Diagnostic value of sputum nucleic acid amplification testing for COVID-19 a meta-analysis

Objective: To systematically evaluate the diagnostic value of nucleic acid test in sputum for COVID-19 and to determine the suitable population for sputum specimens. Method(s): PubMed, CNKI, Scopus, Web of Science, medRxiv and bioRxiv databases were searched for the diagnostic value of sputum nucleic acid test for COVID-19 from December 2019 to April 2022. Two researchers independently screened the literature, extracted data, and evaluated the risk of bias with QUADAS-2 in the included studies. We used sensitivity, specificity, AUC and DOR to evaluate the diagnostic value of sputum specimens. Result(s): A total of 25 studies were included, including 10,731 subjects. Meta-analysis results showed that: The combined sensitivity (SEN), specificity (SPE), diagnostic odds ratio (DOR), and area under operating characteristic curve (AUC) of sputum nucleic acid for the diagnosis of COVID-19 were 89.2% (95% CI, 86.6-91.4), 97.5% (95% CI, 97.2-97.8), 41.4 (95% CI, 11.7-145.9), 0.9474 (95% CI, 0.8964-0.9846). The results of subgroup analysis showed that the Asian group's DOR was 36.835 (95% CI, 10.83-134.570), and the Non-Asian group's DOR was 66.294 (95% CI, 0.719-6109.09). The DOR was 27.207 (95% CI, 2.860-258.780) in the OPS group and 44.165 (95% CI, 4.828-403.970) in the NPS group. DOR of mild patients was 84.255 (95% CI, 9.975-711.690), the DOR of the severe group was 14.216 (95% CI, 3.527-57.142) and was 19.464 (95% CI, 0.724-522.920) in the cured group. Conclusion(s): Current evidence shows that sputum nucleic acid test is of high diagnostic value for COVID-19. Study area and severity of disease are the influencing factors for the diagnostic accuracy of the sputum nucleic acid test. Due to the limitations on the number and quality of the included studies, the above conclusions need to be verified by more high-quality studies.Copyright © 2023, E-Century Publishing Corporation. All rights reserved.

Expert consensus on laboratory testing for sars-COV-2.

With the global outbreak of the coronavirus disease 2019, the laboratory testing for the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) has become the key to the epidemic prevention and control. Based on the questions, issues from the clinical practice and the latest research, the Sub-committee of Clinical Microbiology Laboratory, Chinese Hospital Association proposed "Expert Consensus on Laboratory Testing for SARS-CoV-2". The consensus panel is composed by experts in clinical microbiology, molecular biology and immunology laboratory medicine. The consensus describes the technological characteristics, precautions of clinical application, and biosafety requirements. It also includes the coping strategies for the most frequent problems and the challenges in testing and results explanation of commonly used clinical methods including nucleic acid, antibody and antigen tests, and combined testing of nucleic acid and antibody. We expect this consensus could provide guidances and reference opinions on how to conduct the precise laboratory testing for SARS-CoV-2 on the epidemic prevention and control.Copyright © 2021, Peking Union Medical College Hospital. All rights reserved.

Pulmonary parenchymal involvement secondary to subcutaneous injection of silicone gels: a case report.

Pulmonary parenchymal involvement secondary to the subcutaneous injection of silicone gels is an unusual condition which occurs more frequently in women aged between 22 and 55 years. Although different theories have been put forward about its etiology, it is unknown and the condition may cause local and systemic complications and even have a fatal outcome. Few cases have been reported in South America and there is no report of this unique entity in Peru. We present the case of a previously healthy 28-year-old male transgender patient who, after an illegal subcutaneous injection of silicone gels in the gluteal region given by a non-healthcare professional, showed progressive respiratory distress and stabbing chest pain of approximately 7 out of 10 on the pain scale within the first 24 hours. Upon admission to the emergency room, respiratory failure was objectively evidenced since the patient had an oxygen saturation of 72 % at a FiO2 of 21 %, as well as pulmonary parenchymal involvement both in the CT scan and chest X-ray with signs highly suggestive of this pathology. Using a SARS-CoV-2 RNA real-time RT-PCR test performed on a respiratory specimen, COVID pneumonia, immunodeficiency disorders and pulmonary embolism were ruled out. Since there is no standard treatment, the patient was given relevant support measures such as the administration of supplemental oxygen at a low flow rate by binasal cannula, intravenous systemic corticosteroids and antibiotic therapy, thus achieving good progress with resolution of the initial clinical presentation. Then, after 10 days of intrahospital treatment, the patient was discharged.Copyright © La revista. Publicado por la Universidad de San Martin de Porres, Peru.

