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 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 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.

scholarly journals SILACAK: Bagaimana Penggunaan Aplikasi Pelacakan Kasus Kontak Erat COVID-19 di Indonesia

2021 ◽  
Vol 9 (2) ◽  
pp. 127-137
Author(s):  
Taufiq Hamzah Sitompul ◽  
Popy Meilani ◽  
Syefira Salsabila ◽  
Lalu Lian Hariwangi
Keyword(s):  
Information System ◽  
Action Research ◽  
Health Information ◽  
Health Workers ◽  
Close Contact ◽  
Health Information System ◽  
Contact Tracing ◽  
Research Approach ◽  
Action Research Approach ◽  
Close Contacts

AbstractCOVID-19started outbreaks in Indonesia from March 2020, with a large spread rate making not only Indonesia, but all exposed countries in the world find the difficulties to deal with it. The advance of technology has been used to overcome the COVID-19 cases. The Ministry of Health supported by Health Information System Programme (HISP) Indonesia adopted the DHIS2 platform in the development of a contact tracing application called SILACAK. In this study, we will discuss the development of the SILACAK application which is used as a COVID-19contact tracing application in Indonesia. The method in this study is a qualitative method with an action research approach. The use of SILACAK starts from the primary healthcare level by utilizing health workers and collaboration with volunteers and The Indonesian National Military and The Indonesia National Police. The use of SILACAK was used in stages and in July 2020 it was used by 34 provinces. Currently SILACAK is used as a tool for tracking and monitoring close contact, in which close contact tracing (at least 80%) and the ratio of close contact to confirmation cases are used as a national reference (1:15).  However, for some regions there are those that cannot exceed this provision because tacthe number of close contacts does not exceed the specified limit. So that, another assessment was also carried out to see the performance of contact tracing, which consisted of: close contacts who conducted entry and exit tests, close contacts who were monitored and completed the monitoring.Keyword: SILACAK, DHIS2, COVID-19, contact tracing applicationAbstrakCOVID-19 memasuki Indonesia di bulan Maret 2020, dengan laju penyebaran yang besar membuat tidak hanya Indonesia tapi seluruh negara yang terpapar di dunia merasa kesulitan dalam menghadapinya. Kecanggihan teknologi dimanfaatkan untuk menanggulangi COVID-19. Kementerian Kesehatan didukung oleh Health Information System Programme (HISP) Indonesia mengadopsi platform DHIS2 dalam pengembangan aplikasi Pelacakan Kasus Kontak COVID-19 yang disebut SILACAK. Dalam penelitian ini akan membahas perkembangan aplikasi SILACAK yang digunakan sebagai aplikasi pelacakan kontak COVID-19 di Indonesia. Metode dalam penelitian ini dengan metode kualitatif dengan pendekatan action research. Pemanfaatan SILACAK dimulai dari level puskesmas dengan memanfaatkan tenaga Kesehatan dan berkolaborasi dengan relawan serta TNI dan POLRI. Penggunaan SILACAK digunakan secara bertahap dan di bulan Juli 2020 dimanfaatkan oleh 34 provinsi.  Saat ini SILACAK dijadikan sebagai alat untuk pelacakan dan pemantauan kontak erat, yang mana pelacakan kontak erat (minimal 80%) dan rasio kontak erat dengan kasus konfirmasi yang dijadikan sebagai acuan Nasional (1:15). Namun beberapa daerah belum bisa memenuhi angka tersebut di karena kan angka dari jumlah kontak eratnya tidak memenuhi sampai angka tersebut. Sehingga dalam menilai suatu kinerja dari keberhasilan pelacakan kontak suatu daerah juga dapat mempertimbangkan dari kontak erat yang dilakukan entry tes dan exit tes, kontak erat yang dilakukan pemantauan dan menyelesaikan pemantauannya.Kata Kunci: SILACAK, DHIS2, COVID-19, aplikasi pelacakan kontak

scholarly journals Clinical Characteristics of 24 Asymptomatic Infections with COVID-19 Screened among Close Contacts in Nanjing, China

2020 ◽  
Author(s):  
Zhiliang Hu ◽  
Ci Song ◽  
Chuanjun Xu ◽  
Guangfu Jin ◽  
Yaling Chen ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Clinical Characteristics ◽  
Close Contact ◽  
Contact Tracing ◽  
Severe Illness ◽  
Asymptomatic Carriers ◽  
Asymptomatic Infections ◽  
Clinical Records ◽  
Close Contacts ◽  
Nucleic Acid Tests

