scholarly journals Analysis of the positive rate of 4254 cases of COVID‐19 nucleic acid tests in different aites in Wuhan, China

2020 ◽  
Vol 93 (2) ◽  
pp. 870-877
Author(s):  
Kebin Deng ◽  
Hui Li ◽  
Xin Ma ◽  
Bianbian Yu ◽  
Xinlin Yi ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Positive Rate ◽  
Nucleic Acid Tests

scholarly journals The Positive Rate of Nucleic Acid Testing and the Epidemiological Characteristics of COVID-19 in Chongqing

2022 ◽  
Vol 8 ◽  
Author(s):  
Xiaohua Liang ◽  
Yajun Sun ◽  
Lun Xiao ◽  
YanLing Ren ◽  
Xian Tang
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acid Testing ◽  
Asymptomatic Carriers ◽  
First Case ◽  
Latency Range ◽  
Increased Risk ◽  
Positive Rate ◽  
Epidemiological Characteristics ◽  
Close Contacts ◽  
Nucleic Acid Tests

ObjectiveThe purpose of this study is to analyze the positive rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid testing (NAT), cases of and deaths due to SARS-CoV-2, and the epidemiological characteristics of SARS-CoV-2 to identify high-risk populations.MethodsA retrospective study in Jiulongpo district of Chongqing was conducted by performing continuous observations of the frequency of SARS-CoV-2 NAT, analyzing the data of close contacts of patients and asymptomatic carriers, and collecting epidemiological data. Data were collected from January 20, 2020, when the first case of SARS-CoV-2 infection was reported, to March 26, 2020. Descriptive statistical analysis and Cochrane–Mantel–Haenszel analysis were used to compare the positive detection rates and positive diagnostic rates of different exposure groups.ResultsA total of 7,118 people received 10,377 SARS-CoV-2 nucleic acid tests in one district, and the SARS-CoV-2 positive rates were 0.40% (18/4446) and 0.15% (4/2672) in people receiving one and ≥ two nucleic acid tests (p = 0.06), respectively. Those with suspected cases (12.35%) and close contacts (8%) had higher positive rates than people tested at fever clinics (0.39%) (p < 0.001). The median latency (range) of cases was 5 (2, 9) days, and the median time from diagnosis to recovery was 22 (14, 25) days. One recovered patient received a positive test result at 28 days after recovery when she attempted to donate blood. Six clustered cases, including one patient who died, indicated persistent human-to-human transmission. One patient who was diagnosed after death was found to have infected 13 close contacts. People working in catering and other public service departments (36.36%) and people who are unemployed and retirees (45.45%) have an increased risk of infection compared with technical staff (9.09%) and farmers (9.09%).ConclusionThe total positive rate was low in the tested population, and more effective detection ranges should be defined to improve precise and differentiated epidemic control strategies. Moreover, in asymptomatic carriers, SARS-CoV-2 tests were positive after recovery, and patients with suspected SARS-CoV-2 infection who die may pose serious potential transmission threats.

scholarly journals Re-positive Cases of Nucleic Acid Tests in Discharged Patients With COVID-19: A Follow-Up Study

2020 ◽  
Vol 7 ◽  
Author(s):  
Xi-Min Qiao ◽  
Xiao-Feng Xu ◽  
Hao Zi ◽  
Guo-Xiong Liu ◽  
Bing-Hui Li ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Follow Up Study ◽  
Discharged Patients ◽  
Nucleic Acid Tests

scholarly journals Are RNA-Based Tests Sufficient for COVID-19 Diagnosis? An Inspiration of Three Asymptomatic Cases

2021 ◽  
Vol 30 ◽  
pp. 096368972098545
Author(s):  
Tao Hu ◽  
Xiao Liu ◽  
Qinan Yin ◽  
Xingting Duan ◽  
Li Yan
Keyword(s):  
Computed Tomography ◽  
Nucleic Acid ◽  
Virus Infection ◽  
Severe Acute Respiratory Syndrome ◽  
The Other ◽  
Computed Tomography Scan ◽  
Health Authorities ◽  
History Of ◽  
Tomography Scan ◽  
Nucleic Acid Tests

