Can Bluetooth Contact Tracing Apps Help Fight Pandemics?

A new class of programs uses Bluetooth to automate contact tracing, permitting you to know if you’ve crossed paths with somebody who has tested positive for COVID-19.

New programs from the likes of MIT, Google, and Apple rely on Bluetooth to automate the contact-tracing procedure, which health care professionals use to notify those who might have come into contact with a COVID-19 patient.

The concept is to trace individuals’ movements so that when the individual does eventually test positive, there is a definitive means to track their prior whereabouts–and who was nearby at the moment.

While sound in theory, these programs will only work if a wide swath of the populace adopts them.

Following a patient tests positive for COVID-19, health care professionals start to notify individuals who might have crossed paths with that individual. This is both for their own security and to make sure that infected self-quarantine to quell the spread.

But a March 31 newspaper published in Science details how the break-neck speed of the pandemic can’t be tracked through conventional methods (often involving painstaking in-person interviews). So the pros turn to technology by advocating digital contact tracing as a means to prevent widespread lockdowns.


Countless examples of this form of technology are already in development, such as a joint Google-Apple venture that both tech giants announced April 10, and an academic effort named PACT (Private Automatic Contact Tracing). Directed by the MIT and in partnership with a consortium of universities and public health organizations, PACT scientists have banded together to create a Bluetooth protocol intended to monitor users’ location and COVID-19 status.

Their approach relies on Bluetooth communications in smartphones “as a proxy for inter-person space measurement.” To put it differently, Bluetooth signals on your smartphone may determine how close you have come to some other person by discovering their Bluetooth transmissions. As people test positive, the program will send vulnerability notifications to all smartphone users that have come into close contact with the individual throughout the span of the previous two weeks, while they were infectious.

Significantly, this can be done without revealing any personal information regarding the individuals using the program. Not the government, health care providers, or mobile providers.

But it has one major flaw–everyone should use it.

For digital contact-tracing to operate, a protocol such as the one under development at MIT would have to be pushed through an upgrade on iOS and Android operating systems. An app isn’t compulsory and doesn’t necessarily lead to high adoption rates.

The other issue is restricted testing, meaning there is a fairly good chance that carriers don’t have any idea that they are spreading the virus.


However, evidence from other countries like China and Singapore suggest that this kind of app could prevent additional spread of COVID-19, though those two nations have seen pushback for making data coverage mandatory, something which would almost certainly never fly, here.

In the Netherlands, meanwhile, two different contact-tracing programs are under development, but not yet finished. Hugo de Jonge, the Dutch health minister, said last week that the government is “looking at if you may require everyone” to utilize a contact-tracing app.

Only time will tell if digital contact-tracing will be widely used in the U.S., where privacy is a cornerstone of the nation’s moral code. The way the technology is rolled out, whether it’s pushed as an automatic upgrade and the general speed of adoption will dictate how successful the efforts can become.

In any case, your best bet is to just stay home.