Contact tracing apps: monitoring public health

Contact Tracing in Australia

The last time Australia saw the threat of a potentially deadly infectious disease reach near-pandemic proportions was in 2011. Pertussis (whooping cough) reached a peak of 40,000 infections, leading to hospitalisations and infant mortalities. Some strains of the bacteria proved to be vaccine resistant, meaning contact tracing and self isolation were the only ways to effectively slow and stop transmission.

One of my team was unfortunate enough to catch the cough: he had attended a new year’s eve party where several of the group were infected. He went into a 14-day isolation, and made a flurry of phone calls to anyone he could recall being in contact with. Unfortunately, there was no way to call every stranger he had ridden the bus with, and no doubt some of them became sick too.

In 2011, smartphones were common, but not ubiquitous. Contact tracing leveraging smartphone apps would have likely been ineffective at that time, even with a high app download and usage rate.

Now it is different. Deloitte estimates that there were 17.9 million smartphones in Australia in 2019, which equates to 7 phones for every 10 people, and in response to COVID-19, Australia, like many other countries, are leveraging the widespread availability of smartphones to introduce location tracking mobile apps, that monitor where and when the phones come into contact with each other.

 

How contact tracing apps work

Although lockdown regulations have proven they help flatten the COVID-19 curve, countries risk an increase in the number of infected individuals if fewer restrictions are in place. And the economic consequences of a prolonged lockdown puts significant pressure on Governments to lift restrictions. Consequently, Governments are looking for ways they can isolate only those people who are at risk, rather than the entire population. An effective means of identifying those potentially at-risk is by making use of contact tracing efforts to slow the spread of COVID-19. COVID-19 contact tracing apps are being used because they can track the spread of the virus faster, more reliably, and identify high-infection areas in the community which are leading to significant numbers of new cases.

Contact tracing, simply put, is a way of recording when, and sometimes where, two smart devices are within close proximity of one another. Individuals that return a positive test for COVID-19, or have  been in contact with an infected person, can notify health authorities. If the infected individual was using a contact tracing app, the authorities can determine who may have been in close proximity to the infected individual and warn them to get tested themselves, if they were also using the contact tracing app. 

Countries such as Singapore, Australia and the United Kingdom are a few of the places already leveraging contact tracing. Singapore launched their app, TraceTogether, in March and it leverages Bluetooth to detect the mobile phones of people nearby (provided they also have the app) for later identification. If these people are within two metres of each other for a specific period, the app records the data of the other user, encrypts it and stores it for twenty-one days. If individuals test positive for COVID-19, they need to upload their data to the Ministry of Health, who can then alert their ‘close contacts’ that they have come into contact with someone that has COVID-19.

The Australian Federal Government used Singapore’s app as a basis for their app, COVIDSafe, in an attempt to gradually reduce the current lockdown measures. Apple and Google are also making their interoperable APIs available to public health agencies to create COVID-19 tracing apps that are similar to the Singaporean solution by using Bluetooth signals for the collection of ‘identification keys’ with those in close contact.

There are potential technical limitations to tracing apps. There may be false negatives or positives if the Bluetooth detects other users through walls. Additionally, the app is only available on smartphones, which excludes those without one. Yet, despite the challenges with contact tracing, many consider it a critical step to lift social distancing policies.

 

Public adoption

Contact tracing apps rely on public adoption, so one concern is whether or not enough people are going to download the app. For example, for the voluntary app to be successful in Australia, at least 40% of the population must download it. In the UK, 60% of the population must download the app for it to be effective. So far, only 20% of the Singapore population has installed the app, raising concerns over whether or not the Australian and UK population, in addition to others, are going to have a better uptake.

Individual reservations may be due to the privacy concerns of the app. Others that support the app look at South Korea’s success, where the Government controversially leveraged surveillance footage to trace individuals’ movements, raising the concern of whether or not contact tracing apps should be compulsory for smartphone users. Poland has made it mandatory to download the app if an individual has COVID-19.

