Covid 19 coronavirus: The case to quarantine all travellers at Ōhakea air base

There's a "reasonable case" for all isolation and quarantine facilities to be moved to the Ōhakea air base, public health experts say - but it would likely hurt the "brain gain" from more Kiwis coming home.

In a new blog post, prominent Otago University epidemiologists professors Nick Wilson and Michael Baker have taken a look at the idea of shifting facilities to military bases.

That very concept is being proposed by NZ First, which argues the move would strengthen borders and cost the country "a fraction" of the $500 million set aside by the Government to pay for largely hotel-based managed isolation facilities, along with quarantine centres (MIQ).

The Government however has no new plans to set up any facilities at NZ Defence Force camps or bases.

Wilson and Baker argued the main advantage of a single facility at RNZAF Base Ōhakea in Manawatū would be a reduction in the risk of border control failures, which could potentially involve outbreaks in New Zealand's largest cities with large health and economic impacts.

The flip-side would be slashed numbers of returnees that could be allowed back into New Zealand, with these returnees assisting with economic recovery.

"There is therefore a need for an integrated health and economic analysis with the NZ Government being explicit about its decision-making."

Setting out the main pluses of the idea, they cited a reduced risk of the virus being passed between managed isolation and quarantine (MIQ) workers, or into the community.

That problem had been illustrated by Melbourne's second outbreak - which had been sourced to a single family staying at a quarantine hotel - and also by the fact the virus was likely spread from one person to another through a contaminated lift in an Auckland hotel.

While the source of the current Auckland outbreak remained unknown, and likely always would, it could have also been sparked by a failure at an MIQ facility.

There were also the cases here and in Australia of people escaping from isolation hotels, along with the half-billion dollar cost of operating New Zealand's 32 facilities through til 2021.

The Air Force base at Ōhakea, meanwhile, was relatively self-contained, nearly 30km from the nearest city and had a runway suitable for large aircraft.

"This base could be a 'one-stop-shop' with aircraft flying directly from overseas and so there would be no disease transmission risk with using buses and domestic airlines to move people to facilities around New Zealand," they said.

"The on-base facilities could be re-purposed and new buildings built to quarantine standards."

Hong Kong had used modular integrated construction technology to rapidly build some of its quarantine facilities, and doing the same here could create new jobs.

Workers supporting the facilities could all live on the base for periods such as a month, they said, and be tested before spending any stints away.

"In the remote chance that an infected worker had a false negative test and triggered an outbreak off the base – then this outbreak would be more likely to occur in the nearest city, Palmerston North, a very much smaller city than Auckland," they said.

"As such, the health and economic impact of any restrictions required to control the outbreak would be much less severe."

Otago University epidemiologists professors Michael Baker and Nick Wilson have taken a look at the idea of shifting facilities to military bases. Photo / Supplied

The facilities themselves could be specially designed to lower the risk of the virus spreading - and control by the military would offer "far better security" than hotel facilities in down-town city centres.

"New Zealand needs a permanent isolation and quarantine facility for the future anyway," they said.

"The world is likely to face future pandemics from natural sources, as well as the possibility of synthetic bioweapons.

"It may therefore be a good investment to have purpose-built isolation/quarantine facilities established in advance at a highly secure military base."

They agreed the Ōhakea option would cost much less than the status quo - but the economic analysis would need to factor in the lost benefit to the country from fewer returnees coming in.

The current set-up had enabled nearly 50,000 people to return since late March, with nearly 5400 people staying in the facilities across Auckland, Hamilton, Rotorua, Wellington and Christchurch as at September 8.

"At this time the previous three-day average was 370 people arriving in the country per day which is equivalent to 135,000 per year," they said.

"These numbers are probably at least 10 times what Ōhakea could be readily adapted to manage.

"However, this limit would depend on whether there was a decision to expand the size of the Ōhakea base by renting or buying surrounding farmland, construction of additional facilities, and adding further security fencing."

But the high number of returnees now flowing in would be helping New Zealand's economic recovery, given they were bringing in skills and capital.

"They will also enhance consumer demand in the retail and housing sectors," they said.

"Some might even continue to work for overseas companies while being based in New Zealand and so will not compete with other New Zealanders for jobs."

Taking the pros and cons together, Wilson and Baker saw a reasonable case for a "single high-quality option" at Ōhakea - but one in need of a health and economic analysis by the Government.

New Zealand had a long history of combating animal and plant diseases with some of the toughest biosecurity systems in the world, they said, but "human biosecurity" posed a new challenge.

"This shift in thinking could be part of taking a more strategic approach to our Covid-19 response and building essential infrastructure to manage other external public health threats on the horizon."