Another Look at Privacy-Preserving Automated Contact Tracing

In the current COVID-19 pandemic, manual contact tracing has been proven to be very helpful to reach close contacts of infected users and slow down spread of the virus. To improve its scalability, a number of automated contact tracing (ACT) solutions have been proposed, and some of them have been deployed. Despite the dedicated efforts, security and privacy issues of these solutions are still open and under intensive debate. In this article, we examine the ACT concept from a broader perspective, by focusing on not only security and privacy issues but also functional issues such as interface, usability, and coverage. We first elaborate on these issues and particularly point out the inevitable privacy leakages in existing Bluetooth Low Energy based ACT solutions, including centralized and decentralized ones. In addition, we examine the existing venue-based ACT solutions and identify their privacy and security concerns. Then, we propose a generic venue-based ACT solution and a concrete instantiation based on Bluetooth Low Energy technology. Our solution monitors users’ contacting history only in virus-spreading-prone venues and offers higher-level protection for both security and privacy than its predecessors. Finally, we evaluate our solution from security, privacy, and efficiency perspectives, and also highlight how to reduce false positives in some specific indoor environments.

Russian Archival Documents on the Revitalization of Buddhism Among the Kalmyks in the Late Nineteenth and Early Twentieth Centuries

Baatr Kitinov’s paper uses Russian archival documents to examine the late nineteenth century revitalisation of Buddhism among the Russian Kalmyk population. He identifies three stages in this process: 1. 1860–1880, when Mongols wanted to “find” an incarnation of the Seventh Jebtsundamba Khutughtu among the Kalmyks (“Turgut”) in Russia or Olüts in Chinese Xinjiang; 2. 1880–1904, when the Dalai Lama was in Mongolia and Kalmyks traveled to Tibet; and 3. from 1904 to the first years of Soviet power, during which they maintained close contacts with the Dalai Lama. He also identifies three internal factors for the revitalization of Buddhism amongst the Kalmyks: 1. the revival of Tantrism in khurul practices; 2. the presence of Buddhists from other lands among Kalmyks; 3. and the Russian authorities permitting Kalmyks to visit the Dalai Lama in Urga.

The Positive Rate of Nucleic Acid Testing and the Epidemiological Characteristics of COVID-19 in Chongqing

ObjectiveThe purpose of this study is to analyze the positive rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid testing (NAT), cases of and deaths due to SARS-CoV-2, and the epidemiological characteristics of SARS-CoV-2 to identify high-risk populations.MethodsA retrospective study in Jiulongpo district of Chongqing was conducted by performing continuous observations of the frequency of SARS-CoV-2 NAT, analyzing the data of close contacts of patients and asymptomatic carriers, and collecting epidemiological data. Data were collected from January 20, 2020, when the first case of SARS-CoV-2 infection was reported, to March 26, 2020. Descriptive statistical analysis and Cochrane–Mantel–Haenszel analysis were used to compare the positive detection rates and positive diagnostic rates of different exposure groups.ResultsA total of 7,118 people received 10,377 SARS-CoV-2 nucleic acid tests in one district, and the SARS-CoV-2 positive rates were 0.40% (18/4446) and 0.15% (4/2672) in people receiving one and ≥ two nucleic acid tests (p = 0.06), respectively. Those with suspected cases (12.35%) and close contacts (8%) had higher positive rates than people tested at fever clinics (0.39%) (p < 0.001). The median latency (range) of cases was 5 (2, 9) days, and the median time from diagnosis to recovery was 22 (14, 25) days. One recovered patient received a positive test result at 28 days after recovery when she attempted to donate blood. Six clustered cases, including one patient who died, indicated persistent human-to-human transmission. One patient who was diagnosed after death was found to have infected 13 close contacts. People working in catering and other public service departments (36.36%) and people who are unemployed and retirees (45.45%) have an increased risk of infection compared with technical staff (9.09%) and farmers (9.09%).ConclusionThe total positive rate was low in the tested population, and more effective detection ranges should be defined to improve precise and differentiated epidemic control strategies. Moreover, in asymptomatic carriers, SARS-CoV-2 tests were positive after recovery, and patients with suspected SARS-CoV-2 infection who die may pose serious potential transmission threats.

The Structure of Social Networks and Its Link to Higher Education Students’ Socio-Emotional Loneliness During COVID-19

Lonely students typically underperform academically. According to several studies, the COVID-19 pandemic is an important risk factor for increases in loneliness, as the contact restrictions and the switch to mainly online classes potentially burden the students. The previously familiar academic environment (campus), as well as the exchange with peers and lecturers on site, were no longer made available. In our cross-sectional study, we examine factors that could potentially counteract the development of higher education student loneliness during the COVID-19 pandemic from a social network perspective. During the semester, N = 283 students from across all institutional faculties of a German comprehensive university took part in an online survey. We surveyed their social and emotional experiences of loneliness, their self-reported digital information-sharing behavior, and their current egocentric networks. Here, we distinguished between close online contacts (i.e., mainly online exchanges) and close offline contacts (i.e., mainly in-person face-to-face exchanges). In addition, we derived the interconnectedness (i.e., the densities of the egocentric networks) and heterogeneity (operationalized with the entropy) of students’ contacts. To obtain the latter, we used a novel two-step method combining t-distributed stochastic neighbor embedding (t-SNE) and cluster analysis. We explored the associations of the aforementioned predictors (i.e., information-sharing behavior, number of online and offline contacts, as well as interconnectedness and heterogeneity of the close contacts network) on social and emotional loneliness separately using two hierarchical multiple linear regression models. Our results suggest that social loneliness is strongly related to digital information-sharing behavior and the network structure of close contacts. In particular, high information-sharing behavior, high number of close contacts (whether offline or online), a highly interconnected network, and a homogeneous structure of close contacts were associated with low social loneliness. Emotional loneliness, on the other hand, was mainly related to network homogeneity, in the sense that students with homogeneous close contacts networks experienced low emotional loneliness. Overall, our study highlights the central role of students’ close social network on feelings of loneliness in the context of COVID-19 restrictions. Limitations and implications are discussed.

