Health authorities in KwaZulu-Natal have placed all hospitals on high alert in areas at risk of cholera.
Public service announcements are being run on state radio, calling on communities to be aware of the disease's symptoms and to purify their drinking water.
A victim, believed to be a Zimbabwean national, has died at Durban's Addington Hospital after contracting the disease.
An Ethiopian national is recovering from the highly contagious disease at a hospital in Mahlabithini.
Nine people have died in South Africa, eight in Limpopo, since the disease swept across the border with the tide of people fleeing Zimbabwe. More than 1000 people have reportedly died from the cholera in Zimbabwe and many thousands are infected. Another 28 cases have been reported in Limpopo.
About 1600 cases have been reported in South Africa since mid-November.
Chris Maxon of Kwazulu-Natal's health department said yesterday that no new cholera cases had been reported in the province since the two foreign nationals took ill, but hospitals have been "ordered to treat all diarrhoea-related cases with urgency".
The province has tested more than 20 people showing symptoms of the disease.
"The tests performed on all the patients thought to have been cholera sufferers have come back negative," Maxon said. "But our hospitals in Zululand, Msinga in the Midlands, Port Shepstone on the South Coast and hospitals on the North Coast are on high alert to step up efforts to prevent the spread of cholera.
"We have a number of confirmed cases of cholera that can be traced to Zimbabwe and others not related to the Zimbabwe strain."
lCholera usually emerges in cycles of seven to 10 years.
KwaZulu-Natal suffered a devastating cholera outbreak in 2000 and 2001. It is a water-borne bacterial disease that causes vomiting and acute diarrhoea and can rapidly lead to death from dehydration if not treated.