scholarly journals Comparison of throat swabs and sputum specimens for viral nucleic acid detection in 52 cases of novel coronavirus (SARS-Cov-2) infected pneumonia (COVID-19)

2020 ◽  
Author(s):  
Chenyao Lin ◽  
Jie Xiang ◽  
Mingzhe Yan ◽  
Hongze Li ◽  
Shuang Huang ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Detection Efficiency ◽  
Nucleic Acid Detection ◽  
Sample Collection ◽  
Pcr Assay ◽  
Viral Nucleic Acid ◽  
Detection Rates ◽  
Qrt Pcr ◽  
Positive Rate ◽  
Novel Coronavirus

AbstractBackgroundIn December 2019, a novel coronavirus (SARS-CoV-2) infected pneumonia (COVID-19) occurred in Wuhan, China. Diagnostic test based on real-time reverse transcription polymerase chain reaction assay (qRT-PCR) was the main means of confirmation, and sample collection was mostly throat swabs, which was easy to miss the diagnosis. It is necessary to seek specimen types with higher detection efficiency and accuracy.MethodsPaired specimens of throat swabs and sputum were obtained from 54 cases, and RNA was extracted and tested for 2019-nCoV (equated with SARS-CoV-2) by qRT-PCR assay.ResultsThe positive rates of 2019-nCoV from sputum specimens and throat swabs were 76.9% and 44.2%, respectively. Sputum specimens showed a significantly higher positive rate than throat swabs in detecting viral nucleic acid using qRT-PCR assay (P=0.001).ConclusionsThe detection rates of 2019-nCoV from sputum specimens are significantly higher than throat swabs. We suggest that sputum would benefit for the detection of 2019-nCoV in patients who produce sputum. The results can facilitate the selection of specimens and increase the accuracy of diagnosis.

scholarly journals Comparison of throat swabs and sputum specimens for viral nucleic acid detection in 52 cases of novel coronavirus (SARS-Cov-2)-infected pneumonia (COVID-19)

2020 ◽  
Vol 58 (7) ◽  
pp. 1089-1094 ◽  
Author(s):  
Chenyao Lin ◽  
Jie Xiang ◽  
Mingzhe Yan ◽  
Hongze Li ◽  
Shuang Huang ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Detection Efficiency ◽  
Diagnostic Value ◽  
Nucleic Acid Detection ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Viral Nucleic Acid ◽  
Detection Rates ◽  
Positive Rate ◽  
Novel Coronavirus

AbstractObjectivesIn December 2019, a novel coronavirus (SARS-CoV-2)-infected pneumonia (COVID-19) occurred in Wuhan, China. Laboratory-based diagnostic tests utilized real-time reverse transcriptase polymerase chain reaction (RT-PCR) on throat samples. This study evaluated the diagnostic value to analyzing throat and sputum samples in order to improve accuracy and detection efficiency.MethodsPaired specimens of throat swabs and sputum were obtained from 54 cases, and RNA was extracted and tested for 2019-nCoV (equated with SARS-CoV-2) by the RT-PCR assay.ResultsThe positive rates of 2019-nCoV from sputum specimens and throat swabs were 76.9% and 44.2%, respectively. Sputum specimens showed a significantly higher positive rate than throat swabs in detecting viral nucleic acid using the RT-PCR assay (p = 0.001).ConclusionsThe detection rates of 2019-nCoV from sputum specimens were significantly higher than those from throat swabs. We suggest that sputum would benefit for the detection of 2019-nCoV in patients who produce sputum. The results can facilitate the selection of specimens and increase the accuracy of diagnosis.

scholarly journals Evaluation of the auxiliary diagnosis value of antibodies assays for the detection of novel coronavirus (SARS-Cov-2)

2020 ◽  
Author(s):  
Gao Yong ◽  
Yuan Yi ◽  
Li Tuantuan ◽  
Wang Xiaowu ◽  
Li Xiuyong ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Early Stage ◽  
Clinical Information ◽  
Diagnostic Value ◽  
Nucleic Acid Detection ◽  
Course Of Illness ◽  
Combined Use ◽  
Hospitalization Period ◽  
Positive Rate ◽  
Novel Coronavirus

