Border risk too high, researchers conclude

AUCKLAND: New Zealand faces an “unacceptably high” risk of as many as nearly three border breaches each month — and by some measures the country is more threatened than Australia.

That is according to a new analysis by public health researchers on both sides of the Tasman, who warn that risk of new Covid19 incursions is growing even with vaccinations.

The researchers saw a need for major changes, such as capping travel from nations with a high spread, and requiring more testing, or a stint in quarantine, before travelling.

Study coauthor and University of Otago epidemiologist Prof Nick Wilson said harder measures could also include daily saliva testing of all MIQ workers — and potentially travellers — along with moving facilities to military bases outside cities.

“I’d argue the current risk is unacceptably high, given that we know it can lead to something like the Auckland August outbreak, which cost hundreds of millions of dollars.’’

“Even Auckland’s recent lockdown would have cost tens of millions of dollars, and stressed a lot of people out,” he said.

“Given all of those things, more investment in improving the facilities just seems to make pure economic sense — and pure public health sense.”

The researchers looked at nine border failures in New Zealand, including the August Auckland cluster that resulted in about 180 cases and three deaths, and seven in Australia — six of which led to lockdowns.

Using the estimated number of people who went through both countries’ hotelbased quarantine facilities up to the end of January and the equivalent number of positive cases, they calculated a combined failure rate of one per 20,702 travellers.

That worked out to one failure per 252 positive cases in quarantine and one outbreak leading to a lockdown per 47,319 travellers.

New Zealand had 15.5 failures per 1000 positive cases going through quarantine, compared with two per 1000 in Australia.

Their calculations came with caveats, since control approaches varied by state and country, and estimates could be subject to “chance variations” because of the low number of recorded failures, which may have been underestimated.