The deadly Ebola virus continues to spread in Zaire, chiefly affecting health care workers in up to four areas of the African country.
Some of the latest cases have occurred among families of health workers who apparently transmitted the Ebola virus, one of the deadliest known, before their symptoms developed or became severe or after they had left hospitals in Kikwit, the focus of the outbreak.
Some patients fled the hospital in panic. Others left because their initial flulike symptoms from the Ebola infection had improved, but they then went on to bleed profusely at home, presumably spreading the virus to family members through the blood.
The epidemic apparently spread initially among the surgeons, anesthetists and nurses who had operated on a patient in Kikwit. Transmission presumably was through contaminated blood.
Patients who were transferred for care in hospitals in three other areas apparently transmitted the disease to health workers there.
Six new suspected cases were identified Wednesday and two on Thursday, said Dr. Giorgio Torrigiani, who heads the World Health Organization’s communicable disease division.
A small number of scientists were examining patients and working in hospitals in Kikwit on Thursday, he said. They were wearing hoods and special lightweight coveralls made from non-woven material that does not allow penetration by viruses and other microbes, and they were carrying battery-powered devices to filter the air to protect them against the Ebola virus.
In their initial efforts to stop the spread of Ebola infection, the scientists brought protective gloves and other equipment to improve sanitary conditions at the two hospitals in Kikwit, an agricultural area about 250 miles east of Kinshasa, the capital.
The details of the Ebola epidemic emerged from the first reports that the international team of scientists on the scene sent back on Thursday and Wednesday to officials of the World Health Organization in Geneva and the Centers for Disease Control and Prevention here. The officials spoke in interviews on Thursday night.
Dr. Brian Mahy, a virologist at CDC, said that his team of scientists had confirmed the presence of the Ebola virus in blood samples from 14 of 16 patients from the Zaire epidemic. Of the two patients whose blood did not show evidence of the virus, one survived. Although the investigation of the case is far from complete, it appears that the individual suffered from some other condition.
The strain of virus obtained in the new outbreak is nearly identical to the one that caused the first known epidemic of the disease, in the Ebola region of Zaire in 1976, Mahy said. Experts had expected greater differences since viral strains from different locales tend to vary.
The toll from the current epidemic is not clear, and the numbers reported by different health and news organizations vary widely.
The World Health Organization, which reported earlier this week that there had been at least 59 deaths in the outbreak, said on Thursday that the deaths totaled 27. An additional 22 patients are in a hospital, many of them terminally ill with the Ebola virus infection. The latest figure was based on the scientists’ initial investigation of the cases, one by one.
The Associated Press, which had reported more than 100 deaths, on Thursday gave 170 as the latest total, based on figures from the medical group Doctors Without Borders.
“We in Geneva are confused about the numbers,” said Dr. Ralph H. Henderson, an assistant directorgeneral of the World Health Organization.
Confusion about case totals often occurs in the initial stages of an epidemiologic investigation, particularly in remote areas in developing countries where communications and health surveillance systems are crude. For instance, Henderson and Mahy said they did not know how each group has defined a case of Ebola infection, a crucial fact in any epidemiologic investigation, and that it would take time to sort things out.
An outbreak of dysentery occurred in Kikwit in the weeks preceding the Ebola epidemic. The officials said some confusion might have resulted from lumping cases and deaths from bacillary dysentery with Ebola.
Whatever the number, the toll is expected to rise because the incubation period is from 3 to 18 days.
But Henderson said that although the total may reach several hundred in Zaire, it was unlikely to be thousands or higher. “This should be a very limited epidemic,” Henderson said.
Mahy said laboratory techniques developed since the discovery of Ebola virus in 1976 had enabled his team to determine a partial genetic blueprint of the strain in only four days. The blood samples from the Kikwit epidemic reached CDC only midday on Monday.
2. How Ebola virus attacks blood
MEMO: Only the first graphic ran in the Spokane edition.