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1.
PLoS One ; 16(12): e0261956, 2021.
Article in English | MEDLINE | ID: covidwho-1597233

ABSTRACT

A direct, real-time reverse transcriptase PCR test on pooled saliva was validated in 2,786 participants against oropharyngeal swabs. Among asymptomatic/pre-symptomatic participants, the test was found to be in 99.21% agreement and 45% more sensitive than contemporaneous oropharyngeal swabs. The test was then used for surveillance testing on 44,242 saliva samples from asymptomatic participants. Those whose saliva showed evidence of SARS-CoV-2 within 50 cycles of amplification were referred for confirmatory testing, with 87% of those tested by nasal swab within 72 hours receiving a positive diagnostic result on Abbott ID NOW or real-time PCR platforms. Median Ct values on the saliva PCR for those with a positive and negative confirmatory tests was 30.67 and 35.92 respectively, however, binary logistic regression analysis of the saliva Ct values indicates that Ct thresholds as high as 47 may be useful in a surveillance setting. Overall, data indicate that direct RT-PCR testing of pooled saliva samples is an effective method of SARS-CoV-2 surveillance.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Carrier State/diagnosis , Diagnostic Tests, Routine/methods , Real-Time Polymerase Chain Reaction/methods , Saliva/virology , Humans , Sensitivity and Specificity
2.
PLoS One ; 16(12): e0262159, 2021.
Article in English | MEDLINE | ID: covidwho-1596328

ABSTRACT

INTRODUCTION: GENECUBE® is a rapid molecular identification system, and previous studies demonstrated that GENECUBE® HQ SARS-CoV-2 showed excellent analytical performance for the detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) with nasopharyngeal samples. However, other respiratory samples have not been evaluated. METHODS: This prospective comparison between GENECUBE® HQ SARS-CoV-2 and reference real-time reverse transcriptase polymerase chain reaction (RT-PCR) was performed for the detection of SARS-CoV-2 using anterior nasal samples and saliva samples. Additionally, we evaluated a new rapid examination protocol using GENECUBE® HQ SARS-CoV-2 for the detection of SARS-CoV-2 with saliva samples. For the rapid protocol, in the preparation of saliva samples, purification and extraction processes were adjusted, and the total process time was shortened to approximately 35 minutes. RESULTS: For 359 anterior nasal samples, the total-, positive-, and negative concordance of the two assays was 99.7% (358/359), 98.1% (51/52), and 100% (307/307), respectively. For saliva samples, the total-, positive-, and negative concordance of the two assays was 99.6% (239/240), 100% (56/56), and 99.5% (183/184), respectively. With the new protocol, total-, positive-, and negative concordance of the two assays was 98.8% (237/240), 100% (56/56), and 98.4% (181/184), respectively. In all discordance cases, SARS-CoV-2 was detected by additional molecular examinations. CONCLUSION: GENECUBE® HQ SARS-CoV-2 provided high analytical performance for the detection of SARS-CoV-2 in anterior nasal samples and saliva samples.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Diagnostic Tests, Routine/methods , Nasopharynx/virology , Pandemics , Saliva/virology , Humans , Prospective Studies
3.
Sci Rep ; 11(1): 24234, 2021 12 20.
Article in English | MEDLINE | ID: covidwho-1585791

ABSTRACT

The main strategy for response and control of COVID-19 demands the use of rapid, accurate diagnostic tests aimed at the first point of health care. During the emergency, an increase in asymptomatic and symptomatic cases results in a great demand for molecular tests, which is promoting the development and application of rapid diagnostic technologies. In this study, we describe the development and evaluation of RT-LAMP to detect SARS-CoV-2 based on three genes (ORF1ab, M and N genes) in monoplex and triplex format. RT-LAMP assays were compared with the gold standard method RT-qPCR. The triplex format (RdRp, M and N genes) allowed obtaining comparable results with de RT-qPCR (RdRp and E genes), presented a sensitivity of 98.9% and a specificity of 97.9%, opening the opportunity to apply this method to detect SARS-CoV-2 at primary health-care centers.


