Covid-19: Voluntary saliva testing to be offered to quarantine workers

KEVIN STENT/STUFF
New arrivals coming into New Zealand from high-risk countries will be required to have an additional Covid-19 test.

Border workers in quarantine facilities will be offered voluntary daily Covid-19 saliva tests, Covid-19 Response Minister Chris Hipkins has announced.

The additional option will be rolled out at the Jet Park Quarantine facility in Auckland on Monday, and then to other facilities in Wellington and Christchurch.

It is the first time Covid-19 saliva testing has been offered by the Government.

Testing for Covid-19 through saliva samples will be available for workers in quarantine facilities. (File photo)
Irene Yi/AP
Testing for Covid-19 through saliva samples will be available for workers in quarantine facilities. (File photo)

Previously, New Zealand’s low Covid-19 numbers meant scientists couldn’t try out the efficacy of saliva testing or other options.

READ MORE:
* Covid-19: Govt defends lack of quarantine capacity for large community outbreak
* Covid-19 quarantine system 'couldn't cope' with sustained community outbreak
* Covid-19: Additional coronavirus tests for returnees from higher risk countries

This new precautionary measure is in response to higher rates of infection overseas and the more transmissible variants of Covid-19.

“It’s the latest in a series of added protection measures at the border,” Hipkins said.

The saliva tests will be offered on a voluntary basis, and will not be replacing nasal swabs, Hipkins said.

“Saliva tests have a lower sensitivity than the nasopharyngeal test, so won’t replace our ongoing ‘gold standard’ diagnostic testing methods already in place at the border and in our community.

“They will be offered as an additional screening tool for our highest risk border workers. The tests are less invasive.“

It is hoped the saliva tests will mean any positive cases among workers at quarantine facilities will be picked up faster and workers would be provided with another layer of assurance.

“They are among the most tested people in the country and perform a critical role in keeping Covid-19 out of New Zealand communities. Their ongoing safety is a top priority,” Hipkins said.

The role and effectiveness of saliva testing is still evolving, Hipkins said.

The Ministry of Health will report back with its findings about the testing in early March.

University of Canterbury mathematics professor Michael Plank welcomed saliva testing at the border, alongside nasal swabs.

“It’s likely these new tests are not as sensitive, meaning they will miss some cases, particularly in the early stages of infection. A negative test result isn’t a guarantee that you don’t have Covid-19. So it’s important that the new tests are an addition to existing test requirements, not a replacement.”

Saliva tests were easier and less invasive, Plank said, meaning they could be done more often.

”Modelling shows that regular saliva tests for quarantine workers, in addition to a weekly nasal swab, means that cases are more likely to be detected before they can pass the virus on.

University of Canterbury mathematics professor Michael Plank was part of a group devising math-based models to help the Government with its decision-making throughout the coronavirus pandemic.
University of Canterbury/Supplied
University of Canterbury mathematics professor Michael Plank was part of a group devising math-based models to help the Government with its decision-making throughout the coronavirus pandemic.

“This will reduce the risk of a community outbreak,” Plank said.

Lesley Gray​, a public health expert and senior lecturer at the University of Otago, agreed the tests were a good development.

”There are encouraging signs from initial research overseas that suggest saliva might be a good predictor of Covid-19 severity and one study just published found that testing in saliva samples was as sensitive as the nasal swabs.

“Down the line, potentially there might be a quick near person test using saliva that could help those needing to travel on flights, and potentially could lead to shorter quarantine times if tests are accurate enough.”

Lesley Gray, a University of Otago lecturer and public health expert, said introducing saliva testing was a “great development”.
Supplied
Lesley Gray, a University of Otago lecturer and public health expert, said introducing saliva testing was a “great development”.

On Monday it was announced Air New Zealand staff would help the Institute of Environmental Science and Research (ESR) to work out whether saliva tests could detect Covid-19.

The study will run over two to three months and will take place alongside the existing nose swab tests.

ESR will compare the accuracy of both the saliva and regular swab in their laboratories.

Stuff