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Limited information is currently available on the prevalence of and risk factors for tuberculosis infection (TBI) among close contacts of patients with pulmonary TB (PTB) in China. In this study, we estimated the burden of TBI among close contacts using QuantiFERON-TB Gold In-Tube assay (QFT) and identified factors associated with TB transmission among this high-risk population. From January 1, 2018 to August 31, 2020, we identified laboratory-confirmed patients with PTB from a population-based, multicentered, cluster-randomized control trial for tuberculosis preventive treatment. Close contacts of these patients were identified, interviewed, and tested using the QFT assay. We estimated TBI prevalence and calculated ORs and 95% CIs for TBI risk factors. A total of 3138 index cases and 8117 close contacts were identified. Of these contacts, 36 had PTB (a prevalence of 443.51 cases/100 000 population). Among the remaining 7986 close contacts; 3124 (39.12%) reported a positive QFT result. QFT positivity was significantly associated with older age (adjusted OR, 1.77; [95% CI, 1.27–2.47], 2.20; [95% CI, 1.59–3.05], and 2.74; [95% CI, 1.96–3.82]) for age groups: 35–44, 45–54, and 55–64, respectively) when compared with a younger age group: 5–14; longer contact duration (adjusted OR, 1.44; 95% CI, 1.22–1.69); and sharing of a bedroom (adjusted OR, 1.39; 95% CI, 1.18–1.65). Our findings indicate a high TBI burden among the close contacts of PTB. The results also highlighted that contact tracing and investigation for TBI are necessary and beneficial, particularly for those who are older, have had a longer contact duration, and share a bedroom. [ABSTRACT FROM AUTHOR]

The adoption of COVID-19 contact tracing apps (CTAs) has been proposed as an important measure to contain the spread of COVID-19. Based on a cross-national dataset, this article analyzes public perceptions toward CTAs and the factors that drive CTA acceptance in China, Germany, and the United States. We find that public acceptance of CTAs is significantly higher in China as compared with Germany and the United States. Despite very different sociopolitical contexts, there are striking similarities in the factors that drive CTA acceptance in all three countries. Citizens are willing to accept digital contact tracing despite concerns about privacy infringement and government surveillance, as long as the apps are perceived as effective in lowering infection rates and providing health information. This creates a chicken-and-egg problem for CTAs in Germany and the United States where CTAs are voluntary: a high citizen adoption rate is necessary for CTAs to be effective, but CTAs are only effective if adoption rates are high. [ABSTRACT FROM AUTHOR]

This article offers a critical analysis of China's health code system, a data-powered pandemic control and contact tracing system that supposedly subjects all individuals in the country to its panopticon control, a surveillance system that monitors and categorises the Chinese population into the healthy (green), the dubious (yellow), and the unhealthy (red). The article highlights the pretence of surveillance as care and the digital divide that normalises discrimination against the elderly and other digitally left-behind population. It also illustrates how, from policy making and technological design to user engagement, the health code system is implemented, optimised, and used in everyday life to meet the needs of the vulnerable population. The health code is better taken as a medium of adaptable and communicative process that can reset the relation between the system and the lifeworld. It is the process of interchange between the system and the lifeworld that deserves our critical attention. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) is a major global public health concern. Although the incidence of TB in China is declining, the country continues to face many challenges regarding TB control. This study aimed to develop an active case finding (ACF) strategy for high-risk populations in areas with high TB burden and evaluate the effectiveness of the ACF strategy for early TB detection in patients to reduce TB transmission. This was a descriptive study. From May to October 2019, active TB screening was conducted in Zhejiang Province, China. Overall, 24 high-burden townships were chosen as study sites. Residents aged ≥65 years, suffering from diabetes, diagnosed with HIV/AIDS, or with a history of TB were mobilized for screening. Chest radiography was performed for all participants in the community. Sputum specimens were collected for sputum smear tests and cultures at county-level TB-designed hospitals. A professional medical team performed the final diagnoses. Overall, 130,643 residents were included, accounting for 8.85% of the total population in the selected areas. After screening, 89 confirmed cases and 419 suspected cases were identified. The detection rates for suspected and confirmed cases were 320.72/100,000 and 68.12/100,000, respectively. Individuals with a history of TB accounted for a large proportion of detected cases, and the detection rate was higher among males than in females. This study identified 10.5% of reported cases in the selected areas in 2019. In Zhejiang province, compared with the previous year, the rates of TB notification in 2019 and 2020 declined by 7.0% and 7.4%, respectively, compared with the previous year. However, the TB notification rate in 2019 was almost the same as that in 2018 (a decline of 2.5%) but sharply declined in 2020 (14.4%) in the screened areas. Our findings suggest that the ACF strategy may have helped to maintain the downward trends in TB notification rates by detecting patients with TB and suspected cases in the short term. [ABSTRACT FROM AUTHOR]

During the COVID-19 pandemic, one technology for contact tracing has come to dominate – QR codes. As a technology pioneered in Japan two decades ago and mainstreamed in China, QR codes have quickly become part of quotidian placemaking. While locations such as China have fully incorporated QR code technology into everyday contexts including public transport and mobile wallet applications, QR codes in the West were relatively overlooked. That was, until the pandemic. In this article, we examine some of the ways QR codes are being imagined and reimagined as part of public placemaking practices. In order to do so, we begin with a short history of QR codes – emerging in Japan, becoming mainstream in China and their consequent uptake globally. We then discuss the methods of our Australian study conducted during the pandemic and the seamful/seamless findings from our study. [ABSTRACT FROM AUTHOR]

China had conducted some of the most stringent public health measures to control the spread of successive SARS-CoV-2 variants. However, the effectiveness of these measures and their impacts on the associated disease burden have rarely been quantitatively assessed at the national level. To address this gap, we developed a stochastic age-stratified metapopulation model that incorporates testing, contact tracing and isolation, based on 419 million travel movements among 366 Chinese cities. The study period for this model began from September 2022. The COVID-19 disease burden was evaluated, considering 8 types of underlying health conditions in the Chinese population. We identified the marginal effects between the testing speed and reduction in the epidemic duration. The findings suggest that assuming a vaccine coverage of 89%, the Omicron-like wave could be suppressed by 3-day interval population-level testing (PLT), while it would become endemic with 4-day interval PLT, and without testing, it would result in an epidemic. PLT conducted every 3 days would not only eliminate infections but also keep hospital bed occupancy at less than 29.46% (95% CI, 22.73–38.68%) of capacity for respiratory illness and ICU bed occupancy at less than 58.94% (95% CI, 45.70–76.90%) during an outbreak. Furthermore, the underlying health conditions would lead to an extra 2.35 (95% CI, 1.89–2.92) million hospital admissions and 0.16 (95% CI, 0.13–0.2) million ICU admissions. Our study provides insights into health preparedness to balance the disease burden and sustainability for a country with a population of billions. Author summary: As China continues to be challenged by successive SARS-CoV-2 variants, rethinking population health, broader than health-care system alone, is a prerequisite for health preparedness. China has introduced several changes to its public health measures in response to evolving pandemic risk, however, the effectiveness of public health measures in controlling COVID-19 outbreaks in China and their impacts on the associated disease burden have not been quantitatively assessed at the national level. Here, we developed a stochastic age-stratified metapopulation model based on high resolution human mobility data to address these questions. Our results suggest that there's marginal effects between the testing speed and reduction in the epidemic duration. With a rapid implementation of population-level testing and a short response lag would be critical if aiming at suppression of potential future SARS-CoV-2 waves in China. Furthermore, the underlying health conditions would lead to extra hospital admissions and ICU admissions, where obesity is expected to contribute to most extra hospital admissions, while hypertension could contribute to most extra ICU admissions. [ABSTRACT FROM AUTHOR]

