More Than 1 Million Opt In To MD COVID Alert Notifications

MARYLAND — More than 1 million Marylanders have signed up for MD COVID Alert, an app that notifies users who have had close contact with someone who tested positive for the virus.

Gov. Larry Hogan said the state had passed 1 million users Thursday, a little more than a week since MD COVID Alert was released.

"This incredible response is a testament to the perseverance and vigilance of the people of our state during this unprecedented public health crisis," Hogan said in a statement.

"We are encouraging everyone to opt-in, which will help us stop the spread and protect our fellow Marylanders," Hogan said.

The MD COVID Alert app complements traditional contact tracing efforts. It was made public Nov. 10 and saw hundreds of thousands of people opt in to participate in its first few days alone.

Within 24 hours of the app's rollout, more than 350,000 people in Maryland subscribed, according to Mike Ricci, a spokesman for the governor. The number increased to 826,000 within four days.

"People are excited to have another tool at their disposal,” Dr. Katherine Feldman, the director of contact tracing for the Maryland Department of Health, told Patch soon after MD COVID Alert was released.

Apple and Google worked together on the technology.

"When the pandemic hit, they decided they wanted to do something to help, so they joined forces and developed this technology," Feldman said. “It is by Apple and Google, built into the operating system."

To opt in, Apple users can go to settings and enable exposure notifications.

Android users go to Google Play to download the Google-developed app, Feldman said.

The goal was to “have as few barriers as possible, then make that available to public health authorities,” Feldman said.

How Does MD COVID Alert Work?

The alert system notifies people if they have been in close contact with someone who has the coronavirus. It does not say where or when the exposure occurred.

Using Bluetooth Low Energy, the technology detects where a person has been, so Bluetooth must be enabled.

MD COVID Alert assigns each user a random ID, which changes every two minutes to ensure these numbers cannot be used to identify people or their whereabouts, according to the Maryland Department of Health.

Several times a day, the app processes the random ID numbers to determine whether a user has come in close contact with a person who tested positive for the virus.

Maryland health officials worked with the app's developers — Google and Apple — on establishing the parameters, including what constitutes close contact.

In accordance with the Centers for Disease Control and Prevention definition, "close contact" is being within 6 feet of an infected person for at least 15 minutes total over a 24-hour period that runs from two days before the symptoms began or two days before an asymptomatic person who tested positive underwent testing.

If someone meets these criteria, then the user will get an exposure notification. Both iPhone and Android users can opt in to the free service, which can be disabled anytime.

These jurisdictions have apps that will communicate with MD COVID Alert, according to Feldman: D.C., New York, New Jersey, Delaware, Pennsylvania, North Carolina, Nevada, North Dakota and Wyoming.

Virginia used a third-party developer before the app was made available by Google and Apple, but it is working on becoming interoperable with Maryland's alert system, Feldman said.

Find out more about MD COVID Alert.

Contact Tracing Is Still 'Critically Important'

While officials celebrated the milestone of more than 1 million users opting in to MD COVID Alert, they cautioned that it is not a substitute for traditional contact tracing or preventive measures like mask-wearing, keeping 6 feet of distance from people in public, avoiding large crowds, and frequent hand-washing.

“We still want people to answer the phone," Feldman said, when contact tracers call. "It is critically important."

The app can help fill in gaps in contact tracing, she added.

"Sometimes we don't reach individuals — maybe we have the incorrect phone number," Feldman said. "This will help."

MD COVID Alert will also help notify people who may be not be on the radar of contact tracers.

"It's certainly possible that infected cases might not know other people they were in close contact with," Feldman said.

Two people might be "enjoying coffee outside" and "later one of those people becomes a case," she said as an example.

"They'll be able to name their friend, but they won't necessarily know who at the table next to them," Feldman said. "This fills that gap — it allows you to alert individuals you might not know."

Related: MD Launches COVID Alert For Phone Notifications Of Exposure