 

 

Privacy concerns

Privacy is a vital component of any society, and there is justifiable concern that Government and corporations will maintain the surveillance infrastructure after the pandemic has passed for population control and to monetize the system. Individuals that use Singapore’s app, TraceTogether, must give their consent to participate in the collection of data. There is no collection of other personal data like their contact list or address book. Furthermore, the app cannot establish a user’s exact location because the app only uses Bluetooth and not GPS location data.

When signing up for the app, you have to enter your name — which can be a pseudonym — in addition to your age range, postcode and phone number. The app creates your encrypted code that others with the app will receive over Bluetooth. The app also records the time, date, and duration you were near other contacts. If you receive a positive COVID-19 diagnosis, and you are required to upload your twenty-one days’ worth of anonymised IDs, you remain anonymous when health officials contact your close contacts.

Upon examination of Australia’s COVIDSafe app, software engineer Robert Merkel reveals that your phone’s make and model is sent unencrypted to other phones in the Bluetooth messages. This exacerbates privacy concerns as it is possible, albeit unlikely, that someone can track you this way. Singapore’s app TraceTogether collects similar data, however, in their Terms of Service they state that different phone models transmit different power, so it is necessary to measure distance, phone model information, and signal strength. Unlike Singapore, Australia does not explain this in their Terms of Service, which may make individuals reluctant to download the app.

Another concern is that unless the greater developer community is granted access to review the source code, no one really knows what data the app is gathering, and what it is doing with that data. The code to COVIDSafe is now available. Furthermore all data that is collected will have encrypted identifying information and be stored in Australia.

For the COVIDSafe app to be successful in Australia, 10 million people need to download it, and only 1.13 million have done so as of the 31st of May 2020, which highlights the need to alleviate any privacy concerns. The Australian Prime Minister gave reassurance stating that the Commonwealth does not have access to the data. He shared a determination under the Biosecurity Act 2015 (Cth) to alleviate any data storage and usage concerns and to encourage individuals to use the COVIDSafe app. The determination will restrict access by healthcare authorities so that they can only leverage it for contact tracing purposes. So, individuals have the guarantee that their privacy is maintained and there are restrictions to information accessed from the app. Only the state or territory health authorities have access to the app data and may only leverage it for contact tracing purposes.

Although Australians are encouraged to download the app, there is no apparent oversight of COVIDSafe, according to Kimberlee Weatherall, a technology law professor at the University of Sydney. If someone does have a privacy complaint, they may be able to go to the Office of the Australian Information Commissioner.

 

Leveraging the data

If an Australian tests positive for COVID-19, they must give consent to disclose information to the centralised Data Store. Once the person grants permission, the relevant State or Territory health authority has access to their ‘close contact’ information.

Their close contacts then receive health-related advice. Information regarding close contacts age range and postcode data assist health officials in prioritising who may need urgent attention. Close contacts, over the age of sixty, for example, require more attention than those under the age of thirty.

 

The future of contact tracing applications

Contact tracing apps face an uncertain future. They could become a core part of public health, or they could move into irrelevance. Their long-term success depends upon two criteria:

1. Proven cases where their use has shown to effectively slow or stop a pandemic;
2. Ability of governments to assure ongoing user privacy.

COVID-19 is the world testing ground for contact tracing apps. If these two criteria are achieved, public health professionals will have contact tracing apps up their sleeves as a powerful tool to stop infectious diseases in their tracks, permanently.

 

Fluffy Spider Healthcare Solutions

Fluffy Spider builds custom software solutions for the healthcare industry, bringing together specialised medical devices and cloud services. We work closely with our clients to take ideas to a cutting edge commercial reality. In the telehealth space, we have partnered with the world-leading Australian company, Visionflex, to bring their devices and cloud products to market. Get in touch with me for more information on healthcare software, advice, or to discuss new product concepts.