Factors associated with carrying out molecular tests for the diagnosis of COVID-19 in the State of Espírito Santo, Brazil

Backgroung: Brazil was slow to implement an expanded testing policy for COVID-19, which may have affected the most vulnerable population's access to testing services. Objective: to evaluate the factors associated with performing the molecular test for COVID-19. Methods: cross-sectional study of secondary data from the COVID-19 panel in the state of Espírito Santo. COVID-19 suspicion notification forms were included between September 11, 2020 and March 2, 2021. Hierarchical logistic regression was used to estimate the odds ratio (OR) with 95% confidence interval (CI95%). Results: 419,771 notification forms were analyzed. The prevalence of performing the molecular teste for COVID-19 was 81.1% (CI95% 81.0-81.2). Elderly (OR= 2.70 – CI95% 2.56-2.85), health professional (OR=1.43 – CI95% 1.36-1.50), chronic cardiovascular disease (OR=1.13 – CI95% 1.09-1.17), diabetes mellitus (OR=1.07 – CI95% 1.01-1.14) and hospitalization (OR=5.95 – CI95% 4.53;7.82) were more likely to have undergone the molecular test. Male sex (OR=0.96 – CI95% 0.94-0.98), black skin color (OR=0.75 – CI95% 0.73-0.78), yellow skin color (OR=0.74 – CI95% 0.71-0.77), residing in the northern health region (OR=0.37 – CI95% 0.36-0.39) and the homeless population (OR=0.76 – CI95% 0.67-0.85) had the lowest chance of having undergone the molecular test. Conclusion: Social, economic, contextual factors and the risk of aggravation of the disease were associated with carrying out the molecular test for COVID-19 in the state of Espírito Santo. Actions are needed to guarantee the access of the most vulnerable population to molecular testing. © The authors (2023), this article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4. 0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1. 0/) applies to the data made available in this article, unless otherwise stated.

Performance of the VitaPCR rapid molecular test for SARS-CoV-2 screening at hospital admission.

OBJECTIVE: To evaluate the diagnostic accuracy of rapid VitaPCR™ (Credo) assay as screening test in emergency department (ED) patients prior to transfer or medical interventions. METHODS: In this prospective study 6642 oropharyngeal swabs from nonpreselected ED patients were tested for SARS-CoV-2 with (1) extraction-free VitaPCR and (2) extraction-based reference assays (Aptima®, cobas®, Xpert®Xpress). RESULTS: The median TAT of VitaPCR was 47 minutes (IQR: 38-59), while reference assays required 6.2 hours (IQR: 4.4-13.3). VitaPCR's sensitivity, specificity, PPV and NPV was 77.9%, 99.9%, 97.9%, and 98.9% in relation to Hologic Panther TMA; 78.3%, 99.8%, 96.4%, and 98.5% compared to Roche cobas6800 PCR; 71.2%, 99.2%, 94.9%, and 94.3% using Cepheid GeneXpert PCR as reference. CONCLUSION: High-sensitivity testing is needed to limit nosocomial spread and identify asymptomatic COVID-19 patients. However, time advantage of the VitaPCR must be weighed against its significantly lower sensitivity, especially when used in high-risk environments such as hospitals.

Clinical characteristics of patients with diabetes mellitus complicated with COVID-19.

Objective: To study the clinical characteristics of diabetes mellitus with Coronavirus disease 2019 (COVID-19) and explore the possible mechanism of diabetes predisposition. Method(s): A single center, retrospective and observational study was used to collect 48 inpatients diagnosed with COVID-19 who were admitted to the first ward of the third department of infection, Raytheon hospital, Wuhan from February 23, 2020 to March 30, 2020. Demographic data, symptoms, laboratory tests, comorbidities, treatments and clinical outcomes have been collected. The patients were divided into non-diabetic group and diabetic group according to the combination of diabetes. The clinical data and laboratory test results of the two groups were observed, and the t test, non-parametric test and Chi square test were used for comparison. Result(s): All the 5 patients with COVID-19 diabetes mellitus had fever and respiratory symptoms, chest CT was consistent with typical COVID-19 imaging features, and novel coronavirus nucleic acid test results were positive. There were no statistically significant differences in age, gender composition, co-existing diseases, clinical symptoms, clinical typing, disease course and treatment plan between the diabetic group and the non-diabetic group (P>0.05).There was a statistically significant difference in fasting blood glucose between the non-diabetic group and the diabetic group (P<0.05).The difference of fasting blood glucose at discharge from the diabetes group compared with that at admission was also statistically significant (P<0.05).There was no statistically significant difference between the two groups in other laboratory examination indexes (P>0.05). Conclusion(s): COVID-19 patients with diabetes are mainly manifested by fever and respiratory symptoms.Chest CT shows typical COVID-19 imaging features.Copyright © 2020 by the Chinese Medical Association.

