What is Test and Trace?

Test and Trace is a classic public health approach for containing diseases. It means identifying people who have come into contact with an infected person (contact tracing) , testing them, and then isolating them if they’re sick. This is proven to quickly limit the spread of a deadly disease like COVID-19.

Here’s a basic outline of how Test and Trace works:
1. When someone tests positive for COVID-19, you must find out who they’ve had recent close contact with. This can be done by interviewing them, automatic digital tracing (a recent, modern development), or with public service announcements.

2. Next, notify all of these people (by phone call or text) and have them get tested immediately, even if they don’t have symptoms. They should stay at home until they can get tested.

3. If any of these exposed people test positive, they have to either completely isolate themselves or be isolated at a government facility. This dramatically limits the spread of the virus and asymptomatic transmission.

“If someone is infected, but not yet symptomatic, there’s no way for them to know that they may be contagious…Identifying and isolating presymptomatic individuals is key to limiting transmission.” – Trevor Bedford, epidemiologist at Fred Hutch

Why do we need to implement contact tracing?

Test and Trace is one of the major keys (along with mandatory public mask usage) to simultaneously slowing COVID-19, ending lockdowns and restoring the U.S. economy. It’s part of the solution to the misconception that local and state governments have a binary choice between locking down the economy to save lives, or re-opening the economy and letting people die.

Why? Because ~44% of people with COVID-19 are asymptomatic and CDC research shows that you don’t need to be symptomatic to be contagious. Test and Trace is the only way to identify these asymptomatic people, so that we can isolate them and stop them from infecting others.

Together with other public health measures like social distancing, mandatory public mask usage, and hand-washing, Test and Trace can allow local governments to save their economies without condemning their people to get sick.

“The one thing we hopefully would have in place, and I believe we will have in place, is a much more robust system to be able to identify someone who’s infected, isolate them and then do contact tracing. If you have a really good program of containment, that prevents you from ever having to get into mitigation. We’re in mitigation right now.”–Dr. Anthony Fauci, U.S. director of the National Institute of Allergy and Infectious Diseases (and the United States’ leading expert on infectious diseases)

“The country will need to implement a “robust and comprehensive system” of contact tracing to return Americans to work, reopen schools and ease social distancing guidelines.” –Johns Hopkins University Experts

Proven Test and Trace strategies from countries that have contained COVID-19

What we can learn about testing and tracing from countries that have contained major outbreaks or prevented outbreaks.

“South Korea is showing Covid-19 can be beat with smart, aggressive public health.”
Scott Gottlieb, former commissioner of the U.S. Food and Drug Administration

1. Widespread, Aggressive Testing: 

“Testing is central because that leads to early detection, it minimizes further spread and it quickly treats those found with the virus. That’s the key behind our very low fatality rate.”
Kang Kyung-wha, South Korea’s foreign minister

While South Korea and the U.S. have similar per capita testing numbers, South Korea’s 2% positivity rate (the percentage of COVID-19 tests that test positive) is 10x lower than the U.S.’s 20% positivity rate. This means that South Korea is testing ~10x more aggressively than the U.S.The Atlantic (4/16/20)

Also, in South Korea:Offices, hotels and other large buildings often use thermal image cameras to identify people with fevers. Many restaurants check customers’ temperatures before accepting them.” –New York Times

2. Manual Contact Tracing

South Korea: “When someone tests positive, health workers retrace the patient’s recent movements to find, test — and, if necessary, isolate — anyone the person may have had contact with, a process known as contact tracing. Health officials would retrace patients’ movements using security camera footage, credit card records, even GPS data from their cars and cellphones. –New York Times

“Taiwan began requiring hospitals to test for and report cases. That helped the government identify those infected, trace their contacts and isolate everyone involved, preventing the virus from spreading to the community.” –NBC News

3. Digital Contact Tracing

“South Koreans’ cellphones vibrate with emergency alerts whenever new cases are discovered in their districts. Websites and smartphone apps detail hour-by-hour, sometimes minute-by-minute, timelines of infected people’s travel — which buses they took, when and where they got on and off, even whether they were wearing masks. People who believe they may have crossed paths with a patient are urged to report to testing centers. South Koreans have broadly accepted the loss of privacy as a necessary trade-off.” –New York Times

“Korea changed the law allowing the government to collect a patient’s data and security footage during an outbreak. All their steps are logged and then shared to alert people to stay away from the path of infection. Websites and private apps compile the information allowing everyone to see if a person with a confirmed case of coronavirus went to a pharmacy or the hospital, or anywhere else. And they’ll know how recently they went too. It’s a means of checking the possibility of infection. Citizens are checking the coronavirus locations and are avoiding going to these areas. This information lets people know if they’ve crossed paths with an infected person so they can go get tested for the virus.” –Vox

4. Enforcing Mandatory Self-Quarantining

South Korea:People ordered into self-quarantine must download another app, which alerts officials if a patient ventures out of isolation. Fines for violations can reach $2,500. By identifying and treating infections early, and segregating mild cases to special centers, South Korea has kept hospitals clear for the most serious patients. Its case fatality rate is just over one percent, among the lowest in the world.” –New York Times

