Journal of clinical virology plus最新文献

Introduction

Real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) of nasopharyngeal/ oropharyngeal swab has been the gold standard test for detection of SARS-CoV-2 infection The relationship between cycle threshold (Ct) values of rRT-PCR and severity of disease remain disputable and not clearly defined in COVID-19.

Methodology

This is a single-centered retrospective observational study conducted at Government Corona Hospital (GCH), Guindy, Chennai. In the present study, we compared the Ct value of rRT-PCR from nasopharyngeal swab specimens with a diverse range of symptoms and disease severity among 240 individuals who were hospitalized with COVID-19, viz., mild cases (MC; n = 160), moderately severe cases (MSC; n = 46) and severe cases (SC; n = 34) in the first and second waves of COVID-19 pandemic.

Results

The study included 240 hospitalized COVID-19 patients with a median age of 52 years (range 21 to 90 years). MC, MSC, and SC all had median Ct values of 25.0 (interquartile range – IQR 20.0 to 30.5), 29.5 (IQR 23.0 to 34.0), and 29.0 (IQR 24 to 37.5) for the ORF1ab gene. The Ct value differed significantly between mild vs moderate, and mild vs severe cases. The Ct value of SC group with co-morbidity of type 2 diabetes have a significant difference compared to non-diabetes group (p value <0.05). There was a significant difference in the median Ct value of ORF1ab gene among the MSC group and MC but not in the SC group in the first and second waves of the pandemic (p<0.05).

Conclusion

We conclude that SARS-CoV-2 Ct values of rRT-PCR alone does not have a role in aiding severity stratification among patients with COVID-19 since the viral dynamics and Ct value may vary due to the emerging variants that occur in different waves of the pandemic.

Background

Corona Virus disease - 2019 (COVID-19) disease induces scientific research to find a control to this pandemic from 2020 year up to now. Recently, various advances in pharmacotherapy against COVID-19 have emerged.

Objectives

To compare the efficacy and safety of antibodies cocktail (casirivimab and imdevimab), Remdesivir, and Favipravir in the COVID-19 patients

Study design

This study is a single-blind non-Randomized Controlled Trial (non-RCT). The drugs of the study are prescribed by lectures on chest diseases, faculty of medicine-Mansoura University. The duration of the study is about six months after ethical approval.

265 hospitalized COVID-19 patients were used to represent the COVID-19 population and were assigned into three groups in a ratio of (1:2:2) respectively, Group (A) received REGN3048–3051(Antibodies cocktail (casirivimab and imdevimab)), group (B) received remdesivir, and group (C) received favipravir.

Results

Casirivimab and imdevimab achieve less 28-day mortality rate, and less mortality at hospital discharge than Remdesivir, and Favipravir.

Conclusion

From all of these results, it is concluded that Group A (Casirivimab & imdevimab) achieves more favorable outcomes than B (Remdesivir) & C (Favipravir) intervention groups.

Clinical trial registration

NCT05502081, 16/08/2022, Clinicaltrials.gov

RNA viruses are the most frequent pathogens responsible for respiratory infections, particularly in pediatric patients. Next-generation sequencing, represented by Illumina sequencing, is one of the most comprehensive methods for identifying pathogens. Nanopore sequencing has been used to identify and analyze pathogens with a shorter sequencing time. In this study, we evaluated the utility of nanopore sequencing for the detection of RNA viruses in bronchoalveolar lavage fluid (BALF) of pediatric patients with respiratory failure. Using the seven BALF samples, we first compared the nanopore and Illumina sequencing results. The nanopore sequencing detected the same RNA viruses as the Illumina sequencing. Subsequently, BALF samples from 24 additional pediatric patients with respiratory failure were analyzed by nanopore sequencing, and RNA viral pathogens were detected in 10 out of 24 patients. Among these 10 patients, nanopore sequencing identified the same viral pathogens as detected by the PCR and viral antigen tests in five patients. Furthermore, additional RNA viral pathogens were detected by nanopore sequencing with high genome coverage in five patients that were not detected by PCR and viral antigen tests. In conclusion, nanopore sequencing could comprehensively detect RNA viral pathogens in BALF samples with equivalent sensitivity and genome coverage as Illumina sequencing. This rapid sequencing platform may be more beneficial for detecting RNA viruses in clinical settings.

The most common HIV-1 subtype in South Africa is subtype C, and detection of other subtypes is rare. We report the first known case of HIV-1 subtype CRF18_cpx identified in KwaZulu-Natal, South Africa, the epicenter of the HIV epidemic, through HIV drug resistance genotyping.

The 31-year-old female patient was initiated on fixed dose combination (tenofovir, emtricitabine, efavirenz) in 2017, with failure to achieve virologic suppression. Change to second-line antiretroviral therapy (tenofovir, emtricitabine and ritonavir-boosted lopinavir) was made in 2018. Adherence was impacted by lopinavir-induced diarrhoea. In 2020, she was switched to zidovudine, lamivudine and ritonavir-boosted atazanavir. Virologic failure persisted, and HIV drug resistance genotyping in April 2021 showed multidrug resistance. Third-line regimen (tenofovir, lamivudine, dolutegravir and ritonavir-boosted darunavir) was commenced in May 2021 and virologic suppression was achieved.

