Fears worsened on Wednesday that the year-old Ebola outbreak in the Democratic Republic of Congo could spread to neighboring countries, as a boy in Uganda died from the disease and two of his close relatives there were infected.
The boy, 5, from a Congolese family who had crossed into western Uganda on June 9, was the first confirmed case of Ebola outside the Democratic Republic of Congo since the highly infectious illness erupted last summer in the eastern part of the vast African country.
The World Health Organization, which reported the case on Tuesday, said on Wednesday that the child had died and that his 50-year-old grandmother and 3-year-old brother were confirmed to have tested positive for Ebola. The W.H.O. said a hospital in the Uganda border town of Bwera was treating them in isolation and that at least eight people may have been in contact with the first victim, raising the risk of further infections.
“This first death, of a child, is a sickening reminder of the dangers of this disease,” said Brechtje van Lith, the Uganda director for Save the Children, an international charity. The charity said that “governments, donors and agencies must act immediately to prevent further deaths.”
Ebola, a viral disease that causes internal bleeding, is spread through bodily fluids of infected people and is extremely contagious.
Infectious disease experts expressed alarm about Ebola’s spillover into Uganda, even though that country has long anticipated that possibility and administered a promising new vaccine to thousands of health workers, as have health authorities in Congo.
“The confirmation of new Ebola cases in Uganda is tragic but unfortunately not surprising,” Dr. Jeremy Farrar, director of the Wellcome Trust, a London-based health research institution, said in a statement. “This epidemic is in a truly frightening phase and shows no sign of stopping anytime soon.”
The Congo outbreak is the second-deadliest on record, infecting more than 2,071 people and causing at least 1,396 deaths in the country as of June 10, according to the W.H.O. Its epicenter in a conflict zone has complicated efforts to contain the disease.
Health workers, including doctors, have been attacked and killed, and some treatment centers have been destroyed. In April, the Islamic State claimed its first assault in the affected area.
International health experts also have expressed worry about an acceleration in the number of Ebola infections. While it took about eight months to reach 1,000 cases, it has taken only a few months to surpass 2,000.
A committee of outside experts that advises the director general of the W.H.O., Tedros Adhanom Ghebreyesus, has twice concluded that the outbreak does not represent a global health threat, partly because it had not spread across borders.
Declaring the outbreak as such a health threat, known as a Public Health Emergency of International Concern, would increase the level of attention that the W.H.O.’s member countries devote to combat it.
After the committee’s most recent conclusion, in April, its chairman, Robert Steffen, said the experts were “moderately optimistic” the outbreak could be brought under control. “Not immediately,” he said, “but still within a foreseeable time.”
The largest Ebola outbreak in history ravaged the West African nations of Guinea, Liberia and Sierra Leone from 2014 to 2016, killing more than 11,300 people.