Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content


Hot Topics of the Day|PHGKB
Search PHGKB:

Archive

Hot Topics of the Day are picked by experts to capture the latest information and publications on public health genomics and precision health for various diseases and health topics. Sources include published scientific literature, reviews, blogs and popular press articles.

Sign up MyPHGKB to receive the daily hot topic email alert.

Search Archive:
Archived Hot Topics of the Day By Date
96 hot topic(s) found with the query "Contact tracing"

Viral genome sequencing to decipher in-hospital SARS-CoV-2 transmission events.
Elisabeth Esser et al. Sci Rep 2024 3 (1) 5768 (Posted: Mar 11, 2024 8AM)

From the abstract: "The SARS-CoV-2 pandemic has highlighted the need to better define in-hospital transmissions, a need that extends to all other common infectious diseases encountered in clinical settings. To evaluate how whole viral genome sequencing can contribute to deciphering nosocomial SARS-CoV-2 transmission 926 SARS-CoV-2 viral genomes from 622 staff members and patients were collected. Bioinformatically defined transmission clusters inferred from viral genome sequencing were compared to those inferred from interview-based contact tracing. Clustering analysis of SARS-CoV-2 whole genome sequences can reveal cryptic transmission events missed by classical, interview-based contact tracing, helping to decipher in-hospital transmissions. These results, in line with other studies, advocate for viral genome sequencing as a pathogen transmission surveillance tool in hospitals. "

Transmission Characteristics and Inactivated Vaccine Effectiveness Against Transmission of SARS-CoV-2 Omicron BA.5 Variants in Urumqi, China.
Kai Wang et al. JAMA network open 2023 3 (3) e235755 (Posted: Mar 31, 2023 6AM)

What were the transmission characteristics of SARS-CoV-2 Omicron BA.5 variants, and was inactivated vaccine associated with a protective outcome against the transmission of these variants? This cohort study of 1139 individuals with COVID-19 found that despite active contact tracing, high vaccine coverage, and other intensive control measures, Omicron BA.5 variants had high risks of transmission in household settings and among younger and older individuals. Compared with a 2-dose inactivated vaccine, a booster dose was associated with a protective outcome against Omicron BA.5 transmission.

Epidemiological impacts of the NHS COVID-19 app in England and Wales throughout its first year
M Kendall et al, Nat Comm, February 22, 2023 (Posted: Feb 22, 2023 6AM)

The NHS COVID-19 app was launched in England and Wales in September 2020, with a Bluetooth-based contact tracing functionality designed to reduce transmission of SARS-CoV-2. We show that user engagement and the app’s epidemiological impacts varied according to changing social and epidemic characteristics throughout the app’s first year. We describe the interaction and complementarity of manual and digital contact tracing approaches. We estimate that the app’s contact tracing function alone averted about 1 million cases (sensitivity analysis 450,000–1,400,000) during its first year, corresponding to 44,000 hospital cases (SA 20,000–60,000) and 9,600 deaths (SA 4600–13,000).

Contact tracing reveals community transmission of COVID-19 in New York City
S Pei et al, Nat Comn, October 23, 2022 (Posted: Oct 24, 2022 0PM)

Using contact tracing records for 644,029 cases and their contacts in New York City during the second pandemic wave, we provide a detailed characterization of the operational performance of contact tracing and reconstruct exposure and transmission networks at individual and ZIP code scales. We find considerable heterogeneity in reported close contacts and secondary infections and evidence of extensive transmission across ZIP code areas.

Modelling the impact of rapid tests, tracing and distancing in lower-income countries suggest that optimal policies vary with rural-urban settings
R Jiang et al, MEDRXIV, September 8, 2022 (Posted: Sep 10, 2022 10AM)

In low-density rural communities, we found implementing either high quality (sensitivity > 50%) antigen rapid diagnostic tests or moderate physical distancing could contain the transmission. In urban communities, we demonstrated that both physical distancing and case finding are essential for containing COVID-19 (average infection rate < 10%). In high density communities that resemble slums and squatter settlements, physical distancing is less effective compared to rural and urban communities. Lastly, we demonstrated contact tracing is essential for effective containment.

Context-specific emergence and growth of the SARS-CoV-2 Delta variant
JT McCrone et al, Nature, August 11, 2022 (Posted: Aug 11, 2022 8AM)

Here we analyse 52,992 virus genomes from England together with 93,649 global genomes to reconstruct the emergence of Delta, and quantify its introduction to and regional dissemination across England in the context of changing travel and social restrictions. Through analysis of human movement, contact tracing, and virus genomic data, we find that the geographic focus of Delta’s expansion shifted from India to a more global pattern in early May 2021.

