scholarly journals Rapid systematic review of the sensitivity of SARS-CoV-2 molecular testing on saliva compared to nasopharyngeal swabs

2020 ◽  
Author(s):  
Eliana Peeters ◽  
Sharon Kaur Dhillon Ajit Singh ◽  
Jo Vandesompele ◽  
Pieter Mestdagh ◽  
Veronik Hutse ◽  
...  
Keyword(s):  
Sampling Method ◽  
Saliva Sample ◽  
Relative Sensitivity ◽  
Contact Tracing ◽  
Secondary Outcome ◽  
Molecular Testing ◽  
Non Invasive ◽  
Care Workers ◽  
Clinical Covariates ◽  
Standard Collection

ABSTRACT Background: Nasopharyngeal sampling has been the standard collection method for COVID-19 testing. Due to its invasive nature and risk of contamination for health care workers who collect the sample, non-invasive and safe sampling methods like saliva, can be used alternatively. Methods: A rapid systematic search was performed in PubMed and medRxiv, with the last retrieval on June 6th, 2020. Studies were included if they compared saliva with nasopharyngeal sampling for the detection of SARS-CoV-2 RNA using the same RT-qPCR applied on both types of samples. The primary outcome of interest was the relative sensitivity of SARS-CoV-2 testing on saliva versus nasopharyngeal samples (used as the comparator test). A secondary outcome was the proportion of nasopharyngeal-positive patients that tested also positive on a saliva sample. Results: Eight studies were included comprising 1070 saliva-nasopharyngeal sample pairs allowing assessment of the first outcome. The relative sensitivity of SARS-CoV-2 testing on saliva versus nasopharyngeal samples was 0.97 (95% CI=0.92-1.02). The second outcome incorporated patient data (n=257) from four other studies (n=97 patients) pooled with four studies from the first outcome (n=160 patients). This resulted in a pooled proportion of nasopharyngeal positive cases that was also positive on saliva of 86% (95% CI=77-93%). Discussion: Saliva could potentially be considered as an alternative sampling method when compared to nasopharyngeal swabs. However, studies included in this review often were small and involved inclusion of subjects with insufficient information on clinical covariates. Most studies included patients who were symptomatic (78%, 911/1167). Therefore, additional and larger studies should be performed to verify the relative performance of saliva in the context of screening of asymptomatic populations and contact-tracing.

scholarly journals Role of efficient testing and contact tracing in mitigating the COVID-19 pandemic: a network modelling study

BMJ Open ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. e045886
Author(s):  
Yiying Hu ◽  
Jianying Guo ◽  
Guanqiao Li ◽  
Xi Lu ◽  
Xiang Li ◽  
...  
Keyword(s):  
Real World ◽  
Case Fatality ◽  
Contact Tracing ◽  
Secondary Outcome ◽  
Time Interval ◽  
Fatality Rate ◽  
Real World Data ◽  
Network Modelling ◽  
World Data ◽  
Quantitative Evidence

ObjectivesThis study quantified how the efficiency of testing and contact tracing impacts the spread of COVID-19. The average time interval between infection and quarantine, whether asymptomatic cases are tested or not, and initial delays to beginning a testing and tracing programme were investigated.SettingWe developed a novel individual-level network model, called CoTECT (Testing Efficiency and Contact Tracing model for COVID-19), using key parameters from recent studies to quantify the impacts of testing and tracing efficiency. The model distinguishes infection from confirmation by integrating a ‘T’ compartment, which represents infections confirmed by testing and quarantine. The compartments of presymptomatic (E), asymptomatic (I), symptomatic (Is), and death with (F) or without (f) test confirmation were also included in the model. Three scenarios were evaluated in a closed population of 3000 individuals to mimic community-level dynamics. Real-world data from four Nordic countries were also analysed.Primary and secondary outcome measuresSimulation result: total/peak daily infections and confirmed cases, total deaths (confirmed/unconfirmed by testing), fatalities and the case fatality rate. Real-world analysis: confirmed cases and deaths per million people.Results(1) Shortening the duration between Is and T from 12 to 4 days reduces infections by 85.2% and deaths by 88.8%. (2) Testing and tracing regardless of symptoms reduce infections by 35.7% and deaths by 46.2% compared with testing only symptomatic cases. (3) Reducing the delay to implementing a testing and tracing programme from 50 to 10 days reduces infections by 35.2% and deaths by 44.6%. These results were robust to sensitivity analysis. An analysis of real-world data showed that tests per case early in the pandemic are critical for reducing confirmed cases and the fatality rate.ConclusionsReducing testing delays will help to contain outbreaks. These results provide policymakers with quantitative evidence of efficiency as a critical value in developing testing and contact tracing strategies.

