scholarly journals Salivary detection of COVID-19. Clinical performance of oral sponge sampling for SARS-CoV-2 testing

2021 ◽  
Author(s):  
Charles Hugo Marquette ◽  
Jacques Boutros ◽  
Jonathan Benzaquen ◽  
Marius Ilié ◽  
Mickelina Labaky ◽  
...  
Keyword(s):  
Mass Screening ◽  
Clinical Performance ◽  
Close Contact ◽  
Low Cost ◽  
Sampling Technique ◽  
Contact Tracing ◽  
Rt Pcr ◽  
Community Based ◽  
Attending Physician ◽  
Close Contacts

ABSTRACTBackgroundThe current diagnostic standard for coronavirus 2019 disease (COVID-19) is reverse transcriptase-polymerase chain reaction (RT-PCR) testing with naso-pharyngeal (NP) swabs. The invasiveness and need for trained personnel make the NP technique unsuited for repeated community-based mass screening. We developed a technique to collect saliva in a simple and easy way with the sponges that are usually used for tamponade of epistaxis. This study was carried out to validate the clinical performance of oral sponge (OS) sampling for SARS-CoV-2 testing.MethodsOver a period of 22 weeks, we collected prospectively 409 paired NP and OS samples from consecutive subjects presenting to a public community-based free screening center. Subjects were referred by their attending physician because of recent COVID-19 symptoms (n=147) or by the contact tracing staff of the French public health insurance since they were considered as close contacts of a laboratory-confirmed COVID-19 case (n=262).ResultsIn symptomatic subjects, RT-PCR SARS-CoV-2 testing with OS showed a 96.5% (95%CI: 89.6-94.8) concordance with NP testing, and, a 93.3% [95%CI: 89.1-97.3] sensitivity. In close contacts the NP-OS concordance (93.8% [95%CI: 90.9-96.7]) and OS sensitivity (71.9% [95%CI: 66.5-77.3]) were slightly lower.ConclusionThese results strongly suggest that OS testing is a straightforward, low-cost and high-throughput sampling method that can be used for frequent RT-PCR testing of COVID-19 patients and mass screening of populations.Summary of the “take home” messageOS sampling for SARS-CoV2 RT-PCR is an easy to perform, straightforward self-administered sampling technique, which has a sensitivity of up to 93.3% in symptomatic patients and 71% in close contact subjects.

scholarly journals Salivary detection of COVID-19. Clinical performance of oral sponge sampling for SARS-CoV-2 testing

2021 ◽  
pp. 00396-2021
Author(s):  
Jacques Boutros ◽  
Jonathan Benzaquen ◽  
Charles Hugo Marquette ◽  
Marius Ilié ◽  
Mickelina Labaky ◽  
...  
Keyword(s):  
Mass Screening ◽  
Sampling Method ◽  
Clinical Performance ◽  
Low Cost ◽  
Contact Tracing ◽  
Rt Pcr ◽  
Community Based ◽  
Polymerase Chain ◽  
Attending Physician ◽  
Close Contacts

BackgroundThe current diagnostic standard for coronavirus 2019 disease (COVID-19) is reverse transcriptase-polymerase chain reaction (RT-PCR) testing with naso-pharyngeal (NP) swabs. The invasiveness and need for trained personnel make the NP technique unsuited for repeated community-based mass screening. We developed a technique to collect saliva in a simple and easy way with the sponges that are usually used for tamponade of epistaxis. This study was carried out to validate the clinical performance of oral sponge (OS) sampling for SARS-CoV-2 testing.MethodsOver a period of 22 weeks, we collected prospectively 409 paired NP and OS samples from consecutive subjects presenting to a public community-based free screening center. Subjects were referred by their attending physician because of recent COVID-19 symptoms (n=147) or by the contact tracing staff of the French public health insurance since they were considered as close contacts of a laboratory-confirmed COVID-19 case (n=262).ResultsIn symptomatic subjects, RT-PCR SARS-CoV-2 testing with OS showed a 96.5% (95%CI: 89.6–94.8) concordance with NP testing, and, a 93.2% (95%CI: 89.1–97.3)] sensitivity when using the IdyllaTM platform and a sensitivity of 76.3% [69.4–83.2] on the Synlab Barla laboratory platform. In close contacts the NP-OS concordance (93.8% [95%CI: 90.9–96.7]) and OS sensitivity (71.9% [95%CI: 66.5–77.3]) were slightly lower.ConclusionThese results strongly suggest that OS testing is a straightforward, low-cost and high-throughput sampling method that can be used for frequent RT-PCR testing of COVID-19 patients and mass screening of populations.