In this work, we discovered a new phenomenon—asymptomatic COVID-19 infection, or covert case, during the pandemic. All the 3 patients had a history of exposure, with no symptoms, and no abnormalities were found in computed tomography scan or lab tests. Except for case 2, the other patients’ severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) nucleic acid tests were negative. But their anti-SARS-COV-2 nucleocapsid antibody showed a dynamic trend, consistent with the process of virus infection and clearance. A growing number of asymptomatic or covert cases need more attention. Lack of surveillance may lead to another outbreak. We hope to demonstrate our cases to attract the attention of governments or health authorities that covert cases should be the focus as well.

scholarly journals Nitrocellulose-bound achromopeptidase for point-of-care nucleic acid tests

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Georgios Chondrogiannis ◽  
Shirin Khaliliazar ◽  
Anna Toldrà ◽  
Pedro Réu ◽  
Mahiar M. Hamedi
Keyword(s):  
Nucleic Acid ◽  
Sample Preparation ◽  
Point Of Care ◽  
Dna Amplification ◽  
Recombinase Polymerase Amplification ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Enzymatic Function ◽  
Modern Biotechnology ◽  
Nucleic Acid Tests

AbstractEnzymes are the cornerstone of modern biotechnology. Achromopeptidase (ACP) is a well-known enzyme that hydrolyzes a number of proteins, notably proteins on the surface of Gram-positive bacteria. It is therefore used for sample preparation in nucleic acid tests. However, ACP inhibits DNA amplification which makes its integration difficult. Heat is commonly used to inactivate ACP, but it can be challenging to integrate heating into point-of-care devices. Here, we use recombinase polymerase amplification (RPA) together with ACP, and show that when ACP is immobilized on nitrocellulose paper, it retains its enzymatic function and can easily and rapidly be activated using agitation. The nitrocellulose-bound ACP does, however, not leak into the solution, preventing the need for deactivation through heat or by other means. Nitrocellulose-bound ACP thus opens new possibilities for paper-based Point-of-Care (POC) devices.

Nucleic Acid Tests for BK Polyomavirus Is Critical in Renal Transplant Recipients

2018 ◽  
Vol 50 (8) ◽  
pp. 2489-2492
Author(s):  
Y.-L. Chang ◽  
Y.-T. Cheng ◽  
T.-C. Chen ◽  
Y.-S. Chien ◽  
W.-C. Lee ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Renal Transplant ◽  
Renal Transplant Recipients ◽  
Transplant Recipients ◽  
Bk Polyomavirus ◽  
Nucleic Acid Tests

scholarly journals Efficacy and Safety of Lianhuaqingwen Capsules for the Prevention of Coronavirus Disease 2019: A Prospective Open-Label Controlled Trial

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Xiaowei Gong ◽  
Boyun Yuan ◽  
Yadong Yuan ◽  
Fengju Li
Keyword(s):  
Nucleic Acid ◽  
Treatment Group ◽  
Close Contact ◽  
Controlled Trial ◽  
Control Group ◽  
Open Label ◽  
Medical Observation ◽  
Observation Period ◽  
Close Contacts ◽  
Nucleic Acid Tests

