Tools such as cellphone-based contact tracing are becoming increasingly important in the fight to contain Covid-19, a disease spreading too quickly and silently for conventional disease control measures to contain it, according to experts and researchers who say this could fundamentally involve some compromises on personal privacy.

The problem stems from the insidious nature of Sars-CoV-2, the virus that causes Covid-19: it can be spread by a person who does not show symptoms, and is thus probably unaware of the illness, and merely breathing, coughing and sneezing could pass it on to anyone close by. Tracing contacts through conventional methods, therefore, may be ineffective, require too much manpower, and take too much time for effective containment.

“To defeat this virus, you either need a vaccine or testing, contact-tracing, quarantine, which is the hallmark of epidemiological containment. The issue is that normally viruses don’t spread as fast. Most that kill or are serious are infectious at a stage when someone gets very sick,” said Eric Feigl-Ding, an epidemiologist at Harvard University, who was one of the first prominent public health officials to raise an alarm about the virus in January when it spread mostly within China.

“Contact tracing only works if you trace far enough and people remember well enough. And it needs a huge manpower. In Wuhan alone, they deployed almost 10,000 people,” added Ding during an interview over video.

With a mobile phone-based tool, “you don’t need the manpower and it is instantaneous – the speed is the most crucial aspect. Problems in recalling who an infected person met or where they were too get taken care of,” he said. Ding led efforts to create one of the first such mobile applications back in 2014 called Germ Theory. “During the Ebola crisis, we realised contact tracing is a tedious effort and people have terrible recall,” he said.

The idea was also floated by researchers from Oxford University in a paper published on March 31 in which they said, “a mobile phone app implementing instantaneous contact tracing could reduce transmission enough for sustained epidemic suppression, stopping the virus from spreading further.”

On April 2, the Indian government launched its own contact-tracing mobile application and roughly a week later, Apple and Google – who together dominate the cellphone software platform market almost entirely – announced they are working on similar mechanism for iPhone and Android-based phones.

The apps work on a simple premise: a phone will exchange details – converted into a random, unique alphanumeric – with another phone if the two are in the range of their Bluetooth radios. Bluetooth is a short-distance radio wave, which is picked up only when someone is close enough to, say, be in the same flat or office.

The data will be shared with health authorities in the event that either of the device’s users test positive for an infection, triggering an alert to all other devices that may have been in the contact chain, according to the workings disclosed by India’s Aarogya Setu (health bridge) app and the proposed Google, Apple mechanism.

Union health ministry joint secretary Lav Agarwal, during the daily briefing on Covid-19, said the Aarogya Setu application was downloaded by 35 million people till Monday.

PRIVACY WORRIES
The approach, however, has drawn questions about privacy violations. “People will wonder: who profiteers from these apps? Will there by government intrusion?” said Ding.

India’s Aarogya Setu has drawn criticism by privacy advocacy groups such as the Internet Freedom Foundation, which says the programme has “a systemic lack of auditability and transparency”.

“[There] appears to be a much wider collection and possible sharing [of data] outside of the device, than envisioned under other apps,” said a working paper by IFF, which analysed a similar application used in Singapore and one developed by researchers at MIT.

Technology lawyer Rahul Matthan, who advised the Indian government in the development of the Aarogya Setu app, said the features in the application need to be looked at in the context of the circumstances of the epidemic.

“If we agree we need some sort of a technological solution to carry out contact tracing, we know that the only way to do that is fundamentally privacy invasive,” said Matthan, a partner-lawyer at Trilegal.

“Our approach in designing the privacy features have been to look at what basic privacy principles are around the world,” he said, adding that he supported calls for the programme code to be made public if there was a trust deficit between users and the government.

Matthan said the Aarogya Setu app seeks details needed to create demographic profiles since it is crucial to understand the scale of the disease in India. “Age and gender data is relevant because we know the disease stratifies by age. Location data is used to create heat maps – this is crucial because in India, we are a densely populated country and not a lot of people have smart phones. If you contact only those with phones, you leave out a lot of others,” he said.

Matthan said the app is distinct from an operating system-level solution that Google and Apple are working on because it involves health officials.

“Putting too much trust in algorithmic solution is dangerous. They cannot take into account several factors that can influence the probability of contracting an infection. They may also give people a false sense of hope,” he said, adding that health officials ultimately determine which people identified by the Aarogya Setu must be tested.