Figures released to 1 NEWS reveal “[fewer] than 10” notifications were sent to people’s phones as a result of Bluetooth tracing on the Covid-19 Tracer app in this latest outbreak.
Instead, contact tracers are making greater use of the QR codes people were scanning.
A Ministry of Health spokesperson said on Saturday it hadn’t requested Bluetooth keys from people unless they tested positive for Covid-19.
“A person could be in close proximity with one case for an extended time or multiple cases for less time for a Bluetooth risk threshold to be reached – it depends on a number of variables,” the spokesperson said.
“These settings are in line with an international-consensus based approach and they take into account the inherent reliability issues with Bluetooth.
“So far, there have been a small number (less than 10) of notifications received as a result of the NZ COVID Tracer app’s Bluetooth function being used.”
1 NEWS has asked the Ministry of Health how many people who had tested positive for the virus had shared their Bluetooth data with authorities.
Authorities weren’t able to directly identify anyone who receives a Bluetooth alert — because of the privacy settings built into that system — unless that person calls Healthline, the spokesperson said.
The spokesperson said Bluetooth was meant to support and not replace normal contact tracing methods, such as scanning QR codes.
Since August 17, when the first case in the community in this outbreak was identified, notifications have been sent to more than 3900 devices because they scanned a QR code at a location and time of interest.
The spokesperson didn't answer questions from 1 NEWS about the date authorities had last made a request for a person's Bluetooth keys.
When asked why less than 10 notifications were sent through the Covid Tracer app’s Bluetooth function, the Director-General of Health said contact tracers “have been using it where people said they have had Bluetooth turned on”.
“We’ve used that to send out messages,” Dr Ashley Bloomfield said.
“Because of the number of cases, it wasn’t necessarily a question our contact tracers were asking at the first interview because they were trying to get the most essential information. We’ve given them a nudge around that.
“Secondly, it seems from the demographic of most of our cases, many of them didn’t have Bluetooth turned on.”
ACT Party Leader David Seymour dismissed Bloomfield's response as an excuse and said it "beggars belief".
“The Government’s NZ COVID Tracer App has barely changed since Bluetooth capability was added in December. Rather than continuous improvement to build functionality, it has simply let the NZ COVID Tracer App slide like every other aspect of the response between lockdowns," Seymour said.
“Ashley Bloomfield’s excuse that none of the 400+ cases are in a demographic likely to use Bluetooth contact tracing beggars belief. What did he mean by that? There appear to be a large number of young people amongst the cases, does he not know they have smartphones?
“The real problem is that contact tracers are reportedly not even asking contacts to upload their Bluetooth data. It’s difficult to imagine how a response could be more incompetent or a Government could be more blasé about the costs they’re putting onto New Zealand."
As of August 28, Ministry of Health data, showed more than 1.9 million devices around the country had activated Bluetooth tracing in the past 24 hours.
As of Sunday, there were 511 Covid-19 cases related to the outbreak. Demographic data about the Delta outbreak showed 11.5 per cent of cases are under 9 years old, 22.1 per cent are between the ages of 10 and 19, and 27 per cent are between 20 and 29.
In a further statement to 1 NEWS on Monday, the Ministry of Health said "anecdotal reports" indicated that for "many" of the Covid-19 cases detected, "Bluetooth hasn’t frequently been used or investigated thoroughly" by public health authorities.
"Currently information from Bluetooth hasn’t been used by Public Health Services," the spokesperson said.
The spokesperson said because of privacy protections, information provided by a Blueooth-related notification was limited to the date where exposure to a Covid-19 case may have happened.
"At the early stages of an outbreak, this information can be very general and requires a considerable amount of sifting through to rule out inadvertent links, such as individuals in different vehicles stationary at traffic lights, or in slow moving traffic, or individuals in different rooms but where the phones interpret that as being close.
"As the outbreak changes, and more emphasis goes onto fewer locations, the Ministry will be working with public health units to assess whether Bluetooth activation with positive cases in the small number of workplaces (seven to date) may assist," the spokesperson said.
They said the use of Bluetooth had been included in five recent training sessions for public health and contact tracing staff.
The spokesperson said the Ministry continued to monitor Bluetooth use overseas to see how New Zealand could use it best.
The Bluetooth tracing system, developed by Apple and Google, transmits a signal from one phone to nearby phones when turned on. That allows phones to swap "randomised keys". If someone tests positive for Covid-19, their key can be collected, uploaded to a server, then compared with other users' keys to see if there's a match.