The effect of notification window length on the epidemiological impact of COVID-19 contact tracing mobile applications
T Leng et al, Communications Medicine, June 27, 2022 (Posted: Jun 28, 2022 9AM)

We use an epidemiological model of SARS-CoV-2 transmission that captures the profile of infection to consider the trade-off between notification window length and active app use. We focus on 5-day and 2-day windows, the notification windows of the NHS COVID-19 app in England and Wales before and after 2nd August 2021, respectively. Our analyses show that at the same level of active app use, 5-day windows result in larger reductions in transmission than 2-day windows. However, short notification windows can be more effective at reducing transmission if they are associated with higher levels of active app use and adherence to isolation upon notification.

Smartphone apps in the COVID-19 pandemic
JA Pandit et al, Nature Biotechnology, June 20,2022 (Posted: Jun 20, 2022 6PM)

Smartphone apps, given accessibility in the time of physical distancing, were widely used for tracking, tracing and educating the public about COVID-19. Despite limitations, such as concerns around data privacy, data security, digital health illiteracy and structural inequities, there is ample evidence that apps are beneficial for understanding outbreak epidemiology, individual screening and contact tracing. While there were successes and failures in each category, outbreak epidemiology and individual screening were substantially enhanced by the reach of smartphone apps and accessory wearables.

Prioritizing Case Investigation and Contact Tracing for COVID-19
CDC, February 28, 2022 Brand (Posted: Mar 01, 2022 9AM)

These recommendations are intended to assist state, tribal, local, and territorial (STLT) health departments prioritize COVID-19 case investigation and contact tracing activities. Key Points include: Universal case investigation and contact tracing are not recommended for COVID-19. Health department jurisdictions should prioritize specific settings and groups at increased risk. Case investigation and contact tracing are separate processes with distinct benefits and goals; decisions to initiate either should be made separately. Investigations should focus on COVID-19 cases and close contacts with onsets and exposures in the previous 5 days for those settings and groups at increased risk.

Increased household transmission and immune escape of the SARS-CoV-2 Omicron variant compared to the Delta variant: evidence from Norwegian contact tracing and vaccination data
N Jalali et al, Research Square, February 18, 2022 (Posted: Feb 19, 2022 7AM)

We compared the secondary attack rate (SAR) of the Omicron and Delta variants in households using Norwegian contact tracing data from December 2021 to January 2022. Omicron SAR was higher (51%) than Delta (36%), with a relative risk (RR) of 1.41 (95% CI 1.27–1.56). We observed increased susceptibility to Omicron infection in household contacts compared to Delta independent of vaccination status; however, considering booster vaccinated contacts, the mean SAR was lower for both variants. We found increased Omicron transmissibility in all vaccination groups of primary cases, except partially vaccinated, compared to Delta. In particular, Omicron SAR for boosted primary cases was high, 46% vs 11% for Delta (RR 4.34; 95% CI 1.52–25.16).

Genomic epidemiology of SARS-CoV-2 in a UK university identifies dynamics of transmission
D Aggarwal et al, Nature Comms, February 8, 2022 (Posted: Feb 08, 2022 8AM)

We sequenced 482 SARS-CoV-2 isolates from the University of Cambridge from 5 October to 6 December 2020. We perform a detailed phylogenetic comparison with 972 isolates from the surrounding community, complemented with epidemiological and contact tracing data, to determine transmission dynamics. We observe limited viral introductions into the university; the majority of student cases were linked to a single genetic cluster, likely following social gatherings at a venue outside the university

Increased household transmission and immune escape of the SARS-CoV-2 Omicron variant compared to the Delta variant: evidence from Norwegian contact tracing and vaccination data
N Jalali et al, MEDRXIV, February 8, 2022 (Posted: Feb 08, 2022 7AM)

Observed serial intervals of SARS-CoV-2 for the Omicron and Delta varaints in Belgium based on contact tracing data, 19 November to 31 December 2021
C Kremer, MEDRXIV, January 30, 2022 (Posted: Jan 31, 2022 7AM)

Effectiveness of digital contact tracing for COVID-19 in New South Wales, Australia
F Vogt el al, MEDRXIV, November 19, 2021 (Posted: Nov 21, 2021 10AM)

Limited impact of contact tracing in a University setting for COVID-19 due to asymptomatic transmission and social distancing
DA Stocks et al, MEDRXIV, November 14, 2021 (Posted: Nov 15, 2021 6AM)

We investigate the spread of COVID-19 and the effectiveness of contact tracing in a university population, using a data-driven ego-centric network model constructed with social contact data collected during 2020 and similar data collected in 2010. We find that during 2020, university staff and students consistently reported fewer social contacts than in 2010, however those contacts occurred more frequently and were of longer duration. We find that contact tracing in the presence of social distancing is less impactful than without social distancing. By combining multiple data sources, we show that University-aged populations are likely to develop asymptomatic COVID-19 infections. We find that asymptomatic index cases cannot be reliably back-traced through contact tracing and consequently transmission in their social network is not significantly reduced through contact tracing.

