Andrew Oberle (26) was talking to a tour group on Thursday at the Jane Goodall Institute Chimpanzee Eden in the Umhloti Nature Reserve in Mpumalanga, when two chimps pulled him under a security fence. He was bitten and dragged several hundred metres.
The Mediclinic Nelspruit hospital said on Monday that Oberle remained in intensive care.
His uncle, Carl Oberle, said his nephew had been placed in an induced coma "because he lost so much blood and his blood pressure was so low."
On Monday it was reported that the two male chimpanzees would not be euthanised.
Eugene Cussons, managing director of Chimp Eden, said a Mpumalanga tourism and parks board investigation had found that the chimps had reacted much like any threatened wild animal.
Oberle, who is a post-graduate student in anthropology and primatology at the University of Texas, in San Antonio, reportedly climbed through a fence surrounding their enclosure.
The animals became enraged and pulled him under a second fence, which was electrified.
Oberle reportedly lost parts of his fingers and toes, sustained several bone fractures and was bitten all over his body. – Sapa-AP