Frequency of cervical hpv in women with COVID-19 infection

Aim: At the beginning of 2020, the Coronavirus disease 2019 (COVID-19) caused by the SARS-CoV-2 virus emerged in China. While there are several studies currently being performed to investigate the multi-organ symptoms of COVID-19 infection, significant attention has yet to be paid to its presence in the cervix. This article aims to establish a medical hypothesis of its association with HPV infection as well as the potential impact of COVID-19 infection on the female genital tract. Material(s) and Method(s): This prospective cohort study was performed in ... Research and Training Hospital between January 1 and July 30, 2020. Cervicovaginal samples (co-test) were taken at the gynecological oncology unit, and both HPV screening and Pap smear were studied with the liquid-based method. Two groups of patients who were confirmed by PCR test to have had COVID-19 infection in the last 6 months and patients who did not have a history of infection were included in the study. Result(s): A total of 310 participants were evaluated in the study. Of these participants, 30 (9.7%) were confirmed to have undergone COVID-19 by PCR test. There was no significant difference between the total positive smear results in both groups. However, the rate of HPV-16 positive patients was significantly higher in the COVID-19 group (2.5% vs 10.0%, p=0.027). Discussion(s): As a result, COVID-19 infection may increase the frequency of HPV-16. Apart from this, it can be said that this increase is not reflected in the frequency of cervical cytopathology.Copyright © 2022, Derman Medical Publishing. All rights reserved.

The application value of low-dose CT scan in pregnant women with COVID-19.

Objective: To explore the value of low-dose CT in pregnancy with COVID-19. Method(s): A retrospective analysis was performed on the clinical characteristics, laboratory tests, and chest CT findings of 12 pregnant women with COVID-19 diagnosed by nucleic acid testing in the Renmin Hospital of Wuhan University from January 20, 2020 to February 16, 2020. Two radiologists blinded to the reconstruction algorithm independently scored subjective image quality on a 5-point Likert scale. Image quality score >= 3 was acceptable in clinics. The CT radiation doses were recorded, including CT volume dose index (CTDIvol), dose length product (DLP), and effective radiation dose (E). Two radiologists observed the distribution, shape, density, and other characteristics of lung lesions, and they also decided whether hilar, mediastinal lymphadenopathy, and pleural changed. Result(s): A total of 12 pregnant women with COVID-19, 8 had cough, 4 had fever, 2 had chest tightness, and 1 had dyspnea and diarrhea each. The CT image quality score of all patients was 3-4, with an average of 3.46, which fully met the clinical diagnosis requirements. The CTDIvol value was 1.13-4.31 mGy, with an average of 3.02 mGy. The DLP value was 34.48-75.29 mGy*cm, with an average of 55.48 mGy*cm. The Evalue was 0.48-1.05 mSv, with an average of 0.78 mSv. In all cases, chest CT examination showed abnormal manifestations after clinical symptoms, including unilateral lung lesions in 5 cases and bilateral lung lesions in 7 cases, 1 case of ground-glass opacity, 1 case of solidification, 7 cases of ground-glass and consolidation, 1 case of strip opacity, ground-glass, and consolidation and strip cable shadow coexisted in 2 cases. Conclusion(s): The application of low-dose CT scan in pregnant women with COVID-19 is completely feasible. CT mainly manifested as bilateral lung patchy and flaky ground-glass opacity with consolidation. Active and effective treatment can help recover and improve prognosis.Copyright © 2020 by the Chinese Medical Association.

Problems of PCR diagnostics OF COVID-19.

