Bracing for contact tracing

What should you do if you get a call from a contact tracer letting you know you've been exposed to someone who tested positive for COVID-19? Even our best efforts to stay well — by maintaining distance, washing hands often, restricting the size of our social circles, and wearing masks — may not keep the virus at bay as cities and towns lift restrictions.

That's why many experts recommend three combined approaches to help prevent a dangerous resurgence of illnesses, hospitalizations, and deaths from COVID-19:

• continued mitigation efforts, which includes preventive strategies like those described above
• prompt access to testing, with quick turnaround on results
• contact tracing.

What is contact tracing and who does it?

Generally, contact tracing means locating and testing people known to have been in close contact with a sick person, to prevent an illness like COVID-19 from spreading to an ever-widening circle of people. This strategy works best when case numbers are low — not high or rising fast, as they did in hot spots like New York and California in late March and early April. After the peak passes, contract tracing is feasible. It's proven effective in countries such as Germany, China, and South Korea.

Just how can we make contact tracing work in the US? Public health authorities are trying to figure that out, even as cities and towns recruit people to train as contact tracers. In some places, contact tracers are volunteers; others are paid. And they have a variety of backgrounds, including public health workers, retired healthcare professionals, furloughed hospitality workers, and students. Being able to speak the language and understand the culture of those who will be called are major advantages. So is a healthy amount of empathy.

Three steps in contact tracing for COVID-19

While local processes vary in the US and around the globe, the World Health Organization recommends these three steps for contact tracing programs:

• Identify close contacts. After someone tests positive for the COVID-19 virus, they should first receive appropriate medical care and take measures to isolate themselves. Then, a contact tracer can interview them to get a list of their close contacts. According to the CDC, this list should include intimate partners, household members, and anyone coming within six feet of the infected person for a total of 15 minutes or more over a 24 hour period.  This could include a single exposure of at least 15 minutes or it could be a combination of smaller exposures, such as 10 minutes in the morning and 5 minutes that evening.  Exposure to a close contact begins 48 hours before symptoms began; if the infected person had no symptoms, the exposure period is 48 hours prior to testing. Other factors, such as whether the infected person was coughing or wearing a mask, also affect infection risk. Checking calendars and social media communications can help people retrace their steps and refresh their memories about who they might have exposed.
• Contact close contacts. The contact tracer will call or text each person considered to be at risk for infection. This is tricky. If the call is unexpected, the contact might be distrustful, skeptical, or even uncooperative with the caller.

  If you receive a call, advice will vary depending on the exposure: for a minimal exposure to someone who wasn't coughing, the recommendation may be to just monitor symptoms and call back if any develop. For more intense exposure, you may be advised to self-quarantine for 14 days. Testing may be suggested if you have symptoms, but may not be necessary otherwise.

• Follow-up. After a number of days, the contact tracer should call back to confirm that no symptoms have developed, and answer any questions that have come up. If you test positive for COVID-19, your contacts are called and the process starts over.

How cellphones can help with contact tracing

Researchers and tech companies quickly realized that cell phone technology could help determine who an infected person has come into contact with, with and the status of a person in quarantine. For example, apps exist (or are in development) that can

• alert you if a person you've been near tests positive and lists you as a potential contact
• store location information over a period of time that can be readily retrieved if anyone you've been near tests positive
• automatically text contacts of an infected person every few days to ask if symptoms have developed.

Cell phones have also been used to enforce quarantine in a few countries, although some measures taken may not be acceptable in the US due to concerns about privacy and personal freedoms. But as we enter the "new normal," requests for our cell phone number when entering a restaurant, supermarket, or other business may become more common. Later, if a worker or other customer has a positive test, knowing who has been there and their phone numbers can make it much easier to notify those who could have been exposed.

Using cell phone technology for those who agree to participate will allow contact tracers and public health workers to allot more resources to those who don't have a phone, or who are unwilling to share information by phone.

Challenges to contact tracing

Formidable challenges include:

• Trainees and cost. Current estimates suggest that we'll need between 100,000 and 300,000 contact tracers nationwide. Recruiting, training, and paying them will require significant resources.
• Support services. If a contact is advised to quarantine, they may need help getting food, medications, child care, or other services. The contact tracer can help with this only if such support systems are in place.
• Testing availability. Contact tracing requires ready access to testing and prompt reporting of results.
• Acceptance. As long as participation is voluntary, a contact tracing program can only be effective if there is widespread cooperation and acceptance by the infected person and their contacts.
• Privacy concerns and scammers. Whenever personal medical information is requested, safeguards are needed to prevent accidental or inappropriate sharing of that information. The Federal Trade Commission has some helpful recommendations for avoiding scams that have already surfaced. For example, a legitimate contract tracing program may text to tell you to expect a call, but shouldn't ask you to click on a link or request personal information, such as your social security number or any financial information.

And there is debate about whether data should be stored centrally (for example, by a government agency), whether sharing one's medical information should be mandatory, and whether individuals should be able to opt out of tracing programs.

The bottom line

Hopefully you and those around you are doing everything possible to limit the risk of becoming infected with the virus that causes COVID-19, and you'll never be called by a contact tracer. But if you do, don't be alarmed. What they are doing is a vital part of safely reversing the stay-at-home orders and restrictions made necessary by the pandemic.

Follow me on Twitter @RobShmerling

For more information on coronavirus and COVID-19, see the Harvard Health Publishing Coronavirus Resource Center.