Culture of South Africa originated in South Africa. The first human-to-human heart transplant was performed by cardiac surgeon Christiaan Barnard at Groote Schuur Hospital in December 1967. Max Theiler developed a vaccine against Yellow Fever, Allan McLeod Cormack pioneered x-ray Computed tomography, and Aaron Klug developed crystallographic electron microscopy techniques. These advancements were all (with the exception of that of Barnard) recognised with Nobel Prizes. Sydney Brenner won most recently, in 2002, for his pioneering work in molecular biology. Mark Shuttleworth founded an early Internet security company Thawte, that was subsequently bought out by world-leader VeriSign. South Africa has cultivated a burgeoning astronomy community.
Theiler's disease multiple horses over several months. In the Northern hemisphere it is most common between August to November. It is seen almost exclusively in adult horses, and lactating broodmares given tetanus antitoxin post foaling may be more susceptible. This disease was described in 1919 by Arnold Theiler, a South African veterinary surgeon, after vaccinating horses against African horse sickness using a live virus vaccine and equine antiserum. It was later described in the United States after vaccinating horses for Eastern Equine Encephalitis, again using live virus vaccines and equine-derived antiserum. It has since been reported throughout North America and Europe. Theiler's