Johhanesburg, May 24 : The National Health Department of South Africa has said that it is on high alert to prevent imported cholera from crossing its borders as the Southern African region is experiencing the outbreak. "Given the ongoing cholera outbreak in the Southern African region, there's a high possibility of continued importation of cases to South Africa," said Aneliswa Cele, an official with the department, on Tuesday. The recent cholera outbreak in Hammanskraal, north of Pretoria, South Africa's administrative capital, has resulted in 15 fatalities and more than 90 people have sought medical help, Cele added. South Africa detected its first two cases of cholera in February from two sisters who had travelled back to Johannesburg together from Malawi, Xinhua news agency reported. Cele expressed concerns over the local cholera transmission and associated deaths, calling for efforts to step up surveillance at the country's borders. /IANS