Subject(s)
Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , RNA, Viral/metabolism , SARS-CoV-2/isolation & purification , COVID-19/diagnosis , COVID-19/virology , COVID-19 Nucleic Acid Testing/methods , Coronavirus RNA-Dependent RNA Polymerase/genetics , Humans , Limit of Detection , Nasopharynx/virology , Nucleocapsid Proteins/genetics , Point-of-Care Systems , RNA, Viral/genetics , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , Viral Matrix Proteins/genetics
4.
PLoS One ; 16(12): e0260884, 2021.
Article in English | MEDLINE | ID: covidwho-1581769

ABSTRACT

OBJECTIVES: To exploit the features of digital PCR for implementing SARS-CoV-2 observational studies by reliably including the viral load factor expressed as copies/µL. METHODS: A small cohort of 51 Covid-19 positive samples was assessed by both RT-qPCR and digital PCR assays. A linear regression model was built using a training subset, and its accuracy was assessed in the remaining evaluation subset. The model was then used to convert the stored cycle threshold values of a large dataset of 6208 diagnostic samples into copies/µL of SARS-CoV-2. The calculated viral load was used for a single cohort retrospective study. Finally, the cohort was randomly divided into a training set (n = 3095) and an evaluation set (n = 3113) to establish a logistic regression model for predicting case-fatality and to assess its accuracy. RESULTS: The model for converting the Ct values into copies/µL was suitably accurate. The calculated viral load over time in the cohort of Covid-19 positive samples showed very low viral loads during the summer inter-epidemic waves in Italy. The calculated viral load along with gender and age allowed building a predictive model of case-fatality probability which showed high specificity (99.0%) and low sensitivity (21.7%) at the optimal threshold which varied by modifying the threshold (i.e. 75% sensitivity and 83.7% specificity). Alternative models including categorised cVL or raw cycle thresholds obtained by the same diagnostic method also gave the same performance. CONCLUSION: The modelling of the cycle threshold values using digital PCR had the potential of fostering studies addressing issues regarding Sars-CoV-2; furthermore, it may allow setting up predictive tools capable of early identifying those patients at high risk of case-fatality already at diagnosis, irrespective of the diagnostic RT-qPCR platform in use. Depending upon the epidemiological situation, public health authority policies/aims, the resources available and the thresholds used, adequate sensitivity could be achieved with acceptable low specificity.


Subject(s)
COVID-19/virology , Real-Time Polymerase Chain Reaction/methods , SARS-CoV-2/genetics , Viral Load/methods , Adolescent , Adult , Aged , COVID-19/mortality , COVID-19 Nucleic Acid Testing/methods , Child , Child, Preschool , Female , Genome, Viral , Humans , Logistic Models , Male , Middle Aged , Retrospective Studies , Sensitivity and Specificity , Young Adult
5.
PLoS One ; 16(12): e0261230, 2021.
Article in English | MEDLINE | ID: covidwho-1581758

ABSTRACT

The systematic screening of asymptomatic and pre-symptomatic individuals is a powerful tool for controlling community transmission of infectious disease on college campuses. Faced with a paucity of testing in the beginning of the COVID-19 pandemic, many universities developed molecular diagnostic laboratories focused on SARS-CoV-2 diagnostic testing on campus and in their broader communities. We established the UC Santa Cruz Molecular Diagnostic Lab in early April 2020 and began testing clinical samples just five weeks later. Using a clinically-validated laboratory developed test (LDT) that avoided supply chain constraints, an automated sample pooling and processing workflow, and a custom laboratory information management system (LIMS), we expanded testing from a handful of clinical samples per day to thousands per day with the testing capacity to screen our entire campus population twice per week. In this report we describe the technical, logistical, and regulatory processes that enabled our pop-up lab to scale testing and reporting capacity to thousands of tests per day.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Clinical Laboratory Techniques/methods , Diagnostic Tests, Routine/methods , Mass Screening/methods , Pandemics/prevention & control , Diagnostic Screening Programs , Humans , Universities
6.
Rev Med Virol ; 31(6): e2215, 2021 11.
Article in English | MEDLINE | ID: covidwho-1573992