This study explores the Health Code (Chinese: 健康码), a digital contact tracing application used in Mainland China during the COVID-19 pandemic, and examines the process and impact of its entry into users' lives and gradual infrastructuralisation within the field of internet infrastructure research. Results show that techno-nationalism was the basis for the inception, implementation, and development of the Health Code. Furthermore, the Health Code has gradually transformed from an early digital health credential into a type of 'access infrastructure' by linking physical, information, and communication infrastructure. As access infrastructure, the relationship between the Health Code and users was a tense one, with users actively engaging in 'micro-help' on social media platforms and performing 'soft-resistance' on psychological and operational levels. Concurrently, the Health Code was embedded into users' usage habits and social culture, becoming a shared memory and potential digital infrastructure for the future. [ABSTRACT FROM AUTHOR]

Targeted public health interventions for an emerging epidemic are essential for preventing pandemics. During 2020-2022, China invested significant efforts in strict zero-COVID measures to contain outbreaks of varying scales caused by different SARS-CoV-2 variants. Based on a multi-year empirical dataset containing 131 outbreaks observed in China from April 2020 to May 2022 and simulated scenarios, we ranked the relative intervention effectiveness by their reduction in instantaneous reproduction number. We found that, overall, social distancing measures (38% reduction, 95% prediction interval 31-45%), face masks (30%, 17-42%) and close contact tracing (28%, 24-31%) were most effective. Contact tracing was crucial in containing outbreaks during the initial phases, while social distancing measures became increasingly prominent as the spread persisted. In addition, infections with higher transmissibility and a shorter latent period posed more challenges for these measures. Our findings provide quantitative evidence on the effects of public-health measures for zeroing out emerging contagions in different contexts. China maintained a 'zero-COVID' policy from early in the pandemic until late 2022 that employed various public health interventions with the aim of COVID-19 containment. Here, the authors use data from 131 outbreaks in China to estimate the effects of a range of interventions against different SARS-CoV-2 variants in diverse settings. [ABSTRACT FROM AUTHOR]

This article uses the app Health Code, a smartphone-based application for contact tracing and risk assessment that serves as a COVID-19 health passport, as an example to explore how "biometric citizenship," a new mode of preemptive social regulation, functions and malfunctions in contemporary China. First, through a review of China's transition from socialism to neoliberalism, the authors trace how the tenet of citizenship shifts from biological/biopolitical to biometric as the party-state's agenda changes along the process. Second, drawing on media coverage and comments from social media, we show how Health Code consolidates the biometric paradigm of citizenship and turns the relatively stabilized temporal basis of biological/biopolitical citizenship into fragmented temporalities to tighten social control. This preemptive control system improves the state's acumen for self-revamping and self-preservation and enhances its capacities to harness people's re/productivities. It also disrupts the habituated way of living and further marginalizes the groups with diminishing re/productive potentialities. [ABSTRACT FROM AUTHOR]

Introduction: Brucellosis was made statutorily notifiable in 1955, in China, while in Guizhou Province, the pathogen of human brucellosis was isolated for the first time in 2011. However, currently, the brucellosis epidemic is becoming more and more severe in Guizhou Province. The type distribution and genetic characteristics of Brucella in Guizhou Province, as well as its evolutionary relationship with domestic and foreign strains, are still unclear. Methods: MLST, MLVA, and rpoB typing techniques were used for the molecular epidemiological study of the 83 Brucella isolates in Guizhou province. Results: Among the 83 Brucella strains, MLST identified three ST genotypes, of which ST39 is a newly reported type in China. MLVA-16 generated 49 genotypes, and MLVA-11 generated 5 known genotypes and 2 unreported genotypes. Six genotypes were identified by rpoB technology. Discussion: MLVA has a high resolution, but differences at the Bruce 04 and 16 loci cannot exclude associations between epidemics, and combining MLST and rpoB typing methods for epidemiologic tracing can avoid erroneous judgments. Moreover, through the combined analysis of the three typing techniques, the possible origin of the new Brucella can be reasonably inferred, which is also conducive to promoting the subsequent research of the novel Brucella. [ABSTRACT FROM AUTHOR]

Background: The use of big data in public health will facilitate more specialised, targeted research and clinical trials that will help stratify and separate groups of people who are at risk for various health issues. During the recent COVID-19 pandemic, big data was used to store enormous information about COVID-19 patients, which was used to identify cases and allocate public health resources appropriately. This also allowed scientists, health workers, and epidemiologists to make informed decisions and inspire medical innovation. Objectives: This scoping systematic review aimed to systematically describe the application of big data analytics in contact tracing for covid-19 surveillance. Materials and Methods: A systematic search was conducted in Scopus, ScienceDirect and EBSCOhost following Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR) guidelines, from November until December 2022. The following keywords were used for searching related articles: “big data analytic” AND “contact tracing” OR “closed contact*” AND “Covid19” OR “SARS-CoV2” AND “surveillance”. All included original articles were published in English from the year 2020 until 2022 were imported into EndNote20 for further storage, organization and review processes. Result: Upon rigorous searching and screening, a total of seven studies met the inclusion and exclusion criteria: 3 eligible articles were from China, 1 from Taiwan, 1 from Saudi Arabia, 1 from the United States, and 1 from Italy. Types of big data are digital technology using mobile apps and mobile Geo positioning, spatial-temporal GPS information, earth cognitive system satellites data and visualization tool data-driven documents. Conclusion: Big Data Analysis is essential because it can process and analyse large amounts of data quickly, allowing rapid reactions and timely solutions. Compared to traditional methods, it plays a substantial and effective role in the prevention and management of COVID-19. This analysis shows that this technology is a useful tool for contact tracing, breaking the chain of transmission, and guaranteeing quarantine compliance. [ABSTRACT FROM AUTHOR]

This article critically examines South Korea and China's COVID-19 tracking apps by bridging surveillance studies with feminist technoscience's understanding of the "politics of care". Conducting critical readings of the apps and textual analysis of discursive materials, we demonstrate how the ideological, relational, and material practices of the apps strategically deployed "care" to normalize a particular form of pandemic technogovernance in these two countries. In the ideological dimension, media and state discourse utilized a combination of vilifying and nationalist rhetoric that framed one's acquiescence to surveillance as a demonstration of national belonging. Meanwhile, the apps also performed ambivalent roles in facilitating essential care services and mobilizing self-tracking activities, which contributed to the manufacturing of pseudonormality in these societies. In the end, we argue that the Chinese and South Korean governments managed to frame their aggressive surveillance infrastructure during COVID-19 as a form of paternalistic care by finessing the blurred boundaries between care and control. [ABSTRACT FROM AUTHOR]

• A total of 66,583 close contacts were included to estimate contact patterns. • Interventions reduce contact in public but increase contact within households. • Asymptomatic cases account for over 65% of cases with a high number of contacts. • Asymptomatic cases make up over 80% of cases that caused a high number of secondary cases. To evaluate the impact of early implementation of public health and social measures (PHSMs) on contact rates over time and explore contact behavior of asymptomatic versus symptomatic cases. We used the largest contact tracing data in China thus far to estimate the mean contacts over time by age groups and contact settings. We used bootstrap with replacement to quantify the uncertainty of contact matrixes. The Pearson correlation was performed to demonstrate the number of contacts over time in relation to the evolution of restrictions. In addition, we analyzed the index cases with a high number of contacts and index cases that produced a high number of secondary cases. Rapidly adapted PHSMs can reduce the mean contact rates in public places while increasing the mean contact rates within households. The mean contact rates were 11.81 (95% confidence interval, 11.61-12.01) for asymptomatic (at the time of investigation) cases and 6.70 (95% confidence interval, 6.54-6.87) for symptomatic cases. The percentage of asymptomatic cases (at the time of investigation) meeting >50 close contacts make up more than 65% of the overall cases. The percentage of asymptomatic cases producing >10 secondary cases account for more than 80% of the overall cases. PHSMs may increase the contacts within the household, necessitating the need for pertinent prevention strategies at home. Asymptomatic cases can contribute significantly to Omicron transmission. By making asymptomatic people aware that they are already contagious, hence limiting their social contacts, it is possible to lower the transmission risk. [ABSTRACT FROM AUTHOR]

