I woke up today thinking about Foursquare, which, you may or may not remember, was a popular social media app a decade ago that let users check in to restaurants and other businesses, win badges, know where other people were hanging out and the like.

These days, Foursquare is a "location data and technology platform" and the business of pinpointing people's locations is less a social undertaking and more of a scientific one.

I'm referring, naturally, to contact tracing, which became a top news story in the last week as scientists and governments acknowledged the protocol as a crucial element for being able to restart the economy.

In public health, contact tracing has been a key practice for addressing contagious diseases including HIV, Ebola, SARS and tuberculosis, to name a few prior outbreaks. In essence, contact tracing involves identifying and monitoring people who may have had contact with someone who is infected. This sounds simple enough but is reportedly a massive task. A Kaiser Family Foundation briefing on contact tracing earlier this month estimates enormous figures should the US be able to ramp up testing to appropriate levels (another key step in opening up the economy while waiting for a vaccine). For example, KFF says, if the US needs to perform 750,000 COVID-19 tests per week to try to identify most of the cases (as has been recommended), and if 10% end up positive, then 75,000 cases would require contact tracing. These figures align, KFF points out, with what happened in February in Wuhan, China in which 1,800 contact tracing teams of five people investigated tens of thousands of contacts each day.

No, not Foursquare. But, rather, Google and Apple. The two tech teams announced on April 10 they had teamed up to create the framework for Bluetooth-based contact-tracing apps; next month, they will release an API (application programming interface) that public health apps can use for both Android and iOS systems. In a nutshell, Apple and Google's framework would let one phone's Bluetooth recognize and record another in an anonymous fashion. If someone using a contact tracing app tests positive, the Bluetooth will be able to identify the phones that have been in proximity of that user's phone. For what it's worth, this week, 300 academics signed a public letter supporting the use of Bluetooth technology as more likely to preserve people's privacy than other centralized systems.

Naturally, contact tracing apps' efficacy relies to a large degree on users' willingness to opt in. In this golden age of mistrust of technology and government (let alone technology and government working together), will people use contact tracing apps as energetically as they once voluntarily logged their every visit to restaurants, bars and stores?

Hard to say. I'm inclined to think US Sen. Richard Blumenthal, D-Connecticut, was right when he said, "Apple and Google have a lot of work to do to convince a rightfully skeptical public that they are fully serious about the privacy and security of their contact tracing efforts."

And while digital contact tracing and other types of technology have been cited as one of the reasons China, Taiwan and Singapore were able to contain their cases, it's widely agreed some of those countries' technologies would be less palatable here (such as mandatory electronic wristbands in Hong Kong that alert authorities when quarantined people leave their houses). For a more detailed description of other countries' technologies, as well as the potential concerns of rolling out digital contact tracing in the US, be sure to check out the ACLU's detailed white paper.

As for New Mexico, digital contact tracing sounds like it's coming our way. Right now, the state has about 100 people doing manual contact tracing; they've contacted more than 150,000 people, according to a recent Wall Street Journal report (which the health department confirmed to SFR).

During an April 15 public briefing, Gov. Michelle Lujan Grisham announced the state has been asked to take part in a federal pilot program for testing, surveillance and contact tracing. I asked the governor if that would include digital contact tracing. Yes, she said.

"It is clear if we are going to be doing this with this pandemic for the next year while we're waiting for a vaccine, it's got to be much more robust," she said. "We are interested in all of these new applications. We are working with any number of states and now the federal government in selecting what we think will be the best application." Describing herself as "very optimistic" about expanded contact tracing, the governor noted that having it is "directly related to our ability to do economic recovery."

That prospect may propel otherwise anti-technology people to download that app. For what it's worth, the academics supporting a privacy-forward digital tracing system also say the system should be turned off when the current crisis is over.

What a wonderful day that will be.