ABSTRACT
To combat the ongoing Covid-19 pandemic, many new ways have been proposed on how to automate the process of finding infected people, also called contact tracing. A special focus was put on preserving the privacy of users. Bluetooth Low Energy as base technology has the most promising properties, so this survey focuses on automated contact tracing techniques using Bluetooth Low Energy. We define multiple classes of methods and identify two major groups: systems that rely on a server for finding new infections and systems that distribute this process. Existing approaches are systematically classified regarding security and privacy criteria.Copyright © 2021 ACM.
ABSTRACT
Introduction: Viral upper respiratory tract infections (URTI) such as respiratory syncytial virus, rhinoenterovirus coronavirus, and others are common in children, and they can have serious effects on the pediatric airway. The literature is limited on how often ear, nose, and throat (ENT) clinician involvement is required in patients admitted with a URTI. This project aims to characterize and identify factors associated with ENT involvement in care of pediatric patients with positive respiratory virus panels (RVP) and if any require airway interventions. Method(s): A retrospective study was conducted collecting information on patient demographics, comorbidities, course of treatment, incidence of ENT consultation, and incidence of airway interventions (flexible laryngoscopy, intubation, tracheostomy, direct laryngoscopy, etc) for all pediatric patients with a positive RVP who were treated either inpatient or in the emergency department from January 2018 to January 2020 at a tertiary care academic facility. Result(s): A total of 1019 of 1317 consecutive charts with a positive RVP over a 2-year period were reviewed. Preliminary result analysis was completed for the 1019 completed charts. Twenty-eight patients (2.7%) required an ENT consultation. Congenital birth defects were significantly associated with ENT consultation (odds ratio [OR]=3.75;P=.001). Length of stay was significantly associated with higher rate of ENT consultation per day of stay (OR=1.07 per day of stay;P<.001). All other factors studied were not significantly associated with higher rate of ENT consult. Conclusion(s): The incidence of ENT consultation in inpatients with URTIs is relatively uncommon. The preliminary data of this study suggest congenital birth defects and longer length of stay could be used as potential markers to help identify patients who may be at increased risk for worse airway outcomes and need for further airway intervention.
ABSTRACT
Many solutions have been proposed to improve manual contact tracing for infectious diseases through automation. Privacy is crucial for the deployment of such a system as it greatly influences adoption. Approaches for digital contact tracing like Google Apple Exposure Notification (GAEN) protect the privacy of users by decentralizing risk scoring. But GAEN leaks information about diagnosed users as ephemeral pseudonyms are broadcast to everyone. To combat deanonymisation based on the time of encounter while providing extensive risk scoring functionality we propose to use a private set intersection (PSI) protocol based on garbled circuits. Using oblivious programmable pseudo random functions PSI (OPPRF-PSI) , we implement our solution CERTAIN which leaks no information to querying users other than one risk score for each of the last 14 days representing their risk of infection. We implement payload inclusion for OPPRF-PSI and evaluate the efficiency and performance of different risk scoring mechanisms on an Android device.
ABSTRACT
BACKGROUND AND AIMS: Studies examining kidney failure patients with COVID-19 reported higher mortality in hemodialysis patients than in kidney transplant recipients. However, hemodialysis patients are often older and have more comorbidities. This study investigated the association of type of kidney replacement therapy with COVID-19 severity adjusting for differences in characteristics. METHOD: Data were retrieved from the European Renal Association COVID-19 Database (ERACODA), which includes kidney replacement therapy patients diagnosed with COVID-19 from all over Europe. We included all kidney transplant recipients and hemodialysis patients who presented between February 1st and December 1st 2020 and had complete information reason for COVID-19 screening and vital status at day 28. The diagnosis of COVID-19 was made based on a PCR of a nasal or pharyngeal swab specimens and/or COVID-19 compatible findings on a lung CT scan. The association of kidney transplantation or hemodialysis with 28-day mortality was examined using Cox proportional-hazards regression models adjusted for age, sex, frailty and comorbidities. Additionally, this association was investigated in the subsets of patients that were screened because of symptoms or have had routine screening. RESULTS: A total of 1,670 patients (496 functional kidney transplant recipients and 1,174 hemodialysis patients) were examined. 16.9% of kidney transplant recipients and 23.9% of hemodialysis patients died within 28 days of presentation. In an unadjusted model, the risk of 28-day mortality was 33% lower in kidney transplant recipients compared with hemodialysis patients (hazard ratio (HR): 0.67, 95% CI: 0.52, 0.85). However, in an age, sex and frailty adjusted model, the risk of 28-day mortality was 29% higher in kidney transplant recipients (HR=1.29, 95% CI: 1.00, 1.68), whereas in a fully adjusted model the risk was even 43% higher (HR=1.43, 95% CI: 1.06, 1.93). This association in patients who were screened because of symptoms (n=1,145) was similar (fully adjusted model HR=1.46, 95% CI: 1.05, 2.04). Results were similar when other endpoints were studied (e.g. risk for hospitalization, ICU admission or mortality beyond 28 days) as well as across subgroups. Only age was found to interact significantly, suggesting that the increased mortality risk associated with kidney transplantation was especially present in elderly subjects. CONCLUSION: In this study, kidney transplant recipients had a greater risk of a more severe course of COVID-19 compared with hemodialysis patients when adjusted for age, sex and comorbidities.
ABSTRACT
Super-spreader events have been a driving force of the COVID-19 pandemic. Such events often take place indoors when many people come together. Various systems for automated contact tracing (ACT) have been proposed which warn users if they have come near an infected person. These generally fail to detect potential super-spreader events as only users who have come in close contact with the infected person, but not others who also visited the same location, are warned. Other ACT approaches allow users to check into locations, but this requires user interaction. We propose two designs how broadcast-based ACT systems can be enhanced by using location-specific information without the need for GPS traces or scanning of QR codes. This makes it possible to alert attendees of a potential super-spreader event while providing privacy. Our idea relies on cooperating "lighthouses"which cover a large area and send out pseudonyms. In our passive design the health authority (HA) publishes location pseudonyms collected by infected users. In the active design, lighthouses communicate with HAs. After retrospectively detecting an infected visitor the lighthouse notifies the HA which users' stay overlapped. © 2021 IEEE.
ABSTRACT
Contact tracing is a promising approach to combat the COVID-19 pandemic. Various systems have been proposed to automatise the process. Many designs rely heavily on a centralised server or reveal significant amounts of private data to health authorities. We propose CAUDHT, a decentralized peer-to-peer system for contact tracing. The central health authority can focus on providing and operating tests for the disease while contact tracing is done by the system's users themselves. We use a distributed hash table to build a decentral messaging system for infected patients and their contacts. With blind signatures, we ensure that messages about infections are authentic and unchanged. A strong privacy focus enables data integrity, confidentiality, and privacy. © 2020 IEEE.