scholarly journals COVID-19 in a Rural Community: Outbreak Dynamics, Contact Tracing and Environmental RNA

2020 ◽  
Author(s):  
Isabel G. Fernández de Mera ◽  
Francisco J. Rodríguez del Río ◽  
José de la Fuente ◽  
Marta Pérez Sancho ◽  
Dolores Hervas ◽  
...  
Keyword(s):  
Rural Community ◽  
Public Service ◽  
Contact Tracing ◽  
Rt Pcr ◽  
Rna Surveillance ◽  
Petrol Station ◽  
Early Testing ◽  
Resource Deployment ◽  
The Village ◽  
Close Contacts

Background: Since March 2020, Spain is severely hit by the ongoing pandemic of coronavirus disease 19 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Understanding and disrupting the early transmission dynamics of the infection is crucial for impeding sustained transmission. Methods: We recorded all COVID-19 cases and traced their contacts in an isolated rural community. We also sampled 10 households, 6 public service sites and the wastewater from the village sewage for environmental SARS-CoV-2 RNA. Results: The first village patient diagnosed with COVID-19-compatible symptoms occurred on March 3, 2020, twelve days before lockdown. A peak of 39 cases occurred on March 30. By May 15, the accumulated number of symptomatic cases was 53 (6% of the population), of which only 22 (41%) had been tested and confirmed by RT-PCR as SARS-CoV-2 infected, including 16 hospitalized patients. Contacts (n=144) were six times more likely to develop symptoms. Environmental sampling detected SARS-CoV-2 RNA in two households with known active cases and in two public service sites: the petrol station and the pharmacy. Samples from other sites and the wastewater tested negative. Conclusions: The low proportion of patients tested by RT-PCR calls for urgent changes in disease management. We propose that early testing of all cases and their close contacts would reduce infection spread, reducing the disease burden and fatalities. In a context of restricted testing, environmental RNA surveillance might prove useful for early warning and to identify high-risk settings enabling a targeted resource deployment.

scholarly journals Assessing the burden of Covid-19 in the slums of Bangalore city: Results of Rapid Community Survey

2021 ◽  
Vol 33 (3) ◽  
pp. 475-479
Author(s):  
Ranganath Thimnahalli Sobagaiah ◽  
Ramesh Nugehally Raju Masthi ◽  
Lalitha Krishnappa ◽  
Ambika Rangaiah ◽  
Girish Nagaraja Rao ◽  
...  
Keyword(s):  
Inner Core ◽  
Venous Blood ◽  
Sampling Technique ◽  
Community Survey ◽  
Age Group ◽  
Rt Pcr ◽  
Community Based ◽  
Cross Sectional ◽  
Bangalore City ◽  
Cluster Random Sampling

