New Zealand is now Covid-19 free. 

To keep us here the government has asked us to put our trust in an out-of-sight solution. An app that’s still evolving, that may soon start sending invisible packets of data between us. If we get the next phase of this Covid-19 battle right the reward is sustained elimination. If we get this wrong New Zealand could open itself up to a second wave of the virus, ratcheting up restrictions and further damaging our economy.

In this two-part series we examine the public health benefits and privacy concerns of Covid-19 contact tracing apps designed to inform us with data before things get out of control. 

In part one we investigate the effectiveness of contact tracing technology. In part two, we dig into the risks to our personal privacy of app-based contact tracing and whether this app could become what investigative journalist Nicky Hager describes as a “surveillance camera in every pocket.”  


Part 1: 

Know Your Enemy: contact tracing is nearly as good as a vaccine

“Until a vaccination is developed, contact tracing is the best tool we have to fight the spread,” says Colin Simpson, epidemiologist at Victoria University of Wellington’s Faculty of Health. “In the absence of a vaccine it’s the next best thing. Done the right way it can be as effective.”

In the space of four months New Zealand has gone through radical change; a national emergency that confined us to our houses, a pandemic that at its peak saw 89 people diagnosed with the virus in a day, nearly 300,000 lab tests, 1504 cases and 22 deaths. Now, while Covid-19 continues to ravage other countries overseas, we’re free of the virus.

It’s a success story that can be attributed to the “go hard, go early” strategy, social distancing and a nationalised contact tracing regime to isolate those who may have been infected. 

While Prime Minister Jacinda Ardern joyously announced New Zealanders are now free “do and go wherever you like” at a press conference detailing the move to level 1 at midnight on June 8, she stressed the government is still asking people to keep a record of their movements in case another outbreak occurs. 

Digital technologies are being rapidly developed to assist with contact tracing, adding to the manual system set up in the early stages. As Covid-19 began to spread around New Zealand, the Ministry of Health created a nationalised contact tracing hub which started operating on March 24, the day before New Zealand entered lockdown.

The role of the tracers was to contact those who had been diagnosed with the virus, identify anyone they’d come in contact with who may have caught the virus, and then reach out to those people and advise them to isolate. To check this was done effectively, the Ministry of Health invited University of Otago infectious disease specialist Dr Ayesha Verrall to do an independent audit of the system. 

In her report, Verrall warned our contact tracing system was being overwhelmed by fewer than 100 daily cases. Health authorities lacked basic contact information and only 60 percent of calls actually connected with the people they were after. "Our contact tracing capacity is a fire extinguisher, we need a fire engine," Verrall tweeted at the time. She made a range of recommendations, including that the Ministry of Health introduce a digital contact tracing app.

In response, the Ministry rapidly scaled up its manual contact tracing efforts and signalled that an app was also on the way. There was talk of a ‘Covid card’ that we’d all keep in our pockets and swipe like an eftpos card to register our location, or a Bluetooth-enabled app similar to Australia’s which tracks proximity and has the ability to notify you if you’ve come into contact with anyone who later tests positive. 

But when the app finally became available on May 19, what we got instead was a much simpler QR-code-based “digital diary”. On the same day of the app's release, the Ministry published a privacy assessment laying out the concerns they had considered while designing the app, and noted that more features were planned for it in the future. It’s still unclear what more may be implemented into the app, or when exactly this may happen, but the government hasn’t ruled out Bluetooth functionality.

“Initially there was a lot of excitement about the role of technology and digital solutions. What will be the make or break,” says Michael Baker, professor of public health at the University of Otago. “It isn’t just the digital technology. That can help, but it has got to be very carefully integrated into the system.”

Privacy Commissioner John Edwards was consulted through the process of development and describes this first iteration as basic. He thinks the government's cautious approach strikes the balance, ensuring that privacy concerns are addressed appropriately with this initial step.

“There are people who are chomping at the bit to get more sophisticated technological solutions, such as Bluetooth in there. A really important point to bear in mind is that all of these technologies aren’t proven. So I'm happy with the pace that the Ministry of Health is proceeding with.”

How our contact tracing app works

The current app has two main functions: providing the Ministry of Health with updated contact information and so long as people use its QR code functionality, a digital diary of locations they have visited which can act as a memory prompt if they are interviewed by a contact tracer.

On its first day, 92,000 users downloaded the app but it had a number of problems when it launched. The app was only compatible with only some of the most modern Android and Apple phones, and couldn’t scan the vast array of other QR codes that had been rolled out by other app makers. Head of computer sciences at Victoria University Dave Parry says it was too little too late. "The biggest issue with this app is that it doesn’t really bring much benefit to the person using it. It doesn’t replace the check-in systems to businesses or even allow you to automatically send your history to the contact tracing team.”

As the country moved into alert level 2 the government required many businesses to log the movements of their workers and customers, and without providing a digital tool to do so on day one, a number of private sector apps popped up to fill the gap. So now the government’s app competes with a number of privately run alternatives and often appears alongside several options at places such as bars and cafes.

We have nowhere near enough people using the app for it to be effective

The rate that we’re all logging on shows some serious shortcomings with the way it’s being used. As of June 3 the NZ Covid-Tracer app had been downloaded 487,000 times (around 10 percent of the population) but used 496,000 times, meaning the average person had only used it once since downloading it. 

