The World Health Organization reported four new cases of Ebola in Nigeria Friday, all of them among health care workers and others who had contact with American consultant Patrick Sawyer, a spokesman said.
“They’re all contacts of Patrick Sawyer,” said Gregory Hartl, a spokesman for the WHO in Geneva. He said all are health care workers, cleaners or others at the hospital where Sawyer was taken after he collapsed in the airport following a flight from Liberia to Nigeria. “We know that he had contact with very few people at the airport,” Hartl said.

Sawyer died in Lagos, Nigeria, on July 25. The Liberian-born American citizen collapsed in the Lagos airport after displaying symptoms of Ebola on his flight there. He had been planning to visit the U.S. weeks later to be at the birthday parties for his daughters.

The fact that four people who had contact with Sawyer have Ebola is worrisome because it raises the specter of transmitting the disease beyond Lagos, Hartl said. But the Nigerian ambassador to the U.S. said there have been no Ebola cases outside of the city.

Sawyer is one of three Americans known to be infected with Ebola. The other two — Kent Brantly and Nancy Writebol — were flown back to the U.S. for treatment at Emory University Hospital in Atlanta. And the outbreak has created some concern in the U.S.; earlier this week, Mount Sinai Hospital in New York was testing a patient for Ebola, sparking fears, only for it to turn out that the patient didn’t have it.

The Americans being treated in Atlanta were both given an untested serum for the disease, raising the obvious question of why only these two — rather than anyone in West Africa — were given the treatment. There are issues involving this serum, not the least of which is that there simply isn’t much of it available right now, but the World Health Organization says it will convene a group next week to discuss using experimental treatments to treat the outbreak.

Lenny Bernstein and Caelainn Hogan have the latest updates on the Ebola outbreak at To Your Health.