The National Party is pushing for New Zealand-bound passengers to have a second COVID-19 test before getting on the plane.
It's currently a requirement of anyone coming here to have proof they've tested negative for the SARS-CoV-2 virus within three days of their flight, but there are concerns in places with widespread transmission that people are getting infected after having their test, but before taking off.
Pre-departure testing was a National promise before last year's election, and though they didn't win, the Government adopted the policy in January as a new wave of more infectious strains of the virus swept through the UK.
Now health spokesperson Share Reti wants a second test added - a rapid antigen test conducted immediately before the flight.
"I think we need to think about our high-risk countries, whether we should be doing rapid antigen testing before they hop on the plane," he told The Hui on Monday night.
"That's the test where you get the result back in 15 minutes. It's quite cheap, and again, you get that instant answer."
New Zealand has already controversially blocked flights from India altogether after an unusually high rate of people from there testing positive in managed isolation and quarantine.
"Our concern is they may have a negative pre-departure test three days before they hop on the plane but over that period of three days they then may catch it and they hop on the plane infected," said Dr Reti.
The spread of COVID-19 in India is unknown. While its daily death toll remains below that of Brazil and the US at the peak of the latter's outbreak, there are reports of huge numbers of cremations and burials being carried out, well beyond the official figures, which are already staggering.
Hong Kong banned flights from India this week after 47 people on a single flight tested positive while doing their isolation - despite Hong Kong having similar pre-departure testing requirements as New Zealand.
"If at the airport they were having rapid antigen testing, we've got yet another sensible and cost-effective measure that strengthens up our perimeter," said Dr Reti, who reiterated National's support for the temporary ban on flights from India.
Dr Reti also called for rapid antigen testing to be rolled out for border workers.
"The nasopharyngeal swab does turn people off. We need to make it easy for border workers to do the right thing - widespread use of saliva testing would do that."
While rapid antigen testing is less invasive and quicker to produce results than the nasopharyngeal swabs that have been carried out nearly 2 million times in New Zealand to date, there are concerns over its accuracy.
A review of the evidence published in late March found while they were reasonably good at detecting COVID-19 in people with symptoms, they were less able to pick up asymptomatic or presymptomatic infections.
Only a "very small proportion of the commercially available tests" were accurate enough to meet World Health Organization standards, with some only picking up a third of infections detected through more thorough and invasive measures. On average, they picked up only 72 percent of symptomatic cases and 58 percent of asymptomatic, and their accuracy was partly dependent on the skill of the user.
"All antigen tests will miss some people with infection, so it is important to inform people who receive a negative test result that they may still be infected," said co-author Jac Dinnes of the University of Birmingham, an expert in diagnostic test accuracy.
The review, carried out by respected British institution Cochrane, also found no research "evaluating the accuracy of these tests when used in repeated screening of people with no known exposure to SARS-CoV-2", such as at the border.
"These testing policies have been implemented without any supporting real-world evidence," said co-author and biostatistics professor Jon Deeks of the University of Birmingham.
Nearly 1 percent of rapid tests gave false positives, the review found. In contrast, the Ministry of Health says it expects "very few (if any)" false positives from its nasopharyngeal tests.
