Australia’s former Prime Minister Malcolm Turnbull tested positive for COVID-19 on Saturday, as case numbers hit new highs across the country and health officials warned that the real number of cases is likely much higher than testing shows. 

Turnbull, who was prime minister from 2015 to 2018, confirmed on Twitter he was isolating at home after a positive test.

“Like hundreds of thousands of other Australians I have tested positive for COVID. Symptoms moderate so far. Isolating as required,” Turnbull wrote. “This pandemic and especially this latest wave has put our health professionals under enormous pressure.”

“Please be polite and considerate when dealing with the front-line health workers,” he added. “They have had two years of relentless pressure and it’s now at its most intense. So give them the love and respect they deserve, please.”

The revelation of Turnbull’s case followed the announcement that federal Treasurer Josh Frydenberg also has tested positive.

New South Wales saw a record 45,098 new cases on Saturday — up from 38,625 a day earlier — as the spread of the omicron variant forced the reintroduction of some restrictions in Australia’s most populous state. Dancing and singing in pubs and nightclubs was prohibited from midnight Friday.

Also read: Coronavirus cases surge across Australia as omicron spreads

Susan Pearce, deputy secretary of New South Wales Health, said the state had not yet reached the peak of its omicron surge.

“We expect that peak to occur in around the third to the last week of January,” she said. “We have got some challenging weeks ahead of us. But we have been planning for this pandemic and continuing to reinvent ourselves for two years now.”

Chief Health Officer Kerry Chant said almost 50 percent of cases were in people aged 20 to 39.

“The transmission is happening in a variety of settings,” she said. “Obviously in those household and social gatherings that people are having and also in places like pubs, clubs, nightclubs (hence) the concern around the behavior of dancing and singing.” 

Read: Global covid cases near 280mn as Omicron wave pounds hospitals

Victoria state reported 51,356 cases on Saturday, more than double the number of the day before. The large increase was attributed to a backlog of positive cases resulting from the state’s new self-reporting system.

People who test at home using rapid antigen tests are required to report positive cases to health authorities by phone or through a new web-based system.

Saturday’s figure also included almost 25,000 cases identified through PCR tests.

State Health Minister Martin Foley said Saturday’s spike in numbers would stabilize over time to provide a more accurate picture of the omicron spread. He said the high number of self-reported cases “is in many respects exactly what we wanted to happen.”