This week, 10,754 people in South Australia tested positive for COVID-19, 768 more than last week, with the number of infectious people in hospital also increasing from 164 to 187, including 10 in intensive care.

Twenty-one people died after testing COVID-positive, including two aged under 70 years.

PCR testing increased by three per cent over the past week, with 5171 of the 25,087 tests returning positive results, on top of 5583 positive rapid antigen tests.

BA.5 and related variants continues to be the dominant COVID strain in South Australia, accounting for 60 per cent of analysed samples.

BA.2 and related variants accounted for 26 per cent of analysed samples, while one BA.4 related variant was detected.

The spike in cases comes despite latest modelling released by SA Health showing a drop in infections in time for Christmas.

At the time, chief public health officer Professor Nicola Spurrier said the modelling by the University of Adelaide showed the current COVID wave would be “well on the way down” ahead of the festive season, peaking in late November.

But SA Health’s COVID dashboard, which hasn’t been updated with this week’s data, shows the current wave is yet to decline.

Weekly COVID-19 cases for the last 12 months. Graph: SA Health

In its update this afternoon, SA Health said some non-referral PCR testing sites would remain open until at least the end of January following a federal government announcement to extend funding arrangements.

The Bedford Park, Walkley Heights, Port Adelaide (drive-through and walk-in) and Frome Road (walk-in), as well as dedicated PCR testing sites in regional areas, will remain open past January 8.

“These sites will have the ability to scale up and down in response to demand, and SA’s testing capability will be reviewed again at the end of January,” SA Health said.

National figures released last week showed the rise in COVID cases was slowing after steep increases in November.

University of South Australia epidemiologist Adrian Esterman said a nationwide peak was approaching but warned the data was based only on reported numbers.

“One of the problems is we don’t have a good handle on how many cases there are,” he said.

“All we have is the reported cases and they’re the tip of the iceberg because most people these days aren’t reporting it.”

Esterman said he expected the COVID wave to reach its peak this week or the next, then cases would slowly decline before another wave started – a process that would continue for the foreseeable future.

He chided state and federal authorities for loosening measures designed to slow the spread of the virus.

“They have decided the Australian population has to live with COVID-19 and they keep talking about normalising things,” he said, noting about 12 per cent of people infected with the virus ended up with long-term health problems.

– with AAP