Coronavirus: COVID Tracer usage keeps dropping, despite travel bubble with Australia and Melbourne outbreak

One of New Zealand's top COVID-19 experts is warning New Zealand could end up in lockdown soon if people don't use the COVID Tracer app or get tested for the disease when they fall sick.

The Australian state of Victoria went into a seven-day 'circuit-breaker' lockdown on Thursday night, after another 11 cases in the community were picked up - bringing the total in the new cluster to 26. 

Around 5000 people who travelled from Melbourne to New Zealand recently have been ordered to self-isolate and get tested for the virus. Victoria accounts for 90 percent of Australia's 910 deaths from COVID-19 to date. 

"The case numbers in Australia have jumped quite quickly, and we know that there have been people out in the community while infectious for quite some time, and been to quite a number of places," microbiologist Siouxsie Wiles told Newshub.

"It's a very sensible precaution." 

If anyone here tests positive, a lockdown can be avoided if contact tracers can track the movements of that person or anyone they've been in contact with over the past few weeks. 

While use of the COVID Tracer typically spikes when there is a confirmed case, tracers need to look back in time before the case tested positive. Lockdowns are only really needed when tracers can't figure out who's passed the virus onto who. 

"We know that there's a risk when there are cases in the community either in New Zealand or Australia, because we have this travel bubble. We have to be cautious," said Dr Wiles, who was named New Zealander of the Year for her efforts during 2020

Use of the COVID Tracer app has been dropping. In the second two weeks of February, following an outbreak, there were on average 1.48 million scans a day. That had fallen 50 percent by April, and has dropped further since - averaging 566,000 a day in the last two weeks. 

"We should all still be using the contact tracing app, keeping track of our movements and doing all of those things that we know are ways to stop cases becoming big clusters," said Dr Wiles.

"It's a reminder to all of us that COVID isn't gone - it's still around in the world and it can come into the community. It's about ensuring if cases do appear, they don't turn into large clusters."

The most recent data available on usage of the COVID Tracer is May 25, after the first few cases in the current Melbourne cluster were reported. 

Siouxsie Wiles.
Siouxsie Wiles. Photo credit: The AM Show

Dr Wiles said Australia's vaccine rollout is going too slowly for herd immunity to stop an outbreak.

"It will require a large number of people to be vaccinated before we [can stop using] restrictions like stopping people's movements and contact in order to make sure cases are kept to a minimum. 

"The worry here is been that there have been people who didn't get tested when they developed symptoms. That's the thing we have to remember, especially as we're going into winter - when people have symptoms that could be COVID-19 and they ignore them, thinking 'we don't have COVID in the community here', that's how we end up missing it, and that's exactly what happened in Melbourne.

"We just need everybody here to be vigilant and make sure they get tested if they have any symptoms." 

The number of tests conducted in the community each day has hovered around 3200 a day for the past couple of months.