The head of the World Health Organisation said Wednesday that while Africa so far had seen few cases of COVID-19, the continent should "prepare for the worst".

"Africa should wake up," Tedros Adhanom Ghebreyesus told journalists in a virtual news conference.

Tedros said that to date, 233 cases of the new coronavirus had been registered in sub-Saharan Africa and four people had died, making it the least-affected region in a global pandemic that has infected more than 200,000 people and killed more than 8,000.

But he warned that the official numbers likely did not reflect the full picture.

"Probably we have undetected cases or unreported cases," he said.

And even if there truly were no more than 233 cases of the disease in Africa, he warned that that number could scale up quickly.

"In other countries, we have seen how the virus actually accelerates after a certain tipping point, so the best advice for Africa is to prepare for the worst and prepare today," he said.

"WHO's recommendation is actually that mass gatherings should be avoided," he said, urging Africa to "cut it from the bud, expecting that the worst can happen."

"My continent should wake up," said the former Ethiopian government minister. (AFP)