South African officials say they're ready for the possible spread of coronavirus to African shores.  

The pneumonia-like virus, which has sickened more than 4,500 people in China since it was identified in the city of Wuhan on Dec. 31, has African governments on alert.

Professor Cheryl Cohen of South Africa's National Institute for Communicable Diseases says the nation is taking precautions at the continent's busiest airport, in Johannesburg.

"We have noted the four cases of novel coronavirus that have recently been confirmed in Australia," she said. "These were anticipated due to the proximity of Australia to Asia. We would like to assure South Africans that South Africa is prepared for any eventuality of an outbreak. We have put in place systems to rapidly identify, detect and respond to any imported cases that may reach our borders."

Some 21 million travelers came through Johannesburg's O.R. Tambo International Airport in 2018. It is the only airport in South Africa with direct flights to and from China.

The airport has previously implemented temperature testing and health screening during previous outbreaks of Ebola, Zika and other viruses.

While no cases of the virus have been reported in Africa, China is South Africa's biggest trading partner, and the Johannesburg Stock Exchange slumped as news of the outbreak spread. That is normal, says economist Lara Hodes of Investec Bank, pointing to one study showing that the 2002 SARS epidemic cost global markets as much as $40 billion.

"So it's definitely had an effect, a mild effect," she said. "The JSE has been down. It will generally affect financial markets and, in turn, impact commodity prices and the exchange rate. But it's very early days and there's a lot of hype around it because of ... SARS a few years ago, they're worried about the extent it will spread."

Hodes called the situation a "wait and see," both in terms of the economy and the virus.