ABSTRACT

The novel coronavirus disease-2019 (Covid-19) public health emergency has caused enormous loss around the world. This pandemic is a concrete example of the existing gap between availability of advanced diagnostics and current need for cost-effective methodology. The advent of the loop-mediated isothermal amplification (LAMP) assay provided an innovative tool for establishing a rapid diagnostic technique based on the molecular amplification of pathogen RNA or DNA. In this review, we explore the applications, diagnostic effectiveness of LAMP test for molecular diagnosis and surveillance of severe acute respiratory syndrome coronavirus 2. Our results show that LAMP can be considered as an effective point-of-care test for the diagnosis of Covid-19 in endemic areas, especially for low- and middle-income countries.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , Point-of-Care Testing/organization & administration , SARS-CoV-2/genetics , Bibliometrics , COVID-19/epidemiology , COVID-19/pathology , COVID-19/virology , COVID-19 Nucleic Acid Testing/economics , COVID-19 Nucleic Acid Testing/instrumentation , Humans , Molecular Diagnostic Techniques/economics , Molecular Diagnostic Techniques/instrumentation , Nucleic Acid Amplification Techniques/economics , Nucleic Acid Amplification Techniques/instrumentation , Point-of-Care Testing/economics , RNA, Viral/genetics , SARS-CoV-2/pathogenicity , Sensitivity and Specificity
7.
ACS Appl Mater Interfaces ; 14(1): 138-149, 2022 Jan 12.
Article in English | MEDLINE | ID: covidwho-1574636

ABSTRACT

Highly sensitive, reliable assays with strong multiplexing capability for detecting nucleic acid targets are significantly important for diagnosing various diseases, particularly severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The nanomaterial-based assay platforms suffer from several critical issues such as non-specific binding and highly false-positive results. In this paper, to overcome such limitations, we reported sensitive and remarkably reproducible magnetic microparticles (MMPs) and a surface-enhanced Raman scattering (SERS)-based assay using stable silver nanoparticle clusters for detecting viral nucleic acids. The MMP-SERS-based assay exhibited a sensitivity of 1.0 fM, which is superior to the MMP-fluorescence-based assay. In addition, in the presence of anisotropic Ag nanostructures (nanostars and triangular nanoplates), the assay exhibited greatly enhanced sensitivity (10 aM) and excellent signal reproducibility. This assay platform intrinsically eliminated the non-specific binding that occurs in the target detection step, and the controlled formation of stable silver nanoparticle clusters in solution enabled the remarkable reproducibility of the results. These findings indicate that this assay can be employed for future practical bioanalytical applications.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Magnetite Nanoparticles/chemistry , COVID-19/virology , Coronavirus Envelope Proteins/genetics , Humans , Limit of Detection , Metal Nanoparticles/chemistry , RNA, Viral/analysis , RNA, Viral/chemistry , RNA-Dependent RNA Polymerase/genetics , Reproducibility of Results , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Silver/chemistry , Spectrum Analysis, Raman
8.
Aging (Albany NY) ; 13(23): 24931-24942, 2021 12 12.
Article in English | MEDLINE | ID: covidwho-1573020