scholarly journals Noninvasive ventilation masks with viral filters to protect health care workers from SARS-CoV-2 / Coronavirus infections

2020 ◽  
Author(s):  
Dominic Dellweg ◽  
Peter Haidl ◽  
Jens Kerl ◽  
Dieter Koehler
Keyword(s):  
Health Care ◽  
Health Care Professionals ◽  
Test Chamber ◽  
Rubber Band ◽  
Protection Measure ◽  
Non Invasive ◽  
Non Invasive Ventilation ◽  
Care Workers ◽  
Surgical Masks ◽  
N95 Respirators

Abstract Background:There is a shortage of masks and respirators for the protection of health care professionals during the current SARS-CoV-2 / Coronavirus pandemic. Masks for non-invasive ventilation (NIV) in combination with viral-proof filters could serve as an alternative protection measure. We wanted to determine the aerosol filtering efficacies of such devices in comparison to conventional surgical masks, N95 and FFP3 respirators.Method:Masks and respirators were mounted on a ventilated mannequin head in a test-chamber. Absorption of radioactive particles was measured compared to a non-filtered reference port.Results: Filter efficacies were 93.3 ± 1.5 % for a ResMed AcuCare NIV-mask plus filter, 71.2 ± 0.2 % for a ResMed Mirage Quattro FX NIV-mask plus filter, 89.4 ± 0.9 % for a Loewenstein JOYCEclinc FF NIV-mask plus filter, 48.4 ± 4 % for a surgical mask with rubber band, 60.5 ± 9.1 % for a surgical mask with ribbons, 56.9 ± 7.5 % for a FFP3 respirator, 64.5 % ± 5.1 for a N95 respirator. The ResMed AcuCare and the Loewenstein JOYCEclinic FF mask were more effective than any other of the tested devices (p < 0.001 and p = 0.001 respectively)Conclusion:NIV masks with viral-proof filters effectively filter respirable particles. Two tested NIV masks were more effective than the tested FFP3 and N95 respirators.

Molecular Testing of Nodules with a Suspicious or Malignant Cytologic Diagnosis in the Setting of Non-Invasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features (NIFTP)

2018 ◽  
Vol 29 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Kyle C. Strickland ◽  
Markus Eszlinger ◽  
Ralf Paschke ◽  
Trevor E. Angell ◽  
Erik K. Alexander ◽  
...  
Keyword(s):  
Thyroid Neoplasm ◽  
Molecular Testing ◽  
Cytologic Diagnosis ◽  
Non Invasive ◽  
Nuclear Features

“EPIDEMIOLOGICAL AND CLINICAL CHARACTERIZATION OF COVID19 PATIENTS: A RETROSPECTIVE OBSERVATIONAL STUDY OF 245 CASES IN A GOVERNMENT TEACHING INSTITUTE OF NORTH INDIA.”

2021 ◽  
pp. 50-53
Author(s):  
Divya Jain ◽  
Umesh Shukla ◽  
Jyotsna Madan ◽  
Bhanu K Bhakri ◽  
Devendra Kumar Gupta ◽  
...  
Keyword(s):  
Clinical Characteristics ◽  
North India ◽  
Contact Tracing ◽  
Mild Disease ◽  
Source Of Infection ◽  
Asymptomatic Patients ◽  
Care Workers ◽  
Study Population ◽  
The Mean ◽  
Novel Coronavirus