AbstractBackgroundThe spread of an novel coronavirus (SARS-CoV-2, previously named 2019-nCoV) has already taken on pandemic proportions, affecting over 100 countries in a matter of weeks. Elucidating the diagnostic value of different methods, especially the auxiliary diagnosis value of antibodies assays for SARS-CoV-2 infection is helpful for improving the sensitivities of pathogenic-diagnosis, providing timely treatment, and differentiating the infected cases from the healthy, thus preventing further epidemics.MethodsMedical records from 38 patients with confirmed SARS-CoV-2 infection in the Second People’s Hospital of Fuyang from January 22, 2020 to February 28, 2020 were collected and retrospectively analyzed. Specimens including throat swabs, sputum and serum were collected during the hospitalization period, viral RNAs and serum IgM-IgG antibodies to SARS-CoV-2 were measured respectively. The detectability of different methods as well as the auxiliary diagnosis value of antibodies test for SARS-CoV-2 infection were analyzed.ResultsAmong 38 patients, the total seropositive rate for IgM and IgG was 50.0% and 92.1%, respectively. Two patients remained seronegative throughout the course of illness. In the early phase of illness, the RNA test for sputum specimens possessed the highest detectability(92.3%), followed by the the RNA test for throat swabs (69.2%), and the antibodies assays presented lower positive rates(IgM, 23.0%, IgG, 53.8%). While, the sensitivity of antibodies assays overtook that of RNA test since day 8 after onset (IgM, 50.0%; IgG, 87.5%). Of note, the positive rate of throat swabs was only 13.0% for cases in later phase(≥15 d.a.o), and the sensitivities of IgM and IgG rose to 52.2% and 91.3%, respectively. Combined use of antibodies assay and qRT-PCR at the same time was able to improve the sensitivities of pathogenic-diagnosis, especially for the throat swabs group at the later stage of illness. Moreover, most of these cases with undetectable viral RNA in throat swabs specimens at the early stage of illness were able to be IgM/IgG seropositive after 7 days.ConclusionsThe antibodies detection against SARS-CoV-2 offers vital clinical information for physicians, and could be used as an effective supplementary indicator for suspected cases of negative viral nucleic acid detection or in conjunction with nucleic acid detection in the diagnosis of suspected cases.

The Sampling Locations are Closely Related to the Positive Rate of Novel Coronavirus Nucleic Acid Detection

2020 ◽  
Vol 66 (06/2020) ◽  
Author(s):  
Daming Wang ◽  
Hongfu Wang ◽  
Shaobo Li ◽  
Tingyu Ren ◽  
Zhaopeng Cao ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acid Detection ◽  
Sampling Locations ◽  
Positive Rate ◽  
Novel Coronavirus

scholarly journals Improving Detection Efficiency of SARS-CoV-2 Nucleic Acid Testing

2020 ◽  
Vol 10 ◽  
Author(s):  
Jie Zhang ◽  
Kecheng Li ◽  
Ling Zheng ◽  
Jianbo Zhang ◽  
Zhilin Ren ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Symptom Onset ◽  
Detection Efficiency ◽  
False Negative ◽  
False Negative Rate ◽  
Nucleic Acid Testing ◽  
Detection Rates ◽  
High False Negative Rate ◽  
Before And After ◽  
Positive Rate

BackgroundSARS-CoV-2 nucleic acid testing (NAT) has been routinely used for COVID-19 diagnosis during this pandemic; however, there have been concerns about its high false negative rate. We dissected its detection efficiency with a large COVID-19 cohort study.MethodsWe analyzed SARS-CoV-2 NAT positive rates of 4,275 specimens from 532 COVID-19 patients in Sichuan Province with different disease severities, statuses, and stages, as well as different types and numbers of specimens.ResultsThe total positive rate of the 4,275 specimens was 37.5%. Among seven specimen types, BALF generated a 77.8% positive rate, followed by URT specimens (38.5%), sputum (39.8%), and feces/rectal swabs (34.1%). Specimens from critical cases generated a 43.4% positive rate, which was significantly higher than that of other severities. With specimens from patients at stable status, the SARS-CoV-2 positive rate was 40.6%, which was significantly higher than that of improved status (17.1%), but lower than that of aggravated status (61.5%). Notably, the positive rate of specimens from COVID-19 patients varied significantly from 85 to 95% during 3 days before and after symptom onset, to 20% at around 18 days after symptom onset. In addition, the detection rate increased from 72.1% after testing one throat swab, to 93.2% after testing three consecutive respiratory specimens from each patient.ConclusionsSARS-CoV-2 NAT detection rates vary with patient disease severity and status, specimen type, number of specimens, and especially disease progression. Sampling as close to symptom onset as possible, and consecutively collecting more than one respiratory specimen could effectively improve SARS-CoV-2 NAT detection efficiency.

scholarly journals Cases Report of Cured Novel Coronavirus-infected Pneumonia Patients with Viral Nucleic Acid Test Positive in Fecal Specimens

