Quarantine rules, transmission theory reviewed

The state’s disease experts will review their COVID-19 transmission theory and hotel quarantine policies after it was revealed that the hotel security guard at the centre of Western Australia’s five-day lockdown had no direct contact with the infectious traveller.

Initially, Health Minister Roger Cook had said the transmission was suspected to have occurred on January 24 after the security guard, a man in his 20s now being referred to as case 903, had delivered medication to the room of a traveller who had tested positive for the UK strain of the virus.

But Mr Cook today clarified that was incorrect, and that the guard had remained at a static location near a stairwell at least two doors away from the room of the traveller believed to be responsible for the transmission.

At all times, the guard was consistent with the public health advice and was not required to wear a mask while monitoring the floor and maintaining a safe distance from the room.

The room in question was visited about seven times that day, but only by authorised personnel donning full personal protective equipment. 

It is not yet known how the transmission occurred.

WA Communicable Disease Control director Paul Armstrong said health authorities were now reviewing the transmission hypothesis that has formed the basis of the state’s hotel quarantine system requirements and policies for the past year, exploring all options to determine how the ever-changing virus could have been transmitted and amending the policy accordingly.

Dr Armstrong said the virus was understood to be transmitted by droplets that fall within 1.5 metres of a person, and, as such, the policy was that frontline workers had to wear eyewear and masks when within that distance.

He said there was no evidence to suggest that the guard did not follow the protocols.

“This is an unknown, it’s a working hypothesis, and we haven’t really nailed it yet,” Dr Armstrong said.

“But that’s understandable because we’re dealing with a virus here that’s changing.

“Up until pretty recently, it was clear that the transmission occurs when there is droplet infection within 1.5 metres of another person.

“Now we don’t know whether the higher transmissibility of this virus is caused by it being able to be transmitted by air, but we have to be open to all options.

“It goes against what we understand what we understand about the virus and it may be that a surface was contaminated by that person and he touched that surface; that’s another possibility.

“This is fairly improbable, but we have to keep all options open, we just don’t know how this person became infected.

“The learning so far is that it is not a pathogen that can be transmitted by the air-conditioning, it may have been the air flow in the hotel and the location in which that person was sitting.

“Something has happened there, a chance event.

“We all need to remember that there have been around 37,000 people in those hotels under this policy, with several hundred that have become positive, and we haven’t had any breaches.

“Something is different in this circumstance and we have to learn from it and change our policy in response, if that’s required.”

Initially, Dr Armstrong said the risk assessment found mask wearing unnecessary for stationary guards because the risk was considered to be negligible, but that authorities had brought in a new policy where all frontline staff would be required to wear masks at all times.

Public health officials are expected to provide a full report on the incident in the coming days.

Premier Mark McGowan said the government had not questioned the public health advice, saying it had stood the state in good stead over the last year.

"We have had the best outcomes of just about anywhere in the world, but this is a significant set back," he said.

"We have followed the health advice on this issue. Now the health advice has changed, and we're following that."

WA Police have revealed that there was no CCTV operating on the hotel floor at the centre of the outbreak.