Potential reduction in transmission of COVID-19 by digital contact tracing systems
MJ Plank et al, MEDRXIV, November 2, 2021 (Posted: Nov 02, 2021 2PM)

Factors associated with acceptance of a digital contact tracing application for COVID-19 in the Japanese working-age population
T Ishimaru et al, MEDRXIV, October 30, 2021 (Posted: Oct 31, 2021 8PM)

Contact Tracer’s Interview Tool: Notifying People About an Exposure to COVID-19
CDC, October 19, 2021 Brand (Posted: Oct 20, 2021 4AM)

This document provides suggested communication approaches for COVID-19 contact tracing. Scripts may need to be modified to address locality-specific needs, including but not limited to highlighting available resources, cultural nuances, exposure sites, and the capture of epidemiological data. Public health workers should use what is helpful and the best fit for the interaction; all questions or statements may not be required, and additional probing questions may be necessary. Programs are encouraged to share best practices in framing and phrases as they are identified.

Vaccine effectiveness against SARS‐CoV‐2 transmission to household contacts during dominance of Delta variant (B.1.617.2), August‐September 2021, the Netherlands
P de Gier et al, MEDRXIV, October 14, 2021 (Posted: Oct 15, 2021 6AM)

We estimated vaccine effectiveness against onward transmission by comparing secondary attack rates among household members between vaccinated and unvaccinated index cases, based on source and contact tracing data collected when Delta variant was dominant. Effectiveness of full vaccination of the index against transmission to fully vaccinated household contacts was 40% (95% confidence interval (CI) 20-54%), which is in addition to the direct protection of vaccination of contacts against infection. Effectiveness of full vaccination of the index against transmission to unvaccinated household contacts was 63% (95%CI 46-75%).

Using genomic epidemiology of SARS-CoV-2 to support contact tracing and public health surveillance in rural Humboldt County, California.
G Stoddard et al, MEDRXIV, September 27, 2021 (Posted: Sep 27, 2021 7AM)

853 whole SARS-CoV-2 genomes were generated, representing ~58% of the 1,449 SARS-CoV-2-positive cases detected in Humboldt County as of March 12, 2021. Phylogenetic analysis of these data was used to develop a comprehensive understanding of SARS-CoV-2 introductions to the county and to support contact tracing and epidemiologic investigations of all large outbreaks in the county. In the case of an outbreak on a commercial farm, viral genomic data were used to validate reported epidemiologic links and link additional cases within the community who did not report a farm exposure to the outbreak.

Contact tracing is an imperfect tool for controlling COVID-19 transmission and relies on population adherence
EL Davis et al, Nature Communications, September 13, 2021 (Posted: Sep 13, 2021 4PM)

Emerging evidence suggests that contact tracing has had limited success in the UK in reducing the R number across the COVID-19 pandemic. We investigate potential pitfalls and areas for improvement by extending an existing branching process contact tracing model, adding diagnostic testing and refining parameter estimates. Our results demonstrate that reporting and adherence are the most important predictors of program impact but tracing coverage and speed plus diagnostic sensitivity also play an important role.

Digital exposure tools: Design for privacy, efficacy, and equity
S Landau, Science, September 10, 2021 (Posted: Sep 12, 2021 5PM)

Use of smartphone-based digital contact- tracing apps has shown promise in responding to the COVID-19 pandemic. But such apps can reveal very personal information; thus, their use raises important societal questions, not just during the current pandemic but as we learn and prepare for other inevitable outbreaks ahead. Can privacy-protective versions of such apps work? Are they efficacious? Because the apps influence who is notified of exposure and who gets tested—and possibly treated—we need to consider the apps in the context of health care equity.

Vaccines alone are no silver bullets: a modeling study on the impact of efficient contact tracing on COVID-19 infection and transmission
DB Raja et al, MEDRXIV, August 30, 2021 (Posted: Aug 31, 2021 8AM)

Adoption and continued use of mobile contact tracing technology: Multilevel explanations from a three-wave panel survey and linked data
L Horvath et al,, MEDRXIV, July 16, 2021 (Posted: Jul 17, 2021 7AM)

Digital contact tracing contributes little to COVID-19 outbreak containment
A Burdinski et al, MEDRXIV, June 25, 2021 (Posted: Jun 26, 2021 7AM)

Based on the results of empirical studies and modeling efforts, we show that digital contact tracing apps might have prevented cases on the order of single-digit percentages up until now, at best. We show that this poor impact can be attributed to a combination of low participation rates, a non-flexible reliance on symptom-based testing, low engagement of participants, and delays between testing and test result upload.

We investigated whether digital contact tracing actually worked in the US
B Ladyzhets, MIT Tech Review, June, 2021 (Posted: Jun 21, 2021 11AM)

A year ago, engineers built apps to track potential virus exposure. Our research shows the impact has been mixed—but there's still potential. The end result of our analysis paints a picture of unexplored potential. Many of the country’s exposure notification apps are underutilized, misunderstood, and not well-trusted—and yet this technology may yet come into its own as a public health tool for future disease outbreaks.