2020 ◽  
Author(s):  
Mei Han ◽  
Jingbo Zou ◽  
Wenguang Tian ◽  
Xiaoyu Wei ◽  
Yang Zhou ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Molecular Diagnostic ◽  
Clinical Practices ◽  
Rt Pcr ◽  
Viral Nucleic Acid ◽  
Nucleic Acid Test ◽  
Assessment Standard ◽  
Novel Coronavirus ◽  
Acid Test ◽  
Respiratory Specimens

Abstract Background: The outbreak of the novel coronavirus in China (COVID-19) represents a significant and urgent threat to global health. We report here five cases of COVID-19 infection patients in our clinical practices who are medically stable and presumed to successfully “cleared” the virus after antiviral treatments. Case presentation: The clinical evaluation depends on the viral nucleic acid test in respiratory specimens by real-time PCR reverse transcription (RT-PCR) assays according to the authorized guidance. We found that the stool samples of these cured patients remain positive in RT-PCR assay while the virus is undetectable in respiratory specimens. RT-PCR molecular diagnostic assay was designed to specifically detect the presence of viral RNA. Thus, the positive result in the fecal specimens implies the existence of viable virions with the patients. Conclusions: This highlights the importance to look closely at the assessment standard of medical treatment, as well as the need for reevaluation of the criteria for the initial screening, prevention, and care of patients with this emerging infection.

The application of viral nucleic acid detection and lung CT in COVID-19 diagnosis

2020 ◽  
Author(s):  
Rui Hu
Keyword(s):  
Nucleic Acid ◽  
Clinical Symptoms ◽  
Virus Disease ◽  
False Negative ◽  
False Negative Rate ◽  
Diagnostic Methods ◽  
Nucleic Acid Detection ◽  
Viral Nucleic Acid ◽  
Early Medical Intervention ◽  
Lung Ct

The Corona Virus Disease 2019 (COVID-19) has the characteristics of fast propagation speed and strong pathogenicity and has attracted wide attention of people, medical workers, and researchers around the world. Accurate, rapid, and timely screening and diagnosis of COVID-19 is of great significance to control the development of the epidemic situation and save the lives of patients. Currently, the detection of viral nucleic acid and lung CT is the main screening and diagnostic methods of COVID-19. Nucleic acid detection has the advantages of fast, strong specificity and high sensitivity, but there is a certain false-negative rate. CT result of lung examination is visual, but it is not typical due to the uncertain time of clinical symptoms and the early medical intervention. Therefore, the diagnosis of COVID-19 should include a combination of epidemiological history, clinical symptoms, imaging, and laboratory tests.

scholarly journals Is Pool Testing Method of COVID-19 Employed in Germany and India Effective?

2020 ◽  
Author(s):  
Jia Liu ◽  
Yi Chen ◽  
Kefan Xie ◽  
Xiaohong Chen
Keyword(s):  
Nucleic Acid ◽  
Sample Size ◽  
Infection Rate ◽  
Large Population ◽  
Nucleic Acid Detection ◽  
Testing Method ◽  
Optimal Sample ◽  
The One ◽  
Novel Coronavirus ◽  
Test Result

Abstract At present, several countries, such as Germany and India, have employed a pool testing method on the nucleic acid testing of COVID-19 for the shortage of detection kits. In this method, the testing is performed on several samples of the cases together as a bunch. If the test result of the bunch is negative, then it is shown that none of the cases in the bunch has been infected with the novel coronavirus. On the contrary, if the test result of the bunch is positive, then the samples are tested one by one to confirm which cases are infected. We verified that the pool testing method of COVID-19 is effective in the situation of the shortage of nucleic acid detection kits based on probabilistic modeling. Moreover, the following interesting results are also obtained. (1) If the infection rate is extremely low, while the same number of detection kits are used, the expected number of cases that can be tested by the pool testing method is far more than that by the one-by-one testing method. (2) The pool testing method is effective only when the infection rate is less than 0.3078. While the infection rate decreases from 0.3078 to 0.0018, the optimal sample sizes in one bunch increases from 3 to 25. In general, the higher the infection rate, the smaller the optimal sample size in one bunch. (3) If N samples are tested by the pool testing method, while the sample size in one bunch is G, the number of detection kits required is in the interval (N/G, N). Additionally, the lower the infection rate, the fewer detection kits are needed. Therefore, the pool testing method is not only suitable for the situation of the shortage of detection kits, but also the situation of the overall or sampling detection for a large population.

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