rodriguez ◽  
Lauro Velazquez-Salinas

Vesicular stomatitis virus (VSV) causes a disease in susceptible livestock that is clinically indistinguishable from foot-and-mouth disease. Rapid testing is therefore critical to identify VSV and rule out FMD. We previously developed and validated a multiplex real-time reverse transcription polymerase chain reaction assay (mRRT-PCR) for detection of both VS New Jersey virus (VSNJV) and VS Indiana virus (VSIV). However, it was subsequently apparent that this assay failed to detect some VSNJV isolates in Mexico, especially in genetic group II, lineage 2.1. In order to enhance the sensitivity of the mRRT-PCR for VSNJV, parts of the assay were redesigned and revalidated using new and improved PCR chemistries. The redesign markedly improved the assay by increasing the VSNJV detection sensitivity of lineage 2.1 and thereby allowing detection of all VSNJV clades. The new assay showed an increased capability to detect VSNJV. Specifically, the new mRRT-PCR detected VSNJV in 100% (87/87) of samples from Mexico in 2006-2007 compared to 74% for the previous mRRT-PCR. Furthermore, the analytical sensitivity of the new mRRT-PCR was enhanced for VSNJV. Importantly, the modified assay had the same sensitivity and specificity for VSIV as the previously published assay. Our results highlight the challenges the large genetic variability of VSV pose for virus detection by mRRT-PCR and show the importance of frequent re-evaluation and validation of diagnostic assays for VSV to ensure high sensitivity and specificity.


1999 ◽  
Vol 123 (12) ◽  
pp. 1161-1169 ◽  
Author(s):  
JoséR. Romero

Abstract Objective.—This review focuses on commercial and in-house–developed reverse-transcription polymerase chain reaction (RT-PCR) assays used for the detection of enteroviral infections. In addition to providing details on the performance of RT-PCR, its specificity, and sensitivity, the clinical utility of this diagnostic method with specific reference to its impact on hospitalization and cost savings is addressed. Data Sources.—MEDLINE was searched for reports relating to RT-PCR detection of the enteroviruses in adults and children. The search was restricted to studies reported in English language journals. Study Selection.—Reports documenting detailed information regarding the RT-PCR conditions, primers, sensitivity, specificity and, if relevant, clinical impact were selected for analysis. Data Extraction.—Details regarding method of extraction of the enteroviral genome, the primers used, RT-PCR conditions, and sensitivity and specificity of the assay were extracted from the literature. For reports detailing the use of RT-PCR in the clinical management of enteroviral infections in children, the reduction in duration of hospitalization and health care cost savings were recorded. Data Synthesis.—Reverse-transcription PCR can increase the yield of detection of enteroviruses from cerebrospinal fluid by a mean of approximately 20% over tissue culture. Reverse-transcription PCR of cerebrospinal fluid has been shown to exhibit sensitivity and specificity values of 86% to 100% and 92% to 100%, respectively. Reductions of 1 to 3 days of hospitalization per patient are predicted if RT-PCR is used to diagnose enteroviral meningitis in children. Conclusions.—Reverse-transcription PCR detection of enteroviral infections is an extremely rapid, sensitive, and specific diagnostic modality. Both commercial assays and assays developed in-house appear to be equivalent with regard to sensitivity and specificity. Reverse-transcription PCR diagnosis of enteroviral infections in children could reduce the length of hospitalization and result in significant health care cost savings.


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