South Australia has reported just one new case in its Delta outbreak, with the person involved linked a winery north of Adelaide.

The positive result takes the outbreak to 15 confirmed COVID infections.

Eight are linked to the Tenafeate Creek winery near One Tree Hill.

Several other cases are linked to The Greek restaurant in Adelaide after some infected people attended a birthday party last weekend.

Both the restaurant and the winery are considered super-spreader events.

Premier Steven Marshall said Friday’s result came on the back of another day of record testing with 23,572 swabs processed on Thursday.

He says it was cause for optimism but officials will still needed to monitor the situation as the state’s seven-day lockdown continued.

“It’s early days. We’re day three, but all of the early indications are positive,” he said.

Meanwhile, emergency measures have been invoked to allow food and other supplies to be delivered to South Australian supermarkets around the clock during the state’s COVID-19 lockdown.

Planning Minister Vickie Chapman said the variation to regulations would ensure shelves remained stocked, helping to meet increased demand and prevent supply chain delays.

“When the pandemic hit at the start of last year, we saw supermarket shelves stripped bare as people rushed to stock up on the essentials,” Ms Chapman said.

“This put immense pressure on the supply chain and delivery drivers, who rushed to get food and goods back on the shelves.

“The government responded then, as it is now, to ease the delivery time limits, enabling around-the-clock deliveries.

“It means South Australians can have complete confidence that all of your essential supermarket needs are being restocked regularly and in a timely manner.”

The regulatory changes for supermarket supplies will remain in place until September unless an earlier date is designated.

The Australian Logistic Council welcomed the measures as grocery delivery drivers felt the pinch during lockdowns in NSW and Victoria, as well as SA.

“Freight drivers are under enormous pressure as a result of snap lockdowns and increased demand,” chief executive Rachel Smith said.

“Lifting of delivery curfews is a necessary step in alleviating pressure in the supply chain.

“Freight and logistics workers are the unsung heroes of the pandemic, providing essential groceries and goods to vulnerable communities and those that need it most.”

• See all of SA’s exposure sites here

SA is also setting up new testing centres, including one to be run by the defence force amid early problems with long lines and thousands of people forced to wait many hours.

Despite the slow progress of the outbreak, the number of exposure sites continues to grow, with the Seppeltsfield Winery in the Barossa Valley and a TAFE college in Adelaide among the latest to join the list.

The growing number of locations has meant thousands of people are now in home quarantine with requirements to have three virus tests as the state heads into the third full day of its week-long lockdown.

As the lockdown continues, police have started issuing fines for those breaching the rules, with six people at a party in Port Lincoln on Wednesday evening issued with $1092 on-the-spot fines.

-with AAP