The authorities wanted to avoid the panic and mayhem that occurred in Liberia, and I have to say (though I usually find very little to praise in any government in Nigeria) that the speed and efficiency with which the Lagos State authorities reacted was exemplary. It seems as if the virus has been contained in this city of 20 million people. Agence France-Presse reported this week that 320 people suspected of exposure to the virus have been certified clear and released, and that another 41 remained under surveillance.

But the situation here and elsewhere is still uncertain. Despite all the precautions, one of the nurses who had treated Mr. Sawyer managed to escape a poorly guarded isolation ward and travel to the southern city of Enugu. Her name was never released, and it is not known why a professional nurse would suddenly take flight. In any case, the Enugu state government was quick to act. All of the 20 or so people she is known to have come into close contact with during her daylong trip from Lagos were located and placed under surveillance. Though the nurse, who apparently did not know she was infected, has since been reported to have died, there have been no reports — so far — that any of the people she came in contact with have been infected.

People in Port Harcourt, the oil capital in the south, have not been so lucky. Another suspected carrier also escaped from a Lagos isolation ward. Unlike the nurse, he allegedly knew he was infected. The doctor he consulted died of Ebola on Aug. 22, according to the World Health Organization. The doctor’s wife, who was flown to Lagos for treatment with her three-month-old baby, is also said to have died, according to local media reports. The infant’s fate is unknown. The authorities say the man who infected them may be tried on manslaughter charges. W.H.O. officials said this week that there were three confirmed cases of Ebola infection in the city, and that some 200 people remain under surveillance there.

The tendency to panic in the face of a deadly virus with no known cure is of course understandable, especially given the stories that have been coming out of Monrovia and elsewhere in West Africa. Foreigners from suspect countries are regarded warily. Just recently, the Lagos police, acting on a tip from fearful neighbors, raided a hotel and arrested 39 people, 35 of them from the Democratic Republic of Congo. The others were from Senegal, or Sierra Leone, depending upon what newspapers you read.

There have also been the inevitable quack cures, as well as traditional herbal remedies from folk doctors. In one bizarre case, claims that drinking and bathing in salt water would prevent infection flooded the Internet. A surprising number of people apparently believed it. Two are reported to have died from drinking salt water, and another 20 have been hospitalized.