NEW YORK — Three members of a family in Liberia have contracted Ebola, two months after the country was declared free of the virus, health officials said Friday.
The first documented case in the family was a 10-year-old boy who started showing symptoms last week, said a Liberian health official, speaking on condition of anonymity.
After attending school Monday and Tuesday, the boy was admitted to a hospital and was transported to an Ebola treatment unit Wednesday, the official said.
The boy's test came back positive Thursday, as did subsequent tests for his father and a sibling, the official said, adding that at least seven health care workers may have treated him without the protective equipment essential for Ebola cases.
The World Health Organization declared Liberia free of Ebola on May 9, but a resurgence of the disease the next month made four people sick, two of whom died. The country was declared Ebola-free again on Sept. 3.
In Geneva, Dr. Bruce Aylward, the World Health Organization's special representative for the Ebola response and deputy director general for outbreaks and health emergencies, told officials that the new case had not dimmed hopes that West African countries might still be moving toward eliminating the original outbreak.
The boy's case appears to point to the persistence of the virus among survivors, which can result in occasional resurgence of the disease, Aylward said, adding that flare-ups are expected to be less common and to end in 2016.
Aylward said the boy had no known contacts with a survivor or a history of travel that might have put him at risk. "The investigation is ongoing," Aylward said. "The country has moved extremely quickly."
He said the latest developments were the seventh time the WHO suspected that a flare-up was related to the persistence of the virus in the population of survivors. For example, scientists have shown that the virus remains present for months in the semen of some men who recover from the disease, and could, in rare cases, be transmitted through unprotected sex.
In all cases, however, transmission has been stopped quickly, with a low number of subsequent cases. New tools include an experimental vaccine that can be given to those who come into contact with patients.
Aylward said the new case highlighted the importance of maintaining strong surveillance programs. A slow initial global response to the outbreak has been blamed for the scale and length of the epidemic, which killed more than 11,000 in Guinea, Liberia, and Sierra Leone.
On Sunday, a committee appointed by the WHO's director general called for overhauls at the agency in the wake of the epidemic, including integrating emergency response and outbreak control functions, with oversight by an independent body.
Three other panels, including one convened by Harvard and the London School of Hygiene and Tropical Medicine, and another by the National Academy of Medicine, are expected in the coming weeks to release recommendations on preventing and controlling future pandemics.