scholarly journals Experience with a triplex arbovirus nucleic acid test (NAT) at a Canadian Public Health Laboratory

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Saugata Choudhury ◽  
Raymond Tellier ◽  
Kevin Fonseca ◽  
Byron M. Berenger
Keyword(s):  
Nucleic Acid ◽  
Dengue Virus ◽  
Symptom Onset ◽  
Zika Virus ◽  
Clinical Symptoms ◽  
Clinical History ◽  
Nucleic Acid Test ◽  
Virus Rna ◽  
Prolonged Duration ◽  
Acid Test

Abstract Background Dengue, chikungunya and zika infections occur in tropical and subtropical regions of the world. We describe the utilization of an in-house nucleic acid test (NAT) targeting all three viruses for febrile returning travelers in Alberta, Canada. Methods NAT was performed until 40 days from symptom onset or exposure due to the prolonged duration of zika virus RNA detection. From Sept 1, 2017 to August 31, 2019, 2552 specimens from 1932 patients were tested. Results Approximately 2% of patients tested were NAT positive for dengue virus (n = 42), chikungunya virus (n = 4), and zika virus (n = 1). The majority presented with fever, myalgia and rash. Regions with the most frequent travel included SouthEast Asia (68.5%), South America (25%) and the Caribbean (6.5%). Ct values were stronger (~ 1.5 logs) for patients within 1–3 days following onset of clinical symptoms than those presenting later. Nineteen patients had urine and plasma submitted; 5 were positive for both specimens and 2 were positive only for dengue virus in the urine. Also, Ct values were lower for plasma when compared to the corresponding urine. RNA was detected until 10 days and 5 days post-exposure in plasma and urine respectively for dengue virus. Conclusions Owing to dengue viremia detected beyond the conventional 7 days and low levels of circulating zika virus globally, a cutoff of 14 days from symptom onset to NAT is sufficient to diagnose acute cases. Inclusion of a zoonotic history form that collects appropriate clinical history results in improved test utilization.

A preliminary survey of Zika virus infection by nucleic acid test in the volunteer blood donor samples in Shenzhen China

2020 ◽  
Vol 92 (8) ◽  
pp. 1326-1329
Author(s):  
Xin Zheng ◽  
Jingfeng Zeng ◽  
Xiaoxuan Xu ◽  
Yizhong Liu ◽  
Liu Heng ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Virus Infection ◽  
Blood Donor ◽  
Zika Virus ◽  
Preliminary Survey ◽  
Volunteer Blood Donor ◽  
Nucleic Acid Test ◽  
Zika Virus Infection ◽  
Acid Test

scholarly journals The value of early positive nucleic acid test and negative conversion time of SARS-CoV-2 RNA in the clinical outcome of COVID-19 patients

2021 ◽  
Author(s):  
Yongzhen Zhai ◽  
Xin Zang ◽  
Liangkun Xiong ◽  
Junyao Zhu ◽  
Fangfang Zhao ◽  
...  
Keyword(s):  
Risk Factor ◽  
Nucleic Acid ◽  
Symptom Onset ◽  
Nucleic Acid Detection ◽  
Nucleic Acid Test ◽  
Duration Of Disease ◽  
Conversion Time ◽  
Polymerase Chain ◽  
Acid Test ◽  
Negative Conversion

Abstract Background The outbreak of coronavirus disease (COVID-19) poses a great threat to the global public health. At present, the number of new confirmed COVID-19 cases and new deaths is increasing worldwide. The strategy of comprehensive and scientific detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, the virus that causes COVID-19) through real-time reverse transcriptase polymerase chain reaction (RT-PCR) for special populations and environments provides great support for the prevention and control of this pandemic in China. Our study focused on determining the factors associated with the length of time from symptom onset to the first positive nucleic acid test of throat swabs in COVID-19 patients, evaluating the effect of early positive nucleic acid detection on the disease severity and its significance in prognosis, and predicting the factors associated with the time from positive SARS-CoV-2 RNA test to negative conversion in COVID-19 patients. Methods This study included 116 hospitalized patients with COVID-19 from January 30, 2020 to March 4, 2020 in Wuhan, China. Throat swabs samples were collected for real-time reverse transcriptase polymerase chain reaction (RT-PCR) test of SARS-CoV-2 RNA, and all patients included in this study were positive for this test. Results Multivariate Cox proportional hazards model showed that disease severity and the duration of disease before admission to hospitals were protective factors for the time from symptom onset to positive nucleic acid detection, and the time from positive nucleic acid test to negative conversion was a risk factor for the time from symptom onset to positive nucleic acid detection. Meanwhile, the time from symptom onset to positive nucleic acid detection was an independent risk factor for the prolonged negative conversion of SARS-CoV-2 virus. Conclusions Patients with more severe disease and longer duration of disease before admission to hospitals had a shorter time from symptom onset to positive nucleic acid test. Prolonged time from symptom onset to positive nucleic acid test was an independent risk factor for the prolonged negative conversion time of SARS-CoV-2 virus, and the severity of the disease had no correlation with negative conversion time of SARS-CoV-2 virus.