Regarding the problem of epidemic outbreak prevention and control, infectious disease dynamics models cannot support urban managers in reducing urban-scale healthcare costs through community-scale control measures, as they usually have difficulty meeting the requirements for simulation at different scales. In this paper, we propose combining contact networks at different spatial scales to study the COVID-19 outbreak in Shanghai from March to July 2022, calculate the initial R t through the number of cases at the beginning of the outbreak, and evaluate the effectiveness of dynamic non-pharmaceutical interventions (NPIs) adopted at different time periods in Shanghai using our proposed approach. In particular, our proposed contact network is a three-layer multi-scale network that is used to distinguish social interactions occurring in areas of different sizes, as well as to distinguish between intensive and non-intensive population contacts. This susceptible–exposure–infection–quarantine–recovery (SEIQR) epidemic model constructed based on a multi-scale network can more effectively assess the feasibility of small-scale control measures, such as assessing community quarantine measures and mobility restrictions at different moments and phases of an epidemic. Our experimental results show that this model can meet the simulation needs at different scales, and our further discussion and analysis show that the spread of the epidemic in Shanghai from March to July 2022 can be successfully controlled by implementing a strict long-term dynamic NPI strategy. [ABSTRACT FROM AUTHOR]

The concept of Government as a Platform (GaaP) has recently encountered setbacks in practice worldwide. While existing literature on inter‐governmental collaboration has emphasized organizational restructuring and data sharing, this study argues that a pragmatic way to improve administrative efficiency in the absence of formal institutional change is to adopt an alternative model to GaaP: platform‐enabled government. Enabled by innovations of the middle‐tier platform, this new model of platform governance integrates the functions of distributed systems of multiple departments into a sequential workflow without the requirement of institutional reform or sharing proprietary data. To demonstrate how this model facilitates information flow across institutional boundaries and improves collaborative governance, we analyze horizontal, vertical, and public‐private collaboration using a diverse case study design. We examine administrative review, law enforcement, and contact tracing during the pandemic in the context of China. Our findings suggest accommodating institutional boundaries is a practical and effective approach to advance the digital government agenda in decentralized contexts. [ABSTRACT FROM AUTHOR]

Background: During October 2021, China experienced localized outbreaks of COVID-19 in many cities. We analyzed the small local outbreak in Zunyi (Guizhou Province), a major city in southwestern China, and modeled the effects of different interventions on this outbreak. Methods: Data on infections and contacts, provided by the Health Commission of Guizhou Province, were used to analyze the epidemiological characteristics of the outbreak and calculate the effectiveness of vaccination. A branching process model was used to simulate the outbreak. This model considered the time interval from exposure of the initial case to confirmation, the number of potential infections caused by the initial case, and the effects of the different interventions. Results: From 18 to 25 October 2021, there were 12 patients with COVID-19 in Zunyi. Overall, the average age was 67.17 years-old, 8 patients were females, and 1 patient had an asymptomatic infection. The effectiveness of two-dose inactivated vaccine against SARS-CoV-2 infection was 16.7% (95% CI: 2.8% to 99.7%). The initial case was infected on 11 or 12 October 2021, 6.40 (95% CI: 6.37, 6.42; IQR: 4.92, 7.63) days before confirmation while the travelling in Lanzhou (Gansu Province). There were 10.07 (95% CI: 10.04, 10.09; IQR: 7.86, 11.93) potential secondary cases. When the effective vaccine coverage reached 60%, the probability of cumulative cases exceeding 20 was less than 8.77%, even if contact tracing was relaxed or eliminated. However, if the probability of tracing contacts decreased, earlier initiation of nucleic acid testing was necessary to control the outbreak. Conclusions: The COVID-19 outbreak in Zunyi was controlled quickly due to moderately effective vaccine coverage and rapid contact tracing. For controlling localized outbreaks, vaccination and contact tracing seemed to be more effective than massive nucleic acid testing in the initial phase of transmission. However, if there is low effective vaccine coverage or insufficient contact tracing, nucleic acid testing should start earlier. [ABSTRACT FROM AUTHOR]

Background From August to September 2022, Urumqi, the capital of the Xinjiang Uygur Autonomous Region in China, faced its largest COVID-19 outbreak caused by the emergence of the SARS-CoV-2 Omicron BA.5.2 variants. Although the superspreading of COVID-19 played an important role in triggering large-scale outbreaks, little was known about the superspreading potential and heterogeneity in the transmission of Omicron BA.5 variants. Methods In this retrospective observational, contact tracing study, we identified 1139 laboratory-confirmed COVID-19 cases of Omicron BA.5.2 variants, and 51323 test-negative close contacts in Urumqi from 7 August to 7 September 2022. By using detailed contact tracing information and exposure history of linked case-contact pairs, we described stratification in contact and heterogeneity in transmission across different demographic strata, vaccine statuses, and contact settings. We adopted beta-binomial models to characterise the secondary attack rate (SAR) distribution among close contacts and modelled COVID-19 transmission as a branching process with heterogeneity in transmission governed by negative binomial models. Results After the city lockdown, the mean case cluster size decreased from 2.0 (before lockdown) to 1.6, with decreased proportions of contacts in workplace and community settings compared with household settings. We estimated that 14% of the most infectious index cases generated 80% transmission, whereas transmission in the community setting presented the highest heterogeneity, with 5% index cases seeding 80% transmission. Compared with zero, one, and two doses of inactivated vaccine (Sinopharm), index cases with three doses of vaccine had a lower risk of generating secondary cases in terms of the reproduction number. Contacts of female cases, cases with ages 0-17 years, and household settings had relatively higher SAR. Conclusions In the context of intensive control measures, active case detection, and relatively high vaccine coverage, but with an infection-naive population, our findings suggested high heterogeneity in the contact and transmission risks of Omicron BA.5 variants across different demographic strata, vaccine statuses, and contact settings. Given the rapid evolution of SARS-CoV-2, investigating the distribution of transmission not only helped promote public awareness and preparedness among high-risk groups, but also highlighted the importance of continuously monitoring the transmission characteristics of genetic variants of SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Objective: Contact tracing plays an essential role in mitigating the impact of an epidemic. During the COVID‐19 pandemic, studies of those who have been in close contact with confirmed cases offer critical insights to understand the epidemiological characteristics of SARS‐CoV‐2 better. This study conducts a meta‐analysis of existing studies' infection rates and affecting factors. Methods: We searched PubMed, Web of Science and CNKI from the inception to April 30 2022 to identify systematic reviews. Two reviewers independently extracted the data and assessed risk of bias. Meta‐analyses were conducted to calculate pooled estimates by using Stata/SE 15.1 software. Results: There were 47 studies in the meta‐analysis. Among COVID‐19 close contacts, older age (RR = 1.94, 95% CI: 1.70, 2.21), contacts in households (RR = 2.83, 95% CI: 2.20, 3.65), and people in close contact with symptomatic infections (RR = 3.62, 95% CI: 1.88, 6.96) were associated with higher infection rates. Conclusion: On average, each primary infection corresponded to 5.8 close contacts. Among COVID‐19 close contacts, older age and contacts in households were associated with higher infection rates, and people in close contact with symptomatic infections had three times higher risk of infection compared to people in close contact with asymptomatic infections. In general, there are significantly more studies from China about close contacts, and the infection rate among close contacts was lower compared to other countries. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has radically expanded the role of algorithmic governance in everyday mobility. In China, urban and provincial governments have introduced health codes app as a national contract tracing and quarantine enforcement method to restrict the movements of "risky" individuals through malls, subways, railways, as well as between regions. Yet the health codes have been implemented with uneven efficacy and unexpected consequences. Drawing on glitch politics, we read these unintended consequences as "bugs" emerging from the introduction of platform-based management into everyday life. These bugs mediated individuals' lived experiences of the digital app and the hybrid space constituted by population governance, individual digital navigation, and technology. Drawing on a database of posts scraped from Zhihu, a popular Chinese question-and-answer site, we examine three dimensions of the bug: the algorithmic bug, the territorial bug, and the corporeal bug. This paper sheds light on the significance of end-user experiences in digital infrastructure and contributes to our understanding of the digital geographies of bugs in algorithmic governance and platform urbanism. [ABSTRACT FROM AUTHOR]