Background and objectives: Worldwide literature on presentation of patients infected with novel coronavirus shows huge variability in terms of severity and outcome depending on the demographic characteristics of the affected population. We aim to present epidemiological and clinical characteristics of COVID-19 patients admitted at our facility. Methods: Retrospective analysis of epidemiological, and clinical characteristics of patients admitted at a dedicated COVID hospital in North India. Results: Records of 245 patients were analyzed. The mean (SD) age was 32 (17.87) years ranging from 1 day to 81 years. Children <18 years of age constituted around 18% of the study population of which only about a fourth (23%) were symptomatic. About 52.4% of patients were males. Almost 40% cases were detected through contact tracing of known infected patients and in about 56% cases the source of infection was indeterminate. About 67% were asymptomatic and most of the symptomatic patients had mild disease. Among the symptomatic patients cough (19.9%) and fever (17.1%) were most common symptoms followed by throat irritation. Comorbidities were present in 32 (13.06%) patients, of which hypertension in 6.12% was the most common. There were 22 (8.97%) health care workers (HCW) among the patients. Majority of the affected HCW were working in areas with relatively low infection risk. Six (2.44%) patients required oxygen supplementation. The mean duration of stay in hospital was 9.6 ±.57 days. Interpretations & Conclusions: Our observations indicate a relatively younger age of affected population and high proportion of asymptomatic patients. Children are usually asymptomatic with relatively better prognosis.

scholarly journals Less Is Enough: Assessment of the Random Sampling Method for the Analysis of Magnetoencephalography (MEG) Data

2019 ◽  
Vol 24 (4) ◽  
pp. 98
Author(s):  
Cristina Campi ◽  
Annalisa Pascarella ◽  
Francesca Pitolli
Keyword(s):  
Magnetic Field ◽  
Random Sampling ◽  
Sampling Method ◽  
Brain Activity ◽  
Memory Storage ◽  
Non Invasive ◽  
Regularization Techniques ◽  
Ill Posed ◽  
The Brain ◽  
The Magnetic Field

Magnetoencephalography (MEG) aims at reconstructing the unknown neuroelectric activity in the brain from non-invasive measurements of the magnetic field induced by neural sources. The solution of this ill-posed, ill-conditioned inverse problem is usually dealt with using regularization techniques that are often time-consuming, and computationally and memory storage demanding. In this paper we analyze how a slimmer procedure, random sampling, affects the estimation of the brain activity generated by both synthetic and real sources.

scholarly journals A new non-invasive in situ underwater DNA sampling method for estimating genetic diversity

2020 ◽  
Vol 34 (4) ◽  
pp. 633-644
Author(s):  
Gergely Balázs ◽  
Judit Vörös ◽  
Brian Lewarne ◽  
Gábor Herczeg
Keyword(s):  
Genetic Diversity ◽  
Sampling Method ◽  
Non Invasive ◽  
Dna Sampling

Development of tetranucleotide microsatellite loci and a non-invasive DNA sampling method for Texas horned lizards (Phrynosoma cornutum)

2011 ◽  
Vol 4 (1) ◽  
pp. 43-45 ◽  
Author(s):  
Dean A. Williams ◽  
Cory Leach ◽  
Amanda M. Hale ◽  
Kristopher B. Karsten ◽  
Emmanuela Mujica ◽  
...  
Keyword(s):  
Microsatellite Loci ◽  
Sampling Method ◽  
Phrynosoma Cornutum ◽  
Non Invasive ◽  
Dna Sampling ◽  
Horned Lizards

scholarly journals Girding the loins? Direct evidence of the use of a medieval parchment birthing girdle from biomolecular analysis

2020 ◽  
Author(s):  
Sarah Fiddyment ◽  
Natalie J. Goodison ◽  
Elma Brenner ◽  
Stefania Signorello ◽  
Kierri Price ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Extraction Method ◽  
Sampling Method ◽  
Direct Evidence ◽  
Vaginal Fluid ◽  
Non Invasive ◽  
Biomolecular Analysis ◽  
Made In

AbstractIn this paper we describe a dry non-invasive extraction method to detect palaeoproteomic evidence from stained manuscripts. The manuscript analysed in this study is a medieval parchment birth girdle (Wellcome Collection Western MS. 632) made in England and thought to be used by pregnant women while giving birth. Using a dry non-invasive sampling method we were able to extract both human and non-human peptides from the stains, including evidence for the use of honey, cereals, ovicaprine milk and legumes. In addition, a large number of human peptides were detected on the birth roll, many of which are found in cervico-vaginal fluid. This suggests that the birth roll was actively used during childbirth. This study is the first to extract and analyse non-collagenous peptides from a parchment document using a dry non-invasive sampling method and demonstrates the potential of this type of analysis for stained manuscripts, providing direct biomolecular evidence for active use.

