A microbiologist says it would be extremely rare for a person to become infected with Covid-19 off a lift button.
It's been revealed a maintenance worker at Rydges Hotel who contracted the virus used a lift just minutes after a guest who later tested positive for the same strain.
Microbiologist Siouxsie Wiles told Morning Report surface contamination is possible, but it has only been recorded a few times internationally.
She said there had also been a case overseas where a person took the lift to their apartment, became ill with Covid-19 and didn't leave their apartment for two weeks.
The illness spread to other residents in the same apartment complex and it was thought the source was the lift button.
"So this is something that has been documented. It's thought that maybe touching the lift button is the most likely thing but it seems to be quite a rare thing."
She said it was possible the Auckland case was a combination of surface contamination and a potentially contaminated environment.
Studies in laboratories had shown the virus could survive on metal surfaces for three days, and although large amounts of virus were used during this work and it degraded over that period, it was still viable after the three days.
However, Wiles said surface transmission is not the main way this virus transmits.
"It mainly transmits through face-to-face contact or being in an enclosed space for periods of time with people who are talking and singing and laughing and shouting.
"So there are some documented cases of surface transmission. They're very rare.
"It looks like we might have one of these very rare things happen."
Asked if this should have been something that was simple to avoid at an isolation facility, Wiles responded that in fact it was hard because at the time the person may not have been showing any symptoms.
"This is why we ask everyone to keep washing their hands and not touching their face. I guess this will mean that they'll have to look at putting some more rigorous processes in place but it just shows how sneaky this virus is."