Background: Karnataka, more so Bangalore, reported an increase in number of COVID-19 cases in early April 2021. Objective: To assess the burden of COVID-19 in the slums of Bengaluru city. Materials and Methods: A cross-sectional multi centre community-based study was done in the 2nd and 3rd week of April 2021 in 24 different slums in Bangalore city. WHO cluster random sampling technique was followed. Swabs for RTPCR test and 4 ml of venous blood was collected from 728 subjects more than 18 years of age. Results: A total of 51 (7%) subjects were positive for COVID-19 through RT-PCR. Majority 33 (56.9%) were in the age group of 18-44 years. 148 (20.3%) subjects were sero-positive on blood examination and 18-44 years was the (59.4%) preponderant age group. Overall seropositivity was 20.3% (95%CI; 17.4-23.2) and RT-PCR positivity is 7% (95%CI; 5.2-8.8%) among the subjects surveyed. In the inner core area of Bangalore, seropositivity was 24.2% (95%CI; 21.0 – 27.3) and RT-PCR positivity was 8% (95%CI; 6.1-9.9). Two doses of COVID-19 vaccine were taken only by 1.55% subjects during the study period. Conclusion: The study showed that one in 5 subjects were sero-positive to SARS-CoV-2 and one in 15 individuals had active COVID-19 infection.

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.

scholarly journals LBTrace: A LoRa and Blockchain Based Contact Tracing Method for COVID-19 and Future Pandemics

2021 ◽  
Author(s):  
Jian Fang ◽  
Wenbo Zhao ◽  
Lei Wang ◽  
Zhenquan Qin ◽  
Bingxian Lu
Keyword(s):  
High Stability ◽  
Close Contact ◽  
Scaling Up ◽  
Contact Tracing ◽  
Smart Device ◽  
The Internet ◽  
Epidemiological Investigation ◽  
Stability And Accuracy ◽  
Tracing Method ◽  
Close Contacts

COVID-19 has caused hundreds of millions of infections and hundreds of deaths, and even though vaccinations are increasing, the mutation of the virus makes the pandemic even difficult to control. Existing manual, operator and Bluetooth-based technologies for epidemiological investigation and close contact tracing suffer from high cost, low accuracy, and difficulty in scaling up. Viruses such as Delta variants have a greater ability to survive and spread, making many of the existing human-human close contacts tracing less effective. Also, it is easy to overlook the fact that there is still a large segment of the world's population that does not have access to the Internet and is proficient in using smartphones, which makes the performance of smart device-based tracing much less effective. Inspired by Health Code and Tracetogether, which have been widely accepted in China and Singapore, we propose a LoRa and blockchain-based contact tracing method LBTrace, which is low-power, lightweight, and operation-free. The experimental results demonstrate the high stability and accuracy of our proposed method, which can be used as a complement to existing methods to help some governments effectively control COVID-19 and future outbreaks under certain emergency conditions.

scholarly journals LBTrace: A LoRa and Blockchain Based Contact Tracing Method for COVID-19 and Future Pandemics

2021 ◽  
Author(s):  
Jian Fang ◽  
Wenbo Zhao ◽  
Lei Wang ◽  
Zhenquan Qin ◽  
Bingxian Lu
Keyword(s):  
High Stability ◽  
Close Contact ◽  
Scaling Up ◽  
Contact Tracing ◽  
Smart Device ◽  
The Internet ◽  
Epidemiological Investigation ◽  
Stability And Accuracy ◽  
Tracing Method ◽  
Close Contacts

COVID-19 has caused hundreds of millions of infections and hundreds of deaths, and even though vaccinations are increasing, the mutation of the virus makes the pandemic even difficult to control. Existing manual, operator and Bluetooth-based technologies for epidemiological investigation and close contact tracing suffer from high cost, low accuracy, and difficulty in scaling up. Viruses such as Delta variants have a greater ability to survive and spread, making many of the existing human-human close contacts tracing less effective. Also, it is easy to overlook the fact that there is still a large segment of the world's population that does not have access to the Internet and is proficient in using smartphones, which makes the performance of smart device-based tracing much less effective. Inspired by Health Code and Tracetogether, which have been widely accepted in China and Singapore, we propose a LoRa and blockchain-based contact tracing method LBTrace, which is low-power, lightweight, and operation-free. The experimental results demonstrate the high stability and accuracy of our proposed method, which can be used as a complement to existing methods to help some governments effectively control COVID-19 and future outbreaks under certain emergency conditions.

scholarly journals Remote Health Monitoring in the Workplace for Early Detection of COVID-19 Cases during the COVID-19 Pandemic Using a Mobile Health Application: COVIDApp.

