Danie Gerber's wife Elsabe has now also tested positive for the coronavirus.
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The former Springbok centre's daughter, Elanie, confirmed the news to Netwerk24 on Tuesday.
Sport24 earlier reported that Gerber, 61, and his daughter, 36, had tested positive for Covid-19 and were self-isolating at their home in Bluewater Bay, Port Elizabeth.
Elsabe, 59, moved into a friend's house nearby and initially tested negative for the disease. But she started developing symptoms and a second test confirmed a positive result.
"We think she got the virus at the same time as us, but it just took longer for her to show symptoms. She is asthmatic and coughs a lot. She is [also] struggling with a fever," Elanie told the Afrikaans publication.
Elsabe has since moved back in with her husband and daughter. Elanie said her father was doing well, but that he was worried about his wife.
Elanie said her symptoms are worse in the second week - she has a blocked nose and suffers from headaches and nausea.
"My mother has many of the same symptoms as me."
In an interview with Maroela Media last week, Elanie said she and her father also steamed themselves regularly.
"We saw a video of a doctor in America who had the virus and he said steaming works well to counteract it. We also take medication to boost our immune system while drinking plenty of tea.
"I think dad is drinking stuff nowadays that he has never drunk before," she chuckled, before warning people to adhere to the lockdown laws.
"Stay home. At the same time, we also want to tell people not to live in fear."
It was reported late last month that Gerber had played golf with former 1981 Springbok team-mates in Jan Kempdorp just days before testing positive for Covid-19.
Three of his team-mates have since also tested positive, Sport24 reported.
Due to South Africa's sporting isolation during apartheid, Gerber's international career was limited to 24 Tests for the Springboks between 1980 and 1992.
However, he made enough of an impact for many pundits to regard him as one of the most gifted centres ever to play international rugby.
He was a powerful runner with ball in hand and had a side-step and swerve not often seen in the modern game. It helped him to an impressive 19 tries in 24 Tests for his country.
At domestic level, Gerber played 115 games for Eastern Province, but also had stints with Western Province (40) and Free State (24).
South Africa is currently in a 21-day lockdown due to the Covid-19 pandemic.
- Compiled by Herman Mostert