To date, an adequate and timely assessment of the number of cases is the basis of effective measures aimed at preventing the spread of COVID-19 infection. Real-time reverse transcription polymerase chain reaction (RT-PCR) remains the gold standard for confirming COVID-19. The purpose of the work: to analyze the experience of the city virological center of the S.P. Botkin Clinical Infectious Diseases Hospital (Botkin Hospital) for the examination for the presence of SARS-CoV-2 coronavirus by PCR in the period from 2020 to 2022. Materials and methods. The systematization of PCR studies on COVID-19 for the period 2020-2022 was carried out. A total of 221,901 people were examined, positive results were obtained in 55,372 (24.95%). Among the contingents of the examined patients, patients who underwent inpatient treatment at the Botkin Hospital, Conclusions. This study analyzed the possible causes of false-positive and false-negative PCR results. The correlation of the number of positive results with the dynamics of detection of new cases of COVID-19 in St. Petersburg during the 2020-2022 pandemic is shown. It has been established that the proportion of patients examined more than 3 times during the period of hospitalization remains significant. This fact requires the closest attention, given the high cost and laboriousness of PCR studies.Copyright © 2022 Authors. All rights reserved.

Factors associated with molecular diagnosis for COVID-19: a cross-sectional study, Espírito Santo/Brazil

Introdução: o Brasil demorou a implementar uma política de testagem ampliada para COVID-19 no qual pode ter afetado o acesso da população mais vulnerável aos serviços de testagem. Objetivo: analisar os fatores associados à realização de testes moleculares para o diagnóstico da COVID-19. Método: estudo transversal de dados secundários do painel COVID-19 do estado do Espírito Santo. Foram incluídas fichas de notificação de suspeita de COVID-19 entre 11 de setembro de 2020 a 02 de março de 2021. Empregou-se regressão logística hierárquica para estimativa de razão de chances (odds ratio, OR) com intervalo de confiança de 95% (IC95%). Resultados: Foram incluídos no estudo 419.771 fichas de notificação. A prevalência da realização do teste molecular para COVID-19 foi 81,1 % (IC95% 81,0%;81,2%). Idosos (OR= 2,70 – IC95% 2,56-2,85), profissional da saúde (OR=1,43 – IC95% 1,36-1,50), doença cardiovascular crônica (OR=1,13 – IC95% 1,09-1,17), diabetes mellitus (OR=1,07 – IC95% 1,01-1,14) e hospitalização (OR=5,95 – IC95% 4,53;7,82) apresentaram maior chance de ter realizado o teste molecular. Sexo masculino (OR=0,96 – IC95% 0,94-0,98), cor da pele preta (OR= 0,75 – IC95% 0,73-0,78), cor da pele amarela (OR=0,74 – IC95% 0,71-0,77), residir na região norte de saúde (OR=0,37 – IC95% 0,36-0,39) e a população em situação de rua (OR=0,76 – IC95% 0,67-0,85) apresentaram a menor chance de ter realizado o teste molecular. Conclusão: Fatores sociais, econômicos e o risco de agravamento da doença foram associados a realização do teste molecular para COVID-19 no estado do Espírito Santo. É necessário ações que garantam o acesso da população mais vulnerável ao teste molecular.Alternate : Backgroung: Brazil was slow to implement an expanded testing policy for COVID-19, which may have affected the most vulnerable population's access to testing services. Objective: to evaluate the factors associated with performing the molecular test for COVID-19. Methods: cross-sectional study of secondary data from the COVID-19 panel in the state of Espírito Santo. COVID-19 suspicion notification forms were included between September 11, 2020 and March 2, 2021. Hierarchical logistic regression was used to estimate the odds ratio (OR) with 95% confidence interval (CI95%). Results: 419,771 notification forms were analyzed. The prevalence of performing the molecular teste for COVID-19 was 81.1% (CI95% 81.0-81.2). Elderly (OR= 2.70 – CI95% 2.56-2.85), health professional (OR=1 .43 – CI95% 1.36-1.50), chronic cardiovascular disease (OR=1.13 – CI95% 1.09-1.17), diabetes mellitus (OR=1.07 – CI95% 1.01- 1.14) and hospitalization (OR=5.95 – CI95% 4.53;7.82) were more likely to have undergone the molecular test. Male sex (OR=0.96 – CI95% 0.94-0.98), black skin color (OR=0.75 – CI95% 0.73-0.78), yellow skin color (OR=0.74 – CI95% 0.71-0.77), residing in the northern health region (OR=0.37 – CI95% 0.36-0.39) and the homeless population (OR=0.76 – CI95% 0.67-0.85) had the lowest chance of having undergone the molecular test. Conclusion: Social, economic, contextual factors and the risk of aggravation of the disease were associated with carrying out the molecular test for COVID-19 in the state of Espírito Santo. Actions are needed to guarantee the access of the most vulnerable population to molecular testing.