Overseas estimates have suggested that 60 percent of the population needs to use a single app for it to be effective. Australia has fared slightly better than us with their CovidSafe app being used by 24 percent of the population. But at that rate it has not been a game-changer in Australia - so far their Bluetooth-enabled app has only led to one additional case being identified

Manual contact tracing is labour intensive, relying on interviews over the phone asking people to remember where they were and who they met with while they may have been infected. Before we went into lockdown, the Ministry of Health was contacting between 20 and 25 people per case. 

The Government's current goal is to be able to trace 1000 daily cases which is ten times the amount they could manage to tackle at the height of the virus. We’re still a long way off from being able to do that, with Public Health Units currently able to trace 185 cases daily. 

This is where digital contact tracing apps come in as a way to speed up the contact tracing process by providing clear and accessible details to contact tracers. As the government adds more features to the NZ Covid Tracer app it could also automate aspects of the process in the future to help us reach that number.

Our app won’t help us open up a bubble with Australia

We’ve been slower to adopt this technology than overseas countries. Australia launched its CovidSafe app which received over 1 million downloads in its first 24 hours. Their app uses Bluetooth to monitor who a person has been in proximity with and for how long. The app is meant to notify you if you’ve crossed paths with anyone who is diagnosed with the virus, providing you with an instant notification to quarantine - but it's also sparked a number of privacy concerns. Soon after it launched, software developer Jim Mussared found five ways to exploit the app to track people's location and one that would reveal their username. The government has since worked to address these issues.

Unlike New Zealand's app, CovidSafe works by scanning for other Bluetooth enabled devices in close proximity to the user's phone, and creates a digital handshake when two phones with the app come within 1.5 metres of each other. Once installed the app operates constantly in the background. The only way to stop it from transmitting is to turn off Bluetooth or delete the app. 

Mahmoud Elkhodr, a lecturer in Information and Communication Technologies at CQUniversity Australia has said the stark differences in these apps will be a barrier in opening up a trans-Tasman bubble. “If the Australian COVIDSafe and NZ COVID Tracer apps are to be part of the solution in opening up travel between the nations, much more work will be needed to make the two apps far more compatible with each other.”

Our app is based on QR codes linked to New Zealand Business Numbers, a system that Australia doesn’t have. The government has signalled that it's far more likely that New Zealand’s app will add similar functionality to Australia’s than the other way around.

As we look to open ourselves back up to other countries, our ability to trace the spread of the virus will need to meet that challenge, growing from domestic to global-scale contact tracing, with the systems that we’ve built interfacing with other countries such as Australia’s.

As these systems become more compatible and more information about its spread becomes available, it also presents an opportunity for researchers to better understand and model the spread of the virus.

Technology can help epidemiologists predict the spread of new pandemics

Epidemiologist Colin Simpson is currently leading a research project at Victoria University of Wellington aimed at better understanding the spread of the virus in New Zealand. He says it was the manual contact tracing methods that made New Zealand so successful at stamping out the virus. 

It’s a grim opportunity for an epidemiologist to study the effects of a virus on a population first hand. “Myself and my colleagues are working the hardest we ever have in our professional lives.” Colin and his research team use similar contact tracing methods to the Ministry of Health’s, but are aiming for a different outcome. Rather than tracing someone's contacts to isolate individuals who might have the virus, they’re using data to build a map showing how different strains of the virus spread in New Zealand.

“Over time as the virus transmits between people it mutates. We can look at those small mutations and we can understand if one sample is the same from another and understand if there is a connection between the samples.”

By better understanding how it spreads, we will be better prepared for future waves of the virus. To do that they are gathering swathes of publicly-available information which includes cell phone location data to model population density and paths of transmission. Colin is quick to note he doesn't have information about any individual's location or movements. The information is supplied from the Ministry of Statistics in a way that is anonymised and summarised to protect any identifiable information. 

Having access to this information has the potential to shape not just how we tackle existing viruses but also prevent future pandemics from occurring. He believes with stronger modelling we can better see the patterns of how they emerge and stop potential pandemics at their source. “We need to start suppressing virus transmission between species. So if it happens again, with another pandemic we are in the best possible place to stop transmission as quickly as we can.” 

It’s all about trust

It may be that Covid-19 is a genie that can’t be put back in the bottle - that the global spread may become an ongoing managed part of our lives for decades to come. The potential of this moment and the data and technologies that emerge is that if we implement them correctly we may be able to better contain and eliminate future pandemics before they can get out of control.

But Colin stresses that in order to make these public health efforts, you have to keep people onside. “If the contact tracing app released by the government is to be an effective tool it has to allay any privacy concerns. If people are concerned about privacy and what it's used for then they probably won't use it.” 

Professor Michael Baker says the role of digital technology in our ongoing battle against Covid-19 is still unclear. “Quite a few New Zealanders have got motivated by this challenge and put through good ideas. The next stage is to put forward solutions.” He agrees with Colin Simpson that success depends on public trust. Any new technology would need to meet three criteria, says Baker. “Firstly, it has to work. Then it has to meet privacy concerns and thirdly it has to support equity. We know that those worst affected by pandemics are those most marginalised.”

As the disease itself evolves, so too does our app. But if at any step public trust in that app is undermined, it could pose a threat not just to the lives of New Zealanders who might be affected by a second wave of the virus, but to the potential of these technologies to help us understand and prevent the spread of other viruses in the future. 

In part two of this article series we examine those concerns: whether a contact tracing app is eroding our privacy (either by design or by negligence), and what needs to be done to ensure that a technological solution to Covid-19 doesn’t lead to ever-increasing surveillance.


Graphics by Timothy Armstrong, @tfarmstrong on Instagram.

This project is made with support from the Aotearoa NZ Science Journalism Fund