(1) The overall trends of the number of daily close contacts and infected cases as well as their association during an epidemic of Omicron Variant of SARS-CoV-2 have been poorly described. (2) Methods: This study was to describe the trends during the epidemic of the Omicron variant of SARS-CoV-2 in Shenzhen, China, including the number of close contacts and infected cases as well as their ratios by days and stages (five stages). (3) Results: A total of 1128 infected cases and 80,288 close contacts were identified in Shenzhen from 13 February 2022 to 1 April 2022. Before the citywide lockdown (14 March), the number of daily close contacts and infected cases gradually increased. However, the numbers showed a decrease after the lockdown was imposed. The ratio of daily close contacts to daily infected cases ranged from 20.2:1 to 63.4:1 and reached the lowest during the lockdown period. The growth rate of daily close contacts was consistent with those of infected cases observed 6 days later to some extent. (4) Conclusions: The Omicron variant epidemic was promptly contained by tracing close contacts and taking subsequent quarantine measures. [ABSTRACT FROM AUTHOR]

Background: Countries that aimed for eliminating the cases of COVID-19 with test-trace-isolate policy are found to have lower infections, deaths, and better economic performance, compared with those that opted for other mitigation strategies. However, the continuous evolution of new strains has raised the question of whether COVID-19 eradication is still possible given the limited public health response capacity and fatigue of the epidemic. We aim to investigate the mechanism of the Zero-COVID policy on outbreak containment, and to explore the possibility of eradication of Omicron transmission using the citywide test-trace-isolate (CTTI) strategy. Methods: We develop a compartmental model incorporating the CTTI Zero-COVID policy to understand how it contributes to the SARS-CoV-2 elimination. We employ our model to mimic the Delta outbreak in Fujian Province, China, from September 10 to October 9, 2021, and the Omicron outbreak in Jilin Province, China for the period from March 1 to April 1, 2022. Projections and sensitivity analyses were conducted using dynamical system and Latin Hypercube Sampling/ Partial Rank Correlation Coefficient (PRCC). Results: Calibration results of the model estimate the Fujian Delta outbreak can end in 30 (95% confidence interval CI: 28–33) days, after 10 (95% CI: 9–11) rounds of citywide testing. The emerging Jilin Omicron outbreak may achieve zero COVID cases in 50 (95% CI: 41–57) days if supported with sufficient public health resources and population compliance, which shows the effectiveness of the CTTI Zero-COVID policy. Conclusions: The CTTI policy shows the capacity for the eradication of the Delta outbreaks and also the Omicron outbreaks. Nonetheless, the implementation of radical CTTI is challenging, which requires routine monitoring for early detection, adequate testing capacity, efficient contact tracing, and high isolation compliance, which constrain its benefits in regions with limited resources. Moreover, these challenges become even more acute in the face of more contagious variants with a high proportion of asymptomatic cases. Hence, in regions where CTTI is not possible, personal protection, public health control measures, and vaccination are indispensable for mitigating and exiting the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

The first case of Corona Virus Disease 2019 (COVID-19) was reported in Wuhan, China in December 2019. Since then, COVID-19 has quickly spread out to all provinces in China and over 150 countries or territories in the world. With the first level response to public health emergencies (FLRPHE) launched over the country, the outbreak of COVID-19 in China is achieving under control in China. We develop a mathematical model based on the epidemiology of COVID-19, incorporating the isolation of healthy people, confirmed cases and contact tracing measures. We calculate the basic reproduction numbers 2.5 in China (excluding Hubei province) and 2.9 in Hubei province with the initial time on January 30 which shows the severe infectivity of COVID-19, and verify that the current isolation method effectively contains the transmission of COVID-19. Under the isolation of healthy people, confirmed cases and contact tracing measures, we find a noteworthy phenomenon that is the second epidemic of COVID-19 and estimate the peak time and value and the cumulative number of cases. Simulations show that the contact tracing measures can efficiently contain the transmission of the second epidemic of COVID-19. With the isolation of all susceptible people or all infectious people or both, there is no second epidemic of COVID-19. Furthermore, resumption of work and study can increase the transmission risk of the second epidemic of COVID-19. [ABSTRACT FROM AUTHOR]

Background: Tuberculosis (TB) seriously threatens individual and public health. Recently, TB outbreaks in schools have been reported more frequently in China and have attracted widespread attention. We reported three TB outbreaks in high schools in Hunan Province, China. Methods: When a tuberculosis patient was reported in a school, we carried out field epidemiological investigations, including tuberculin skin testing (TST), chest X-ray (CXR) and laboratory test for all close contacts, and whole-genome sequencing (WGS) analyses to understand the transmission patterns, the causes and the risk factors for the outbreaks, thereby providing a foundation for the control of TB epidemics in schools. Results: A total of 49 students with TB patients were identified in the three schools where TB outbreaks occurred, including nine patients in School A, 14 patients in School B, and 26 patients in School C. In Schools A, B and C, the putative attack rates in the classes of the index case were 13.8% (8/58), 7.6% (5/66), and 40.4% (21/52), while the putative attack rates of expanding screening in the school were 0.3% (1/361), 0.2% (9/3955), and 0.2% (5/2080), respectively. Thirteen patients had patient delay, with a median delay interval of 69 days (IQR 30.5– 113 days). Twelve patients had a healthcare diagnostic delay with a median delay interval of 32 days (IQR 24– 82 days). Phylogenetic analysis of culture-positive patients revealed that most of them shared a small genetic distance (≤ 12 SNPs), with three separate genetic clusters (including one MDR-TB genomic cluster), indicating the recent transmission of Mycobacterium tuberculosis strains. Conclusion: This combination of field investigation and WGS analysis revealed the transmission of three TB outbreaks in schools. Reinforced implementation is needed to improve timely case finding and reduce diagnosis delay in routine TB control in the school population. [ABSTRACT FROM AUTHOR]

Approximately 80% of primary healthcare facilities in China were ready to deliver hepatitis care services by 2021. This study aimed to assess hepatitis B and C test uptake, identify the factors associated with testing and determine the predictors of hepatitis stigma among primary care patients. We conducted a cross‐sectional survey among patients seeking care in the family medicine and primary care unit of the University of Hong Kong‐Shenzhen Hospital, China. Participants were 30 years or older and had not tested for HBV and HCV in the preceding 12 months. Test uptake was defined as self‐reported previous HBV and HCV testing. Descriptive statistics, Chi‐square test, forward multivariable logistic regression and stepwise multiple linear regression were conducted, and a p‐value <.05 was deemed statistically significant. A total of 750 eligible patients completed the survey, and 54.5% (404 ± 0.9) were between 30 and 40 years old. Most participants were heterosexuals 98.0% (n = 735), female 57.5% (n = 431), married 78.3% (587) and earned ≤1500 USD per month 54.4% (n = 408). A 66.1% (n = 496) and 13.7% (n = 103) self‐reported previous HBV and HCV testing, respectively, and 62% (n = 468) were vaccinated. HCV testing was associated with HBV testing (aOR = 13.7, 95% CI:2.1–91.5); and HBV testing was associated with family history of HBV (aOR = 2.4, 95%CI:1.1–5.5). Overall hepatitis stigma was about average and decreased with family history of HBV (p =.017). In conclusion, HCV testing uptake among primary care patients was low and needs to be further promoted. Integrating HBV and HCV testing interventions and fostering family‐based support for disclosure could effectively improve testing uptake. [ABSTRACT FROM AUTHOR]

Background: HIV partner notification services (HIV PS) have been poorly implemented in most low- and middle-income countries, including China. Understanding the social context of partner services for key populations is important for scaling up HIV testing services. This study aims to examine facilitators and barriers of HIV PS using qualitative analysis.Methods: This article qualitatively analyzed the texts obtained from a crowdsourcing open call and adopted the socioecological framework to understand the social context of Chinese men who have sex with men (MSM) living with HIV that influenced their uptake of HIV partner services. Crowdsourcing means collecting ideas from and sharing solutions with the public. The open call was held to solicit ideas to enhance HIV partner services for Chinese MSM. Two coders conducted a content analysis of the texts from the submissions using inductive and deductive coding methods to identify facilitators and barriers of HIV PS.Results: Textual data from 53 submissions were analyzed. The most mentioned barrier, stigma associated with HIV PS, was deeply embedded at several levels, highlighting the urgent need for stigma reduction. Among the facilitators, many people mentioned anonymous online notification could protect the privacy and avoid social harm for index partners. Differentiated partner services may improve HIV PS uptake by providing tailored intervention according to the individual circumstances. Some people suggested implicit notification, which meant testing the attitude of the partner before direct disclosure. This was feasible and acceptable in many settings.Conclusions: The unique social context of MSM living with HIV provides opportunities for embedding HIV partner services. More clinical trials that test the acceptability and effectiveness of the HIV PS interventions are needed. [ABSTRACT FROM AUTHOR]