Estimates of cases and hospitalizations averted by COVID-19 case investigation and contact tracing in 14 health jurisdictions in the United States
S Jeon et al, MEDRXIV, May 30, 2021 (Posted: May 30, 2021 10AM)

Performance by jurisdictions varied widely. Jurisdictions isolated between 12 and 86% of cases (including contacts which became cases) within 6 to 10 days after exposure-and-infection. We estimated that CICT-related reductions in transmission ranged from 0.4% to 32%. For every 100 cases prevented by nonpharmaceutical interventions, CICT averted between 4 and 97 additional cases.

Contact-tracing app curbed the spread of COVID in England and Wales
CJ Wang, Nature News, May 25, 2021 (Posted: May 26, 2021 6AM)

Digital contact tracing has the potential to limit the spread of COVID-19. A contact-tracing smartphone app that has been readily adopted by people in England and Wales has shown efficacy in reducing disease spread.

Contact Tracing for Covid-19 - A Digital Inoculation against Future Pandemics.
O'Connell James et al. The New England journal of medicine 2021 5 (Posted: May 20, 2021 9AM)

Digital contact tracing is not a perfect intervention, given the risks to privacy, personal data, and false positive or false negative characterization of contact status. However, as in a Swiss cheese model, imperfect interventions can work together to curb epidemics. South Korea’s deployment of digital technology to augment contact tracing was an example of speed trumping perfection.

The first GAEN-based COVID-19 contact tracing app in Norway identifies 80% of close contacts in "real life" scenarios.
H Meijerink et al, MEDRXIV, May 7, 2021 (Posted: May 08, 2021 6AM)

Testing at scale during the COVID-19 pandemic
TR Mercer et al, Nature Rev Genetics, May 4, 2021 (Posted: May 04, 2021 3PM)

This Review describes the changing role of testing during the COVID-19 pandemic, including the use of genomic surveillance to track SARS-CoV-2 transmission around the world, the use of contact tracing to contain disease outbreaks and testing for the presence of the virus circulating in the environment. Despite these efforts, widespread community transmission has become entrenched in many countries and has required the testing of populations to identify and isolate infected individuals, many of whom are asymptomatic.

Modelling digital and manual contact tracing for COVID-19. Are low uptakes and missed contacts deal-breakers?
A Rusu et al, MEDRXIV, May 2, 2021 (Posted: May 03, 2021 0PM)

Contact tracing apps for the COVID-19 pandemic: a systematic literature review of challenges and future directions for neo-liberal societies
A Akinbi et al, Health Info and Systems, April 2021 (Posted: Apr 18, 2021 7AM)

An integrated analysis of contact tracing and genomics to assess the efficacy of travel restrictions on SARS-CoV-2 introduction and transmission in England from June to September, 2020
D Aggarwal et al, MEDRXIV< March 17, 2021 (Posted: Mar 17, 2021 10AM)

We describe the genomic epidemiology of travel-related cases in England and evaluate the effectiveness of this travel policy. Methods: Between 27/05/2020 and 13/09/2020, probable travel-related SARS-CoV-2 cases and their contacts were identified and combined with UK SARS-CoV-2 sequencing data. We found a large travel-related cluster dispersed across England identified through genomics and confirmed with contact-tracing data.

Digital proximity tracing on empirical contact networks for pandemic control
G Cencetti et al, Nature Comms, March 2021 (Posted: Mar 16, 2021 8AM)

We investigate how well contact tracing apps, coupled with the quarantine of identified contacts, can mitigate the spread in real environments. We find that restrictive policies are more effective in containing the epidemic but come at the cost of unnecessary large-scale quarantines. Policy evaluation through their efficiency and cost results in optimized solutions which only consider contacts longer than 15–20 minutes and closer than 2–3 meters to be at risk. Our results show that isolation and tracing can help control re-emerging outbreaks when some conditions are met

Anatomy of digital contact tracing: role of age, transmission setting, adoption and case detection
JA Moreno et al, MeDRXIV, March 4, 2021 (Posted: Mar 05, 2021 10AM)

Contact-tracing apps help reduce COVID infections, data suggest Evaluations find apps are useful, but would benefit from better integration into health-care systems.
D Lewis, Nature News, February 22,2 021 (Posted: Feb 23, 2021 6AM)

Contact Tracing Resources for Health Departments
CDC, February 2021 Brand (Posted: Feb 21, 2021 7AM)

Resources for Conducting Contact Tracing to Stop the Spread of COVID-19. CDC guidance for COVID-19 may be adapted by state and local health departments to respond to rapidly changing local circumstances.

Time to evaluate COVID-19 contact-tracing apps
V Colizza et al, Nature Medicine, February 15, 2021 (Posted: Feb 16, 2021 7AM)

Digital contact tracing via smartphone apps was established as a new public-health intervention in many countries in 2020. Most of these apps are now at a stage at which they need to be evaluated as public-health tools. We present here five key epidemiological and public-health requirements for COVID-19 contact-tracing apps and their evaluation.

