A maintenance worker at the Rydges Hotel managed isolation facility in Auckland has tested positive for Covid-19 but isn’t linked to the current cluster. What does that mean for our response? Marc Daalder reports
Analysis: The picture of the community Covid-19 outbreak in Auckland has just become a little more complicated.
On Tuesday afternoon, the Ministry of Health released the results of the latest round of genome sequencing of community cases, which is being carried out to help officials trace the origins and scope of the cluster.
One case that had yet to be linked to the Americold cluster through contact tracing was confirmed to be connected to the cluster via the sequencing. The virus genome of a second unlinked case, however, was identified as a different variant from the one that makes up the cold storage cluster.
The person infected is a maintenance worker at the Rydges Hotel in Auckland, which currently serves as a managed isolation facility. He tested positive as part of newly-mandatory testing of managed isolation and quarantine staff. Although he developed a cough on August 11, he put it off to a preexisting condition and continued to attend work. He was swabbed on August 13 and the result was returned on August 16, at which point he was contact traced and isolated.
“He was picked up as part of routine testing, so this was the system working as intended,” Siouxsie Wiles, a microbiologist and expert on infectious diseases at the University of Auckland, told Newsroom.
The man does not have face-to-face contact with guests. However, the genome of the virus that infected him matches that of a woman who travelled to New Zealand from the United States on July 28, tested positive as part of day three testing and was moved to quarantine on July 31.
The facility that woman was originally placed in? The Rydges Hotel.
The Ministry of Health says that reviews of CCTV footage shows no scenarios where the two cases may have come in contact. Housing Minister Megan Woods, who is responsible for non-health aspects of the managed isolation and quarantine system, said access card data from the hotel room showed that, per protocols, no one accessed the room between July 31 and August 14, when it was disinfected.
“At this stage there is no obvious person-to-person connection between the worker and the returnee from the USA but investigations continue,” the Ministry of Health said in a statement.
The hotel worker in question never entered the room either.
All of this raises more questions than it answers.
In the worst case scenario, this could indicate that there is a second outbreak moving through the Rydges Hotel or even Auckland more broadly.
This, however, seems unlikely. Director-General of Health Ashley Bloomfield said that the genomes of all new cases were being sequenced and matched against both domestic and international databases. This is the first community case to return a result that didn’t match the variant that makes up the cold store infections. Moreover, more than 100 people at the Rydges Hotel have returned a negative day 12 test result since July 31. No others have tested positive.
If the Rydges Hotel outbreak was widespread, we could expect to see more genome sequencing results come back aligned with the case of the returnee from America and the hotel worker. In the absence of that, however, it is likely that the outbreak is smaller in scope.
“There may be some secondary spread from the case that’s positive, given they were infectious for a few days. But all of their close contacts are in isolation now, so that would hopefully catch that,” Wiles said.
“So it wouldn’t surprise me if we ended up with a few more cases from that, but not the wider spread.”
That leads to the best-case scenario – the case from the United States infected the hotel worker without infecting anyone else. This could come from person-to-person contact between the two that hasn’t yet been identified. It could also have a surface – or multiple surfaces – as an intermediary. Perhaps a doorknob or elevator button.
It is unclear how likely this scenario is. The World Health Organisation says there are no known reports of person-to-surface-to-person (fomite) transmission, but notes that it is likely that it has occurred.
“People who come into contact with potentially infectious surfaces often also have close contact with the infectious person, making the distinction between respiratory droplet and fomite transmission difficult to discern. However, fomite transmission is considered a likely mode of transmission for SARS-CoV-2, given consistent findings about environmental contamination in the vicinity of infected cases and the fact that other coronaviruses and respiratory viruses can transmit this way,” WHO advice reads.
Lastly, there is the possibility of indirect infection through a smaller chain of transmission. Perhaps the case from the United States infected another hotel worker or guest – in-person or via a surface – who then infected the hotel worker in question.
Wiles said the path for infection was uncertain. “The more mysterious thing is how it happened. It’s one of these things where the virus is just so damned tricky and hard to pin down,” she said.
“Nobody else has tested positive. So if it had been [transmission via an intermediary person], you’d expect somebody to test positive.”
Rydges Hotel staff and residents are being retested and results are pending.
Either way, it currently seems likely that the Rydges Hotel infection chain is limited in scope, at least when compared with the cold store cluster. But the entire saga underscores the need for more rigorous testing of managed isolation and border workers.
This is a policy that was announced on June 23. Cabinet believed it had been implemented, but it was in fact still being rolled out when the news of the cold store cluster broke last week. Bloomfield has indicated that the health system – operating as usual at Level 1 – simply didn’t have the capacity to roll out widespread regular testing of thousands of workers more quickly, though questions are still unanswered as to how the miscommunication between officials and ministers occurred.
The situation also raises further questions about the rigour of health protocols in managed isolation facilities.
When the hotel worker in question showed up to work with a cough the day after the Prime Minister announced there were four cases in the community in Auckland, why was he permitted to work his shift instead of sent home to await testing?
“Is it actually completely unworkable to stand down somebody every time they’ve got a little cough? This is what makes it really difficult,” Wiles said. She said Covid-19 has symptoms that are incredibly common with other illnesses and chronic conditions.
“If any sign of any symptom, even if you’ve got an underlying health condition, you get stepped down – what does that mean? Does it mean you don’t work for three months because your asthma’s flaring up?
“When you’ve got a disease like this that can manifest in these really insidious ways that mimic so many things that people live with, what does that mean in the long term?”