Heath code apps, along with robust testing, isolation, and the care of cases, are a vital strategy for containing the spread of the COVID-19 outbreak in China. They have remained stable and consistent, allowing China to extensively restore its social and economic development. However, the ethical and legal boundaries of deploying health code apps for disease surveillance and control purposes are unclear, and a rapidly evolving debate has emerged around the promises and risks of their fast promotion. The article outlines the legal challenges by applying the core values of the Personal Information Protection Law (PIPL), the fundamental law for personal information protection in China, into the context of the nationwide use of health code apps. It elaborates on the balance between the demands for upholding individuals' rights to the security of their personal information and those for public access to such information to prevent the spread of infectious diseases. It identifies the current gaps in addressing personal information harms during the use of the apps, particularly with regard to user consent, transparency, necessity, storage duration, and security safeguards. [ABSTRACT FROM AUTHOR]

As states increasingly use algorithms to improve the legibility of society, particularly during the COVID-19 pandemic, it is common for concerns about the expanding power of the algorithm or the state to be raised in a deterministic manner. However, how are the algorithms for states' legibility projects enacted, contested, and reconfigured? Drawing on interviews and media data, this study fills this gap by examining Health Code (jiankangma), the Chinese contact tracing and risk assessment algorithmic system that serves as the COVID-19 health passport. I first explore the intensive and invisible work and infrastructures that enact and stabilize Health Code's sociotechnical assemblage. I then show how this assemblage is frequently challenged and destabilized by errors, breakdowns, and exclusions. Facing unintended engagements from heterogeneous social actors, local interests, and power hierarchies, Health Code reassembles into multiple and contradictory assemblages at different periods and social localities. Finally, I examine how people game and bypass the algorithm's surveillance with their agencies. Recognizing this messiness and heterogeneity contributes to a more nuanced and realistic understanding of states' use of algorithms, including the risks. Doing so also urges us to rethink the politics of citizenship and inequality in the digital age beyond inclusion. [ABSTRACT FROM AUTHOR]

Objective: In order to facilitate the tracing of infectious diseases in a small area and to effectively carry out disease control and epidemiological investigations, this research proposes a novel spatiotemporal model to estimate effective reproduction number(Re)for infectious diseases, based on the fundamental concept of contact tracing., Methods: This study utilizes the incidence of hand, foot, and mouth disease (HFMD) among children in Bishan District, Chongqing, China from 2015 to 2019. The study incorporates the epidemiological characteristics of HFMD and aims to construct a Spatiotemporal Correlation Discrimination of HFMD. Utilizing ARC ENGINE and C# programming for the creation of a spatio-temporal database dedicated to HFMD to facilitate data collection and analysis. The scientific validity of the proposed method was verified by comparing the effective reproduction number obtained by the traditional SEIR model., Results: We have ascertained the optimal search radius for the spatiotemporal search model to be 1.5 km. Upon analyzing the resulting Re values, which range from 1.14 to 4.75, we observe a skewed distribution pattern from 2015 to 2019. The median and quartile Re value recorded is 2.42 (1.98, 2.72). Except for 2018, the similarity coefficient r of the years 2015, 2016, 2017, and 2019 were all close to 1, and p <0.05 in the comparison of the two models, indicating that the Re values obtained by using the search model and the traditional SEIR model are correlated and closely related. The results exhibited similarity between the Re curves of both models and the epidemiological characteristics of HFMD. Finally, we illustrated the regional distribution of Re values obtained by the search model at various time intervals on Geographic Information System (GIS) maps which highlighted variations in the incidence of diseases across different communities, neighborhoods, and even smaller areas., Conclusion: The model comprehensively considers both temporal variation and spatial heterogeneity in disease transmission and accounts for each individual's distinct time of onset and spatial location. This proposed method differs significantly from existing mathematical models used for estimating Re in that it is founded on reasonable scientific assumptions and computer algorithms programming that take into account real-world spatiotemporal factors. It is particularly well-suited for estimating the Re of infectious diseases in relatively stable mobile populations within small geographical areas., (© 2024. The Author(s).)

Background: Digital contact tracing (DCT) is a method of tracing contact relying on tracking systems using artificial intelligence (AI) as an epidemic prevention solution for the COVID-19 pandemic. This review compares the DCT systems such as Bluetooth, Quick Response (QR) code, Global Positioning System (GPS) or Radio Frequency Identification (RFID) technologies that are used in Malaysia, New Zealand and China during early COVID-19 pandemic. Materials and Methods: A review was conducted based on the multiple data sources from existing electronic articles, newspapers, press releases, government documents, reports and web pages that are available online. Result: There are five mobile applications and one Bluetooth device in used by these countries; Malaysia uses MySejahtera app and MyTrace app, New Zealand uses NZ Covid Trace and Bluetooth COVIDCard and China uses a Health Code app that is available in WeChat and Alipay. All apps are available in Apple store, Google Play and App Gallery, except the NZ COVID tracer is not supported by the App Gallery. All 3 countries utilise the QR code as the main DCT with additional features in a centralised data architecture framework. Based on other available databases; MySejahtera has recorded around 74.9% users in Malaysia as at December 2020, NZ CovidTrace logged around 55.1% as at 19th April 2021, and Alipay tracked around 64.3% as at early 2021. . Conclusion: Effective human resources management with digitalisation is crucial in managing pandemics with multi-approach public health interventions which could enhance public health outcomes with less public rejection. Integration of DCT during pandemic is advantageous and valuable for successful disease control. [ABSTRACT FROM AUTHOR]

Aim: The virulence of the novel coronavirus disease (COVID-19) has facilitated its rapid transition towards becoming a pandemic. Hence, this study aims to investigate the association between population migration and the number of confirmed COVID-19 cases in China while investigating its measures for pandemic prevention and control. Subject and methods: A susceptible–exposed–infected–recovered–dormancy (SEIRD) model for the spread of COVID-19 in China was created to theoretically simulate the relationship between the populations migrating from Wuhan and the number of confirmed cases. Data from Baidu's real-time dynamic pandemic monitoring system were elicited to empirically examine the theoretical inferences. Results: Populations migrating from Wuhan to other cities increased the initial number of latently infected cases in these cities, raising the number of confirmed cases. Hence, implementing social distancing between the susceptible and infected populations could effectively lower the number of infected cases. Using data from Baidu's real-time dynamic pandemic monitoring system, the empirical results revealed that an increase of 1000 persons migrating from Wuhan raised the number of confirmed cases by 4.82 persons. Conclusion: This study confirmed the positive association between population migration and the number of confirmed COVID-19 cases. Based on the theoretical and empirical analysis, China's pandemic prevention and control measures are discussed. [ABSTRACT FROM AUTHOR]

The SARS-CoV-2 B.1.617.2 (Delta) variant flared up in late May in Guangzhou, China. Transmission characteristics of Delta variant were analysed for 153 confirmed cases and two complete transmission chains with seven generations were fully presented. A rapid transmission occurred in five generations within 10 days. The basic reproduction number (R0) was 3.60 (95% confidence interval: 2.50–5.30). After redefining the concept of close contact, the proportion of confirmed cases discovered from close contacts increased from 43% to 100%. With the usage of a yellow health code, the potential exposed individuals were self-motivated to take a nucleic acid test and regained public access with a negative testing result. Facing the massive requirement of screening, novel facilities like makeshift inflatable laboratories were promptly set up as a vital supplement and 17 cases were found, with 1 pre-symptomatic. The dynamic adjustment of these three interventions resulted in the decline of Rt from 5.00 to 1.00 within 9 days. By breaking the transmission chain and eliminating the transmission source through extending the scope of the close-contact tracing, health-code usage and mass testing, the Guangzhou Delta epidemic was effectively contained. [ABSTRACT FROM AUTHOR]