Upping uptake of COVID contact tracing apps
S Toussaert, Nature Human Behavior, January 2021 (Posted: Jan 28, 2021 9AM)

To contain the COVID-19 pandemic, many countries around the world rushed to develop digital contact tracing apps. However, the low rates of app installation have undermined the efficacy of such tools. A new study shines light on potential barriers to adoption, as well as levers that could be used to increase uptake.

COVID-19 Case Investigation and Contact Tracing Efforts from Health Departments — United States, June 25–July 24, 2020
KD Spencer et al, MMWR, January 21, 2021 (Posted: Jan 21, 2021 4PM)

Analysis of case investigation and contact tracing metric data reported by 56 U.S. health departments found wide variation in capacity and ability to conduct timely and effective contact tracing. Investigator caseload was inversely related to timely interviewing of patients and number of contacts identified per case.

COVIDTracer and COVIDTracer Advanced
CDC, January 19, 2021 Brand (Posted: Jan 20, 2021 7AM)

COVIDTracer and COVIDTracer Advanced are spreadsheet-based tools that allow state- and local-level public health officials and policy makers to compare the effectiveness, and the resources needed, of three user defined contact tracing and monitoring strategies.

Simulating SARS-CoV-2 epidemics by region-specific variables and modeling contact tracing app containment
A Ferrari et al, NPJ Digital Medicine, January 14, 2021 (Posted: Jan 14, 2021 9AM)

We built an expanded SIR model of COVID-19 epidemics that accounts for region-specific population densities, and we used it to test the impact of a contact-tracing app in a number of scenarios. Our results show that, in support of efficient isolation of symptomatic cases, app-mediated contact-tracing can successfully mitigate the epidemic even with a relatively small fraction of users, and even suppress altogether with a larger fraction of users.

Bidirectional contact tracing could dramatically improve COVID-19 control
WJ Bradshaw et al, Nature Comms, January 11, 2021 (Posted: Jan 12, 2021 11AM)

Contact tracing is critical to controlling COVID-19, but most protocols only “forward-trace” to notify people who were recently exposed. Using a stochastic branching-process model, we find that “bidirectional” tracing to identify infector individuals and their other infectees robustly improves outbreak control. In our model, bidirectional tracing more than doubles the reduction in effective reproduction number achieved by forward-tracing alone.

Contact Tracing
CDC, January 5, 2021 Brand (Posted: Jan 05, 2021 0PM)

Contact tracing helps protect you, your family, and your community by: Letting people know they may have been exposed to COVID-19 and should monitor their health for signs and symptoms of COVID-19; Helping people who may have been exposed to COVID-19 get tested; Asking people to self-isolate if they have COVID-19 or self-quarantine if they are a close contact.

Modeling of Network Based Digital Contact Tracing and Testing Strategies for the COVID-19 Pandemic
D Xu, ARXIV, December 28, 2020 (Posted: Dec 29, 2020 8AM)

Why many countries failed at COVID contact-tracing — but some got it right Rich nations have struggled with one of the most basic and important methods for controlling infectious diseases.
D Lewis, Nature News, December 14, 2020 (Posted: Dec 14, 2020 8AM)

Extinction of COVID-19 Clusters in a Lebanese Village: A Quick, Adapted Molecular and Contact tracing
A Chamieh et al, MEDRXIV, November 30, 2020 (Posted: Nov 30, 2020 2PM)

Effective control of SARS-CoV-2 transmission in Wanzhou, China
Q Shi et al, Nature Medicine, November 30, 2020 (Posted: Nov 30, 2020 10AM)

The effectiveness of control measures to contain coronavirus disease 2019 (COVID-19) in Wanzhou, China was assessed. Epidemiological data were analyzed for 183 confirmed COVID-19 cases and their close contacts from five generations of transmission. The spread of COVID-19 was effectively controlled in Wanzhou by breaking the transmission chain through social distancing, extensive contact tracing, mass testing and strict quarantine of close contacts.

Transmission heterogeneities, kinetics, and controllability of SARS-CoV-2
K sun et al, Science, November 24, 2020 (Posted: Nov 24, 2020 1PM)

Based on detailed patient and contact tracing data in Hunan, China we find 80% of secondary infections traced back to 15% of SARS-CoV-2 primary infections, indicating substantial transmission heterogeneities. Transmission risk scales positively with the duration of exposure and the closeness of social interactions and is modulated by demographic and clinical factors.

Implementation of a Pooled Surveillance Testing Program for Asymptomatic SARS-CoV-2 Infections on a College Campus — Duke University, Durham, North Carolina, August 2–October 11, 2020
TN Denny et al, MMWR, November 17, 2020 (Posted: Nov 18, 2020 11AM)

In fall 2020, Duke University’s COVID-19 prevention strategy included risk reduction behaviors, frequent testing using pooled SARS-CoV-2 polymerase chain reaction testing, and contact tracing. Among 10,265 students who received testing 68,913 times, 84 had positive results. One half of infections were asymptomatic, and some had high viral loads. Pooled testing reduced the need for resources while allowing high throughput with high sensitivity and rapid turnaround of results.

