Know who you came in contact with in the last 24 hours? That’s a key to beating COVID-19

If you are unfamiliar with the phrase “contact tracing,” you will soon get to know it well. Health officials say it is a key to overcoming COVID-19. But it will feel intrusive and like an infringement on one’s privacy.

Yet it must be allowed to work if California is to win the war against the coronavirus.

How it works

Contact tracing is a epidemiological sleuthing process to find anyone who had contact or was near to a person infected with COVID-19. The idea is to isolate both the infected person, and those who came in contact with that person, so as to limit the virus’ spread.

That also allows those who remain healthy to do the normal routines of life. Contact tracing becomes particularly important as California begins to reopen to regular activities. Dr. Rais Vohra, Fresno County’s interim public health officer, says the countries that have successfully flattened the pandemic curve have had strong contact tracing efforts.

Here is a hypothetical to show how tracing works:

A person goes out to dinner with family at a restaurant and feels fine. But two days later that person develops COVID-19 symptoms. In consultation with a physician, the person gets tested, and has a positive result for infection.

A contact tracer — a public health staffer trained in the sleuthing process — is notified about the positive result. That tracer then interviews the infected person to find out who was within earshot of them at the restaurant. Anyone that close was at risk of being exposed to the virus. Besides family, that would mean the restaurant staff and people sitting nearby.

The contact tracer then laboriously tracks down those people and advises them to be in self-isolation for 14 days to see if COVID-19 will develop. The infected person must be isolated for seven days — a shorter period since the disease was already underway.

As one can imagine, the process of tracking down contacts is involved and requires no small degree of detective work. The tracer also has to be capable of conducting interviews sensitively and confidentially to assure patient privacy.

For tracing to perform best, contacts have to be made quickly once a patient is identified. That is the best way to keep flattening the curve of infections.

Local efforts

Fresno County public health has a team of about 30 people now doing contact tracing. But Vohra said 300 are needed for the county to effectively do tracing.

He will be working with state officials to determine how to best get that larger group assembled. “We will need them this year and into next year,” he said.

In addition, Vohra said large employers will be responsible for performing contact tracing of their work force.

Privacy concerns

Apple and Google, with the encouragement of the Trump administration, are launching an app that can help with the tracing effort. But a host of privacy concerns have been identified by groups like the ACLU and Brookings Institution over how the data will be collected, stored and used, not to mention how the apps might yield false positives and false negatives.

There are also questions over whether Americans will view the apps with suspicion and not use them, which limits the effectiveness of any app-based effort. The tracing app is supposed to be available to public health agencies by the middle of this month.

Congress and federal agencies will need to make sure the privacy rights of Americans are not violated in the technological quest to battle the pandemic. It will be hard enough for some people to acquiesce and disclose their activities and social interactions to a human public health representative.

Even so, contact tracing has been around for decades, and the Centers for Disease Control encourages states and county health departments to make full use of the method in the battle against the coronavirus.

If someone knocks on your door, identifies that they are with county public health and says you may have been exposed to someone with COVID-19, it would be wise to cooperate. Contact tracing is here.

This story was originally published May 5, 2020 at 5:00 AM.