Daily use of the Government's Covid-19 contact tracing app has fallen off a cliff with less than 0.2 per cent of the population scanning posters.
Scientists say Kiwis have become complacent without community transmission and are warning if there's an outbreak, the Covid Tracer app would hardly be of any use.
Ministry of Health figures show daily poster scans in the last 10 days have dropped to about 10,000 on average - down from their peak of 50,000 during alert level 2.
And the number of people registered with the app is 11.7 per cent with 590,000 downloads.
The seven-day average for poster scans is 9616 - just 0.2 per cent of the population with the generous assumption that equates to one QR code scan per person per day.
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Advice from health officials to Cabinet said digital contact tracing is complementary, but not a replacement, to manual efforts though are a "valuable tool" especially because they provide accurate contact details and speed up the process.
Public health expert Nick Wilson said the usage numbers were "tiny" and if there were a community outbreak "it would hardly help at all".
"This system is obviously not working – and for a very good reason in that New Zealanders are relaxed about the country's success in having eliminated community transmission of the pandemic virus.
"So the Ministry of Health should probably wind up this scheme at this point."
Wilson, an Otago University public health professor, said the Government should be using this time to explore more effective options for contact tracing like the system in South Korea that uses telecommunications and credit card data.
But community consultation on it should be happening now, Wilson said.
Digital contact tracing expert Dr Andrew Chen said it appeared the Government was holding back putting more time and money into the app while it waited for a better digital solution.
The data on usage of the app had to be pulled from each of the Covid-19 press releases and crunched by the Herald because the Health Ministry couldn't provide daily active user information.
Chen said this in itself was concerning because the Government should know how many people were actually using the app and signing into businesses, not just downloading it.
"My understanding is that the Government has put zero additional funding into digital contract tracings at the current time. I think the finding is a good way of showing priority.
"Behind the scenes I suspect they may be considering other tools."
The Government needed to decide if it was backing its current app and put efforts into encouraging uptake, like sending workers to businesses with portable printers to create posters, Chen said.
Simple improvements could also be made - such as a manual diary - with more advertising and messaging.
A rush in people using the app if there was a community outbreak would be too late because contact tracers needed someone's movements for at least 14 days.
Or there should be more transparency about what else is in the pipeline, Chen said.
Among the Cabinet papers included in the "document dump" last month was advice on digital contact tracing solution, but anything of interest was redacted, said Chen.
Chen said he wouldn't paint the poor app usage as a failure of the Ministry of Health because countries around the world were struggling to encourage uptake of voluntary apps.
Health Minister Chris Hipkins said while there were other digital contact tracing options being explored, he did want to see more people using the app.
"The QR system is a good system. Obviously it's not being as widely used as we would like to see it being used but we'll keep pushing on the QR system."
On Monday, Prime Minister Jacinda Ardern said the amount of people scanning posters hadn't kept pace with the number of businesses creating QR codes.
"We can understand why that would be, people are listening out for community transmission and they're perhaps not as alert as they were.
"But we do still need people to keep a record of where they are going because at any time if we do have a case that emerges in our community we need you to retrospectively be able to tell us where you've been - that is still critically important to us."