Objectives: Research on family caregiving for older adults has largely focused on primary caregivers. We identify caregiving task-sharing patterns among multiple caregivers, including family members and live-in hired workers. In addition, we investigate caregiver and care-recipient characteristics associated with these patterns. Methods: We interviewed 278 primary family caregivers of home-dwelling older adults in Singapore about who provides what assistance across 3 domains: activities of daily living, health and social services use, and socioemotional and other needs. Latent class analysis was used to identify caregiving task-sharing patterns. Results: Three patterns were identified: (a) “Shared-Diverse” (39%)—multiple caregivers assisting in all 3 domains, (b) “Shared-Domestic” (32%)—multiple caregivers assisting with activities of daily living and socioemotional and other needs, and (c) “Solo-Diverse” (29%)—a sole caregiver assisting in all 3 domains. “Solo-Diverse” caregivers were less likely to be employed and had higher depressive symptoms relative to “Shared-Diverse” primary family caregivers. Discussion: The predominance of caregiving task-sharing patterns involving multiple caregivers calls for expansion of research, policies, and programs beyond primary caregivers. Greater attention should be given to how families and live-in hired workers share caregiving tasks for older adults, and how this varies across cultural settings, especially in familial Asian societies. The findings further highlight the vulnerabilities of solo caregivers, whose employment capacity and mental health may be adversely affected by their caregiving duties. Policy-makers should ensure that solo caregivers have access to support programs that address their financial and mental health needs.

Background: One hundred days after SARS-CoV-2 was first reported in Vietnam on January 23 ^rd , 270 cases have been confirmed, with no deaths. We describe the control measures used by the Government and their relationship with imported and domestically-acquired case numbers, with the aim of identifying the measures associated with successful SARS-CoV-2 control. Methods: Clinical and demographic data on the first 270 SARS-CoV-2 infected cases and the timing and nature of Government control measures, including numbers of tests and quarantined individuals, were captured by Vietnam’s National Steering Committee for COVID-19 response. Apple and Google mobility data provided proxies for population movement. Serial intervals were calculated from 33 infector-infectee pairs and used to estimate the proportion of pre-symptomatic transmission events and time-varying reproduction numbers. Findings: After the first confirmed case on January 23 ^rd , the Vietnamese Government initiated mass communications measures, case-contact tracing, mandatory 14-day quarantine, school and university closures, and progressive flight restrictions. A national lockdown was implemented between April 1 ^st and 22 ^nd . Around 200 000 people were quarantined and 266 122 RT-PCR tests conducted. Population mobility decreased progressively before lockdown. 60% (163/270) of cases were imported; 43% (89/208) of resolved infections remained asymptomatic for the duration of infection. 21 developed severe disease, with no deaths. The serial interval was 3.24 days, and 27.5% (95% confidence interval, 15.7%-40.0%) of transmissions occurred pre-symptomatically. Limited transmission amounted to a maximum reproduction number of 1.15 (95% confidence interval, 0.37-2.36). No community transmission has been detected since April 15 ^th . Interpretation: Vietnam has controlled SARS-CoV-2 spread through the early introduction of mass communication, meticulous contact-tracing with strict quarantine, and international travel restrictions. The value of these interventions is supported by the high proportion of asymptomatic and imported cases, and evidence for substantial pre-symptomatic transmission. Funding: The Vietnam Ministry of Health and Wellcome Trust, UK. Research in context: Evidence before this study: Vietnam was one of the first countries outside of China to detect imported and human-to-human transmitted SARS-CoV-2 within its borders. Yet, as of May 1 ^st , a total of only 270 cases have been confirmed, no deaths have occurred, and no community transmission has been detected since April 15 ^th despite intensive screening, tracing and testing. We did a PubMed database search to identify studies investigating COVID-19 response in Vietnam using the terms “Vietnam”, “COVID-19”, and “SARS-CoV-2”. All relevant articles were evaluated. Studies describe cases of COVID-19 and their management, aspects of the government response from newspapers and online government sources, but there are no previous reports using national data to describe and investigate the national epidemic and the impact of control measures cases over time. Added value of this study: We used data from the National Steering Committee for COVID-19 response to give a comprehensive account of the first 100 days of the SARS-CoV-2 epidemic in Vietnam, including case numbers and their symptomatology, the estimated reproductive number by week, and their relation to the multiple control measures instituted by the Vietnam Government over time. We show two distinctive features of Vietnam’s response. First, the Government took rapid actions to restrict international flights, closed schools and universities, and instituted meticulous case-contact tracing and quarantining from late January, well before these measures were advised by WHO. Second, they placed mass communication, education, and the identification, serial testing, and 14-day quarantine of all direct contacts of cases, regardless of symptom development, at the heart of the response. The value of strict contact-tracing and quarantine is supported by the high proportion of asymptomatic cases (43%) and imported cases (60%), and evidence for substantial pre-symptomatic transmission. Implications of all the available evidence: Vietnam has had remarkable success in controlling the emergence of SARS-CoV-2. Our report provides a complete picture of the control of SARS-CoV-2 in Vietnam, with lessons for other Governments seeking to extend national SARS-CoV-2 control or prevent future epidemics. Our findings shows the importance of acting early, before the virus becomes established in the community, and before the case numbers overwhelm systems of case-contact tracing and mass quarantine. They also demonstrate the value of effective mass communication in rapidly educating the public in infection prevention measures and providing real-time information on the state of the epidemic.