ABSTRACT

Since the Coronavirus 19 (COVID-19) pandemic, several SARS-CoV-2 variants of concern (SARS-CoV-2 VOC) have been reported. The B.1.1.7 variant has been associated with increased mortality and transmission risk. Furthermore, cluster and possible co-infection cases could occur in the next influenza season or COVID-19 pandemic wave, warranting efficient diagnosis and treatment decision making. Here, we aimed to detect SARS-CoV-2 and other common respiratory viruses using multiplex RT-PCR developed on the LabTurbo AIO 48 open system. We performed a multicenter study to evaluate the performance and analytical sensitivity of the LabTurbo AIO 48 system for SARS-CoV-2, influenza A/B, and respiratory syncytial virus (RSV) using 652 nasopharyngeal swab clinical samples from patients. The LabTurbo AIO 48 system demonstrated a sensitivity of 9.4 copies/per PCR for N2 of SARS-CoV-2; 24 copies/per PCR for M of influenza A and B; and 24 copies/per PCR for N of RSV. The assay presented consistent performance in the multicenter study. The multiplex RT-PCR applied on the LabTurbo AIO 48 open platform provided highly sensitive, robust, and accurate results and enabled high-throughput detection of B.1.1.7, influenza A/B, and RSV with short turnaround times. Therefore, this automated molecular diagnostic assay could enable streamlined testing if COVID-19 becomes a seasonal disease.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Influenza, Human/diagnosis , Multiplex Polymerase Chain Reaction/methods , Respiratory Syncytial Virus Infections/diagnosis , Adult , Aged , COVID-19/virology , Female , Humans , Influenza A virus/genetics , Influenza A virus/isolation & purification , Influenza, Human/virology , Influenzavirus B/genetics , Influenzavirus B/isolation & purification , Male , Middle Aged , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Viruses/genetics , Respiratory Syncytial Viruses/isolation & purification , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Sensitivity and Specificity , Young Adult
9.
Viruses ; 13(12)2021 12 02.
Article in English | MEDLINE | ID: covidwho-1554951

ABSTRACT

During COVID-19 pandemics, the availability of testing has often been a limiting factor during patient admissions into the hospital. To circumvent this problem, we adapted an existing diagnostic assay, Seegene Allplex SARS-CoV-2, into a point-of-care-style direct qPCR (POC dqPCR) assay and implemented it in the Emergency Department of Clinical Hospital Center Rijeka, Croatia. In a 4-month analysis, we tested over 10,000 patients and demonstrated that POC-dqPCR is robust and reliable and can be successfully implemented in emergency departments and similar near-patient settings and can be performed by medical personnel with little prior experience in qPCR.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Emergency Service, Hospital , Point-of-Care Testing , SARS-CoV-2/isolation & purification , COVID-19/epidemiology , Croatia/epidemiology , Humans , RNA, Viral/genetics , Reproducibility of Results , SARS-CoV-2/genetics , Sensitivity and Specificity
10.
Biomed Pharmacother ; 144: 112353, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1544808

ABSTRACT

Almost 80% of people confronting COVID-19 recover from COVID-19 disease without any particular treatments. They experience heterogeneous symptoms; a wide range of respiratory symptoms, cough, dyspnea, fever, and viral pneumonia. However, some others need urgent intervention and special treatment to get rid of this widespread disease. So far, there isn't any unique drug for the potential treatment of COVID 19. However, some available therapeutic drugs used for other diseases seem beneficial for the COVID-19 treatment. On the other hand, there is a robust global concern for developing an efficient COVID-19 vaccine to control the COVID-19 pandemic sustainably. According to the WHO report, since 8 October 2021, 320 vaccines have been in progress. 194 vaccines are in the pre-clinical development stage that 126 of them are in clinical progression. Here, in this paper, we have comprehensively reviewed the most recent and updated information about coronavirus and its mutations, all the potential therapeutic approaches for treating COVID-19, developed diagnostic systems for COVID- 19 and the available COVID-19 vaccines and their mechanism of action.


