Covid-19: ACT urges saliva testing for essential workers as PM and Ministry of Health signal shift in attitude

Wednesday, 1 September 2021

David Seymour says the Government needs to deliver saliva testing more widely.

ACT leader David Seymour wants private saliva testing to be rolled out more widely after Prime Minister Jacinda Ardern signalled she believes it is good enough to replace nasal swabbing.

The Ministry of Health also changed its tune on saliva testing. A spokeswoman said the ministry was “now confident” there were situations where saliva testing could be used instead of nasal swab testing. The shift came after new information on saliva testing came to light in April.

The ministry said saliva testing had the potential to identify cases earlier, and before chains of transmission were generated.

Seymour said a statement from Ardern on Tuesday showed there were no longer significant accuracy concerns around saliva testing, and a less invasive Covid-19 test should be made available more widely.

Director General of Health Dr Ashley Bloomfield says the health ministry will look to private firms to roll out saliva Covid-19 tests at the border.

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”Essential workers could get a Government-funded or subsidised saliva testing regime, you could test them every second day, and you'd have a much more robust response against outbreaks than what we're currently dealing with.”

Jacinda Ardern says saliva testing is accurate enough to replace nasal swab testing.

Ardern told Parliament on Tuesday the Government was now satisfied with the accuracy of saliva testing.

“What we've been having discussions around is, if we're going to increase the frequency of testing, how can we use saliva as the replacement so that we aren't causing that ongoing discomfort and sometimes damage?

“Important to note that the saliva testing we've been using is still a polymerase chain reaction … it's not an instant test, but it does have the same level of accuracy that you would expect, and that's really important for our programme.”

Ardern added the caveat that saliva testing would draw on lab resources already being used for nasal swabbing, but Seymour said private labs specialising in saliva testing could offer capacity not in use for nasal swabbing right now.

The ministry put in its own caveat too, that its saliva testing programme was approved for “surveillance” not diagnostic testing, unlike its nasal swabbing one.

Anne Wyllie says New Zealand should be aiming for testing capacity of 100,000 PCR tests per day.

“Diagnostic testing, rather than surveillance testing, is needed to confirm a positive Covid-19 test, and to enable genome sequencing of the positive case to be undertaken, which is a vital part of our response,” a ministry spokeswoman said.

Rako Science’s test has been diagnostically validated, but it has not been contracted by the ministry to deliver saliva testing.

Stuff earlier reported on a stoush between Rako Science and the ministry over a $60 milion saliva testing contract, after ministry boffins passed over Rako’s test in favour of one from the Asia Pacific Healthcare Group, a test which did not have diagnostic validation at the time, but instead had analytical validation, using “spiked” saliva samples artificially “spiked” with Covid-19.

Testing accuracy was given a weighting of 10 per cent within the tender process.

Yale school of public health scientist Anne Wyllie, a leading authority on saliva testing, wrote a letter to the Government shortly before the Delta outbreak where she questioned their decision to use a test that had not been diagnostically validated.

Rako Science executive director Leon Grice, left, says their test is being used in private hospitals.

Politicians, scientists, and businesspeople have called for polymerase chain reaction (PCR) saliva testing to be more readily accessible to the general population, because it is less invasive than a nasal swab, is thought to be better for the early detection of Covid-19, and can be run more frequently than a nasal swab test.

Te Whānau o Waipareira Trust announced plans to test people using Rako Science’s diagnostically validated saliva PCR test, and its chief executive John Tamihere called for public funds to be made available to pay for saliva testing.

Tamihere has rubbished previous Ministry of Health claims where it implied Rako’s saliva test should only be used for “surveillance” testing of border workers, and not the public.

“If it’s good enough to be used for surveillance, what does surveillance mean? Surveillance means we’re under surveillance to look to see if we have a positive.

“Why is it approved for surveillance if you’re not going to use the results? Do they think we’re all thick?”

Saliva PCR testing is different from antigen rapid saliva testing. Antigen can deliver results in one or two hours, but carries with it a high error rate. No form of antigen saliva test has received emergency use authorisation from the US Food and Drug Administration (FDA).

However, certain forms of saliva PCR testing have been given emergency use authorisation, and are still faster than nasal swab testing. Rako Science’s test normally delivers results within 8 hours.

Rako Science executive director Leon Grice said its lab capacity was not being used for nasal swabbing, and could ramp up to handle 10,000 saliva tests a day.

Seymour said the tussle over saliva testing was symbolic of the Government’s inability use the private sector to expand its ability to deal with pandemic.

“There's a deeper theme, and it is that the Government is unable and unwilling to work with the private sector, or to partner generally, to raise productivity, and increase its capacity.”