Belief of having had unconfirmed Covid-19 infection reduces willingness to participate in app-based contact tracing
P Bachtiger et al, NPJ Digital Medicine, November 6, 2020 (Posted: Nov 06, 2020 8AM)

Digital contact-tracing during the Covid-19 pandemic: an analysis of newspaper coverage in Germany, Austria, and Switzerland
J Amann et al, MEDRXIV, October 26, 2020 (Posted: Oct 28, 2020 8AM)

Risk estimation of SARS-CoV-2 transmission from bluetooth low energy measurements
F Sattler et al, NPJ Digital Medicine, October 6, 2020 (Posted: Oct 06, 2020 8AM)

Digital contact tracing approaches based on Bluetooth low energy (BLE) have the potential to efficiently contain and delay outbreaks of infectious diseases We propose a machine learning based approach to reliably detect subjects that have spent enough time in close proximity to be at risk of being infected. Our study is an important proof of concept to slow down the rapid spread of COVID-19.

Early Evidence of Effectiveness of Digital Contact Tracing for SARS-CoV-2 in Switzerland
M Salathe et al, MEDRXIV, October 4, 2020 (Posted: Oct 05, 2020 1PM)

Predicting public take-up of digital contact tracing during the COVID-19 crisis: Results of a national survey
YE Saw et al, MEDRXIV, October 5, 2020 (Posted: Oct 05, 2020 1PM)

Early Evidence of Effectiveness of Digital Contact Tracing for SARS-CoV-2 in Switzerland
M Salathe et al, MEDRXIV, September 19, 2020 (Posted: Sep 21, 2020 9AM)

Leveraging pathogen sequence and contact tracing data to enhance vaccine trials in emerging epidemics
R Kahn et al, MEDRXIV, September 16, 2020 (Posted: Sep 18, 2020 8AM)

Clustering and superspreading potential of SARS-CoV-2 infections in Hong Kong
DC Adam et al, Nature Medicine, September 17, 2020 (Posted: Sep 17, 2020 9AM)

Using contact tracing data from 1,038 cases in Hong Kong, we identified and characterized all local clusters of infection. We identified 4–7 SSEs across 51 clusters (n?=?309 cases) and estimated that 19% (95% confidence interval, 15–24%) of cases seeded 80% of all local transmission.

The impact of digital contact tracing on the SARS-CoV-2 pandemic - a comprehensive modelling study
TR Pollman et al, MEDRXIV, September 14, 2020 (Posted: Sep 15, 2020 7AM)

Automated Contact Tracing: a game of big numbers in the time of COVID-19
H Kim et al, MEDRXIV, September 13, 2020 (Posted: Sep 14, 2020 7AM)

Automatic Contact Tracing for Outbreak Detection Using Hospital Electronic Medical Record Data
ME Dewitt, MEDRXIV, September 134, 2020 (Posted: Sep 13, 2020 10AM)

Prevalence of Third-Party Tracking on COVID-19–Related Web Pages
MS McCoy et al JAMA, September 8, 2020 (Posted: Sep 08, 2020 11AM)

This study found that 99% of COVID19 related web pages included a third-party data request. Amid debate focused on the privacy implications of COVID-19 contact-tracing apps, The findings suggest that attention should be paid to privacy risks of online information seeking.

"A Menace to the Public Health" - Contact Tracing and the Limits of Persuasion.
Mooney Graham et al. The New England journal of medicine 2020 Sep (Posted: Sep 03, 2020 7AM)

Potential reduction in transmission of COVID-19 by digital contact tracing systems
MJ Plank et al, MEDRXIV, September 1, 2020 (Posted: Sep 02, 2020 9AM)

Towards a digital solution: Predicting public take-up of Singapore′s contact tracing application during the COVID-19 crisis
YE Saw et al, MEDRXIV, September 1, 2020 (Posted: Sep 01, 2020 10AM)

Modeling Contact Tracing Strategies for COVID-19 in the Context of Relaxed Physical Distancing Measures
A Bilinski et al JAMA Network Open, August 21, 2020 (Posted: Aug 21, 2020 0PM)

To support efforts to control COVID-19, contact tracing must be implemented alongside prompt and extensive community case detection, and a high proportion of contacts must be reached. Our estimates imply that contact tracing could support partial relaxation of physical distancing measures but not a full return to levels of contact before lockdown.

Widespread testing, case isolation and contact tracing may allow safe school reopening with continued moderate physical distancing: a modeling analysis of King County, WA data
C Bracis et al, MEDRXIV, August 16, 2020 (Posted: Aug 16, 2020 7AM)

We predict that widespread implementation of "test and isolate" policy alone is insufficient to prevent the rapid re-emergence of SARS CoV-2 without moderate physical distancing. Widespread testing, contact tracing and case isolation would allow relaxation of physical distancing, as well as opening of schools, without a surge in local cases and deaths

Modelling the impact of testing, contact tracing and household quarantine on second waves of COVID-19
A Aleta et al, Nature Human Behavior, August 5, 2020 (Posted: Aug 07, 2020 9AM)

We integrate anonymized, geolocalized mobility data with census and demographic data to build a detailed model of transmission in Boston. We find that strict social distancing followed by testing, contact-tracing and quarantine could keep the disease within capacity of healthcare system while enabling the reopening of economic activities.

