A case of 2019 novel coronavirus infected pneumonia with twice negative 2019-nCoV nucleic acid testing within 8 days

A large-scale (>20,000 tests per day) standardized and fully-automated laboratory (Huo-Yan) was built as an ad-hoc measure to meet the requirement of virus detection after the novel coronavirus (COVID-19) outbreak in Wuhan, China. We integrated the brief data from Health Commission of Hubei Province and the real-world operation data of Huo-Yan laboratory, into a novel differential model with non-linear transfer coefficients and competitive compartments, to evaluate the trend of suspected cases under different nucleic acid testing capacities, including suspected cases with/without coronavirus infection, to evaluate the achievement of “daily settlement” condition of suspected cases and the control of the epidemic under different nucleic acid testing capacities.

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Clinical Outcomes in 55 Patients With Severe Acute Respiratory Syndrome Coronavirus 2 Who Were Asymptomatic at Hospital Admission in Shenzhen, China

The Journal of Infectious Diseases ◽

10.1093/infdis/jiaa119 ◽

2020 ◽

Vol 221 (11) ◽

pp. 1770-1774 ◽

Cited By ~ 115

Author(s):

Yanrong Wang ◽

Yingxia Liu ◽

Lei Liu ◽

Xianfeng Wang ◽

Nijuan Luo ◽

...

Keyword(s):

Nucleic Acid ◽

Young People ◽

Severe Acute Respiratory Syndrome ◽

Hospital Admission ◽

Clinical Outcomes ◽

Close Contact ◽

Nucleic Acid Testing ◽

Pharyngeal Swab ◽

Asymptomatic Carriers ◽

Novel Coronavirus

Abstract An epidemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has spread unexpectedly in Wuhan, Hubei Province, China, since December 2019. There are few reports about asymptomatic contacts of infected patients identified as positive for SARS-CoV-2 through screening. We studied the epidemiological and clinical outcomes in 55 asymptomatic carriers who were laboratory confirmed to be positive for SARS-CoV-2 through nucleic acid testing of pharyngeal swab samples. The asymptomatic carriers seldom occurred among young people (aged 18–29 years) who had close contact with infected family members. In the majority of patients, the outcome was mild or ordinary 2019 novel coronavirus disease during hospitalization.

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An Overview of Nucleic Acid Testing for the Novel Coronavirus SARS-CoV-2

Frontiers in Medicine ◽

10.3389/fmed.2020.571709 ◽

2021 ◽

Vol 7 ◽

Author(s):

Huiling Wang ◽

Gang Li ◽

Jing Zhao ◽

Yanjie Li ◽

Yushu Ai

Keyword(s):

Nucleic Acid ◽

Early Diagnosis ◽

Treatment Plan ◽

False Negative ◽

Nucleic Acid Testing ◽

The Novel ◽

Negative Results ◽

Literature Overview ◽

False Negative Results ◽

Novel Coronavirus

In this note we analyze the problems in the nucleic acid testing (NAT) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and we also give some suggestions for improving the accuracy of NAT diagnosis. NAT testing is considered to be the diagnostic “gold standard”; at present there are few reviews on NAT for SARS-CoV-2. Moreover, many false-negative results always appear in the procedure of detecting, which has affected early diagnosis of the disease and brought a great challenge to mitigation and containment of the pandemic. In conclusion, comprehensive analyses of serological and imaging findings should be performed to guide the formulation of an accurate clinical diagnosis, treatment plan, and monitoring therapeutic efficacy, in an effort to achieve early diagnosis, containment, and treatment of the disease, thereby effectively reducing progression of the pandemic. This article presents a literature overview of SARS-CoV-2 nucleic acid testing, aiming to provide support for clinicians.

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Design and in-silico screening of Peptide Nucleic Acid (PNA) inspired novel pronucleotide scaffolds targeting COVID-19

Current Computer - Aided Drug Design ◽

10.2174/1573409916666200923143935 ◽

2020 ◽

Vol 16 ◽

Author(s):

Bichismita Sahu ◽

Santosh Kumar Behera ◽

Rudradip Das ◽

Tanay Dalvi ◽

Arnab Chowdhury ◽

...