Subject(s)
COVID-19 Vaccines/therapeutic use , COVID-19/drug therapy , COVID-19/prevention & control , Biosensing Techniques/methods , COVID-19/diagnosis , COVID-19 Nucleic Acid Testing/methods , Dexamethasone/therapeutic use , Glucocorticoids/therapeutic use , Humans , Molecular Diagnostic Techniques/methods , Mutation , Nucleic Acid Amplification Techniques/methods , Point-of-Care Testing , SARS-CoV-2/genetics , World Health Organization
11.
J Med Virol ; 93(12): 6837-6840, 2021 12.
Article in English | MEDLINE | ID: covidwho-1544319

ABSTRACT

BACKGROUND: Gargle samples have been proposed as a noninvasive method for detection of SARS-CoV-2 RNA. The clinical performance of gargle specimens diluted in Cobas® PCR Media and in Cobas® Omni Lysis Reagent was compared to oropharyngeal/nasopharyngeal swab (ONPS) for the detection of SARS-CoV-2 RNA. STUDY DESIGN: Participants were recruited prospectively in two COVID-19 screening clinics. In addition to the ONPS, participants gargled with 5 ml of natural spring water split in the laboratory as follows: 1 ml was added to 4.3 ml of polymerase chain reaction (PCR) media and 400 µl was added to 200 µl of lysis buffer. Testing was performed with the Cobas® SARS-CoV-2 test on the Cobas® 6800 or 8800 platforms. RESULTS: Overall, 134/647 (20.7%) participants were considered infected because the ONPS or at least one gargle test was positive. ONPS had, respectively, a sensitivity of 96.3% (95% confidence interval [CI]: 91.3-98.5); both gargle processing methods were slightly less but equally sensitive (90.3% [95% CI: 83.9-94.3]). When ONPS and gargle specimens were both positive, the mean cycle threshold (Ct ) was significantly higher for gargles, suggesting lower viral loads. CONCLUSION: Gargle specimens directly added in PCR Media provide a similar clinical sensitivity to chemical lysis, both having a slightly, not significantly, lower sensitivity to ONPS.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , COVID-19/virology , Nasopharynx/virology , Oropharynx/virology , SARS-CoV-2/genetics , Diagnostic Tests, Routine/methods , Humans , Mass Screening/methods , Prospective Studies , RNA, Viral/genetics , Saliva/virology , Specimen Handling/methods , Viral Load/genetics
12.
J Med Virol ; 93(12): 6803-6807, 2021 12.
Article in English | MEDLINE | ID: covidwho-1544308

ABSTRACT

We evaluated the Panbio™ COVID-19 Ag Rapid Test Device as a point-of-care diagnostic tool for COVID-19 in 357 patients at a pediatric emergency department. Thirty-four patients tested positive by reverse transcription polymerase chain reaction, of which 24 were positive by the antigen assay. The sensitivity and specificity of the assay were 70.5% and 100%, respectively.


Subject(s)
Antigens, Viral/immunology , COVID-19/diagnosis , COVID-19/immunology , SARS-CoV-2/immunology , COVID-19 Nucleic Acid Testing/methods , COVID-19 Serological Testing/methods , Child , Child, Preschool , Emergency Service, Hospital , Female , Humans , Immunologic Tests/methods , Infant , Male , Nasopharynx/immunology , Nasopharynx/virology , Point-of-Care Testing , Prospective Studies , Sensitivity and Specificity
13.
Viruses ; 13(12)2021 11 29.
Article in English | MEDLINE | ID: covidwho-1542799

