Covid 19 Delta outbreak: The battle for elimination and the idea that appeared ‘racist and dangerous’

Government advisers were at loggerheads at a key moment in September over whether a change in the Covid-19 testing strategy in South Auckland was needed to improve the country’s chances of eliminating the virus.

On September 7, Rodney Jones, principal at Wigram Capital Advisors and an adviser to the Government on its Covid-19 response, told officials that despite the trend lower of case numbers he remained deeply concerned that the Covid positivity rate for Auckland’s Pasifika was too high for an elimination strategy.

Jones advised that broad surveillance testing – beyond the testing of case contacts and those with symptoms, among South Auckland’s Pasifika, was needed to detect “background cases”; without it he feared elimination was unobtainable.

The advice immediately met stiff opposition. Emily Harvey, a principal investigator at Te Punaha Matatini (TPM), replied that Jones’ suggestion: “appears racist and dangerous”.

She argued that broad surveillance testing was not suitable in the circumstances, and specifically it was not suitable for the Pasifika community, given its very high testing rates at the time. The pair also disagreed over the utility of Wigram’s raw positivity rate for Pasifika (a function of positive tests and total tests administered).

The exchange took place in a chain of emails between officials at the Treasury, the Department of the Prime Minister and Cabinet (DPMC), the Ministry of Health (MoH), and included Harvey and Jones. The officials were members of the Covid-19 Modelling Steering Group, chaired by the Treasury. Both Te Punaha Matatini and Wigram hold government contracts to supply both modelling and advice to inform New Zealand’s Covid-response, though their modelling approaches are very different.

The correspondence of September 7 unfolded at what Jones said, in an interview this week, was a pivotal moment in New Zealand’s ultimately failed effort to eliminate the Delta variant of the virus. The emails were obtained under the Official Information Act.

“… in past outbreaks I would be optimistic at this point. But Reffs [the effective reproduction number of the virus, also called the R number or value] have to be interpreted in light of positivity rates, and the Pasifika positivity rate remains around 1 per cent. This is far too high for an elimination strategy, and suggests that there remain undetected background cases. To get a handle on this, we need to start surveillance testing among the Pasifika community in South Auckland. This is critical,” Jones wrote.

Harvey took an opposing view: “In order to find ‘every last case’ it is much better to focus your testing on those at highest risk. Given that approximately 85 per cent of Covid cases develop symptoms (if you include mild symptoms in your case definition), this is an important group in the population to target. Another important aspect will be to make sure testing is high in areas and communities who have new unlinked cases popping up, and new locations of interest.”

Harvey noted that Jones did not have detailed public health data, for example, to show the extent to which testing already targeted areas with unlinked cases. “… As such, your blanket suggestion to target ‘surveillance testing’ on the ‘Pasifika community in South Auckland’, who have by far the highest testing rate even after removing all the tests for known contacts, appears racist and dangerous,” she wrote.

Jones’ reply was emphatic: “What you propose is not sufficient, as number of tests NOT in already identified contacts is not an unbiased sample. It is merely a sample of those presenting for tests, ie on MoH guidance are symptomatic. For Delta [which spreads more rapidly than the original ‘wild’ type], this is an insufficient sample, given the number of asymptomatic carriers. If the goal is elimination, we require a large unbiased sample of the population to have any confidence. In the absence of that, a simple measure indicates that there is an underlying problem here. With Delta we have to find every last case, and a sample based on symptomatic presentation, excluding contacts, is not sufficient. This is the issue.”

In another email Jones insisted that: “what is racist and dangerous is to ignore the specific vulnerability of the South Auckland communities at this time.”

Contacted this week, Harvey reiterated that public health teams and the Ministry of Health were best placed to identify the groups of people seemingly not presenting for testing.

“Based on the data [Rodney and I had available], the ‘Pasifika community in South Auckland’ was not a community they [public health] were ‘missing’ in their testing,” she said.

In the following weeks more general community-based testing was introduced, largely centred in South Auckland’s suburbs (for people without symptoms or positive contacts). But this week, Jones said, it came too late.

Also, it has never achieved the scale that Jones argued was required once spread of the virus was established in the large, inter-generational households of South Auckland Pasifika, often living in considerable poverty.

“We would have had to throw everything we had at South Auckland, all of our testing capability [20,000 PCR tests a day], all of our vaccination capability and at that point [September 7] we had to do it fast. People talk about September 23rd when we moved to level 3 as the time when we lost elimination. That’s a red herring. The battle for elimination was lost much earlier than that,” Jones said this week.

Rapid antigen tests could have been used as well, he noted, but the MoH didn’t receive its first shipment until September 15.

On September 6, the MoH did modify its testing focus to include surveillance testing for healthcare and other essential workers. It came into effect in piecemeal fashion, for example testing for essential workers crossing the Auckland border became mandatory on the 17th.

Starting on September 14, director-general of health Dr Ashley Bloomfield began identifying “suburbs of interest” in daily press conferences. The purpose was to prioritise the areas with the greatest likelihood for undetected community cases, a Ministry of Health spokesperson said. Symptomatic or not, people living in those suburbs were encouraged to be tested.

It was the first step toward the far-reaching testing for which Jones had argued. But the numbers remained low: on the 13th there were 4250 total tests performed in Auckland in the previous 24-hour period.

At the same time the Northern Region Health Coordination Centre (NRHCC) contracted primary healthcare providers to start to take mobile testing capabilities into homes, though the daily numbers were likely fewer than 100 per day initially.

South Seas Healthcare Trust, based in Otara and with a clientele that is roughly 94 per cent Pasifika, was among the providers.

“It’s something we’d already been doing [as a primary care provider] but small numbers, maybe about 10 or so tests a day, along with vaccination and other services for our elderly and disabled who aren’t able to come out,” CEO Silao Vaisola-Sefo said.

“We got a contract through from NRHCC about the middle of September to start going out to homes to test their referrals, contacts [of positive cases] they’d identified, and from that we were doing other tests, door to door. So we’d have a contract to go and test Kate, for example, but testing Kate just gets us into the household, if there are seven or eight people in there we test them too, and we’re armed with food parcels and a social worker, and then maybe Kate tells us there’s a family down the road we should test and she gives them a call to tell them we’re coming round and that’s how it goes…”

Vaisola-Sefo said the Trusts’ mobile team is now giving hundreds of at-home tests per week, “but it would have been useful for our Pacific population earlier.”

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