2021 ◽  
Vol 19 (1) ◽  
pp. 167
Author(s):  
Patricia Echeverría ◽  
Jordi Puig ◽  
José María Ruiz ◽  
Jordi Herms ◽  
Maria Sarquella ◽  
...  
Keyword(s):  
Early Detection ◽  
Real Time ◽  
Close Contact ◽  
Contact Tracing ◽  
Rt Pcr ◽  
Negative Results ◽  
Mobile Health Application ◽  
Work Area ◽  
Health Application ◽  
Rapid Activation

Background: COVIDApp is a platform created for management of COVID-19 in the workplace. Methods: COVIDApp was designed and implemented for the follow-up of 253 workers from seven companies in Catalonia. The assessment was based on two actions: first, the early detection and management of close contacts and potential cases of COVID-19, and second, the rapid remote activation of protocols. The main objectives of this strategy were to minimize the risk of transmission of COVID-19 infection in the work area through a new real-time communication channel and to avoid unnecessary sick leave. The parameters reported daily by workers were close contact with COVID cases and signs and/or symptoms of COVID-19. Results: Data were recorded between 1 May and 30 November 2020. A total of 765 alerts were activated by 76 workers: 127 green alarms (16.6%), 301 orange alarms (39.3%), and 337 red alarms (44.1%). Of all the red alarms activated, 274 (81.3%) were activated for symptoms potentially associated with COVID-19, and 63 (18.7%) for reporting close contact with COVID-19 cases. Only eight workers (3.1%) presented symptoms associated with COVID-19 infection. All of these workers underwent RT-PCR tests, which yielded negative results for SARS-CoV2. Three workers were considered to have had a risk contact with COVID-19 cases; only 1 (0.4%) asymptomatic worker had a positive RT-PCR test result, requiring the activation of protocols, isolation, and contact tracing. Conclusions: COVIDApp contributes to the early detection and rapid activation of protocols in the workplace, thus limiting the risk of spreading the virus and reducing the economic impact caused by COVID-19 in the productive sector. The platform shows the progression of infection in real time and can help design new strategies.

scholarly journals COVID-19 outbreak prevention by early containment in Shantou, China

2020 ◽  
Vol 14 (07) ◽  
pp. 742-747
Author(s):  
Xubin Zhang ◽  
Dangui Zhang ◽  
Chi Zhang ◽  
Lijun Yao ◽  
Lu Xu ◽  
...  
Keyword(s):  
Mainland China ◽  
Lag Time ◽  
Contact Tracing ◽  
Linear Regression Models ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Community Screening ◽  
First Case ◽  
Containment Measures ◽  
Close Contacts

Introduction: To report about the successful outbreak containment of COVID-19 in Shantou, one of the prefectural cities of Guangdong province in the mainland China. Methodology: All patients confirmed as having COVID-19 between 23 January and 25 March 2020 by RT-PCR assay in the clinical lab of Shantou CDC were included and divided into three groups based on the source of identification: hospital diagnosis, contact tracing, and community screening. Collected data was analyzed and compared among these three groups. Results: A total of 25 COVID-19 cases were identified in Shantou. The first case was identified on 14 January 2020 at one of two COVID-19 dedicated hospitals in Shantou. The majority of the cases were either imported from Wuhan or linked to Wuhan/Hubei. The median lag time for diagnosis (i.e., the time between symptom onset and case confirmation) was 2 days (IQR, 2.0-4.0) for all cases, 9 days (IQR, 7.0-10.0) for the cases diagnosed in hospitals, 2 days (IQR, 1.5-2.0) for the cases in contact tracing, and 4 days (IQR, 2.5-4.5) for cases in community screening, with a significantly longer diagnosis lag time in hospitals (p = 0.003). Multivariate linear regression models showed larger family size and severe cases as the significant predictor for increasing number of close contacts. Conclusions: The current pandemic appears to exist for an uncertain period. The early containment measures applied in Shantou, a city with insufficient healthcare resources for COVID-19, seems to be appropriate for cities or areas with similar profiles.