ABSTRACT

As SARS-CoV-2 continues to spread among human populations, genetic changes occur and accumulate in the circulating virus. Some of these genetic changes have caused amino acid mutations, including deletions, which may have a potential impact on critical SARS-CoV-2 countermeasures, including vaccines, therapeutics, and diagnostics. Considerable efforts have been made to categorize the amino acid mutations of the angiotensin-converting enzyme 2 (ACE2) receptor binding domain (RBD) of the spike (S) protein, along with certain mutations in other regions within the S protein as specific variants, in an attempt to study the relationship between these mutations and the biological behavior of the virus. However, the currently used whole genome sequencing surveillance technologies can test only a small fraction of the positive specimens with high viral loads and often generate uncertainties in nucleic acid sequencing that needs additional verification for precision determination of mutations. This article introduces a generic protocol to routinely sequence a 437-bp nested RT-PCR cDNA amplicon of the ACE2 RBD and a 490-bp nested RT-PCR cDNA amplicon of the N-terminal domain (NTD) of the S gene for detection of the amino acid mutations needed for accurate determination of all variants of concern and variants of interest according to the definitions published by the U.S. Centers for Disease Control and Prevention. This protocol was able to amplify both nucleic acid targets into cDNA amplicons to be used as templates for Sanger sequencing on all 16 clinical specimens that were positive for SARS-CoV-2.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , Diagnostic Tests, Routine/methods , SARS-CoV-2/genetics , Binding Sites/genetics , COVID-19/diagnosis , COVID-19/virology , Humans , Mutation , Protein Domains/genetics , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2/isolation & purification , Sequence Analysis, DNA , Spike Glycoprotein, Coronavirus/genetics
14.
J Korean Med Sci ; 36(44): e301, 2021 Nov 15.
Article in English | MEDLINE | ID: covidwho-1526760

ABSTRACT

We used serial rectal swabs to investigate the amount and duration of virus secretion through the gastrointestinal tract and assessed the association between fecal shedding and gastrointestinal symptoms and to clarify the clinical usefulness testing rectal swabs. We enrolled ten adult patients hospitalized with symptomatic coronavirus disease 2019 (COVID-19). Respiratory and stool specimens were collected by physicians. The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was confirmed using real-time reverse-transcription polymerase chain reaction. All ten patients had respiratory symptoms, six had diarrhea, and seven were positive for SARS-CoV-2 on rectal swabs. The viral loads in the respiratory specimens was higher than those in the rectal specimens, and no rectal specimens were positive after the respiratory specimens became negative. There was no association between gastrointestinal symptoms, pneumonia, severity, and rectal viral load. Rectal swabs may play a role in detecting SARS-CoV-2 in individuals with suspected COVID-19, regardless of gastrointestinal symptoms.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/virology , Rectum/virology , SARS-CoV-2/isolation & purification , Virus Shedding , Adolescent , Adult , Aged , Aged, 80 and over , COVID-19/complications , COVID-19/transmission , Diarrhea/etiology , Diarrhea/virology , Feces/virology , Female , Humans , Male , Middle Aged , Nasopharynx/virology , Prospective Studies , Real-Time Polymerase Chain Reaction , Severity of Illness Index , Time Factors , Viral Load
15.
Transplant Proc ; 53(4): 1126-1131, 2021 May.
Article in English | MEDLINE | ID: covidwho-1525970

ABSTRACT

Coronavirus disease 2019 drastically impacted solid organ transplantation. Lacking scientific evidence, a very stringent but safer policy was imposed on liver transplantation (LT) early in the pandemic. Restrictive transplant guidelines must be reevaluated and adjusted as data become available. Before LT, the prevailing policy requires a negative severe acute respiratory syndrome coronavirus 2 real-time polymerase chain reaction (RT-PCR) of donors and recipients. Unfortunately, prolonged viral RNA shedding frequently hinders transplantation. Recent data reveal that positive test results for viral genome are frequently due to noninfectious and prolonged convalescent shedding of viral genome. Moreover, studies demonstrated that the cycle threshold of quantitative RT-PCR could be leveraged to inform clinical transplant decision-making. We present an evidence-adjusted and significantly less restrictive policy for LT, where risk tolerance is tiered to recipient acuity. In addition, we delineate the pretransplant clinical decision-making, intra- and postoperative management, and early outcome of 2 recipients of a liver graft performed while their RT-PCR of airway swabs remained positive. Convalescent positive RT-PCR results are common in the transplant arena, and the proposed policy permits reasonably safe LT in many circumstances.


