Gunnison county explores COVID-19 contact tracing app

Need 60 percent public opt-in rate for biggest impact

By Katherine Nettles

Imagine getting a notification on your phone that you’ve been exposed to coronavirus, and at what level (low, moderate or high) the exposure was. That could be the future for some people, should they choose it—and should Gunnison County choose it as well.

As promised, the Gunnison County Investigative Science Development (ISD) Team gave an overview on Monday afternoon, June 23, of a new mobile device application that the county is seriously considering for future use in COVID-19 contact tracing to counteract the virus’ spread.

A collaboration between Google and Apple has made the app available for free to the county health department and the main question is whether people would use it if it were rolled out within the county late this summer or fall.

ISD team member and app developer Erik Niemeyer presented the app’s potential role and specifications Monday in a virtual town hall meeting, also aired on Facebook Live. The app would notify people who may have been exposed to another person who has tested positive for COVID-19. Downloading and activating the app would be voluntary for individuals and it would not collect or share their personal data or location information.

Niemeyer described two ways technology can digitally track the virus: through Bluetooth tracing or location-based tracing. The county would use the Bluetooth option because of much stronger privacy protections.

“Bluetooth contact tracing is what the majority of apps in democratized nations use today. It anonymizes your interaction,” Niemeyer said, and it doesn’t record any user location. The other methods, he explained, do track locations and therefore eliminate the need for users to download the app. “The drawback is that [location-based tracking] is fairly invasive,” he said.

The technology is essentially brand new, and Google and Apple announced their joint effort to enable this Bluetooth method in April to help governments and health agencies reduce the spread of COVID-19. The technology is being released in two phases. The first phase began on May 4, when the system was made available to developers, and the second phase began a few weeks ago with the release of an operating system on mobile devices that allows for exposure notification as a built-in feature.

People who use the app would have the choice to release their positive test results or not. Niemeyer emphasized that the app would not replace traditional contact tracing but would be used in conjunction with it. It would also not translate to other areas of the state or county, even if they use the same app.

“But even if you activate on your phone, you must have a public health provider service,” Niemeyer said.

The app maintains privacy by issuing a random ID to your device, and will periodically check positive IDs within its own list. If one of those IDs that you’ve been around in the last two weeks reports a positive test, then you get informed. You also receive a notification of what level of exposure you had, using four parameters: how infectious the virus is; how long were you around the other person; how long it has been since your exposure; and how close you were. The app measures Bluetooth signal strength for the proximity measurement.

All these combine to give an aggregate score of risk level and what public health recommends you do.

The app can also send public health alerts, and COVID 19-related resources. “These are all items the app could help us with beyond contact tracing,” said Niemeyer. “What we need to do now is determine what the community participation would be on this.”

If the community determines the app is worthwhile, then next steps will be local adaptation and deployment, most likely in September or October.

“All development would be done publicly and transparently. The source code will be available to everyone. It’s on GitHub,” said Niemeyer, referring to a software development platform where people can verify the information themselves. “We are interested in sharing all this information in transparent ways,” he said.

Gunnison County commissioner Jonathan Houck spoke about Apple and Google updates for smart phones, and noted people are concerned about seeing COVID-related apps on their phones since they have not opted in.

Niemeyer explained that those updates are simply a new feature, but require the three key pieces in place to be used. People have to have the app, opt in to using it, and have a government-authorized service implementation.

Niemeyer also pointed out that many people don’t even realize many apps and services they use do track them. Apple and Google have rejected any location tracking for this app. “Even if we wanted to add that, Apple and Google would reject it,” said Niemeyer. “Contact tracing, at least the way we intend to be using it, uses Bluetooth tracking only. It doesn’t know you are in City Market.”

“There are a lot of other things that are tracking them. This is not that,” agreed Houck.

The question remains as to whether the app can be used widely enough, and how to ease people’s worries. Niemeyer said the app needs greater than 60 percent of the community to opt-in to have some significant impact on outbreaks.

Representatives from all municipalities within Gunnison County were listening in, and many said the concerns they have heard are about either privacy or getting blamed by contacts for spreading the virus to them.

“A couple of people have asked questions about if they get sick and start sharing information, that they will get backlash from others who [the virus] spread to,” said Gunnison mayor Jim Gelwicks.

Niemeyer shared the news that he has just learned in a routine screening for a voluntary surgical procedure that he tested positive for COVID-19, despite being completely asymptomatic. He said he had felt compelled to call everyone he has seen in the last seven days. “So the app could relieve a lot of that,” he said, and people would not need to divulge anyone’s identity.

Houck reiterated, “No one is going to get an alert saying John Smith has COVID.”

“If they contact Public Health they can then walk through the more traditional steps of contact tracing. In order to do that, we need to have those other steps in place,” said Public Health director Joni Reynolds.

County commissioner Roland Mason suggested that messaging to visitors would be important, and asked how this app would sync up with the apps in other places if visitors come here and have already used the app at home. Niemeyer said currently there is no way to sync. “Visitors with an app from their own municipality would need to get this area’s app. Apple and Google are working to make that translatable, though,” he answered.

Finally, Niemeyer acknowledged that this is one tool in the toolbox and a multitude of different tools and methods are needed to slow down an epidemic.

“The whole code is open and out there for anyone who wants to investigate it more,” said response team public information officer Andrew Sandstrom.