PM Jacinda Ardern thanked staff for their 'cutting edge' work at an ESR Covid-19 testing facility. Video / Pool
Revelations a hotel worker may have contracted Covid-19 simply by using an elevator could lead to stricter rules being enforced on those in managed isolation or quarantine, a health expert says.
Director general of Health Dr Ashley Bloomfield today said a Rydges Hotel maintenance worker who contracted Covid-19 was found to have used a hotel lift "minutes" after an infected guest in the managed isolation facility.
The possibility the worker was infected by a contaminated surface or Covid-19-containing droplets suspended in the air was now a "strong line of investigation" for health teams.
Epidemiologist Michael Baker said the case could shed new light on how the virus spread, given the role contaminated surfaces played was still poorly understood.
Should health teams find the worker was likely infected simply by using the lift after an isolation guest, it could mean stricter controls were needed, he said.
"So for example, saying, 'you are really not going to leave your room until you have a negative test' - we might need to get tougher on that," Baker said.
"And if you are positive at any point, you are taken to a quarantine facility in Auckland and you really are going to have to be segregated from everyone else."
It comes as one study overseas revealed an asymptomatic woman rode an elevator alone, but then 71 people got Covid-19.
The study by the US Centres for Disease Control (CDC) showed the woman did everything right after returning to her home apartment after a travel trip.
She had no symptoms, but she self-quarantined anyway. She stayed in her apartment. She ordered-in food. But she became patient zero in a 71-case cluster.
A maintenance worker who tested positive for Covid used the Rydges Hotel lift minutes after an infected guest. Photo / Supplied
Although she had no direct contact with anyone, researchers believed the daughter who lived on the floor below must have touched her face, eyes or nose after later using the same buttons or leaning against the same panels.
She is thought to have then spread the virus to others.
However, New Zealand health authorities appear to have picked up the maintenance worker's infection before it spread widely to others and caused a second Covid-19 cluster in Auckland.
They earlier revealed the worker later tested positive to Covid-19 on August 13, but his strain of the virus was different to that involved in the big Auckland cluster, which has forced the city into a two-week level 3 lockdown.
It instead matched the strain of female managed isolation guest at Rydges, who had earlier flown in from the United States before testing positive for Covid-19 before being transferred to a quarantine facility.
But that had presented a mystery to those trying to find out how the man caught the virus because there appeared to have been no direct physical contact between him and the female guest.
Initially, health teams thought the virus must have spread from the woman to the worker via a third person.
But new analysis revealed the man had used the lift with a "matter of minutes" after the woman.
Bloomfield said "it could be" that the maintenance worker was infected by touching the same button as the Covid-positive returnee.
While it's usually "low risk" of contamination from touching an infected surface, the pair's close proximity meant there was a good chance that could be how the infection occurred, he said.
Health teams are still hunting for the way a Rydges Hotel worker contracted Covid-19 from a woman in managed isolation. Photo / Will Trafford
He also said he didn't know if the woman was wearing a mask while using the lift.
He said health authorities provided guidance to isolation facility workers about what personal protective equipment they should wear
Baker said researchers knew Covid-19 most easily spread through face-to-face contact when people laughed, talked, sneezed or coughed and droplets of virus-containing saliva were thrown into the air.
But just how infectious tiny droplets suspended in the air are after an infected person had left the area or contaminated surfaces is still being researched.
It could be health teams never know exactly how the maintenance worker contracted the virus, Baker said.
On the other hand, the case together with improved technology, such as genome sequencing to identify different strains of the virus, could help unpick the chain of transmission.
That would not just be good for solving this mystery but helping to inform how New Zealand better protected its borders in the future, he said.