scholarly journals Clinical Significance of an IgM and IgG Test for Diagnosis of Highly Suspected COVID-19

2021 ◽  
Vol 8 ◽  
Author(s):  
Xingwang Jia ◽  
Pengjun Zhang ◽  
Yaping Tian ◽  
Junli Wang ◽  
Huadong Zeng ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Clinical Significance ◽  
Clinical Symptoms ◽  
Treatment Protocol ◽  
Antibody Detection ◽  
Igg Antibody ◽  
Epidemic Disease ◽  
Detection Rates ◽  
Nucleic Acid Test ◽  
Acid Test

Background: Nucleic acid detection and CT scanning have been reported in COVID-19 diagnosis. Here, we aimed to investigate the clinical significance of IgM and IgG testing for the diagnosis of highly suspected COVID-19.Methods: A total of 63 patients with suspected COVID-19 were observed, 57 of whom were enrolled (24 males and 33 females). The selection was based on the diagnosis and treatment protocol for COVID-19 (trial Sixth Edition) released by the National Health Commission of the People's Republic of China. Patients were divided into positive and negative groups according to the first nucleic acid results from pharyngeal swab tests. Routine blood tests were detected on the second day after each patient was hospitalized. The remaining serum samples were used for detection of novel coronavirus-specific IgM/IgG antibodies.Results: The rate of COVID-19 nucleic acid positivity was 42.10%. The positive detection rates with a combination of IgM and IgG testing for patients with COVID-19 negative and positive nucleic acid test results were 72.73 and 87.50%, respectively.Conclusions: We report a rapid, simple, and accurate detection method for patients with suspected COVID-19 and for on-site screening for close contacts within the population. IgM and IgG antibody detection can identify COVID-19 after a negative nucleic acid test. Diagnostic accuracy of COVID-19 might be improved by nucleic acid testing in patients with a history of epidemic disease or with clinical symptoms, as well as CT scans when necessary, and serum-specific IgM and IgG antibody testing after the window period.

scholarly journals Clinical characteristics and outcomes of COVID-19 long-term nucleic acid positive patients

2021 ◽  
pp. 1-10
Author(s):  
Xuan Zhu ◽  
Xinxin Zhu ◽  
Min Wang ◽  
Fang Yang ◽  
Zhibing Sun ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Clinical Characteristics ◽  
Clinical Symptoms ◽  
Control Group ◽  
Viral Shedding ◽  
Imaging Characteristics ◽  
And Gender ◽  
Acid Test ◽  
Pulmonary Ct

OBJECTIVE: This study aimed to investigate the clinical characteristics and outcomes of coronavirus disease-19 (COVID-19) long-term nucleic acid positive patients (hereinafter referred to as CLTAPs). METHODS: Patients were recruited from the Xiaogan Central Hospital between 16 January 2020 and 28 March 2020. Among the 562 cases of patients with laboratory-identified COVID-19 infection by real-time polymerase chain reaction (qtPCR), 19 cases of COVID-19 patients with more than 41 days from the first to the last time of nucleic acid test were selected as the study group, and 76 cases of age- and gender-matched COVID-19 patients were selected as the control group (hereinafter referred to as C-CLTAPs). Demographic characteristics, clinical symptoms, laboratory examination and computed tomography (CT) imaging characteristics were retrospectively analyzed. RESULTS: On admission, among the 562 cases of patients with COVID-19, there were 398 cases of ordinary COVID-19 patients, 99 cases of severe COVID-19 patients and 99 cases of critical COVID-19 patients. CLTAPs had milder clinical symptoms and longer viral shedding time in comparison to C-CLTAPs. Compared to C-CLTAPs, CLTAPs had a lower infection index at admission. CLTAPs used less oxygen therapy and a higher proportion of hydroxychloroquine treatment in comparison to C-CLTAPs. In comparison to C-CLTAPs, CLTAPs showed slower pulmonary CT progression and faster pulmonary CT absorption. CONCLUSION: In this study, out of the 562 cases, we found 19 CLTAPs. The clinical differences between CLTAPs and C-CLTAPs were compared and analyzed. We hope that these finding can provide a theoretical basis for the treatment of CLTAPs.