Subject(s)
COVID-19 Nucleic Acid Testing/standards , COVID-19/diagnosis , Health Policy , Liver Transplantation/legislation & jurisprudence , SARS-CoV-2/genetics , COVID-19/prevention & control , COVID-19 Nucleic Acid Testing/methods , Female , Humans , Infection Control/legislation & jurisprudence , Infection Control/methods , Liver Transplantation/adverse effects , Male , Middle Aged , Postoperative Complications/prevention & control , Postoperative Complications/virology , Preoperative Care/legislation & jurisprudence , Preoperative Care/methods , Reference Values , Tissue Donors , Virus Shedding
16.
Bioanalysis ; 13(23): 1731-1741, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1518698

ABSTRACT

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.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , China , Humans , SARS-CoV-2
17.
Minerva Pediatr (Torino) ; 73(5): 460-466, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1513377

ABSTRACT

Inevitably, along with other healthcare specializations, pediatric surgery was affected by the Coronavirus disease-19 (COVID-19) pandemic. Children were reported to manifest mild to moderate symptoms and mortality was primarily observed in patients aged <1 year and having underlying comorbidities. Most of the cases were asymptomatic in children, hence, posing a challenge for pediatric surgery centers to take drastic measures to reduce the virus transmission. Telemedicine was introduced and out-patient consultations were conducted online as out-patient clinics were closed. Elective surgeries were postponed with delayed appointments while the healthcare sector was diverted towards tackling COVID-19. Case urgency was classified and triaged, leading to limited surgeries being performed only in COVID-19 negative patients following an extensive screening process. The screening process consisted of online history taking and RT-PCR tests. Newer practices such as mouth rinse, video laryngoscopy, and anesthesia were introduced to restrict patients from crying, coughing, and sneezing, as an attempt to avoid aerosolization of viral particles and safely conduct pediatric surgeries during the pandemic. Surgical trainees were also affected as the smaller number of surgeries conducted reduced the clinical experience available to medical enthusiasts. There is still room for advanced practices to be introduced in pediatric surgery and restore all kinds of surgeries to improve the quality of life of the patient.


Subject(s)
COVID-19/epidemiology , COVID-19/prevention & control , Pandemics , Pediatrics , Surgical Procedures, Operative , Asymptomatic Infections/epidemiology , COVID-19/diagnosis , COVID-19 Nucleic Acid Testing/methods , Child , Child, Preschool , Elective Surgical Procedures , General Surgery/education , Humans , Incidence , Infant , Patient Selection , Pediatrics/education , Preoperative Care/methods , Surgical Procedures, Operative/education , Telemedicine/organization & administration , Triage
18.
J Infect Dis ; 224(8): 1287-1293, 2021 10 28.
Article in English | MEDLINE | ID: covidwho-1505875

ABSTRACT

BACKGROUND: Previous studies demonstrated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA can be detected for weeks after infection. The significance of this finding is unclear and, in most patients, does not represent active infection. Detection of subgenomic RNA has been proposed to represent productive infection and may be a useful marker for monitoring infectivity. METHODS: We used quantitative reverse-transcription polymerase chain reaction (RT-qPCR) to quantify total and subgenomic nucleocapsid (sgN) and envelope (sgE) transcripts in 185 SARS-CoV-2-positive nasopharyngeal swab samples collected on hospital admission and to relate to symptom duration. RESULTS: We find that all transcripts decline at the same rate; however, sgE becomes undetectable before other transcripts. The median duration of symptoms to a negative test is 14 days for sgE and 25 days for sgN. There is a linear decline in subgenomic compared to total RNA, suggesting that subgenomic transcript copy number is dependent on copy number of total transcripts. The mean difference between total and sgN is 16-fold and the mean difference between total and sgE is 137-fold. This relationship is constant over duration of symptoms, allowing prediction of subgenomic copy number from total copy number. CONCLUSIONS: Subgenomic RNA may be no more useful in determining infectivity than a copy number threshold determined for total RNA.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , RNA, Viral/isolation & purification , SARS-CoV-2/isolation & purification , Viral Load , Aged , COVID-19/transmission , COVID-19/virology , COVID-19 Nucleic Acid Testing/standards , COVID-19 Nucleic Acid Testing/statistics & numerical data , Coronavirus Envelope Proteins/genetics , Coronavirus Nucleocapsid Proteins/genetics , Feasibility Studies , Female , Humans , Male , Middle Aged , Nasopharynx/pathology , Nasopharynx/virology , Phosphoproteins/genetics , Real-Time Polymerase Chain Reaction/statistics & numerical data , Reference Values , Retrospective Studies , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity
19.
Sci Rep ; 11(1): 21658, 2021 11 04.
Article in English | MEDLINE | ID: covidwho-1503936

