Prime Minister Scott Morrison has temporarily taken on the federal health portfolio while Greg Hunt is off sick with cellulitis.
Mr Hunt spent the night under observation in hospital as doctors pumped him with fluid and antibiotics.
He is expected to make a full recovery.
“Testing confirmed Minister Hunt’s diagnosis to be cellulitis, a bacterial infection in his leg,” his office said on Wednesday.
“The Minister is improving and will be discharged in the coming days and expects to be back at work next week.”
Cellulitis is a bacterial infection of the skin and the tissues just under it. It is usually caused by staphylococcus aureus (golden staph) and group A beta-haemolytic streptococcus and can result in the infected area becoming inflamed and painful.
Mr Morrison was adamant Mr Hunt’s illness was not connected to the Minister’s recent coronavirus vaccine, based on medical advice he has been provided.
And he was confident Mr Hunt would be back in time for parliament next week.
“He will be fine by next week, he will be back up on his feet,” Mr Morrison said.
“Minister Hunt and I have worked hand-in-glove over this last year in particular on this matter and until he returns I will be personally addressing the ministerial responsibilities of health and aged care, together with minister [Richard] Colbeck.”
Trade Minister Dan Tehan has spoken to his cabinet colleague and is confident Mr Hunt will bounce back.
“He was the normal vibrant, bubbly Greg and he’s as keen to get back to work as he possibly can be,” Mr Tehan told the ABC.
There are now three federal cabinet ministers on sick leave.
Attorney-General Christian Porter and Defence Minister Linda Reynolds have both taken indefinite leave after being caught up in separate rape allegations.
Victorian Premier Daniel Andrews was also admitted to hospital on Tuesday. He spent Tuesday night in intensive care after suffering broken ribs and damaged vertebrae in a fall.
Mr Hunt was joined by former prime minister Julia Gillard and Health secretary Brendan Murphy in Melbourne on Sunday, when the three became some of the first Australians to receive the AstraZeneca jab.
At the time, Mr Hunt said vaccinations safeguarded the community from more than just coronavirus.
“Whether it’s smallpox, measles, mumps, rubella, whooping cough, influenza, and now COVID-19, vaccinations can save lives and protect lives,” he told reporters.
Mr Hunt, who has been health minister since 2017, has been overseeing Australia’s medical response to the coronavirus pandemic.
On Wednesday, Mr Morrison visited the Canberra headquarters of the Therapeutic Goods Administration, where he said more than 100,000 Australians had so far had their first shot of a coronavirus vaccine.
I’m pleased to say a quarter of those vaccines have been administered to the most vulnerable of Australians, in aged care facilities and those with disabilities, and so the vaccination program is under way,” he said.