Australia can expect another wave of COVID-19 infections in coming weeks, experts say, as case numbers rise and new variants circulate.
In a report released on Thursday, NSW Chief Health Officer, Kerry Chant, warned infections would soon increase.
"By looking at all the local information we have and what’s happening overseas, we believe COVID cases will rise in the coming weeks," she said.
The NSW rise mirrors Victoria, where a 25 per cent increase in case numbers was recorded last week.
Victoria's Chief Health Officer, Brett Sutton, said the numbers signalled the start of another surge.
Catherine Bennett, chair of epidemiology at Deakin University, said the next wave was starting across Australia.
"We could see this and maybe another wave early next year. It just means there's that constant exposure risks going ahead," she said.
In contrast to this time last year, cases are now only reported on a weekly basis across Australia.
The data showed that in the last week of October, numbers increased in all states and territories except Queensland.
NSW health recorded 9,707 positive diagnoses in the week ending October 29, an 11 per cent increase on the week before.
There were 68,883 tests reported in NSW, with an increase in positive cases from 7.3 per cent to 9.2 per cent.
Professor Bennett said numbers were an underestimate because some cases were asymptomatic.
In addition, it is no longer mandatory to report a positive COVID test in NSW, though health authorities recommend people do so voluntarily.
In the week ending October 29, hospital admissions of people with COVID were down to an average of 32 per week in NSW, from 33 the week before.
NSW health data has shown that hospitalisations typically lag symptom onset by a week or more, so a rise in cases has not yet resulted in an increase in hospitalisations.
There are currently 820 people in NSW hospitals with COVID and 17 COVID-related deaths were recorded in the last week of October.
Dr Chant said the BA.4 and BA.5 omicron variants continued to be the most common variants.
"However, we are seeing a rise in XBB, BQ 1.1 and the B2 sub-lineages," she said.
These variants are sub-lineages of omicron, according to a World Health Organisation media release on October 27.
The release noted that there was no evidence to suggest the sub-lineages were a greater risk than other omicron lineages, but the data came from a limited number of countries and might not apply elsewhere.
Professor Bennett said the new sub-lineages were related to BA.5, which had caused most of the infections in Australia in recent months.
"So I'm hopeful that it won't have as good a foothold here because we've had so many people with BA.5 that maybe there's a bit more cross reactive immunity here," she said.
Dr Chant urged everyone to get tested for COVID and then stay at home if they had cold and flu symptoms.
"Make sure you're up to date with your vaccinations. This is your best protection including against the latest variants," she said.