ABSTRACT

More than one year since Coronavirus disease 2019 (COVID-19) pandemic outbreak, the gold standard technique for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection is still the RT-qPCR. This is a limitation to increase testing capacities, particularly at developing countries, as expensive reagents and equipment are required. We developed a two steps end point RT-PCR reaction with SARS-CoV-2 Nucleocapsid (N) gene and Ribonuclease P (RNase P) specific primers where viral amplicons were verified by agarose gel electrophoresis. We carried out a clinical performance and analytical sensitivity evaluation for this two-steps end point RT-PCR method with 242 nasopharyngeal samples using the CDC RT-qPCR protocol as a gold standard technique. With a specificity of 95.8%, a sensitivity of 95.1%, and a limit of detection of 20 viral RNA copies/uL, this two steps end point RT-PCR assay is an affordable and reliable method for SARS-CoV-2 detection. This protocol would allow to extend COVID-19 diagnosis to basic molecular biology laboratories with a potential positive impact in surveillance programs at developing countries.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , SARS-CoV-2/genetics , COVID-19/genetics , COVID-19 Nucleic Acid Testing/economics , COVID-19 Testing/methods , Coronavirus Nucleocapsid Proteins/genetics , DNA Primers , Electrophoresis, Agar Gel/methods , Humans , Laboratories , Nasopharynx/virology , RNA, Viral/genetics , Ribonuclease P/genetics , Ribonuclease P/metabolism , SARS-CoV-2/pathogenicity , Sensitivity and Specificity
20.
Sci Rep ; 11(1): 21460, 2021 11 02.
Article in English | MEDLINE | ID: covidwho-1500518

ABSTRACT

Population screening played a substantial role in safely reopening the economy and avoiding new outbreaks of COVID-19. PCR-based pooled screening makes it possible to test the population with limited resources by pooling multiple individual samples. Our study compared different population-wide screening methods as transmission-mitigating interventions, including pooled PCR, individual PCR, and antigen screening. Incorporating testing-isolation process and individual-level viral load trajectories into an epidemic model, we further studied the impacts of testing-isolation on test sensitivities. Results show that the testing-isolation process could maintain a stable test sensitivity during the outbreak by removing most infected individuals, especially during the epidemic decline. Moreover, we compared the efficiency, accuracy, and cost of different screening methods during the pandemic. Our results show that PCR-based pooled screening is cost-effective in reversing the pandemic at low prevalence. When the prevalence is high, PCR-based pooled screening may not stop the outbreak. In contrast, antigen screening with sufficient frequency could reverse the epidemic, despite the high cost and the large numbers of false positives in the screening process.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , SARS-CoV-2/genetics , Antigens, Viral/genetics , Antigens, Viral/metabolism , COVID-19/epidemiology , COVID-19/virology , COVID-19 Nucleic Acid Testing/economics , False Negative Reactions , False Positive Reactions , Humans , Pandemics , Polymerase Chain Reaction/economics , Reproducibility of Results , SARS-CoV-2/isolation & purification , Viral Load
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