CANBERRA -- Australian health authorities warned that a projected looming spike in COVID-19 cases could overwhelm the hospital system.

According to the modelling, the number of Australians being treated for COVID-19 in hospitals during the BA.4 and BA.5 wave of infections is expected to surpass 5,000.

There were 4,327 COVID-19 cases being treated in hospitals on Monday, up from 3,511 a week earlier.

Australian Medical Association (AMA) vice-president Chris Moy said hospitals were facing a big threat as the country also reports an increasing number of influenza cases.

"This wave is scaring us because the BA.4 and Omicron subvariant strains are more infectious, cause more reinfections and also can cause more severe disease," he told Seven Network television.

"So we are really worried about being overwhelmed and in a situation where essentially, people with COVID, and also without COVID, are going to have delayed care in an emergency."

It comes after health authorities in the Australian Capital Territory (ACT) on Monday warned daily COVID-19 case numbers could triple before peaking in late July or early August.

"This new wave of COVID-19, combined with the ACT's first influenza season in three years and increases in other respiratory illnesses, are already impacting our community and workplaces," said ACT Chief Health Officer Kerryn Coleman.

On Tuesday, Australia reported more than 40,000 new COVID-19 cases and more than 50 deaths.

Chief Medical Officer (CMO) Paul Kelly repeated the federal government's stance that Australians should take responsibility for their health.

"Wear a mask if you're indoors, if you are eligible for treatments, go find out about that from your General Practitioner now because that will decrease your chance of having severe disease," he said on Tuesday, calling people to get vaccinated.

As of Monday afternoon, a total of 8,511,844 cases of COVID-19 have been reported in Australia, including 10,326 deaths, and 311,332 active cases, according to the latest figures from the Department of Health.