One case of novel coronavirus pneumonia complicated with acute appendicitis in children.

Emergent laparoscopic appendectomy was performed for a boy of occult novel coronavirus pneumonia with a presenting symptom of acute appendicitis at Wuhan Children's Hospital. Postoperative lung computed tomography (CT) indicated a round dense shadow with slightly ground-glass-like margins in the dorsal segment of right lower lung. Pharyngeal swab nucleic acid test was positive for 2019-nCoV and thus a definite diagnosis of COVID-19 was made. Prior to the onset, he had close contacts with his grandmother with a definite diagnosis of COVID -19. It proved that intra-family transmission was an important transmission route for pediatric 2019-nCoV infection. In this case, the respiratory symptoms of COVID-19 were not obvious during an early stage. The major symptoms were nausea, vomiting and abdominal pain. For individuals coming from the epidemic area, with a history of exposure and developing acute surgical conditions, preoperative pulmonary CT scan is necessary for screening COVID-19.Copyright © 2020 by the Chinese Medical Association.

Integrated smart analytics of nucleic acid amplification tests via paper microfluidics and deep learning in cloud computing

Pandemics such as COVID-19 have exposed global inequalities in essential health care. Here, we proposed a novel analytics of nucleic acid amplification tests (NAATs) by combining paper microfluidics with deep learning and cloud computing. Real-time amplifications of synthesized SARS-CoV-2 RNA templates were performed in paper devices. Information pertained to on-chip reactions in time-series format were transmitted to cloud server on which deep learning (DL) models were preloaded for data analysis. DL models enable prediction of NAAT results using partly gathered real-time fluorescence data. Using information provided by the G-channel, accurate prediction can be made as early as 9 min, a 78% reduction from the conventional 40 min mark. Reaction dynamics hidden in amplification curves were effectively leveraged. Positive and negative samples can be unbiasedly and automatically distinguished. Practical utility of the approach was validated by cross-platform study using clinical datasets. Predicted clinical accuracy, sensitivity and specificity were 98.6%, 97.6% and 99.1%. Not only the approach reduced the need for the use of bulky apparatus, but also provided intelligent, distributable and robotic insights for NAAT analysis. It set a novel paradigm for analyzing NAATs, and can be combined with the most cutting-edge technologies in fields of biosensor, artificial intelligence and cloud computing to facilitate fundamental and clinical research.Copyright © 2023 Elsevier Ltd

National consensus on perioperative managements for congenital heart disease in children infected with Corona Virus Disease 2019.

As a severe acute respiratory infectious disease, novel coronavirus pneumonia (COVID -19) appeared in Wuhan China in December 2019. The pathogen of COVID -19 is identified to be 2019 novel coronavirus (2019-nCoV) and children are susceptible to 2019-nCoV. Spreading mostly through respiratory tract and close contacts, the virus invades heart, lung, kidney and gastrointestinal tract. Since the clinical symptoms of viral infection are similar to those of congenital heart disease (CHD), the therapeutic complexity of CHD becomes more troublesome. COVID -19 is definitely diagnosed by nucleic acid detection and CT imaging. With the in-depth understandings and the accumulation of experiences of diagnosing and treating COVID -19 and coping with the gravest challenges of prevention and management, Section of Cardiothoracic Surgery of Branch of Pediatric Surgery of Chinese Medical Association has convened domestic experts and specialists from such an epidemic areas as Wuhan to discuss and formulate the Expert Consensus of Perioperative Management of CHD Children Infected by 2019-nCoV. COVID -19, 2019-nCoV infection, surgical options, protective measures and essential therapeutic points for COVID -19 were summarized for CHD children.Copyright © 2020 by the Chinese Medical Association.

False-positive Xpert® Xpress SARS-CoV-2 assay in an emergency room and trauma center: A retrospective chart review study.

