While Leah Tutu and her family were anxious about former Archbishop Desmond Tutu's health, they were positive he would pull through. Their daughter, Reverend Canon Mpho Tutu said on Thursday.

Tutu, 83, was admitted to a Cape Town hospital on Tuesday after oral antibiotics failed to treat a persistent infection, she confirmed at a media briefing.

“He is now receiving intravenous antibiotic treatment,” she said, explaining that the course could take three to five days.

Mpho did not confirm the infection, but described it as “below the belt”.

“It was unrelated to the prostate cancer Tutu has been battling for the past decade. This remains dormant, thanks to his medication, she said.

"My father is not quite as young as he looks, so it has to be recognised that his energy is waning a little bit," she said.

She added that he’s not dropping off the scene, as he is slowing down, which is good and appropriate.

Tutu's hospitalisation has made headlines around the world, with social media awash with well wishes for the Nobel Peace Prize laureate.

While the face of the foundation would not be part of its Mandela Day plans, the team of the Desmond and Leah Tutu Legacy Foundation would hand out food in the waiting rooms of Groote Schuur Hospital on Friday, said Mpho, who only two weeks ago officiated at her parent's renewal of their wedding vows as they celebrated 60 years of marriage.