Sixteen thousand inmates have been tested for the novel coronavirus so far, according to Justice and Correctional Services Minister Ronald Lamola.
"As we speak now, we have screened about 16 000 inmates across the country and the screening is ongoing every day.
"Our intention is that we need to screen as many as possible to prevent and minimise the impact and risk of Covid-19 in cells," Lamola said when he briefed the media on Wednesday.
The minister launched screening at the Johannesburg prison known as Sun City, which houses about 9 000 inmates.
"This is a huge number and we are working on ensuring screening is done but it has to be done on an ad hoc basis because we do not have the capacity to screen them at the same time. However, all officials are screened every time they come in for their shifts and the inmates are screened when they move around," Lamola added.
Sun City has designated isolation and quarantine units to accommodate inmates if they become infected.
In addition, inmates' court appearances are held via a video platform from the prison.
Health Minister Zweli Mkhize said he was satisfied with mass screenings and testing in the country.
"We have started mass testing in all nine provinces, I was in the Western Cape and they have started in Khayelitsha; Bloemfontein as well, Alexandra and KZN and it is starting to gather momentum. The process is picking up speed and I am comfortable with the momentum" he said at the Motsepe Foundation on Tuesday where he received a donation of personal protective equipment.
At the time of publication, South Africa had 1 749 confirmed positive cases and 13 deaths. The 13th person who died was a 60-year-old male from KwaZulu-Natal who had Stage 4 of cancer.