When it comes to a pandemic like the corona virus (COVID19) several governments have thought about a technological miracle to resolve the contact-tracing problem -- a mobile app. Many even think of it as the ultimate solution to control the COVID19 spread.
In India, the union government has mandated that the Aarogya Setu app will have to be downloaded by all, even though it is untested in real field. While many have raised concerns about privacy violations due to this app, several experts from across the world are questioning the viability and practical use of what is seen as a ‘golden app pill’ for dealing with COVID19.
Such apps are capable of providing several false negatives as well as false positives, making its use very questionable in the fight against the pandemic.
According to a paper published on Brookings.edu
, contact tracing can be an important component of an epidemic response especially when the prevalence of infection is low.
“Such efforts are most effective where testing is rapid and widely available and when infections are relatively rare—conditions that are currently unusual in the US. Ideally, manual contact tracing by trained professionals can help identify candidates for testing and quarantine to help contain the spread of coronavirus," it says.
This paper was published by independent researcher and technologist, Ashkan Soltani and Prof Ryan Calo from University of Washington and Prof Carl Bergstrom from the same university, who has extensive experience in the epidemiology of emerging infectious diseases.
"The lure of automating the painstaking process of contact tracing is apparent. But to date, no one has demonstrated that it is possible to do so reliably despite numerous concurrent attempts. Apps that notify participants of disclosure could, on the margins and in the right conditions, help direct testing resources to those at higher risk. Anything else strikes us as implausible at best, and dangerous at worst," the experts warns in the paper.
According to the description provided by Aarogya Setu on Google play store, "the app tracks, through a Bluetooth and GPS generated social graph, your interaction with someone who could have tested COVID19 positive."
Aarogya Setu requires the user to switch on her Bluetooth and GPS and keep location sharing always in ‘on’. "You will be alerted if someone you have come in close proximity of, even unknowingly, tests COVID19 positive. The app alerts are accompanied by instructions on how to self-isolate and what to do in case you develop symptoms that may need help and support."
C Levy-Bencheton (@clevybencheton), who holds a Ph D in telecommunication and work in cyber security, explains contact tracing in a series of tweets. He says, "Application developers do not know or do not care about the physical properties of the channel. They usually take the assumption that it is a perfect circle. So, if you receive a packet with a certain signal strength at 2 meter (+/-), you are in the contamination zone."
“There are other problems", he says adding, "Everybody needs the app. Not everyone has a smartphone and there are too many issues for the government to provide one to everybody. Security and privacy are of utmost importance. Anyone could abuse the app to make people isolate."
In short, the app can only inform you when someone you have exchanged your device's Bluetooth ID with has been tested and reported sick. However, this does not mean you have been exposed.
According to Jason Bay, the product lead for TraceTogether, the world’s first nationwide Bluetooth contact tracing system, false positives and false negatives have real-life (and death) consequences as there are lives at stake.
"If you ask me whether any Bluetooth contact tracing system deployed or under development, anywhere in the world, is ready to replace manual contact tracing, I will say without qualification that the answer is, No. Not now and, even with the benefit of artificial intelligence (AI) or machine learning (ML) and — God forbid — blockchain?? (throw whatever buzzword you want), not for the foreseeable future," he says in a blog post
Bruce Schneier, a privacy expert and fellow at the Berkman Klein Center for Internet and Society at Harvard University is more forthright on contact tracing apps. "The idea that contact tracing can be done with an app, and not human health professionals, is just plain dumb," he says in his blogpost
According to Mr Schneier, this is a classic identification problem, and efficacy depends on two things: false positives and false negatives.
On false positives, he says, "any app will have a precise definition of a contact: let us say it is less than six feet for more than 10 minutes. The false positive rate is the percentage of contacts that do not result in transmissions. This will be because of several reasons. One, the app's location and proximity systems -- based on GPS and Bluetooth -- just are not accurate enough to capture every contact. Two, the app will not be aware of any extenuating circumstances, like walls or partitions. And three, not every contact result in transmission; the disease has some transmission rate that is less than 100% (and I do not know what that is)."
Talking about false negatives, Mr Schneier, says, "This is the rate the app fails to register a contact when an infection occurs. This also will be because of several reasons. One, errors in the app's location and proximity systems. Two, transmissions that occur from people who do not have the app (even Singapore did not get above a 20% adoption rate for the app). And three, not every transmission is a result of that precisely defined contact -- the virus sometimes travels further."
"Assume you take the app out grocery shopping with you and it subsequently alerts you of a contact. What should you do? It is not accurate enough for you to quarantine yourself for two weeks. And without ubiquitous, cheap, fast, and accurate testing, you cannot confirm the app's diagnosis. So, the alert is useless. Similarly, assume you take the app out grocery shopping and it does not alert you of any contact. Are you in the clear? No, you are not. You actually have no idea if you have been infected. The end result is an app that does not work. People will post their bad experiences on social media, and people will read those posts and realize that the app is not to be trusted. That loss of trust is even worse than having no app at all," says Mr Schneier, a public-interest technologist.
There are some users who were surprised to receive an alert in two kms radius, that too in a green zone. As per definition from the Indian ministry of home affairs, green zones are districts with either zero confirmed cases till date or no confirmed cases over the past 21 days. Now, imagine how the user might have been feeling after receiving the red alert from Aarogya Setu app in green zone.
When the user checked with a senior official from the district administration, he was told that "We are investigating. Physically we did not find anyone, (it) might be a technical glitch (in the app) still we will try to find (about this)."
So the final word is, you do not need an app to tell you will be infected with corona virus. In a country with huge population and less space for physical distancing, chances are everyone may be infected. The three lockdowns announced so far in India are to treat patients in batches so that doctors and medical professionals do not die of fatigue.
Importantly, we still do not have enough doctors, nurses and other medics and personal protective equipment (PPE) kits, masks and hand gloves for them and sufficient hospital beds for COVID19 patients. In such scenario, even a God send app will not solve the problem. If not combined with testing, and testing and more testing, these contact tracing apps like Aarogya Setu are bound to remain elusive at best.