Sarah KV, a real estate agent in Denver, was thrilled when Colorado introduced an app to warn people of potential coronavirus exposures.
Based on software from Apple and Google, the state’s smartphone app uses Bluetooth signals to detect users who are in close contact. If a user later tests positive, that person can anonymously inform other app users with whom the person has crossed paths at restaurants, trains, or elsewhere.
Ms. KV immediately downloaded the app. But after testing positive for the virus in February, she was unable to obtain the special verification code needed to warn others from the state, she said, even after making three calls to Colorado’s Department of Health.
“They advertise this app to make people feel good,” Ms. KV said, adding that she had since removed the app, CO Exposure Notifications, in desperation. “But it’s not really doing anything.”
The Colorado Department of Health said it has improved its process and now automatically issues verification codes to every person in the state who tests positive.
When Apple and Google Announced last year That they were working together to create a smartphone-based system to help prevent viruses, their collaboration seemed like a game changer. Human interactions were conflicting with the tracer spiking virus caseload, and the trillion-dollar rival companies – whose systems run 99 percent of the world’s smartphones – had the ability to quickly and automatically alert far more people.
Soon Austria, Switzerland and other countries introduced virus apps based on Apple-Google software, as did some two dozen US states, including Alabama and Virginia. So far, the app has been downloaded more than 90 million times, according to an analysis by sensor tower, an app research firm.
But some researchers say companies’ product and policy choices have limited the utility of the system, raising questions over Big Tech’s power to set global standards for public health equipment.
Computer scientists have reported accuracy problems with Bluetooth technology used to detect proximity between smartphones. Some users have reported failed notifications. And to date there has been little rigorous research on whether the ability of apps to accurately alert people at risk of viruses outweighs potential drawbacks – such as giving false warnings to unsuspecting people, over-testing, or virus exposure. Failed to detect users coming in.
“It’s still an open question whether these apps are helping with actual contact tracing or not, just a distraction, or whether they can also cause problems,” Stephen Farrell And Doug leith, Computer science researchers at Trinity College in Dublin, wrote A report on Ireland’s virus alert app in April.
In the United States, some public health officials and researchers said the apps had demonstrated modest but significant benefits. In Colorado, more than 28,000 people have used the technology to inform their exposure to potential virus exposure. In California, which introduced a virus-tracking app called Inform ca In December, about 65,000 people have used the system to alert other app users, the state said.
“Exposure notification technology has shown success,” said Dr. Christopher Longhurst, Chief information officer at UC San Diego Health, which manages the California app. “Whether it saves hundreds of lives or dozens or a handful, if we save lives, it’s a big deal.”
In a joint statement, Apple and Google said: “We are proud to collaborate with public health officials and provide a resource – enabled by many millions of people worldwide – that helped protect public health is.”
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Partly based on Singapore and the ideas developed by it Educationals, Apple and Google’s systems incorporated privacy protections that gave health agencies a choice of more aggressive apps. Unlike virus-tracing apps that continuously track users’ whereabouts, Apple and Google software rely on Bluetooth signals, which can estimate the distance between smartphones without knowing people’s locations. And it uses a rotating ID code to log app users who have been in close contact for 15 minutes or longer – not real names.
Some health agencies predicted last year that the technology would be able to notify users of the risk of the virus faster than human contact tracers. Others said they hoped the app could warn passengers sitting next to an infected stranger on a bus, train or plane – people at risk they would not normally identify.
“Everyone who uses the app is helping to keep the virus under control,” said Chancellor Angela Merkel of Germany. Said in a video last year Is promoting the country’s alert system, called Corona-Warne-App.
But the apps never received large-scale efficacy testing, usually before the government introduced public health interventions such as vaccines. And the software’s privacy features – which prevent government agencies from identifying app users – have made it difficult for researchers to determine whether the information helped to hinder the transmission of the virus, said Michael T. OsterholmDirector of the Center for Infectious Disease Research and Policy at the University of Minnesota.
“Apps played almost no role in being able to investigate outbreaks that occurred here,” Dr. Osterholm said.
There were some limitations before the release of the apps. For one thing, some researchers note, exposure notification software naturally excludes some vulnerable populations, such as elderly people who cannot afford smartphones. For another thing, they say, apps can send false alarms because the system is not set up to contain mitigation factors such as users being vaccinated, wearing masks or sitting outside.
Proximity detection in virus alert apps can also be inconsistent. Last year, A study on Google’s system For Android phones operating on light-rail trams in Dublin, metal walls, floors and ceilings have been reported to distort Bluetooth signal strength to the extent that the possibility of accurate proximity detection is “randomly selected” Will be similar to triggering notifications “. .
Such disturbances have upset the early adopters such as Kimbley Craig, Mayor of Salinas, California. Last December, when the virus rate was rising there, she said, she downloaded the state’s exposure notification app on her Android phone and soon tested positive for Kovid-19. But after entering the verification code, she said, the system failed to send an alert to her partner with whom she lives and who also downloaded the app.
“If it doesn’t raise a person in the same house, I don’t know what to tell you,” Mayor Craig said.
In a statement, Stephan Hannon, Google’s senior director of product management for exposure notifications, said there were “known challenges in using Bluetooth technology to estimate accurate distances between devices” and the company continued to work to improve accuracy Was getting it done.
Companies’ policies have also influenced usage trends. In some US states, for example, iPhone users can activate exposure notifications with one click – by simply turning on a feature on their settings – but Android users must download a different app. As a result, about 9.6 million iPhone users in California had turned on notifications by May 10, the state said, far more than the 900,000 app downloads on Android phones.
Google said that it has created its own system for states to work on a wide range of devices and deploy as quickly as possible.
Some public health experts acknowledged that the exposure alert system was an experiment in which they and tech giants were learning and incorporating improvements.
One issue they quickly discovered: To prevent false alarms, states verify positive test results before a person can send exposure notifications. But local labs can sometimes take several days to send test results to health agencies, limiting app users’ ability to quickly alert others.
For example, in Alabama, the state’s GuideSafe Virus Alert app has been downloaded nearly 250,000 times, according to Censor Tower. But state health officials said they have only been able to confirm the positive test results of 1,300 app users. This is a much lower number than the health authorities expected, he said, noting that more than 10 percent of the alumni tested positive For coronavirus.
“If those processes were less manual and more automated, the app would have been much more efficient,” said Dr. Scott Harris, who oversees the Alabama Department of Public Health.
Colorado, which automatically issues verification codes to people who test positive, has reported higher usage rates. And in California, UC San Diego Health has set up a dedicated help line that app users can call if they haven’t received their verification code.
The medical center’s chief information officer, Dr. Longhurst, said the California app has proven useful as part of a larger statewide public health campaign that also includes wearing masks and virus testing.
“It’s not a panacea,” he said. But “it can be an effective part of an epidemic response.”