South Africa says non-citizens arriving from Ebola-affected areas of West Africa will not be allowed into the country, with borders closed to people from Guinea, Liberia and Sierra Leone.
All non-essential outgoing travel to the affected countries has been banned.
Senegal also said it was suspending flights with Ebola-affected countries, and closing the border with Guinea.
Cameroon and the Ivory Coast earlier imposed travel bans, despite World Health Organization warnings not to.
South African nationals will be allowed to re-enter the country when returning from high-risk countries, but will undergo strict screening, the health ministry said on Thursday.
Usual screening procedures are in place for those who travel between Nigeria, Kenya and Ethiopia, which have been defined as medium-risk countries.
South Africa has experienced two Ebola scares in recent weeks, involving passengers arriving from Liberia and Guinea, but the country has so far remained Ebola-free.
Johannesburg has one of the major transit airports, connecting southern Africa with the rest of the continent. Several airlines, including British Airways and Emirates Airlines, have stopped flights to some of the affected countries. Read More: http://www.bbc.com/news/world-africa-28879020
Meanwhile Thursday, the United Nations public health expert charged with coordinating global efforts to fight the spread of the virus was headed to Liberia.
David Nabarro has said his visit will focus on plans to revitalize health sectors in Guinea, Liberia, Nigeria and Sierra Leone, the four countries where outbreaks have taken place.
The WHO says just under 2,500 people have been infected by the virus, with more than 1,350 people dying from it.
Elsewhere, Guinea has started deploying civilian and military medical officers to its borders with Sierra Leone and Liberia as part of efforts to contain the spread of the Ebola virus.