JOHANNESBURG - Government believes its screening process at ports of entry is up to scratch.
Two people with Hantavirus entered OR Tambo International Airport.
One of them died while the other is being treated at a Sandton hospital.
The victims were allegedly affected on board a cruise ship.
Authorities are tracing people the travellers may have come into contact with.
One of the patients, a British national, is in critical condition in intensive care in Johannesburg. Attempts to treat him on Ascension Island were unsuccessful, prompting a medical evacuation to a private health facility in Sandton for further care.
READ | 'Low' risk to public of hantavirus after cruise ship deaths, WHO says
The second case involves a 69-year-old woman who reportedly collapsed at the airport while trying to catch a connecting flight to her home country, the Netherlands.
Her spouse, a 70-year-old man, is believed to have fallen ill during the voyage from Ushuaia to St Helena Island. He presented with symptoms including fever, headache, abdominal pain and diarrhoea, and died upon arrival at St Helena. His remains are awaiting repatriation to the Netherlands.
The group had been travelling on a cruise ship from Argentina to Cape Verde.
Health Minister Aaron Motsoaledi says contact tracing is underway, but not yet complete.
“I can't really say we have got in contact with all of them. We have just started today. We are being helped by the NICD, because they have a very good mechanism for tracing people," he said.
“And because this was a multinational trip, and the people were there from many nations, the World Health Organization has entered the fray. They are helping us in the tracing process."
Ship carrying 150 people, virus spreading by rodents
The ship was carrying about 150 passengers and travelled past several locations, including mainland Antarctica, the Falklands, South Georgia, Nightingale Island, Tristan da Cunha, St Helena and Ascension.
According to the Centers for Disease Control and Prevention, hantaviruses are a group of viruses that can cause severe illness and even death. They are primarily spread by rodents, with symptoms typically appearing one to eight weeks after exposure.
Common symptoms include fatigue, fever, headaches and dizziness.
READ | Three dead after suspected hantavirus outbreak on cruise ship
As authorities continue contact tracing efforts, Motsoaledi has urged the public to remain calm.
He emphasised that transmission generally requires close contact.
“We must emphasise that. The two people must be in close proximity to each other before one can infect the other. That is why we are tracing people who could have come into close proximity with these people who were infected and those who passed.
"And ordinarily, you and I, who have never been nearer there, we need to sit and relax,” said Motsoaledi.