“We wish this would not have blown up,” he said.

African nations, of course, are no less vulnerable than any other country to the virus — and, in fact, in many ways are far more so. As nations around the world compete for limited medical supplies to battle the pandemic, wealthier ones are elbowing aside poorer ones. That leaves much of Africa and Latin America out of luck.

Even in the best of times, the health systems in many African nations struggle with lack of supplies — including ventilators — making them susceptible to being overwhelmed in a large outbreak.

For now, in many parts of Africa, from areas that are international travel hubs to those that are more isolated, the coronavirus has been slow to take hold. But the number of confirmed cases and deaths is climbing, raising fears about the continent’s readiness to deal with a pandemic.

With huge populations of vulnerable citizens, experts say the impact could be devastating. Some nations have sealed borders to commercial flights to try to limit the spread of the virus.

China, Russia, Cuba and even Somalia are sending doctors and supplies to Western nations suffering from the pandemic. Some researchers say that African migrants who risked their lives to sail to European countries in search of a better life are now, with rising infections there, returning home.

“With this coronavirus, everything is upside down,” said Boubacar Boris Diop, a Senegalese author and screenwriter.

In conversations, Americans based in various African countries — to work for governments, aid groups or businesses — gave a variety of reasons for staying put, even if they had the means to leave.