This study focuses on the role of primary care in China's response to COVID-19. A retrospective, reflective approach was taken using data available to one of the authors who led the national community response to COVID-19, first in Wuhan and then multiple cities in ten provinces/municipalities across the country. At the peak of the pandemic, primary care providers shoulder various public health responsibilities and work in close partnerships with other key stakeholders in the local communities. Primary care providers keep playing a 'sentinel'/surveillance role in identifying re-emerging cases after the elimination of community transmissions of COVID-19. Critically, however, the pandemic once again highlights some key limitations of the primary care sector, including the lack of gatekeeping, limited capacity and weak integration between medical care and public health. [ABSTRACT FROM AUTHOR]

The coronavirus disease 2019 (COVID-19) pandemic has affected almost all countries and territories. As of December 6, 2020, the United States of America and India have the highest prevalence. Each country has implemented different strategies to control and reduce the spread of disease. Here, the association between prevalence number and health policies is evaluated by comparing 2 groups of countries: (1) Italy, the United States of America, Germany, Spain, and India with a higher prevalence than a linear trend line; and (2) Singapore and China with a lower or equal prevalence than linear forecasts. A rapid overview revealed that many countries have similar strategies for controlling COVID-19, including the suspension of air travel, the lockdown on the cities with the most cases detected, active case findings, monitoring of close contacts, and raising public awareness. Also, they used a gradual and phased plan to reopen activities. So, the difference between countries in the burden of COVID-19 can be attributable to the strict mode and nonstrict mode of implementation of strategies. Limitations at the national levels call for systemic rather than regional strategies. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19) is an infectious disease of humans caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the first case was identified in China in December 2019 the disease has spread worldwide, leading to an ongoing pandemic. In this article, we present an agent-based model of COVID-19 in Luxembourg, and use it to estimate the impact, on cases and deaths, of interventions including testing, contact tracing, lockdown, curfew and vaccination. Our model is based on collation, with agents performing activities and moving between locations accordingly. The model is highly heterogeneous, featuring spatial clustering, over 2000 behavioural types and a 10 minute time resolution. The model is validated against COVID-19 clinical monitoring data collected in Luxembourg in 2020. Our model predicts far fewer cases and deaths than the equivalent equation-based SEIR model. In particular, with R0 = 2.45, the SEIR model infects 87% of the resident population while our agent-based model infects only around 23% of the resident population. Our simulations suggest that testing and contract tracing reduce cases substantially, but are less effective at reducing deaths. Lockdowns are very effective although costly, while the impact of an 11pm-6am curfew is relatively small. When vaccinating against a future outbreak, our results suggest that herd immunity can be achieved at relatively low coverage, with substantial levels of protection achieved with only 30% of the population fully immune. When vaccinating in the midst of an outbreak, the challenge is more difficult. In this context, we investigate the impact of vaccine efficacy, capacity, hesitancy and strategy. We conclude that, short of a permanent lockdown, vaccination is by far the most effective way to suppress and ultimately control the spread of COVID-19. [ABSTRACT FROM AUTHOR]

During the COVID-19 pandemic, China has implemented the most stringent lockdown measures across major cities during moments of heightened risk of infection. This mechanism is aided by the mandated Health QR Code to surveil and contain spread of the virus. This research scrutinizes the varying degrees and forms of disconnect in the context of the Health Code mandate. Informed by extensive focus group interviews of diverse resident groups, supplemented with thematic analysis of 136 newspaper news stories covering the enforcement of the Health Code, the research results offer insight over the multiplicity of voluntary and involuntary disconnective practices at both the individual/internal and societal/external level. These findings are contextualized for their theoretical relevance towards the overall line of inquiry into information technology non-use, and the pragmatic implications of the Health Code are discussed for contact tracing app design and utility in general. [ABSTRACT FROM AUTHOR]

Objectives. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging virus causing substantial morbidity and mortality worldwide. We performed a cross-sectional investigation of SARS-CoV-2 clusters in Suzhou to determine the transmissibility of the virus among close contacts and to assess the demographic and clinical characteristics between index and secondary cases. Methods. We review the clustered patients with SARS-CoV-2 infections in Suzhou between 22 January and 29 February 2020. The demographic and clinical characteristics were compared between index and secondary cases. We calculated the basic reproduction number ( R 0 ) among close contacts with SLI model. Results. By 22 February, 87 patients with SARS-CoV-2 infection were reported, including 50 sporadic and 37 clustered cases, who were generated from 13 clusters. On admission, 5 (20.8%) out of 24 secondary cases were asymptomatic. The male ratio of index cases was significantly higher than that of secondary cases. Additionally, the index cases were more likely to have fever and increased CRP levels than the secondary cases. The R 0 values of clusters displayed a significantly declining trend over time for all clusters. The relative risk of infection in blood-related contacts of cases versus unrelated contacts was 1.60 for SARS-CoV-2 (95% CI: 0.42-2.95). Conclusions. In conclusion, SARS-CoV-2 has great person-to-person transmission capability among close contacts. The secondary cases are more prone to have mild symptoms than index cases. There is no increased RR of secondary infection in blood relatives versus unrelated contacts. The high rate of asymptomatic SARS-CoV-2 infections highlights the urgent need to enhance active case finding strategy for early detection of infectious patients. [ABSTRACT FROM AUTHOR]

Substantial tuberculosis transmission occurs outside of households, and tuberculosis surveillance in schools has recently been proposed. However, the yield of tuberculosis outcomes from school contacts is not well characterized. We assessed the prevalence of Mycobacterium tuberculosis infection among close school contacts by performing a systematic review. We searched PubMed, Elsevier, China National Knowledge Infrastructure, and Wanfang databases. Studies reporting the number of children who were tested overall and who tested positive were included. Subgroup analyses were performed by study location, index case bacteriological status, type of school, and other relevant factors. In total, 28 studies including 54,707 school contacts screened for M. tuberculosis infection were eligible and included in the analysis. Overall, the prevalence of M. tuberculosis infection determined by the QuantiFERON Gold in-tube test was 33.2% (95% CI, 0.0-73.0%). The prevalences of M. tuberculosis infection based on the tuberculin skin test (TST) using 5 mm, 10 mm, and 15 mm as cutoffs were 27.2% (95% CI, 15.1-39.3%), 24.3% (95% CI, 15.3-33.4%), and 12.7% (95% CI, 6.3-19.0%), respectively. The pooled prevalence of M. tuberculosis infection (using a TST ≥5-mm cutoff) was lower in studies from China (22.8%; 95% CI, 16.8-28.8%) than other regions (36.7%; 95% CI, 18.1-55.2%). The pooled prevalence of M. tuberculosis infection was higher when the index was bacteriologically positive (43.6% [95% CI, 16.5-70.8%] versus 23.8% [95% CI, 16.2-31.4%]). These results suggest that contact investigation and general surveillance in schools from high-burden settings merit consideration as means to improve early case detection in children.