The importation of SARS-CoV-2 through air travel poses substantial risks to generate new COVID-19 outbreaks. Timely contact tracing is particularly crucial to limit onwards transmission in settings without established community transmission. We conducted an in-depth analysis of the response to a big flight-associated COVID-19 outbreak in Vietnam in March 2020 that involved contact tracing, systematic testing and strict quarantine up to third generation contacts. 183 primary contacts from the flight as well as 1000 secondary and 311 third generation contacts were traced, tested, and quarantined across 15 provinces across Vietnam. The protracted confirmation of the index case at 3 days and 19 h after arrival resulted in isolation/quarantine delays of 6.8 days (IQR 6.3–6.8) and 5.8 days (IQR 5.8–7.0) for primary and secondary cases, respectively, which generated 84.0 and 26.4 person-days of community exposure from primary and secondary cases, respectively. Nevertheless, only 5 secondary cases occurred. A large flight-related COVID-19 cluster was successfully contained through timely, systematic and comprehensive public health responses despite delayed index case identification. Multiagency collaboration and pre-established mechanisms are crucial for low and middle income countries like Vietnam to limit community transmission after COVID-19 importation through air travel.

Digital contact tracing (DCT) interventions have been deployed at unprecedented scale during COVID-19. However, no comprehensive appraisal of the evidence exists to date regarding their effectiveness. We aimed to systematically review the global literature for a holistic understanding of DCT effectiveness during COVID-19, and to identify factors that enabled or hindered its effectiveness. Systematic scoping review. We searched six databases for peer-reviewed literature relevant to the evaluation of DCT interventions during COVID-19 (January 2024) (CRD42021268586). We compiled implemented DCT interventions from grey literature. Effectiveness appraisals, different operationalizations, measurements, and definitions of DCT effectiveness, as well as associated factors were synthesized qualitatively. Study quality was assessed using the Mixed Methods Appraisal Tool. We followed Cochrane and PRISMA guidance. We identified 133 studies evaluating 121 different DCT implementations. Seventy-three (60 %) studies found DCT to be effective, mostly when evaluating epidemiological impact metrics. Public trust emerged as crucial for DCT to be effective, which requires high and enforceable data safety and privacy standards, clear and transparent communication, high accuracy and reliability of the intervention, and an acceptance-enhancing implementation approach of other pandemic response measures by public health authorities more broadly. Most evaluations took place in high rather than low-resource settings. While technical performance matters, DCT effectiveness primarily depends on a relatively small number of non-technical drivers centred around public trust. DCT should only be implemented as integrated part of a broader public health framework. Our findings hold important insights for the design, implementation, and evaluation of other digital technology for pandemic response.

Background: International air travel plays an important role in the global spread of SARS-CoV-2, and tracing of close contacts is an integral part of the public health response to COVID-19. We aimed to assess the timeliness of contact tracing among airline passengers arriving in Vietnam on flights containing COVID-19 cases and investigated factors associated with timeliness of contact tracing. Methods: We included data from 2228 passengers on 22 incoming flights between 2 and 19 March 2020. Contact tracing duration was assessed separately for the time between the date of index case confirmation and date of contact tracing initiation (interval I), and the date of contact tracing initiation and completion (interval II). We used log-rank tests and multivariable Poisson regression models to identify factors associated with timeliness. Results: The median duration of interval I and interval II was one (IQR: 1–2) and 3 days (IQR: 2–5), respectively. The contact tracing duration was shorter for passengers from flights where the index case was identified through mandatory testing directly upon arrival (median = 4; IQR: 3–5) compared to flights with index case detection through self-presentation at health facilities after arrival (median = 7; IQR: 5–8) (p-value = 0.018). Cumulative hazards for successful tracing were higher for Vietnamese nationals compared to non-Vietnamese nationals (p < 0.001). Conclusions: Contact tracing among flight passengers in the early stage of the COVID-19 epidemic in Vietnam was timely though delays occurred on high workload days. Mandatory SARS-CoV-2 testing at arrival may reduce contact tracing duration and should be considered as an integrated screening tool for flight passengers from high-risk areas when entering low-transmission settings with limited contact tracing capacity. We recommend a standardized risk-based contact tracing approach for flight passengers during the ongoing COVID-19 epidemic.