AbstractBackgroundPrevious studies have showed clinical characteristics of patients with the 2019 novel coronavirus disease (COVID-19) and the evidence of person-to-person transmission. Limited data are available for asymptomatic infections. This study aims to present the clinical characteristics of 24 cases with asymptomatic infection screened from close contacts and to show the transmission potential of asymptomatic COVID-19 virus carriers.MethodsEpidemiological investigations were conducted among all close contacts of COVID-19 patients (or suspected patients) in Nanjing, Jiangsu Province, China, from Jan 28 to Feb 9, 2020, both in clinic and in community. Asymptomatic carriers were laboratory-confirmed positive for the COVID-19 virus by testing the nucleic acid of the pharyngeal swab samples. Their clinical records, laboratory assessments, and chest CT scans were reviewed.FindingsNone of the 24 asymptomatic cases presented any obvious symptoms before nucleic acid screening. Five cases (20.8%) developed symptoms (fever, cough, fatigue, etc.) during hospitalization. Twelve (50.0%) cases showed typical CT images of ground-glass chest and 5 (20.8%) presented stripe shadowing in the lungs. The remaining 7 (29.2%) cases showed normal CT image and had no symptoms during hospitalization. These 7 cases were younger (median age: 14.0 years; P = 0.012) than the rest. None of the 24 cases developed severe COVID-19 pneumonia or died. The median communicable period, defined as the interval from the first day of positive nucleic acid tests to the first day of continuous negative tests, was 9.5 days (up to 21 days among the 24 asymptomatic cases). Through epidemiological investigation, we observed a typical asymptomatic transmission to the cohabiting family members, which even caused severe COVID-19 pneumonia.InterpretationThe asymptomatic carriers identified from close contacts were prone to be mildly ill during hospitalization. However, the communicable period could be up to three weeks and the communicated patients could develop severe illness. These results highlighted the importance of close contact tracing and longitudinally surveillance via virus nucleic acid tests. Further isolation recommendation and continuous nucleic acid tests may also be recommended to the patients discharged.

scholarly journals Assessing testing strategies and duration of quarantine in contact tracing for SARS-CoV-2: a retrospective study of San Francisco’s COVID-19 contact tracing program, June- August, 2020

2021 ◽  
Author(s):  
M J A Reid ◽  
P Prado ◽  
H Brosnan ◽  
A Ernst ◽  
H Spindler ◽  
...  
Keyword(s):  
Retrospective Study ◽  
San Francisco ◽  
Contact Tracing ◽  
Testing Strategies ◽  
Close Contacts

Abstract We sought to assess the proportion of elicited close contacts diagnosed with COVID-19 at the start, and before exiting quarantine, in San Francisco, USA. From June 8th to August 31st, 6946 contacts were identified; 3008 (46.3%) tested, 940 (13.5%) tested positive; 90% tested positive in first 9 days of quarantine.

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 Automated Dental Identification with Lowest Cost Path-Based Teeth and Jaw Separation

2016 ◽  
Vol 22 (2) ◽  
pp. 44-56 ◽  
Author(s):  
Jan-Vidar Ølberg ◽  
Morten Goodwin
Keyword(s):  
High Stability ◽  
Distance Measure ◽  
State Of The Art ◽  
Test Set ◽  
X Ray ◽  
Dental Identification ◽  
Verification Process ◽  
Stability And Accuracy ◽  
New System ◽  
Dental Work

Abstract Teeth are some of the most resilient tissues of the human body. Because of their placement, teeth often yield intact indicators even when other metrics, such as finger prints and DNA, are missing. Forensics on dental identification is now mostly manual work which is time and resource intensive. Systems for automated human identification from dental X-ray images have the potential to greatly reduce the necessary efforts spent on dental identification, but it requires a system with high stability and accuracy so that the results can be trusted. This paper proposes a new system for automated dental X-ray identification. The scheme extracts tooth and dental work contours from the X-ray images and uses the Hausdorff-distance measure for ranking persons. This combination of state-of-the-art approaches with a novel lowest cost path-based method for separating a dental X-ray image into individual teeth, is able to achieve comparable and better results than what is available in the literature. The proposed scheme is fully functional and is used to accurately identify people within a real dental database. The system is able to perfectly separate 88.7% of the teeth in the test set. Further, in the verification process, the system ranks the correct person in top in 86% of the cases, and among the top five in an astonishing 94% of the cases. The approach has compelling potential to significantly reduce the time spent on dental identification.