OBJECTIVES: To review reports false-positive Xpert results in an emergency room and trauma center. METHODS: Patients' data with false-positive Xpert results from November 2020 to February 2022 at Pusan National University Hospital, Busan, Republic of Korea, were extracted from the electronic medical records. RESULTS: The positive predictive value of Xpert was 40%. Of the 12 patients with false-positive results, 5 (41.7%) were re-positives (such as, patients recovered from coronavirus disease-19 [COVID-19]), and 4 (33.3%) had head or facial trauma. Two out of 4 head or facial trauma cases had documented sample contamination with blood. CONCLUSION: We found a high incidence of false-positive Xpert results among patients who recovered from COVID-19 and those with head or facial injury. Careful history taking for COVID-19 and physical examination of the sample collection site is essential before Xpert analysis.

Coronavirus Disease 2019 in Pediatric Emergency Room: The Dilemma of Cycle Threshold Value

Objective The havoc caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic could not have been predicted, with children being affected worldwide. Testing for SARS-CoV-2 infection helped to define the interventions against the spread of the disease. A polymerase chain reaction (PCR) test has been the mainstay of diagnostic testing. Cycle threshold (Ct) is a semiquantitative value that indicates approximately how much viral genetic material was in the sample. The aim of this study was to evaluate the impact of Ct values among children with SARS-CoV-2 infection. Methods Between May 3, 2020 and August 3, 2020, clinical laboratory input and the data of patients with positive SARS-CoV-2 PCR tests were retrospectively studied. Results There was no statistical significance between Ct values and the patient's status, symptoms other than fever, or other laboratory findings. However, the Ct value of patients who had symptoms at the time of admission to the hospital was significantly lower. Conclusion In this study, symptomatic patients had lower Ct than asymptomatic patients that reflected higher viral loads. In evidence-based medicine applications, it might be useful to correlate the clinical history with laboratory test results. Even symptomatic patients with high Ct value coinfections, or an alternative acute infection, should be considered. © 2022. Thieme. All rights reserved.

An early return-to-work program for COVID-19 close contacts in healthcare during the Omicron wave in Japan

During the coronavirus disease 2019 (COVID-19) pandemic, maintaining adequate staffing in healthcare facilities is important to provide a safe work environment for healthcare workers (HCWs). Japan's early return-to-work (RTW) program may be a rational strategy at a time when there is an increased demand for the services of HCWs. We assessed whether the early RTW program for HCWs who have been in close contact with a COVID-19 case in our hospital was justified. Close contacts were identified according to the guidance document of the World Health Organization. HCWs who met all of the following conditions were eligible to apply to an early RTW program: (1) difficult to replace with another HCW, (2) received the third dose of a COVID-19 mRNA vaccine, (3) a negative COVID-19 antigen test before each work shift, and (4) consent from relevant HCWs and their managers to participate in the program. Between January and March 2022, 256 HCWs were identified as close contacts (median age, 35 years;192 female). Thirty-seven (14%) secondary attack cases of COVID-19 were detected. Among 141 HCWs (55%) who applied to the early RTW program, nurses and physicians comprised about three-quarters of participants, with a higher participation rate by physicians (78%) than nurses (59%). Eighteen HCWs tested positive for COVID-19 by the sixth day after starting the early RTW program. No COVID-19 infection clusters were reported during the observation period. These findings suggest that the early RTW program for COVID-19 close contacts was a reasonable strategy for HCWs during the Omicron wave. © 2022 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases

SARS-CoV-2 detection by RT-qPCR using saliva in outpatients tested for COVID-19

Background: The COVID-19 pandemic has affected millions of people around the world. Part of control strategies is testing a large proportion of the population to identify and isolate the infected sub-jects. Aim(s): To evaluate the SARS-CoV-2 detection by the performance of a reverse transcription and quantitative polymerase chain reaction (RT-qPCR) against SARS-CoV-2, using saliva as a matrix compared to a nasopharyngeal swab (NPS) to simplify obtaining a diagnostic sample. Method(s): Adults in outpatient care were recruited, 95% of them symptomatic. We studied 530 paired saliva and NPS samples by SARS-CoV-2 RT-qPCR. Result(s): Fifty-nine individuals tested positive in NPS and 54 in saliva samples. Sensitivity for saliva sample was 91%, specificity 100%, positive predictive value (PPV) 100%, negative predictive value (NPV) 98%. The Kappa index was 0.95 and LR-0.08. On average, the cycle threshold (CT) of saliva was 3.99 points higher than those of NPS (p < 0.0001) showing that viral load (VL) is lower in saliva than in NPS. Viral load in both decreased over the time after onset of symptoms. Saliva sampling was preferred by subjects instead of NPS. Conclusion(s): This study demonstrates that SARS-CoV-2 RT-qPCR using saliva, even with lower VL, is suitable for the diagnosis of COVID-19 in outpatient adults, especially at early stage of symptoms. Copyright © 2022, Sociedad Chilena de Infectologia. All rights reserved.