scholarly journals Prospective Comparison of Saliva and Nasopharyngeal Swab Sampling for Mass Screening for COVID-19

2021 ◽  
Vol 8 ◽  
Author(s):  
Mathieu Nacher ◽  
Mayka Mergeay-Fabre ◽  
Denis Blanchet ◽  
Orelie Benoit ◽  
Tristan Pozl ◽  
...  
Keyword(s):  
Mass Screening ◽  
Saliva Sample ◽  
Field Testing ◽  
Contact Tracing ◽  
N Gene ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Prospective Comparison ◽  
Asymptomatic Patients ◽  
Patient Groups

Current testing for COVID-19 relies on 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. One hundred sixty two had a positive COVID-19 RT-PCR, 61% were mildly symptomatic and 39% asymptomatic. The sensitivity of RT-PCR on saliva samples vs. 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 &lt;25 for three genes. For symptomatic patients for whom the interval between symptoms onset and sampling was &lt;10 days sensitivity was 77% but when excluding persons with isolated N gene positivity (54/162), sensitivity was 90%. In asymptomatic patients, the sensitivity was only 24%. When we looked at patients with Cts &lt;30, sensitivity was 83 or 88.9% when considering two 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.

scholarly journals Transmission Risk of SARS-CoV-2 Among Close Contacts- Results of Case- Contact Tracing

2020 ◽  
Author(s):  
Haimei Jia ◽  
Minhong CHen ◽  
Hanwei Wang ◽  
Chenping Guan ◽  
Yangwei Chen ◽  
...  
Keyword(s):  
Virus Disease ◽  
Close Contact ◽  
Secondary Infection ◽  
Transmission Risk ◽  
Contact Tracing ◽  
Anal Swab ◽  
Novel Coronavirus ◽  
Asymptomatic Case ◽  
Epidemiological Characteristics ◽  
Close Contacts

Abstract Background: The ongoing outbreak of corona virus Disease-19 (COVID-19) is rapid escalation and global spread.The epidemiological characteristics and particularly its ability to spread in the human population of COVID-19 were uncertainty. We analyzed infection of 2019 novel coronavirus pneumonia (COVID-19) and close contacts in Fuzhou, Fujian Province, and to understand the risk of infection and morbidity in different exposure mode. Methods: We investigated cases and their close contacts by face-to –face or telephone interview and conducted laboratory test on nasopharyngeal or oropharyngeal swabs or anal swab for evidence of COVID-19 infection. Information on cases including the epidemiology, expose and laboratory were collected. Results: There were 72 patients of COVID-19 and 1 asymptomatic case were confirmed in Fuzhou. A total of 1159 close contacts were traced, the secondary infection rate (SIR) was 2.07% (24/1159), the median of interval was 12 days (rang 2-21 days). In the relationship between close contact and cases, the SIR of old people under care were the highest (28.57% ) than family members (5.52%), medical staff (3.23%), relatives (2.41%) and colleagues / classmates (1.67%), respectively( 2＝534.38， P＜0.00 ). Among the contact ways, the SIR of Nursing (nursing home) were the highest (28.57% ) than medical care (3.23%), family gathering (2.82%), same building (1.77%) and short talk or handle affairs (1.55%),respectively. The median of incubation period was 5days (rang1-12days). Conclusions: The COVID-19 has highly contagious. Timely and strict quarantine should be conducted for close contacts to reduce the possibility of community communication.

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