scholarly journals Revised guidelines for Australian laboratories performing mycobacteriology testing

2020 ◽  
Vol 44 ◽  
Author(s):  
Ivan Bastian ◽  
Lisa Shephard ◽  
Richard Lumb ◽  
Keyword(s):  
Peer Review Process ◽  
Contact Tracing ◽  
Molecular Testing ◽  
Reference Laboratory ◽  
Work Practices ◽  
Quality Work ◽  
Molecular Tests ◽  
Assessment Approach ◽  
National Tuberculosis ◽  
Risk Categorisation

Mycobacteriology laboratories play a key role in tuberculosis (TB) control by providing phenotypic and molecular diagnostics, by performing molecular typing to aid contact tracing, and by supporting research and similar laboratories in Australia’s neighbouring countries where TB is prevalent. The National Tuberculosis Advisory Committee (NTAC) published a set of laboratory guidelines in 2006 aiming to document the infrastructure, equipment, staffing and work practices required for safe high-quality work in Australian mycobacteriology laboratories. These revised guidelines have the same aims and have been through a similar extensive consultative peer-review process involving the Mycobacterium Reference Laboratory (MRL) network, the Mycobacterium Special Interest Group (SIG) of the Australian Society for Microbiology (ASM), and other relevant national bodies. This revised document contains several significant changes reflecting the publication of new biosafety guidelines and tuberculosis standards by various national and international organisations, technology developments – such as the MPT64-based immunochromatographic tests (ICTs) and the Xpert MTB/RIF assay, and updated work practices in mycobacteriology laboratories. The biosafety recommendations affirm the latest Australian/New Zealand Standard 2243.3: 2010 and promote a biorisk assessment approach that, in addition to the risk categorisation of the organism, also considers the characteristics of the procedure being performed. Using this biorisk assessment approach, limited manipulations, such as Ziehl-Neelsen (ZN) microscopy, MPT64 ICTs, and culture inactivation/DNA extraction for molecular testing, may be performed on a positive TB culture in a PC2 laboratory with additional features and work practices. Other significant changes include recommendations on the integration of MPT64 ICTs and novel molecular tests into TB laboratory workflows to provide rapid accurate results that improve the care of TB patients. This revised document supersedes the original 2006 publication. NTAC will periodically review these guidelines and provide updates as new laboratory technologies become available.

scholarly journals Prospective comparison of saliva and nasopharyngeal swab sampling for mass screening for COVID-19

2020 ◽  
Author(s):  
◽  
mathieu nacher ◽  
magalie demar
Keyword(s):  
Mass Screening ◽  
Saliva Sample ◽  
Field Testing ◽  
Contact Tracing ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Prospective Comparison ◽  
Asymptomatic Patients ◽  
Patient Groups ◽  
Trained Staff

Current testing for COVID-19 relies on quantitative reverse-transcriptase polymerase chain reaction from a nasopharyngeal swab specimen. Saliva samples have advantages regarding ease and painlessness of collection, which does not require trained staff and may allow self-sampling. We enrolled 776 persons at various field-testing sites and collected nasopharyngeal and pooled saliva samples. 162 had a positive COVID-19 RT-PCR, 61% were mildly symptomatic and 39% asymptomatic. The sensitivity of RT-PCR on saliva samples versus nasopharygeal swabs varied depending on the patient groups considered or on Ct thresholds. There were 10 (6.2%) patients with a positive saliva sample and a negative nasopharyngeal swab, all of whom had Ct values<25. For symptomatic patients for whom the interval between symptoms onset and sampling was <10 days sensitivity was 77% but when excluding persons with isolated Ngen positivity (54/162), sensitivity was 90%. In asymptomatic patients, the sensitivity was only 24%. When we looked at patients with Cts <30, sensitivity was 83% or 88.9% when considering 2 genes. The relatively good performance for patients with low Cts suggests that Saliva testing could be a useful and acceptable tool to identify infectious persons in mass screening contexts, a strategically important task for contact tracing and isolation in the community.

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