scholarly journals Efficacy and Safety of Lianhuaqingwen Capsules for the Prevention of Coronavirus Disease 2019: A Prospective Open-Label Controlled Trial

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Xiaowei Gong ◽  
Boyun Yuan ◽  
Yadong Yuan ◽  
Fengju Li
Keyword(s):  
Nucleic Acid ◽  
Treatment Group ◽  
Close Contact ◽  
Controlled Trial ◽  
Control Group ◽  
Open Label ◽  
Medical Observation ◽  
Observation Period ◽  
Close Contacts ◽  
Nucleic Acid Tests

Coronavirus disease 2019 (COVID-19) has become a global pandemic. Community and close contact exposures continue to drive the COVID-19 pandemic. There is no confirmed effective treatment for suspected cases and close contacts. Lianhuaqingwen (LH) capsules, a repurposed Chinese herbal product that is currently on the market, have proven effective for influenza and COVID-19. To determine the safety and efficacy of LH capsules for the prevention of COVID-19, we conducted a prospective open-label controlled trial of LH capsules on subjects who had close contact with people infected with COVID-19. Subjects received LH capsules (4 capsules, three times daily) or the usual medical observation for 14 days. The primary endpoint was the rate of positive nucleic acid tests of nasal and pharyngeal swabs during the quarantine medical observation period. We included 1976 patients, including 1101 in the treatment group and 875 in the control group. The rate of positive nucleic acid tests in the treatment group was significantly lower than that in the control group (0.27% vs. 1.14%, respectively; mean difference: −0.87%; 95% CI: −1.83 to −0.13; p = 0.0174 ) during the quarantine medical observation period (14 days). Among subjects with different close contact states, there was no significant difference in the rate of positive nucleic acid test results among close contacts in the treatment group and the control group (6.45% vs. 11.43%, respectively; p = 0.6762 ). Among secondary close contacts, the rate of positive nucleic acid tests in the treatment group was significantly lower than that in the control group (0.09% vs. 0.71%, respectively; p = 0.0485 ). No serious adverse events were reported. Taken together, and in light of the safety and effectiveness profiles, these results show that LH capsules can be considered to prevent the progression of COVID-19 after close contact with an infected person. This trial is registered with ChiCTR2100043012.

scholarly journals SARS-CoV-2 Immunoglobulin g (IgG) Kinetics in Healthcare Workers and Their Close Contacts Reduced Risk of Re-infection: South-East Asian Region

2021 ◽  
Author(s):  
Mradul Kumar Daga ◽  
Govind Mawari ◽  
Vijay Kumar Karra ◽  
Meghachandra Singh ◽  
Siddharth Chand ◽  
...  
Keyword(s):  
Immunoglobulin G ◽  
Healthcare Workers ◽  
Close Contact ◽  
Antibody Test ◽  
New Delhi ◽  
Igg Antibody ◽  
Symptomatic Infection ◽  
Medical College ◽  
Reduced Risk ◽  
Close Contacts

Abstract BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for global pandemic, and it has caused more than 2.3 million deaths. Persistence and stability of immunoglobulin G (IgG) response after recovery from COVID-19 infection is still uncertain. MethodsWe performed a longitudinal cohort study in healthcare workers (HCW) and their close contacts (Non-HCW) with known resolved SARS-CoV-2 infection and undiagnosed infection at Maulana Azad Medical College and associated Lok Nayak hospital, New Delhi. Baseline IgG antibody titers was determined and the participants were followed over a period of six months. We also examined relationship between SARS-CoV-2 immunoglobulin G (IgG) response and new symptomatic infection in HCW and Non-HCW over time. Results176 (70.9%) healthcare workers and 72 (29.0%) non-healthcare workers were recruited from two cohorts. 82 subjects recovered from SARS-CoV-2 infection and 166 undiagnosed for the infection having history of close contact with COVID-19 patients were followed up for a median of 227 days (interquartile range, 166 to 202) after a positive IgG antibody test. In the recovered subjects 70.7% (58) were seropositive for first anti-spike IgG assay at baseline, followed by 80.0%, 90.6% and 82.6% at three visits respectively. In undiagnosed subjects 37.3% (62) were seropositive at baseline, followed by 70.9%, 75.8% and 82.2% respectively. Also, 46.8% (29) were asymptomatic with no symptoms of COVID-19 and were seropositive at baseline. However, presence of IgG antibodies was associated with substantial reduced risk of re-infection over the follow up duration.ConclusionOur data showed that the antibodies levels measured increased over the first three months and decreased slightly after that and remained at a plateau and relatively stable for at least a period of six months.

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