Keyword(s):

Nucleic Acid ◽

In Silico ◽

Peptide Nucleic Acid ◽

Large Set ◽

Nonstructural Proteins ◽

In Silico Screening ◽

Replication Process ◽

Enveloped Virus ◽

Treatment Regimens ◽

Novel Coronavirus

Introduction: The outburst of the novel coronavirus COVID-19, at the end of December 2019 has turned itself into a pandemic taking a heavy toll on human lives. The causal agent being SARS-CoV-2, a member of the long-known Coronaviridae family, is a positive sense single-stranded enveloped virus and quite closely related to SARS-CoV. It has become the need of the hour to understand the pathophysiology of this disease, so that drugs, vaccines, treatment regimens and plausible therapeutic agents can be produced. Methods: In this regard, recent studies uncovered the fact that the viral genome of SARS-CoV-2 encodes nonstructural proteins like RNA dependent RNA polymerase (RdRp) which is an important tool for its transcription and replication process. A large number of nucleic acid based anti-viral drugs are being repurposed for treating COVID-19 targeting RdRp. Few of them are in the advanced stage of clinical trials including Remdesivir. While performing close investigation of the large set of nucleic acid based drugs, we were surprised to find that the synthetic nucleic acid backbone is explored very little or rare. Results: We have designed scaffolds derived from peptide nucleic acid (PNA) and subjected them for in-silico screening systematically. These designed molecules have demonstrated excellent binding towards RdRp. Compound 12 was found to possess similar binding affinity as Remdesivir with comparable pharmacokinetics. However, the in-silico toxicity prediction indicates compound 12 may be a superior molecule which can be explored further due to its excellent safety-profile with LD50 (12,000mg/kg) as opposed to Remdesivir (LD50 =1000mg/kg). Conclusion: Compound 12 falls in the safe category of class 6. Synthetic feasibility, equipotent binding and very low toxicity of this peptide nucleic acid derived compounds can serve as a leading scaffold to design, synthesize and evaluate many of similar compounds for the treatment of COVID-19.

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Elevated white blood cell count does not predict Clostridium difficile nucleic acid testing results

Clinical Infectious Diseases ◽

10.1093/cid/ciab106 ◽

2021 ◽

Author(s):

Dustin E Bosch ◽

Patrick C Mathias ◽

Niklas Krumm ◽

Andrew Bryan ◽

Ferric C Fang ◽

...

Keyword(s):

Nucleic Acid ◽

Clostridium Difficile ◽

Blood Cell ◽

Cell Count ◽

Prognostic Marker ◽

White Blood Cell Count ◽

White Blood Cell ◽

Inpatient Setting ◽

Nucleic Acid Testing ◽

Blood Cell Count

Abstract Background An elevated white blood cell count (>15 thousand/μL) is an established prognostic marker in patients with Clostridium difficile infection (CDI). Small observational studies have suggested that a markedly elevated WBC should prompt consideration of CDI. However, there is limited evidence correlating WBC elevation with the results of C. difficile nucleic acid testing (NAAT). Methods Retrospective review of laboratory testing, outcomes, and treatment of 16,568 consecutive patients presenting to 4 hospitals over four years with NAAT and WBC testing on the same day. Results No significant relationship between C. difficile NAAT results and concurrent WBC in the inpatient setting was observed. Although an elevated WBC did predict NAAT results in the outpatient and emergency department populations (p<0.001), accuracy was poor, with receiver-operator areas under the curve of 0.59 and 0.56. An elevated WBC (>15 thousand/μL) in CDI was associated with a longer median hospital length of stay (15.5 vs. 11.0 days, p<0.01), consistent with leukocytosis as a prognostic marker in CDI. NAAT-positive inpatients with elevated WBC were more likely to be treated with metronidazole and/or vancomycin (relative ratio 1.2, 95% confidence interval 1.1–1.3) and die in the hospital (relative ratio 2.9, 95% CI 2.0–4.3). Conclusions Although WBC is an important prognostic indicator in patients with CDI, an isolated WBC elevation has low sensitivity and specificity as a predictor of fecal C. difficile NAAT positivity in the inpatient setting. A high or rising WBC in isolation is not a sufficient indication for CDI testing.

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