How virus mysteriously resurfaced in NZ
With New Zealand back in lockdown, officials are now investigating the possibility that the new coronavirus cases came through imported freight.
The cases have no known source, and health experts are now scrambling to figure out how, in a country that closed its borders months ago and was so successful at containment, four people managed to contract the virus.
New Zealand has long received global praise for its swift response to the coronavirus pandemic, and until Tuesday had not recorded a single case in more than 100 days.
Authorities said the new cases had no connection to overseas travel. The first case confirmed was a man in his 50s who presented to their GP with symptoms on Monday.
The man had strong symptoms including a fever and a cough, and the man's partner also had strong symptoms, both later tested positive, alongside two other family members. On Wednesday, another confirmed case was linked to the outbreak and four other close contacts are isolating after showing symptoms.
VIRUS MAY HAVE TRAVELLED ON IMPORTED FREIGHT
Officials are now investigating the possibility that the virus travelled into New Zealand on refrigerated freight.
The country's health director-general Dr Ashley Bloomfield said surface testing was under way in an Auckland cool storage facility where a man from the infected family worked.
"We do know from studies overseas, that actually, the virus can survive in some refrigerated environments for quite some time," he said.
China has reported instances of coronavirus being detected on the packaging of imported frozen seafood.
Dr Bloomfield was unsure if the cool store was receiving international freight that had been refrigerated for its whole journey.
The cool storage facility where the man worked, in Mount Wellington, had been closed down along with three other sites the company had around the city, he said. The 160 staff across all the facilities would be tested for COVID-19.
Professor Michael Plank, an expert at the University of Canterbury in Christchurch, said "surface contamination" was a possibility for how the virus may have re-emerged in New Zealand.
"The most likely scenario is still that the outbreak started at the border, either with an international arrival or someone working at government-managed isolation," he told news.com.au. "The fact that there is no known link between the new cases and a border worker suggests that there are several links in the chain that we don't yet know about.
"For example, it could have been passed on by an asymptomatic carrier, someone who didn't get tested, or possibly via an environmental route like surface contamination."
New Zealand authorities said environmental factors will be examined closely during investigations. At a press conference earlier today, Prime Minister Jacinda Ardern and Dr Bloomfield said the positive case's workplace has been closed at all sites.
"They are all shut down and there is both testing of all those who work there and also of the environment in that workplace. We want to see if possibly the environment is implicated here," Dr Bloomfield said.
Prof Plank said authorities will need to undertake a lot of testing to work out how far the virus has spread.
"It's more effective at this stage to target this to high-risk groups than just do random testing. This means people with symptoms and people identified by contact tracing teams."
He also warned that the lack of a known link means there could be several more cases in New Zealand that are yet to be discovered.
"The fact that these new cases have no known link to international travel or people working at the border makes the situation more serious."
Associate Professor Garry Nixon from the University of Otago suggested there was always a threat of new cases, even after 100 days without community transmission.
"This is disappointing but not entirely unexpected," he said.
"Different alert levels between different parts of the country is a sensible approach in the circumstances. But this is something we have not previously seen.
"Minimising movement between regions is now more important. People shifting out of the cities to sit out the last lockdown at the beach was a problem last time. Now it risks not only putting undue pressure on stretched rural health services, it also risks introducing the virus into communities at lower alert levels, where it can spread more easily."
FROM 'SUCCESSFUL ELIMINATION' TO LOCKDOWN
With a population of five million, New Zealand won widespread praise for its effective handling of the coronavirus pandemic after closing its borders on March 19.
The World Health Organisation (WHO) hailed the country as an example to others for having "successfully eliminated community transmission".
Since the first patient was diagnosed in February there have been 1223 confirmed cases of the virus in New Zealand. Until yesterday, the last case of community transmission was recorded on May 1.
While massive surges broke out in the United States, Brazil, India and Russia, New Zealanders were enjoying a near-normal, pre-coronavirus lifestyle with no social distancing. Spectators were allowed at sports and cultural events.
Other than the border being strictly controlled and all arrivals required to spend 14 days in quarantine, life inside New Zealand had basically resumed as normal.
Ms Ardern's government did maintain the prospect of a second wave remained a possibility, and pushed for all households to keep emergency supply kits, including masks, on hand.
As of midday Wednesday, new rules are in place. Auckland is at stage 3 restrictions, while the rest of the country is at stage 2.
This means people living in Auckland will have to work from home unless they are an essential services worker. Schools will only remain open for students whose parents are essential workers.
Public facilities, bars, restaurants and businesses in Auckland will be forced to close, and gatherings of more than 10 people are prohibited. For the rest of the country, mass gatherings are now limited to 100 people.
Ms Ardern has also urged everyone to wear masks to help prevent the spread of the virus, noting people can fashion their own face covering if needed.
Supermarkets have already moved to immediately restrict the sale of some essential products to ensure demand can be met and prevent stockpiling.
WHAT'S THE WORST CASE SCENARIO?
While it's expected that Aucklanders will most likely stay in lockdown for longer than three days, a worst-case scenario would mean it could be seven weeks, a top scientist warned.
Epidemiologist Professor Michael Baker told The New Zealand Herald it all came down to determining how far this outbreak had already spread and if a direct link to an overseas case could be identified.
"You would expect a longer lockdown would be more likely. The most positive outcome is if contact tracing identifies a clear line of transmission from an imported case or someone working at managed quarantine," Prof Baker said.
"If the direct line to imported cases is established quickly, that's very helpful and then it's finding out the extent of infection among the contacts. If some of them are infected then it's working out the extent of infection among their contacts and so it goes on."
Prof Baker said the extreme scenario would be that New Zealand would go back to the situation in March when the virus was extinguished after five weeks at level 4 and then two weeks at level 3.
"I don't think anyone is imagining that will be necessary this time around, but if you are taking the extreme range of possibilities, we know from experience in March that it was very effective."
Prof Baker said the wider the outbreak and the more time it took to contact trace, the longer people will be in lockdown.
- with Emma Russell
Originally published as How virus mysteriously resurfaced in NZ