LAGOS, Nigeria – The coronavirus has spread to sub-Saharan Africa for the first time as stock market losses around the world deepened amid investor alarm over a potential global pandemic.

Nigeria’s health minister, Osagie Ehanire, said the first case in the region was an Italian citizen who worked in Nigeria and had returned from Italy to Lagos on 25 February.

“The patient is clinically stable, with no serious symptoms, and is being managed at the Infectious Disease Hospital in Yaba, Lagos,” Ehanire said on Friday.

The case is just the third on the African continent, something that has puzzled health specialists given the continent’s close ties China. The WHO said Africa’s “fragile health systems” also meant the threat posed by the virus “is considerable”.

Egypt had the first case of Covid-19 in Africa, announced on February 14. Algeria declared it had a case on Tuesday, an Italian adult who arrived in the country on 17 February. That prompted the WHO’s regional director for Africa, Dr Matshidiso Moeti, to warn that the “window of opportunity the continent has had to prepare for coronavirus disease is closing.”

His warning was reiterated by WHO chief Tedros Adhanom Ghebreyesus on Thursday, who said the epidemic was at a “decisive point globally” and that it could “get out of control” if affected countries did not move swiftly to contain it.

The outbreak, which began in December, has already killed more than 2,800 people and infected more than 78,000 in China.

Ghebreyesus said the spread of the virus to countries with weaker health systems was “our biggest concern”.

“These patients require intensive care using equipment such as respiratory support machines that are, as you know, in short supply in many African countries and that’s a cause for concern,” he said.

Several African carriers including Kenya Airways have suspended flights to China, although the continent’s biggest airline Ethiopian Airlines has kept its China routes open.

The spread of the virus prompted investors to take decisive action on Friday, when global markets plummeted again. The Dow Jones suffered its biggest one day fall on Thursday, plunging 1,190 points, or 4.4%, with analysts warning the virus could cause as much damage as the 2008/09 global financial crisis. Shares followed suit in the Asian trading session on Friday while Brent crude was poised to dip below $50 a barrel for the first time in four years.

“The coronavirus now looks like a pandemic. Markets can cope even if there is big risk as long as we can see the end of the tunnel,” said Norihiro Fujito, chief investment strategist at Mitsubishi UFJ Morgan Stanley Securities. “But at the moment, no one can tell how long this will last and how severe it will get.”