ANALYSIS:
Contact tracing wasn't up to scratch for the months of the Delta outbreak when daily case numbers were the highest, the latest Ministry of Health report shows.
If the performance targets had been met, it essentially means more people would have been isolating sooner - and the outbreak could have been more contained.
This is not just about the officials involved. It's also on testing labs failing to tell people of positive results within 24 hours, and symptomatic people not getting tested in a timely manner.
The key benchmark for public health teams is having 80 per cent of close contacts isolated within 48 hours of a positive case being notified in the system.
As previously reported, they struggled to achieve this when the Delta outbreak started in mid-August.
It was only reached after the lockdown saw daily case numbers fall from the first peak of 83, but dropped below par again from October, when case numbers trended back up towards 50-plus a day.
The latest report, covering October 18 to January 16, shows performance remaining between 70 and 80 per cent for several weeks until the start of December, including throughout the second Delta wave that peaked in mid-November with 222 cases a day.
The Government had abandoned elimination at this point, and was hoping contact tracing and surge vaccination efforts would keep Delta from exploding as it had in Sydney and Melbourne.
The 80 per cent benchmark was reached again only at the start of December, when daily case numbers dropped below 100 once more.
This is not to disparage the hard work of public health officials on the ground in Auckland. The start of the reporting period was also a time when teams were short-staffed because health officials were burnt out, and a number were resigning.
Associate Health Minister Ayesha Verrall has also defended the sub-par performance in early October, citing the challenges of getting marginalised people to cooperate with contact tracers.
The latest report said these challenges slowed case investigations.
"At certain times during the outbreak, it took longer to complete the case investigation, frequently due to additional information being provided late in the process, which impacted the public health sector's ability to meet [this] target," the report said.
"The average time to case interview has fluctuated each week, with the weekly average for this period ranging from 7.8 hours to 19.3 hours. When it takes longer to complete a case investigation, the overall time taken to reach and isolate associated close contacts is extended."
But we also know that independent experts, including Sir Brian Roche, have warned the Government repeatedly about the need to boost contact tracing capacity, as well as the likelihood of staff burnout.
Roche and his team have questioned the Ministry of Health's apparent reluctance for the need to be able to contact trace 1000 cases a day, and then its reluctance to stress-test the system, having finally agreed to building this capacity.
By the time of the Delta outbreak, the ministry claimed to have surge capacity for 6000 contacts a day, but it fell far short of that during the first Delta wave.
The report also covered a period when the definition of a close contact was narrowed, so overall performance, all other things being equal, might have been expected to improve.
The previous report covered eight weeks including almost 40,000 close contacts for 1994 cases, whereas this report covered three months and almost five times the number of cases (9134), but fewer close contacts (33,394).
Testing labs were nowhere near the benchmark of notifying 80 per cent of all positive results within 24 hours of the sample arriving at the lab.
For the weeks when Delta cases were consistently hitting more than 100 per day in November, only 30 per cent were told about their positive results within that timeframe.
Each part of the system's performance affects containment of the outbreak. If someone isn't notified of a positive result in a timely fashion, it takes longer to reach them and their contacts to ensure they're isolating.
This was at a point in the outbreak when contact-tracing was targeted to the most vulnerable people, and officials were scrambling to support hundreds of infected people to isolate at home rather than in MIQ.
It was also during level 3.2 in Auckland, so people who didn't know they had to isolate could have been heading out for food supplies, outdoor picnics, or even to libraries or retail shops.
The report puts this poor lab performance down to a data entry issue.
"Delayed data entry into EpiSurv (the national notifiable disease surveillance database) is largely responsible for the low performance against this indicator, rather than the turnaround time for sample processing."
It also showed that people weren't getting tested quickly when they became symptomatic.
This is not new. A survey of 1000 people in June last year, commissioned by the Royal College of Pathologists of Australasia, showed almost two-thirds of people not getting tested despite having cold and flu-like symptoms in the previous six months.
For the period covered in the report, only 29 per cent of cases were tested within 48 hours of their first symptoms. Multiple factors affect this, including accessibility of tests, how the Government pushes its key public health messages, and how much time people have to get tested.
On average, it took more than a week after those first symptoms for 80 per cent of a case's close contacts to be isolated.
Contact tracing was vital when elimination was still the goal, when the deadlier Delta variant was spreading, and at the start of the Omicron outbreak to delay the onslaught of cases as much as possible.
Since then, as cases hit tens of thousands a day, its importance has diminished. The ministry stopped publishing locations of interest months ago, while up to a third of all Kiwis are thought to have had, or have, Omicron.
People who are sick don't have to drive to a testing station and wait for a result, but can have a rapid antigen test at home.
The report - quietly dropped late on Friday, when the Government wants information to get the least amount of attention - is also less useful because the period it covers ended more than two months ago; fortnightly reports used to be released frequently, but that has ceased since Delta arrived.
But contact tracing - and the accountability of these reports - will become vital once again when a new variant inevitably arrives in New Zealand.
The report underlines how indispensable it is to have good contact tracing in the early days of an outbreak with a new variant, especially if it is more transmissable and deadlier than Omicron.
That means being as prepared as possible: resourcing public health teams as well as managing staff burnout, building enough contact tracing capacity - including in labs - and stress-testing it, and involving culturally suitable people to engage with the marginalised, who suffer disproportionately in any outbreak.
It also shows the importance of staying home if sick, regardless of the result of any PCR or rapid antigen test.
With so many infections nationwide, and with winter just around the corner, isolating at the first sign of symptoms will go a long way to minimising the harm the virus can inflict - regardless of how long a health official might take to reach you.
Minister Andrew Bayly sat down with Tom Raynel to discuss his 2024, and what comes next.