Of the six new cases confirmed by Mkhize on Wednesday, five are in Gauteng, one in KwaZulu-Natal and one in the Western Cape.
The number previously stood at seven, with the infected coming from a group of 10 people who had recently travelled to Italy.
In Gauteng, the new cases are of a 33-year-old female who was part of the Italy group, a 34-year-old and a 33-year-old couple who recently travelled to Germany and the 57-year-old male who is now in critical condition.
In KwaZulu-Natal, a 40-year-old male who returned from Portugal on Saturday has tested positive while in the Western Cape it is a 36-year-old male who travelled to several countries including Germany, Austria, Switzerland and Turkey.
“All the patients have now been advised. Those who are symptomatic have started receiving treatment. Some of these patients are already in hospital while some, specifically those who are asymptomatic, are in self-quarantine. Contact tracing has also started for all these cases,” Mkhize said.
Mkhize said that so far a total of 645 South Africans have been tested for the coronavirus.