Coronavirus disease 2019 (COVID-19) has become a global pandemic. Community and close contact exposures continue to drive the COVID-19 pandemic. There is no confirmed effective treatment for suspected cases and close contacts. Lianhuaqingwen (LH) capsules, a repurposed Chinese herbal product that is currently on the market, have proven effective for influenza and COVID-19. To determine the safety and efficacy of LH capsules for the prevention of COVID-19, we conducted a prospective open-label controlled trial of LH capsules on subjects who had close contact with people infected with COVID-19. Subjects received LH capsules (4 capsules, three times daily) or the usual medical observation for 14 days. The primary endpoint was the rate of positive nucleic acid tests of nasal and pharyngeal swabs during the quarantine medical observation period. We included 1976 patients, including 1101 in the treatment group and 875 in the control group. The rate of positive nucleic acid tests in the treatment group was significantly lower than that in the control group (0.27% vs. 1.14%, respectively; mean difference: −0.87%; 95% CI: −1.83 to −0.13; p = 0.0174 ) during the quarantine medical observation period (14 days). Among subjects with different close contact states, there was no significant difference in the rate of positive nucleic acid test results among close contacts in the treatment group and the control group (6.45% vs. 11.43%, respectively; p = 0.6762 ). Among secondary close contacts, the rate of positive nucleic acid tests in the treatment group was significantly lower than that in the control group (0.09% vs. 0.71%, respectively; p = 0.0485 ). No serious adverse events were reported. Taken together, and in light of the safety and effectiveness profiles, these results show that LH capsules can be considered to prevent the progression of COVID-19 after close contact with an infected person. This trial is registered with ChiCTR2100043012.

scholarly journals Key points of technical review for the registration of SARS-CoV-2 nucleic acid tests in China

Bioanalysis ◽  
2021 ◽  
Author(s):  
Hongran Li ◽  
Tong Jiao ◽  
Peirong Wang ◽  
Juanjuan An ◽  
Gang Deng ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Medical Device ◽  
Product Safety ◽  
Technical Review ◽  
Key Points ◽  
Safety Effectiveness ◽  
Unified Command ◽  
And Control ◽  
Nucleic Acid Tests

In response to the outbreak of COVID-19, in accordance with the principles of ‘unified command, early involvement, prompt review and scientific approval’ as well as the requirements of ensuring product safety, effectiveness and controllable quality, the Center for Medical Device Evaluation (CMDE) has issued Key Points of Technical Review for the Registration of SARS-CoV-2 Nucleic Acid Tests ( Key Points) to provide the requirements of tests. Because of the sustainability of the pandemic, more efforts and attempts are needed for SARS-CoV-2 detection and control. This article interprets the Key Points issued by the CMDE and provides certain refinements to wider audiences.

Repeated Nucleic Acid Tests Are Necessary for Early Diagnosis of Atypical COVID-19: A Case Report

Nano LIFE ◽  
2020 ◽  
Vol 10 (01n02) ◽  
pp. 2040005 ◽  
Author(s):  
Lihong Qu ◽  
Wujun Xiong ◽  
Chenghui Fan ◽  
Sheng Kang
Keyword(s):  
Nucleic Acid ◽  
Early Diagnosis ◽  
Ct Scan ◽  
Infected Individual ◽  
Left Lung ◽  
Atypical Symptoms ◽  
First Case ◽  
History Of ◽  
Ground Glass Nodules ◽  
Nucleic Acid Tests

In Wuhan, China, the first case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported on December 8, 2019. The patient’s symptoms included fever, coughing and breathing difficulties. According to the sixth China version of 2019 coronavirus disease (COVID-19) diagnostic criteria, some patients with COVID-19 may present atypical symptoms and have negative nucleic acid tests (NATs), possibly leading to misdiagnosis and viral transmission. Our patient was a 29-year-old woman who complained of a three-day history of nasal obstruction, and no fever, coughing or breathing difficulties were noted. Physical examination revealed no obvious signs of pneumonia. On January 16, 2020, the patient flew from Wuhan to Germany for a business trip and returned to Shanghai on January 28, a passenger on her flight was tested positive for SARS-CoV-2 later. Although two consecutive NATs performed at an interval of 24 h were negative, considering her direct contact with a SARS-CoV-2-infected individual, a 64-slice computed tomography (CT) scan showed a few scattered ground-glass nodules in the left lung, suggesting possible viral pneumonia. Given the clinical characteristics, epidemiological records, CT findings and a third positive NAT, our patient was diagnosed with COVID-19. The combination of history of epidemiology, clinical symptom, lung CT scan and routine blood test will improve the clinical diagnosis of asymptomatic COVID-19, but the early diagnosis of COVID-19 can be confirmed only by the repeated NATs.

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