Your phone says you’re here. Should you be?
Keith Lynch explains why we aren’t using ‘‘selfieapps’’ and cell towers to stop the rule-breakers.
Auckland ended its seventh day of lockdown today, its second stint in level 3 this year. The cost of these lockdowns is significant, not only from an economic perspective but on the wellbeing of those socially restricted.
Prime Minister Jacinda Ardern said we needed this lockdown because ‘‘Covid-19 kills people’’. It does, and the UK variant, which caused this outbreak, is particularly infectious.
Over the past week, there had been a lot of talk about blame. While Ardern said some people broke the rules, her own Government’s communications suggest otherwise.
It’s easy to blame so-called rule-breakers – for both the public and politicians. It’s easy to say people should be isolating when you don’t have to. It’s much harder to ask if the systems we have to keep New Zealand Covid19 free are working. This is a look at how self-isolation works and whether it could be any better.
How it works now?
Covid-19 spreads easily, so it’s necessary to keep those who may be carrying the disease away from others. Positive cases in the community have mostly been moved into isolation facilities; their close contacts are meant to self-isolate.
This sounds like a no-brainer. A close contact could be symptomless, yet to return a positive test, but still infectious. It’s been anything but for this outbreak, with the Government seemingly telling a woman who later tested positive she didn’t need to isolate.
The Government does have the power to tell groups of people to isolate. It introduced a Health Act order on February 23 directing Papatoetoe High School staff, students and families to do just that.
But with most close and casual contacts, health officials may be essentially asking people to stay at home because it’s the right thing to do.
Health officials have also decided another category of contacts needs to isolate this time around. This outbreak is different because of the more contagious UK variant. But we’ve also had potential mass exposure events. A woman with Covid-19 went to work at KFC. A 21-year-old man with Covid-19 went to a supermarket, the gym and Manukau Institute of Technology.
This means a lot of people may have come into contact with the virus. The Ministry of Health’s standard approach is to isolate only close contacts (family members and the like), but officials have now decided to isolate what’s called casual-plus contacts (the ministry categorises people who had contact with an infected person in four ways. ‘Casual-plus’ is a recent addition).
Director-General of Health Dr
Ashley Bloomfield said on Thursday about 5000 people at risk of exposure to Covid-19 had been identified. About 2100 are close contacts. The rest are casual-plus.
Only a handful of people had not been reached by contact tracers. All of those who had heard from the ministry were told to isolate.
How many people are currently in isolation?
The ministry said the number is continually changing, as casual and casual-plus contacts are only required to isolate until they receive a negative test result.
Close contacts are required to isolate for 14 days and as at noon on March 5, there were approximately 2000 close contacts from the February outbreak being monitored.
Close contacts are phoned daily to monitor their wellbeing, check that they are adhering to self-isolation advice and are being tested on day 5 and 12 from exposure, the ministry said.
How does the ministry police this?
A health worker typically rings the person in isolation and asks a range of questions including: where are you and have you had a Covid-19 test?
The people in isolation are released once they’re served their 14 days and had the required number of Covid-19 tests.
Could more be done?
The Government could conceivably use technology to help ensure people are isolating.
There’d be two aspects to this:
❚ Using technology to identify where a person is.
❚ Verifying that person is with their phone.
There are a range of examples from overseas we could consider.
Taiwan, for example, identifies the location of a mobile device’s location using cell towers. The person isolating receives several calls a day to check they are with their phone.
The density of cell towers in Taiwan means health workers can pinpoint an individual’s location. In New Zealand, you’d likely end up only being able to identify someone within about a 200-metre radius, says Dr Andrew Chen, an Auckland University researcher.
That said, we have the means to do this. But the data may not be accurate enough to tell health workers a sick person has left their tiny Auckland flat to pop down to the dairy.
‘‘If we’re saying we need to put that person in a 5x5 metre box, I don’t think we could achieve that,’’ Chen explains.
To illustrate this, turn off your wi-fi and ‘precise location’ on your Google Maps app. You’ll see a rather big, not very precise circle. This is where the phone thinks you are, based on cell data. It may change over time as more towers ID your phone. But it’s not very accurate.
Hong Kong, meanwhile, uses GPS bracelets, utilising very similar technology to the Department of Corrections’ home detention solutions.
Poland had a mandatory GPS app, which requires people isolating to take selfies to verify their identity (the app has facial recognition).
Are all of these approaches technically possible here? Yes, they are.
For example, mobile phone companies already know where
their customers are. And they will have sold anonymised versions of this data to industries that want to understand how people move around, Chen says.
But it’s unlikely New Zealand would accept such interventions at this time.
‘‘If this pandemic was much worse [in New Zealand], I think there might be a point where public safety does justify using big data, with suitable privacy safeguards,’’ epidemiologist Professor Michael Baker has said.
Dr Jennifer Summers, the lead author of a new Otago University study comparing Taiwan’s Covid19 response to New Zealand’s, says a combination of lockdowns and modern technology may well be extremely effective, but it’s unlikely Kiwis would go for it.
The Government has also been very clear on this point: it is not interested in using big data – beyond the NZ Covid Tracer App – to fight Covid-19.
So what do we do? Firstly, people who have been tested need clear instructions, Chen says. Are they required to isolate or not?
And if they are isolating, there needs to be sufficient resource available to check whether they are at home or not.
It would also be worthwhile, Chen says, to understand why people aren’t isolating. Is it out of economic necessity? Is it because the messaging has not been clear? Is it because the NZ Covid Tracer App has still to be translated to other languages?
We should then remove the barriers that prevent people from following the rules, he says.
‘‘I tend to not like solutions that look like people are being incarcerated in their own homes. I don’t like the use of technology to ensure people are staying at home, particularly if we wouldn’t even employ the same technology in prisons.’’