The design of optimized non-pharmaceutical interventions (NPIs) is critical to the effective control of emergent outbreaks of infectious diseases such as SARS, A/H1N1 and COVID-19 and to ensure that numbers of hospitalized cases do not exceed the carrying capacity of medical resources. To address this issue, we formulated a classic SIR model to include a close contact tracing strategy and structured prevention and control interruptions (SPCIs). The impact of the timing of SPCIs on the maximum number of non-isolated infected individuals and on the duration of an infectious disease outside quarantined areas (i.e. implementing a dynamic zero-case policy) were analyzed numerically and theoretically. These analyses revealed that to minimize the maximum number of non-isolated infected individuals, the optimal time to initiate SPCIs is when they can control the peak value of a second rebound of the epidemic to be equal to the first peak value. More individuals may be infected at the peak of the second wave with a stronger intervention during SPCIs. The longer the duration of the intervention and the stronger the contact tracing intensity during SPCIs, the more effective they are in shortening the duration of an infectious disease outside quarantined areas. The dynamic evolution of the number of isolated and non-isolated individuals, including two peaks and long tail patterns, have been confirmed by various real data sets of multiple-wave COVID-19 epidemics in China. Our results provide important theoretical support for the adjustment of NPI strategies in relation to a given carrying capacity of medical resources., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background The relative contributions of asymptomatic, presymptomatic, and symptomatic transmission of severe acute respiratory syndrome coronavirus 2 have not been clearly measured, although control measures may differ in response to the risk of spread posed by different types of cases. Methods We collected detailed information on transmission events and symptom status based on laboratory-confirmed patient data and contact tracing data from 4 provinces and 1 municipality in China. We estimated the variation in risk of transmission over time and the severity of secondary infections by symptomatic status of the infector. Results There were 393 symptomatic index cases with 3136 close contacts and 185 asymptomatic index cases with 1078 close contacts included in the study. The secondary attack rates among close contacts of symptomatic and asymptomatic index cases were 4.1% (128 of 3136) and 1.1% (12 of 1078), respectively, corresponding to a higher transmission risk from symptomatic cases than from asymptomatic cases (odds ratio, 3.79; 95% confidence interval, 2.06–6.95). Approximately 25% (32 of 128) and 50% (6 of 12) of the infected close contacts were asymptomatic from symptomatic and asymptomatic index cases, respectively, while more than one third (38%) of the infections in the close contacts of symptomatic cases were attributable to exposure to the index cases before symptom onset. Conclusions Asymptomatic and presymptomatic transmissions play an important role in spreading infection, although asymptomatic cases pose a lower risk of transmission than symptomatic cases. Early case detection and effective test-and-trace measures are important to reduce transmission. [ABSTRACT FROM AUTHOR]

COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), spread rapidly and affected most of the world since its outbreak in Wuhan, China, which presents a major challenge to the emergency response mechanism for sudden public health events and epidemic prevention and control in all countries. In the face of the severe situation of epidemic prevention and control and the arduous task of social management, the tremendous power of science and technology in prevention and control has emerged. The new generation of information technology, represented by big data and artificial intelligence (AI) technology, has been widely used in the prevention, diagnosis, treatment and management of COVID-19 as an important basic support. Although the technology has developed, there are still challenges with respect to epidemic surveillance, accurate prevention and control, effective diagnosis and treatment, and timely judgement. The prevention and control of sudden infectious diseases usually depend on the control of infection sources, interruption of transmission channels and vaccine development. Big data and AI are effective technologies to identify the source of infection and have an irreplaceable role in distinguishing close contacts and suspicious populations. Advanced computational analysis is beneficial to accelerate the speed of vaccine research and development and to improve the quality of vaccines. AI provides support in automatically processing relevant data from medical images and clinical features, tests and examination findings; predicting disease progression and prognosis; and even recommending treatment plans and strategies. This paper reviews the application of big data and AI in the COVID-19 prevention, diagnosis, treatment and management decisions in China to explain how to apply big data and AI technology to address the common problems in the COVID-19 pandemic. Although the findings regarding the application of big data and AI technologies in sudden public health events lack validation of repeatability and universality, current studies in China have shown that the application of big data and AI is feasible in response to the COVID-19 pandemic. These studies concluded that the application of big data and AI technology can contribute to prevention, diagnosis, treatment and management decision making regarding sudden public health events in the future. [ABSTRACT FROM AUTHOR]

The incubation period and generation time are key characteristics in the analysis of infectious diseases. The commonly used contact‐tracing–based estimation of incubation distribution is highly influenced by the individuals' judgment on the possible date of exposure, and might lead to significant errors. On the other hand, interval censoring–based methods are able to utilize a much larger set of traveling data but may encounter biased sampling problems. The distribution of generation time is usually approximated by observed serial intervals. However, it may result in a biased estimation of generation time, especially when the disease is infectious during incubation. In this paper, the theory from renewal process is partially adopted by considering the incubation period as the interarrival time, and the duration between departure from Wuhan and onset of symptoms as the mixture of forward time and interarrival time with censored intervals. In addition, a consistent estimator for the distribution of generation time based on incubation period and serial interval is proposed for incubation‐infectious diseases. A real case application to the current outbreak of COVID‐19 is implemented. We find that the incubation period has a median of 8.50 days (95% confidence interval [CI] [7.22; 9.15]). The basic reproduction number in the early phase of COVID‐19 outbreak based on the proposed generation time estimation is estimated to be 2.96 (95% CI [2.15; 3.86]). [ABSTRACT FROM AUTHOR]

A one-step 3 h melting curve analysis-based technology for spacer oligonucleotide typing (McSpoligotyping) analyzed with the SITVIT2 database was applied to detect epidemiological events of Mycobacterium tuberculosis (MTB) in a coastal city of China from 2016 to 2018. 306 MTB isolates were identified by Fuzhou tuberculosis designated hospitals between 2016 and 2018. The results showed that the MTB isolates were divided into Beijing family and non-Beijing families, accounting for 45.42% (139/306) and 54.58% (167/306), respectively. H and T families were the prevalent genotypes in non-Beijing families. Herein, the spoligotyping technology has practical application for the classification and tracing of tuberculosis in the public. [ABSTRACT FROM AUTHOR]

Aim: To share our experiences of resuming the treatments for gynecologic patients after lifting the lockdown in a hotspot area for the Coronavirus Disease 2019 (COVID‐19) pandemic. Methods: The triage process used to resume medical activities for gynecologic patients at the Wuhan Union Hospital after a 76‐day lockdown of the city is described, and its effectiveness in preventing COVID‐19 nosocomial transmission is shown. Results: Nonemergency patients were pretriaged based on their contact history and body temperature at an outpatient clinic, and negative COVID‐19 screening test results were required for admission to the buffering rooms at the gynecologic department. The buffering lasted at least 3 days for symptom monitoring, and a second round of COVID‐19 testing was required before patients could be transferred to the regular gynecologic wards. For patients who needed emergency surgery, the first screening was completed at the isolation wards after surgery, followed by buffering at the gynecologic department. We received 19 298 outpatient visits, admitted 326 patients, and performed 223 operations in the first 2 months after the lockdown was lifted. No COVID‐19 cases occurred in the hospitalized patients, while the proportion of potentially high‐risk patients with cancer and severe anemia was increased in comparison to that observed during the same period in 2019 and the first 2 months of 2020 before the lockdown. Conclusions: We provide an effective triage system with buffering at two levels to guarantee safe and timely treatment for non‐COVID‐19 gynecologic patients in the postlockdown phase. [ABSTRACT FROM AUTHOR]

• In early 2020, the first large COVID-19 outbreak outside China occurred in Daegu • The SARS-CoV-2 strain involved in Daegu outbreak has an R0 of 3.6 (range: 2.3 to 5.6) • The Daegu outbreak was successfully controlled without restricting movement. • A combination of social distancing and testing-contact tracing is highly effective. • Both interventions must be enacted for successful control of an COVID-19 outbreak In Spring 2020, South Korea applied non-lockdown social distancing (avoiding mass gathering and non-essential social engagement, without restricting the movement of people who were not patients or contacts), testing-and-isolation (testing), and tracing-and-quarantine the contacts (contact tracing) to successfully control the first large-scale COVID-19 outbreak outside China. However, the relative contributions of these two interventions remain uncertain. We constructed an SEIR model of SARS-CoV-2 transmission (disproportionately through superspreading events) and fit the model to outbreak data in Daegu, South Korea, from February to April 2020. We assessed the effect of non-lockdown social distancing (population-wide control measures) and/or testing-contact tracing (individual-specific control measures), alone or combined, in terms of the basic reproductive number (R0) and the trajectory of the epidemic. The point estimate for baseline R0 is 3.6 (sensitivity analyses range: 2.3 to 5.6). Combined interventions of non-lockdown social distancing and testing-contact tracing can suppress R0 to less than one and rapidly contain the epidemic, even under the worst scenario with a high baseline R0 of 5.6. In contrast, either intervention alone will fail to suppress R0. Non-lockdown social distancing alone just postpones the peak of the epidemic, while testing-contact tracing alone only flattens the curve but does not contain the outbreak. To successfully control a large-scale COVID-19 outbreak, both non-lockdown social distancing and testing-contact tracing must be implemented. The two interventions are synergistic. [ABSTRACT FROM AUTHOR]