Hong Kong: “To ensure people under compulsory home quarantines do not stray from the confines of their apartments, the Hong Kong government has rolled out electronic tracker wristbands that alert authorities to rogue escapees. If someone tries to breach the quarantine by leaving their home, the app triggers a warning and alerts the government. Anyone violating their quarantine could face up to six months in prison and a fine of up to HK$25,000 ($3,200).” –Quartz

“Taiwan is believed to be the first to have used mobile phone tracking to enforce quarantines, which the government reportedly reinforces by calling those in quarantine twice a day to ensure they do not evade tracking by leaving their phones at home.” –Harvard Business Review

5. Relentless Public Service Announcements

Relentless public messaging urges South Koreans to seek testing if they or someone they know develop symptoms. Visitors from abroad are required to download a smartphone app that guides them through self-checks for symptoms. Television broadcasts, subway station announcements and smartphone alerts provide endless reminders to wear face masks, pointers on social distancing and the day’s transmission data. The messaging instills a near-wartime sense of common purpose.” –New York Times

6. Widespread Public Mask Usage

“The big mistake in the U.S. and Europe, in my opinion, is that people aren’t wearing masks.” –China’s CDC Director

South Korea: “Television broadcasts, subway station announcements and smartphone alerts provide endless reminders to wear face masks” –New York Times

“Masks were hard to come by in South Korea until late February. Then the government stepped in and ensured a supply for every person in the country. Up until then, South Korea showed a similar-shaped exponential trajectory to Italy. After that point, the exponential growth slowed, and today the number of active cases is decreasing. There is no economic lockdown there.” –The Guardian

“Masks mandatory on Taiwan trains, intercity buses starting [April 1].” –Taiwan News

Some challenges regarding implementing Test and Trace in the U.S.

1. Testing Improvements Needed

A) Greater availability of tests and loosened testing criteria so that asymptomatic people who came in close contact with someone who’s infected can get tested. Right now the CDC has made contact tracing tests a “non-priority” but they have made it clear that they plan to change this policy once more testing is available.

B) Faster test turnaround times: Right now test results can take up to 5-10 days. Test and Trace requires quick testing turnaround times so that you can stop asymptomatic spreading.

2. Manual/Digital Contact Tracing Improvements Needed

A) Scaling the number of workers doing contact tracing:  “We are going to need a substantial expansion of public health fieldworkers. We have over 600 people in the field right now from the CDC in all the states trying to help with this response, but we are going to have to substantially amplify that.” –Robert Redfield, U.S. CDC Director

B) Implementing a digital contact tracing strategy that works for the U.S.: The U.S. has very different privacy laws than South Korea and Taiwan so private and public leaders need to figure out an approach that will be effective without compromising privacy. 

Who's working on contact tracing?

Some Examples of Government Leaders Working On This:

NY/NJ/CT: Launching a large contact tracing program backed by Michael Bloomberg and in partnership with Johns Hopkins and Vital Strategies.

Senate Proposal: Gillibrand, Bennet propose hiring thousands for new ‘Health Force’

Senate Proposal: Warren, Levin roll out plan for coronavirus ‘containment corps’

Massachusetts: COVID-19 Contact Tracing Has Launched In Mass. Here’s How The Effort Is Going So Far

Vermont: State ramps up contact tracing teams to contain Covid-19

Expert Plans:

A National Plan to Enable Comprehensive COVID-19 Case Finding and Contact Tracing in the US by a group at the Johns Hopkins Center for Health Security and the Association of State and Territorial Health Officials

Bloomberg: 3 things mayors can do to help build an army of coronavirus ‘contact tracers’

Tomas Pueyo: Coronavirus: How to Do Testing and Contact Tracing

US Digital Response: Understanding Digital Contact Tracing: Limitations, Implications and Recommendations

National coronavirus response: A road map to reopening (the plan relies heavily on Test and Trace) written by American Enterprise Institute, led by former FDA Commissioner Scott Gottlieb

Digital Contract Tracing:

Apple and Google: They’re working together to create a Bluetooth powered digital contact tracing system

Contact Tracing Rights: A list of Data Rights (created by data experts) created with the purpose of being the standard framework for anyone developing a Digital Contact Tracing and Alerting app.

Covid Safe Paths: Bluetooth privacy oriented tracing. Built in collaboration with MIT.

Covid Watch: Bluetooth privacy oriented tracing. Built in collaboration with Stanford.

CoEpi: Bluetooth privacy oriented tracing.

Trace to Zero: Privacy oriented tracing.

ZeroBase: QR code tracing. Working with the Harvard Data Science Institute.

Other Helpful Resources:

Covid Exit Strategy: Has lists of targets for how many tests states need in order to implement Test and Trace.

Help With Covid: Volunteer on COVID-19 projects/initiatives

How You Can Help

We’re the team behind #Masks4All that helped the homemade masks movement reach more than a billion people in three weeks. Now we’re working to popularize and implement Test and Trace in the U.S. – please get involved!

1. If you’re a member of the public

a) Join our email list to stay informed about major Test and Trace updates + get notified when we need help pressuring government leaders to implement Test and Trace

b) Join our slack group if you’d like to work on helping to popularize and implement Test and Trace

c) Share this resource with others on social media!

2. If you’re working on implementing Test and Trace (public health worker, technologist, government employee, etc.)

Join our slack group to connect, get advice/help and share learnings with lots of other people working to implement and popularize Test and Trace. We’re all in this together! 

Get Involved.

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