Characteristics and Outcomes of Contacts of COVID-19 Patients Monitored Using an Automated Symptom Monitoring Tool — Maine, May–June 2020
A Krueger et al, MMWR, August 3, 2020 (Posted: Aug 03, 2020 2PM)

Maine found that using automated symptom monitoring as a part of the state’s contact tracing program was well received, with the majority of monitored contacts (96.4%) agreeing to automated symptom monitoring. Automated symptom monitoring promptly identified COVID-19 diagnoses among monitored contacts.

Engineering Better Medicine for Public Health Crises and the Future
RI Pettigrew, National Academy of Medicine, July 27, 2020 (Posted: Jul 27, 2020 2PM)

The engineering “to-do” list to combat COVID-19 and assist in safely opening society is long. It includes the expedited design and distribution of rapid point-of-care and at-home diagnostic tests, predictive analytics that indicate infection before symptoms are evident, efficient contact tracing systems, effective anti-viral and immunomodulatory drugs and more.

Anatomy of digital contact tracing: role of age, transmission setting, adoption and case detection
JA Moreno Lopez et al, MEDRXIV, July 25, 2020 (Posted: Jul 26, 2020 11AM)

Contact Tracing: An Overview of Technologies and Cyber Risks
F Legendre et al, ARXIV, July 6, 2020 (Posted: Jul 09, 2020 9AM)

Decentralized Blockchain for Privacy-Preserving Large-Scale Contact Tracing
W Lv et al, ARXIV, July 2, 2020 (Posted: Jul 04, 2020 8AM)

Applications of digital technology in COVID-19 pandemic planning and response
S Whitelaw et al, Lancet Digital Health, June 29, 2020 (Posted: Jun 30, 2020 8AM)

This Viewpoint provides a framework for the application of digital technologies in pandemic management and response, highlighting ways in which successful countries have adopted these technologies for pandemic planning, surveillance, testing, contact tracing, quarantine, and health care.

A Survey of COVID-19 Contact Tracing Apps
N Ahmed et al, ARXIV June 18, 2020 (Posted: Jun 22, 2020 8AM)

Digital Contact Tracing Using IP Colocation
M Malloy et al, ARXIV, June 16, 2020 (Posted: Jun 18, 2020 8AM)

The need for privacy with public digital contact tracing during the COVID-19 pandemic
Y Bengio et al, Lancet Digital Health, June 2, 2020 (Posted: Jun 03, 2020 7AM)

Despite their potential advantages, most of the applications in use or under consideration have an impact on individual privacy that democratic societies would normally consider to be unacceptably high. In a free and democratic society, there are major concerns regarding privacy.

Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis
DK Chu et al, The Lancet, June 1, 2020 (Posted: Jun 02, 2020 6AM)

The findings support physical distancing of 1 m or more and provide quantitative estimates for models and contact tracing to inform policy. Optimum use of face masks, respirators, and eye protection in public and health-care settings should be informed by these findings and contextual factors.

Ethical guidelines for COVID-19 tracing apps-Protect privacy, equality and fairness in digital contact tracing with these key questions.
J Morley et al, Nature, News May 28, 2020 (Posted: May 30, 2020 7AM)

Here we set out 16 questions to assess whether — and to what extent — a contact-tracing app is ethically justifiable. These questions could assist governments, public-health agencies and providers to develop ethical apps — they have already informed developments in France, Italy and the UK. They will also help watchdogs and others to scrutinize such technologies.

How countries are using genomics to help avoid a second coronavirus wave
C Watson, Nature News, May 27, 2020 (Posted: May 29, 2020 10AM)

Countries that have successfully suppressed infections are entering the next phase of the pandemic — where there's a risk of new cases appearing. Researchers say that genomics will be crucial to quickly track and control these outbreaks. Studies already show that outbreaks tend to be shorter and smaller when genomics is used to help contact tracing.

COVID-19 and Your Smartphone: BLE-based Smart Contact Tracing
PC Ng et al ARXIV, May 28, 2020 (Posted: May 29, 2020 7AM)

CoVista: A Unified View on Privacy Sensitive Mobile Contact Tracing Effort
D Culler et al, ARXIV, May 27, 2020 (Posted: May 28, 2020 8AM)

Automated and partially-automated contact tracing: a rapid systematic review to inform the control of COVID-19
I Braithwaite et al, MEDRXIV, May 28, 2020 (Posted: May 28, 2020 7AM)

Digital Smartphone Tracking for COVID-19- Public Health and Civil Liberties in Tension
IG Cohen et al, JAMA, may 27, 2020 (Posted: May 27, 2020 0PM)

This Viewpoint compares manual and digital strategies for coronavirus disease 2019 (COVID-19) contact tracing, describes how countries in Asia and Europe have used smartphone tracking, and discusses privacy and discrimination concerns and strategies for balancing public health and civil liberties in the US.