During the COVID‐19 pandemic, comprehensive, accurate, and timely digital contact tracing serves as a decisive measure in curbing viral transmission. Such a strategy integrates corporate innovation, government decision‐making, citizen participation, and community coordination with big data analytics. This article explores how key stakeholders in an open innovation ecosystem interact within the digital context to overcome challenges to public health and socio‐economic welfare imposed by the pandemic. To enhance the digital contact tracing effectiveness, communities are deployed to moderate the interactions between government, enterprises and citizens. As an example, we study the community‐based digital contact tracing in Wuhan, a representative case of China's 'virus exceptionalism' in COVID‐19 mitigation. We discuss the effectiveness of this strategy and raise critical ethical concerns regarding decision‐making in R&D management. [ABSTRACT FROM AUTHOR]

Background: Tuberculosis (TB) is caused by a bacterium called Mycobacterium tuberculosis (Mtb). China is the third in top 8 high TB burden countries and Guangxi is one of the high incidence areas in South China. Determine bacterial factors that affected TB incidence rate is a step toward Ending the TB epidemic.Results: Genomes of M. tuberculosis cultures from a relatively high and low incidence region in Guangxi have been sequenced. 347 of 358(96.9%) were identified as M. tuberculosis. All the strains belong to Lineage 2 and Lineage 4, except for one in Lineage 1. We found that the genetic structure of the M. tuberculosis population in each county varies enormously. Low incidence rate regions have a lower prevalence of Beijing genotypes than other regions. Four isolates which harbored mutT4-48 also had mutT2-58 mutations. It is suggested that strains from the ancestors of modern Beijing lineage is circulating in Guangxi. Strains of modern Beijing lineage (OR=2.04) were more likely to acquire drug resistances than Lineage 4. Most of the lineage differentiation SNPs are related to cell wall biosynthetic pathways.Conclusions: These results provided a higher resolution to better understand the history of transmission of M. tuberculosis from/to South China. And the incidence rate of tuberculosis might be affected by bacterial population structure shaped by demographic history. Our findings also support the hypothesis that Modern Beijing lineage originated in South China. [ABSTRACT FROM AUTHOR]

Introduction: In late 2019, a novel coronavirus was detected in China. Supported by its respiratory transmissibility, even by people infected without symptomatic disease, this coronavirus soon began to rapidly spread worldwide. Background: Many countries have implemented different infection control and containment strategies due to ongoing community transmission. In this context, contact tracing as well as adequate testing and consequent quarantining of high-risk contacts play leading roles in containing the virus by interrupting infection chains. This approach is especially important in the hospital setting where contacts often cannot be avoided and physical distance is usually not possible. Furthermore, health care workers (HCWs) usually have contact with a variety of vulnerable people, making it essential to identify infections among hospital employees as soon as possible to interrupt the rapid spread of SARS-CoV-2 in the facility. Several electronic tools for contact tracing, such as specific software or mobile phone apps, are available for the public health sector. In contrast, contact tracing in hospitals often has to be carried out without helpful electronic tools, and an enormous amount of human resources is typically required. Aim: For rapid contact tracing and effective infection control and management measures for HCWs in hospitals, adapted technical solutions are needed. Methods: In this study, we report the development of our containment strategy to a web-based contact tracing and rapid point-of-care-testing workflow. Results/conclusion: Our workflow yielded efficient control of the rapidly evolving situation during the SARS-CoV-2 pandemic from May 2020 until January 2021 at a German University Hospital. [ABSTRACT FROM AUTHOR]

Objective: Contact tracing has been used in China and several other countries in the WHO Western Pacific Region as part of the COVID-19 response. We describe COVID-19 cases and the number of contacts traced and quarantined per case as part of COVID-19 emergency public health response activities in China. Methods: We abstracted publicly available, online aggregated data published in daily COVID-19 situational reports by China's National Health Commission and provincial health commissions between 20 January and 29 February 2020. The number of new contacts traced by report date was computed as the difference between total contacts traced in consecutive reports. A proxy for the number of contacts traced per case was computed as the number of new contacts traced divided by the number of new cases. Results: During the study period, China reported 80 968 new COVID-19 cases and 659 899 contacts. In Hubei Province, there were 67 608 cases and 264 878 contacts, representing 83% and 40% of the total, respectively. Non-Hubei provinces reported tracing 1.5 times more contacts than Hubei Province; the weekly number of contacts traced per case was also higher in non-Hubei provinces than in Hubei Province and increased from 17.2 in epidemiological week 4 to 115.7 in epidemiological week 9. Discussion: More contacts per case were reported from areas and periods with lower COVID-19 case counts. With other non-pharmaceutical interventions used in China, contact tracing and quarantining large numbers of potentially infected contacts probably contributed to reducing SARS-CoV-2 transmission. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has dramatically impacted public health and economic and social stability worldwide since the WHO's Public Health Emergency of International Concerns declaration in early March 2020. The COVID-19 virus was first discovered in December 2019 in Wuhan city, China, and eventually resulted in the global pandemic, of which the cumulative cases have reached 181,367,824 at the time of writing. Taiwan encountered severe public health threats because of the frequent travelers as many as 10 million who commuted annually between mainland China and Taiwan. Recognizing the imminent threats arising from an intensive flow of people from mainland China due to the lockdown policy adopted by the Chinese government, Taiwan has adopted strict border control, sophisticated contact tracing and monitoring measures, and most importantly the securing of sufficient Personal Protection Equipment supply for citizens to prevent community spread. Taiwan's quick and precise COVID-19 response at the early stage of containing the virus has been proven very successful since the outbreak of the COVID-19 global pandemic in late February 2020. Taiwan is now struggling to fight the recent outbreak for lacking sufficient vaccines and testing capacities and shall learn from other country's experience for countermeasures against a massive epidemic. This article aims to explore the key elements for the early success of containing the COVID-19 virus, including the comprehensive legal framework for preventing infectious disease, highly trained public health officials and governance system, and citizen self-awareness. The article then discusses the potential legal controversies and their long-term impacts on Taiwan. Finally, this article provides the concluding observation and suggestions for fighting massive infectious diseases. [ABSTRACT FROM AUTHOR]

• The negative converting ratio was 16.4% and 41.0% on days 7 and 14, respectively. • 34.1% and 60.3% of subjects had least one negative RT-PCR result on days 7 and 14. • Joint testing represents an effective means of minimizing the misdiagnosis. The real-time polymerase chain reaction (RT-PCR) test is recommended for the diagnosis of COVID-19 and provides a powerful tool to identify new infections and facilitate contact tracing. In fact, as the prevalence of COVID-19 decreases, this RT-PCR testing remains as the main preventive measure to avoid rebound. However, inconsistent results can lead to misdiagnoses in the clinic. These inconsistencies are due to the variability in (1) the collection times of biological samples post infection, and (2) sampling procedures. We applied the Kaplan–Meier method and multivariate logistic regression on RT-PCR results from 258 confirmed patients with COVID-19 to evaluate the factors associated with negative conversion. We also estimated the proportion (%) of negative conversion among patients who had tested twice or more, and compared the proportions arising from oropharyngeal swabs, sputum, and combined double testing, respectively. The proportion of negative conversion was 6.7% on day 4, 16.4% on day 7, 41.0% at 2 weeks, and 61.0% at 3 weeks post-admission. We also found that 34.1% and 60.3% of subjects had at least one negative RT-PCR result on days 7 and 14 after the onset of symptoms, respectively. The proportion of negative conversions following sputum testing was higher than that from oropharyngeal swabs in the early stages but this declined after the onset of symptoms. In the absence of effective treatments or vaccines, efficient testing strategies are critical if we are to control the COVID-19 epidemic. According to this study, early, consecutive and combined double testing, will be the key to identify infected patients, particularly for asymptomatic and mild symptomatic cases. These strategies will minimize misdiagnosis and the ineffective isolation of infected patients. [ABSTRACT FROM AUTHOR]