What is the meaning of a nonresolved viral nucleic acid test-reactive minipool?

Transfusion ◽  
2014 ◽  
Vol 55 (2) ◽  
pp. 395-404 ◽  
Author(s):  
Lunan Wang ◽  
Le Chang ◽  
Yunzheng Xie ◽  
Chengyin Huang ◽  
Lei Xu ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Viral Nucleic Acid ◽  
Nucleic Acid Test ◽  
Acid Test

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.

Prevalence and risk factors associated with repeat positive SARS-CoV-2 nucleic acid test results among discharged COVID-19 patients

Medicine ◽  
2021 ◽  
Vol 100 (48) ◽  
pp. e27933
Author(s):  
Yanru Cui ◽  
Jilin Wang ◽  
Gaofeng Wang ◽  
Xiuguo Xie ◽  
Lizhen Tian
Keyword(s):  
Risk Factors ◽  
Nucleic Acid ◽  
Test Results ◽  
Nucleic Acid Test ◽  
Factors Associated ◽  
Acid Test

Abstract W P172: Prevalence of Positive Dwi Findings in Relation to Tia Etiology

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Yasufumi Gon ◽  
Manabu Sakaguchi ◽  
Syuhei Okazaki ◽  
Hideki Mochizuki ◽  
Kazuo Kitagawa
Keyword(s):  
Symptom Onset ◽  
Clinical Symptoms ◽  
Motor Symptom ◽  
Unknown Etiology ◽  
Symptom Duration ◽  
Motor Symptoms ◽  
Duration Of Symptoms ◽  
Prolonged Duration ◽  
History Of ◽  
Toast Classification

Objective: Previous studies have shown that the prolonged duration of TIA symptoms or ABCD2 score are associated with DWI abnormality, and the presence of DWI abnormality is associated with an increased early risk of stroke. However, there are few reports that show the relation between TIA clinical etiology and DWI abnormality. Our aim of this study is to clarify the prevalence of positive DWI in relation to characteristics of patients and TIA. Methods: The subjects were enrolled from patients who were admitted to our stroke unit within 7 days after symptom onset from January 2006 to July 2013. The diagnosis of TIA was done by NINDS criteria, and we classified TIA etiology by TOAST classification based on clinical symptoms, ECG monitoring, carotid ultrasound, MR angiography and transesophageal echocardiography. All patients underwent DWI-MRI within 7 days after symptom onset. We examined an association between TIA etiology, symptom, duration of symptoms and DWI abnormality. Results: A total of 141 patients (mean 64 years; 63% men) were admitted with TIA during this period. Those included lacuna TIA (n=17, 12.1%), atherothrombotic TIA (n=32, 22.7%), cardioembolic TIA (n=23, 16.3%), TIA due to other causes (n=35, 24.8%), and TIA with unknown etiology (n=34, 24.1%). Prevalence of positive DWI findings were 47.1% in lacunar TIA, 43.7% in atherothrombotic TIA, 52.1% in cardioembloic TIA, 42.8% in TIA due to other causes, and 23.5% in TIA with unknown etiology. DWI abnormality was the most frequent in cardiogenic TIA. In relation to symptom duration, the prevalence of DWI positive findings were 45.2% in less than 1 hour (N=53), 36.6% in 1-3 hour (N=41), 25.0% in 3-6 hour (N=12) and 42.9% in 6-24 hours (N=35). In relation to motor symptoms, there was no difference in prevalence of DWI abnormality between patient with motor symptoms (39.8%, N=113) and without (42.8%, N=28). There was no relation between DWI abnormalities and age, a history of stroke/TIA episode or vascular risk factors. Conclusion: Prevalence of DWI positive findings was high in cardiogenic TIA, and low in TIA with unclassified etiology. There were no relation between DWI abnormality, duration of symptom, and motor symptom.

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