Reproducing SARS-CoV-2 epidemics by region-specific variables and modeling contact tracing App containment
A Ferrari et al, MEDRXIV, May 19, 2020 (Posted: May 19, 2020 8AM)

Nearly 40% of Icelanders are using a covid app—and it hasn’t helped much- The country has the highest penetration of any automated contact tracing app in the world, but one senior figure says it “wasn’t a game changer.”
M Johnson, MIT Tech Review, May 11, 2020 (Posted: May 13, 2020 10AM)

Ethics and governance for digital disease surveillance
MM Mello et al, Science, May 11, 2020 (Posted: May 12, 2020 9PM)

Several countries have taken digital epidemiology to the next level in responding to COVID-19. Focusing on core public health functions of case detection, contact tracing, and isolation and quarantine, we explore ethical concerns raised by digital technologies and new data sources in public health surveillance during epidemics

Quantifying SARS-CoV-2 transmission suggests epidemic control with digital contact tracing
L Ferretti et al, Science, May 8, 2020 (Posted: May 08, 2020 1PM)

Given the virus infectiousness and the high proportion of transmissions from presymptomatic individuals, controlling the epidemic by manual contact tracing is infeasible. A contact-tracing app with a memory of proximity contacts and notifies them would be sufficient to stop the epidemic, in particular when combined with other measures such as physical distancing

CDC launches national viral genomics consortium to better map SARS-CoV-2 transmission
CDC Press Release, May 1, 2020 Brand (Posted: May 04, 2020 5PM)

Genomic sequence data can give unprecedented insight into the biology of SARS-CoV-2, and help define the changing landscape of the pandemic. By sequencing viruses from across the US, CDC and other public health authorities can monitor changes in the virus and use this information to guide contact tracing, public health mitigation efforts, and infection control.

SARS-CoV-2 Sequencing for Public Health Emergency Response, Epidemiology, and Surveillance (SPHERES)
CDC, May 1, 2020 Brand (Posted: May 01, 2020 10AM)

This CDC initiative will help monitor important changes in the virus as it continues to circulate, gain important insights to support contact tracing, provide crucial information to aid in identifying diagnostic and therapeutic targets, and advance public health research in the areas of transmission dynamics, host response, and evolution of the virus.

Show evidence that apps for COVID-19 contact-tracing are secure and effective
Nature editorial, April 29, 2020 (Posted: Apr 30, 2020 9AM)

Key questions need answers: One serious concern is accuracy. If incorrect information has been sent to a large group of contacts, it will have caused unnecessary alarm. An equally important concern is privacy. It is becoming easier to identify individuals from anonymized data sets.

An army of virus tracers takes shape in Massachusetts.
E Barry, NY Times, April 16, 2020 (Posted: Apr 16, 2020 7AM)

Asian countries have invested heavily in digital contact tracing which uses technology to warn people when they have been exposed to the coronavirus. Massachusetts is using an old-fashioned means: people

Evaluating the effectiveness of social distancing interventions against COVID-19
L Matrajt et al, MEDRXIV, March 30, 2020 (Posted: Mar 30, 2020 8AM)

Our models suggest that social distancing interventions will buy crucial time but need to occur in conjunction with testing and contact tracing of all suspected cases to mitigate transmission of SARS-CoV-2.

Europe eyes smartphone location data to slow virus spread
PBS, March 23, 2020 (Posted: Mar 24, 2020 7AM)

Britain, Germany and Italy are evaluating powerful and invasive tools for what epidemiologists call contact-tracing, the mapping of personal interactions that could spread the virus. These apps would use real-time phone data to pinpoint virus carriers and people they might have infected.

Cellphone tracking could help stem the spread of coronavirus. Is privacy the price?
Science, March 22, 2020 (Posted: Mar 22, 2020 3PM)

At its simplest, digital contact tracing might work like this: Phones log their own locations; when the owner of a phone tests positive for COVID-19, a record of their recent movements is shared with health officials; owners of any other phones that recently came close to that phone get notified of their risk of infection and are advised to self-isolate.


Disclaimer: Articles listed in Hot Topics of the Day are selected by Public Health Genomics Branch to provide current awareness of the scientific literature and news. Inclusion in the update does not necessarily represent the views of the Centers for Disease Control and Prevention nor does it imply endorsement of the article's methods or findings. CDC and DHHS assume no responsibility for the factual accuracy of the items presented. The selection, omission, or content of items does not imply any endorsement or other position taken by CDC or DHHS. Opinion, findings and conclusions expressed by the original authors of items included in the Clips, or persons quoted therein, are strictly their own and are in no way meant to represent the opinion or views of CDC or DHHS. References to publications, news sources, and non-CDC Websites are provided solely for informational purposes and do not imply endorsement by CDC or DHHS.
TOP