Co-incidentally we discovered from the HIV drug resistance sequence report that the patient was infected with HIV-1 subtype CRF18_cpx. Analysis of the HIV sequence using REGA HIV-1 Subtyping Tool confirmed sequence subtype assignment as HIV-1 CRF 18_cpx (bootstrap confidence = 90%). Subtyping was also confirmed with the COMET HIV-1 tool, HIV BLAST tool and phylogenetic analysis.

Based on our incidental finding, CRF18_cpx may be circulating locally as the patient had no travel history. Introduction of non-subtype C and recombinant viruses are expected to have increased in South Africa due to increased travel. This highlights the need to characterize subtype diversity in South Africa, particularly in KwaZulu-Natal, as HIV subtype can influence pathogenesis, treatment response, drug resistance and efforts towards vaccine development.

The SARS-CoV-2 pandemic led to an urgent need for rapid diagnostic testing in order to inform timely patients’ management. This study aimed to assess the performance of the STANDARD™ M10 SARS-CoV-2 assay as a diagnostic tool for COVID-19. A total of 400 nasopharyngeal or oropharyngeal swabs were tested against a reference real-time RT-PCR, including 200 positive samples spanning the full range of observed Ct values. The sensitivity of the STANDARD™ M10 SARS-CoV-2 assay was 98.00% (95% CI 94.96% to 99.45%, 196/200), while the specificity was also estimated at 97.50% (95% CI 94.26% to 99.18%, 195/200). The assay proved highly efficient for the detection of SARS-CoV-2, even in samples with low viral load (Ct>25), presenting lower Ct values compared to the reference method. We concluded that the STANDARD™ M10 SARS-CoV-2 assay has a similar performance compared to the reference method and other molecular point-of-care assays and can be a valuable tool for rapid and accurate diagnosis.

Although real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR) remains as a golden standard for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, it can not be easily expanded to large-scaled screening during outbreaks, and the positive results do not necessarily correlate with infectious status of the identified subjects. In this study, the performance of Vstrip® RV2 COVID-19 Antigen Rapid Test (RAT) and its correlation with virus infectivity was examined by virus culture using 163 sequential respiratory specimens collected from 26 SARS-CoV-2 infected patients. When the presence of cytopathic effects (CPE) in cell culture was used as a reference method for virus infectivity, the sensitivity, specificity and accuracy of Vstrip® RV2 COVID-19 Antigen Rapid Test was 96.43%, 89.63%, and 90.8%, respectively. The highest Ct value was 27.7 for RdRp gene and 25.79 for E gene within CPE-positive samples, and the highest Ct value was 31.9 for RdRp gene and 29.1 for E gene within RAT positive samples. When the Ct values of specimens were below 25, the CPE and RAT results had high degree of consistency. We concluded that the RAT could be a great alternative method for determining the infectious potential of individuals with high viral load.

Objectives

Determining an accurate estimate of SARS-CoV-2 seroprevalence has been challenging in African countries where malaria and other pathogens are endemic. We compared the performance of one single-antigen assay and three multi-antigen SARS-CoV-2 IgG assays in a Nigerian population endemic for malaria.

Methods

De-identified plasma specimens from SARS-CoV-2 RT-PCR positive, dried blood spot (DBS) SARS-CoV-2 RT-PCR positive, and pre-pandemic negatives were used to evaluate the performance of the four SARS-CoV-2 assays (Tetracore, SARS2MBA, RightSign, xMAP).

Results

Results showed higher sensitivity with the multi-antigen (81% (Tetracore), 96% (SARS2MBA), 85% (xMAP)) versus the single-antigen (RightSign (64%)) SARS-CoV-2 assay. The overall specificities were 98% (Tetracore), 100% (SARS2MBA and RightSign), and 99% (xMAP). When stratified based on <15 days to ≥15 days post-RT-PCR confirmation, the sensitivities increased from 75% to 88.2% for Tetracore; from 93% to 100% for the SARS2MBA; from 58% to 73% for RightSign; and from 83% to 88% for xMAP. With DBS, there was no positive increase after 15-28 days for the three assays (Tetracore, SARS2MBA, and xMAP).

Conclusion

Multi-antigen assays performed well in Nigeria, even with samples with known malaria reactivity, and might provide more accurate measures of COVID-19 seroprevalence and vaccine efficacy.

The emergence of SARS-CoV-2 has caused worldwide pandemic of COVID-19. Infection is difficult to diagnose early as some patients remain asymptomatic and may carry this virus to other people. Currently, qRT-PCR is the widely accepted mode for detection. However, the need for sophisticated instrument and trained personnel may hinder its application, especially in remote and facility-lacking areas. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) may serve as a potential approach for detection of SARS-CoV-2 as the resources needed in its application is far less complex than those of qRT-PCR. Herein, we evaluated RT-LAMP based analytical method (COVIDNow), relative to qRT-PCR, in detecting SARS-CoV-2 by using 63 clinical respiratory samples. Based on our finding, COVIDNow exhibited sensitivity and specificity values of 87.5% and 80.6%, respectively. Taken together, RT-LAMP based detection of SARS-CoV-2 by utilizing COVIDNow might serves as a valuable diagnostic tool in the management of global COVID-19 pandemic condition.