Specificity of 2019-nCoV nucleic acid detection kit (fluorescence PCR)

Objective To evaluate the specificity of three consecutive batches of 2019-nCoV nucleic acid detection kit (fluorescence PCR) manufactured by Shanghai GeneoDx Biotech Co., LTD. Methods A total of 55 common respiratory pathogens, including endemic human coronaviruses (HKU1, OC43, NL63 and 229E), severe acute respiratory syndrome conronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS), seasonal influenza virus, rhinovirus, adenovirus, Klebsiella pneumonia and Mycobacterium tuberculosis, were grouped and used for verification of cross reactivity of the detection kit. According to the requirements in the Key Points of Technical Review for Registration of 2019 New Coronavirus Nucleic Acid Detection Reagents issued by Center for Medical Device Evaluation, National Medical Products Administration (NMPA), human mucoprotein, human blood, phenylephrine, oxymetazoline, sodium chloride (including those as preservatives) and other 29 interfering substances were selected to verify the anti-interference substances of this kit. Results In the verification for cross reactivity, the test results of mixed positive samples by the three consecutive batches of kit were positive, while those of negative samples were negative, indicating a coincidence rate of accuracy of 100%. The cross-reactive substances showed no effect on the test result by the kit. All the test results of positive and borderline positive samples were positive, while those of negative samples were negative, indicating a coincidence rate of accuracy of 100%. All the 29 kinds of endogenous / exogenous interfering substances showed no influence on the test results by this kit. Conclusion Hie new coronavirus 2019-nCoV nucleic acid detection kit (fluorescence PCR method) manufactured by Shanghai GeneoDx Biotech Co., LTD. showed no cross-reactivity with 55 common respiratory pathogens, while showed anti-interference properties against endogenous and exogenous interfering substances such as host tissue, common respiratory pathogen and common drugs for respiratory diseases in clinic. The specificity test result of the kit met the requirements for registration of 2019 new coronavirus nucleic acid detection reagents. The test results of three consecutive batches of kits were highly stable. Copyright © 2021 Changchun Institute of Biological Products. All rights reserved.

Modeling the effects of vaccination, nucleic acid testing, and face mask wearing interventions against COVID-19 in large sports events.

The transmission of SARS-CoV-2 leads to devastating COVID-19 infections around the world, which has affected both human health and the development of industries dependent on social gatherings. Sports events are one of the subgroups facing great challenges. The uncertainty of COVID-19 transmission in large-scale sports events is a great barrier to decision-making with regard to reopening auditoriums. Policymakers and health experts are trying to figure out better policies to balance audience experiences and COVID-19 infection control. In this study, we employed the generalized SEIR model in conjunction with the Wells-Riley model to estimate the effects of vaccination, nucleic acid testing, and face mask wearing on audience infection control during the 2021 Chinese Football Association Super League from 20 April to 5 August. The generalized SEIR modeling showed that if the general population were vaccinated by inactive vaccines at an efficiency of 0.78, the total number of infectious people during this time period would decrease from 43,455 to 6,417. We assumed that the general population had the same odds ratio of entering the sports stadiums and becoming the audience. Their infection probabilities in the stadium were further estimated by the Wells-Riley model. The results showed that if all of the 30,000 seats in the stadium were filled by the audience, 371 audience members would have become infected during the 116 football games in the 2021 season. The independent use of vaccination and nucleic acid testing would have decreased this number to 79 and 118, respectively. The combined use of nucleic acid testing and vaccination or face mask wearing would have decreased this number to 14 and 34, respectively. The combined use of all three strategies could have further decreased this number to 0. According to the modeling results, policymakers can consider the combined use of vaccination, nucleic acid testing, and face mask wearing to protect audiences from infection when holding sports events, which could create a balance between audience experiences and COVID-19 infection control.