The source of the Northern Territory’s first community outbreak of COVID-19 a mystery, as another new infection is recorded.
The new case is a partially vaccinated 21-year-old woman who arrived in Darwin from Queensland on October 29.
She is a close contact of the index case, an unvaccinated man in his 20s, but health authorities say she is unlikely to be the first case in the cluster.
“It seems likely there is another case that these two acquired it from,” Deputy Chief Health Officer Charles Pain told reporters on Saturday.
Dr Pain said “sequencing of (the woman’s) infectiousness doesn’t imply” she is the source of the outbreak.
“We’re still not clear about that and we still don’t know where this has come from,” he said.
“We still have this mystery as to the origin.”
More genomic testing would help connect the cluster with cases across Australia, Dr Pain said.
The woman spent last weekend with the index case at the Mantra Hotel in Darwin after she arrived from Cairns.
There had been speculation the woman could be the source of the outbreak but authorities now say the man could have infected her.
He also visited Monsoons pub and nightclub before testing positive for the virus on Thursday in Katherine, 320km south of Darwin.
The diagnosis plunged Katherine into a three-day lockdown and Greater Darwin into a lockout, with only vaccinated people permitted to freely move about the community.
Restrictions are expected to end at midnight on Sunday, however Chief Minister Michael Gunner has warned they could be extended if the situation deteriorates.
Contact tracing teams have identified 100 close contacts, including the man’s housemate who tested positive for the virus on Friday.
All three infected people are now in quarantine at the National Centre for Resilience, as health workers race to track down 20 outstanding contacts.
Mr Gunner said the outbreak was at a critical stage and test results from 80 close contacts who are isolating would help provide answers.
“We haven’t yet seen any spread beyond the very close contacts and that’s good news, but there are still too many unknowns,” he said.
“What concerns us most it that we don’t have certainty about how these three acquired it.
More exposure sites and close contacts related to the woman’s movements are expected to be identified.
“Hopefully tomorrow we’ll have a clearer picture about how we are going and we can make the big decisions then about the midnight (end of restrictions),” Mr Gunner said.
The outbreak has prompted many people to get the jab. Friday was the NT’s second busiest day for vaccinations, with 2150 doses administered.
The uptick in numbers came as police set up roadblocks around Darwin to stop unvaccinated people attending a so-called freedom rally to protest the NT’s vaccination mandate.
Across the territory, 78 per cent of people aged 16 and over have had one dose of a COVID-19 vaccine and 65 per cent have had two jabs, according to federal government data.