Factors preventing nosocomial outbreak following a single case of COVID-19 diagnosed during hospitalization: A retrospective review

Objective: Our hospital experienced a hospital shutdown and quarantine for two weeks after one case of COVID-19 was diagnosed during hospitalization. We analyzed the reopening process following hospital closure and possible factors that prevented hospital spread. Methods: We retrospectively reviewed the confirmed patient’s medical records and results of epidemiological survey available from the infection control team of our hospital. Results: A total of 117 hospital staff members were tested, 26 of whom were self-isolated. Of the 54 inpatients tested, 28 on the same floor and two close contacts in the endoscopic room were quarantined in a single room. Finally, all quarantined hospital staff, inpatients and outpatients were tested for COVID-19 on the 14th day of close contact. The results were all negative, and the hospital work completely resumed. Conclusion: Although closing and isolating the hospital appeared to have played a useful role in preventing the spread of COVID-19 inside the hospital and to the local community, it is still debated whether or not the duration of hospital closure or quarantine was appropriate. The lessons from the two-week hospital closure suggest that wearing a mask, hand hygiene and the ward environment are important factors in preventing nosocomial outbreaks of COVID-19.

Analysis of Bluetooth RSSI for Proximity Detection of Ship Passengers

Concern about the health of people who traveled onboard was raised during the COVID-19 outbreak on the Diamond Princess cruise ship. The ship’s narrow space offers an environment conducive to the virus’s spread. Close contact isolation remains one of the most critical current measures to stop the virus’s rapid spread. Contacts can be identified efficiently by detecting intelligent devices nearby. The smartphone’s Bluetooth RSSI signal is essential data for proximity detection. This paper analyzes Bluetooth RSSI signals available to the public and compares RSSI signals in two distinct poses: standing and sitting. These features can improve accuracy and provide an essential basis for creating algorithms for proximity detection. This allows for improved accuracy in identifying close contacts and can help ships sustainably manage persons onboard in the post-epidemic era.

Semi-Private Spheres as Safe Spaces for Young Social Media Users' Political Conversation

The incorporation of social media as spaces for political participation performances—especially among youth—has brought various issues into debate, including the formats of these practices and, at the same time, the significances of these repertoires for public conversation. In order to address this topic, this chapter explores the digital practices of political participation among young people in Argentina. Based on a qualitative approach in which 30 in-depth interviews to people from 18 to 24 years old were carried out, the findings of this research note that these segments of the population join the discussion of issues on the public agenda using emojis and hashtags and prefer reduced digital spaces to talk with their close contacts about polarized issues in order to avoid the aggression and violence that they say they observe in the digital space.

How much does TB screening cost? A systematic review of economic evaluations

BACKGROUND: Systematic screening for TB has been recommended as a method to control TB on a global level; however, this involves significant costs that place a burden on the health system.METHODS: We conducted a systematic review of the existing economic literature on systematic screening for TB to summarise costs, cost-effectiveness and affordability, and the key factors that influence costs and cost-effectiveness. Specific populations of interest included the general population, children and close contacts of TB patients.RESULTS: We identified 21 studies that provided both cost and outcome data on TB screening among the populations of interest. All were from low- and middle-income settings. Studies were heterogenous in the intervention, and included costs and reported outcomes. The incremental cost-effectiveness ratio (ICER) estimates ranged from USD281 to USD698 per disability-adjusted life-year (DALY) averted among the general population, USD619/DALY averted among children and USD372–3,718/DALY averted among close contacts.CONCLUSION: Prevalence of TB among targeted high-risk groups was identified across the majority of studies as a driver of cost-effectiveness. The heterogeneity of the included costs and outcomes across the economic literature for systematic screening suggests a need for standardisation of included cost components and key economic evaluation methods to improve comparability and generalisability of results.

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

COVID-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

Probabilistic Combinatorial Model of the Epidemic for a University

The aim of the research was to identify the main causes of infection of teachers and students in a university. Two probabilistic combinatorial problems are considered analytically to determine the probabilities and rates of infection of teachers and students in a university as a result of the appearance of infected persons among the contingent of students. The mathematical apparatus of probability theory and combinatorics is used to solve the problems. For the factorials of combinations arising in the structure, the asymptotic Stirling’s formula is used. Convergent series arise in the final formulas, reflecting the multiplicity of scenarios of the probabilistic approach. Analytical formulas for the sums of series, probabilities and rates of infection of teachers and students are obtained. It is shown that the infection of teachers and students occurs through «dangerous» spatially close contacts, when a teacher and a student talk at a distance of less than 0.5 meter. It is impossible to exclude such contacts in the students’ environment during full-time study. Among teachers, there is also a less probable classroom mechanism of infection through the volume of air infected with viruses.