GENEVA — An outbreak of the Ebola virus in the Democratic Republic of Congo poses a high risk to the region, though the danger of the disease spreading worldwide was described as low, international health officials said on Friday.
More than 20 people are believed to have died in the latest outbreak, which the Congo government said on Wednesday had affected North Kivu Province, where conflict between armed groups has displaced more than a million people. North Kivu, in northeastern Congo, has borders with Rwanda and Uganda.
The outbreak is “at the top of the scale” in terms of the difficulty of responding, Dr. Peter Salama, head of the World Health Organization’s emergency response unit, told reporters in Geneva.
Suspected cases are under investigation across an area of more than 150 square miles, Dr. Salama added, citing the challenges of operating over large distances in a conflict zone.
The results of government laboratory tests make it “extremely likely” that the outbreak was the “Zaire” strain of the Ebola virus, Dr. Salama said.
The authorities in Congo declared 10 days ago that an outbreak of the same strain of Ebola in the northwestern province of Équateur had ended. That outbreak caused 33 deaths but was contained with the help of vaccines in storage in the capital, Kinshasa. Those vaccines should also be available to tackle the latest cases.
The Zaire strain is, however, the deadliest form of Ebola, a highly infectious disease that causes hemorrhaging, fever, bloody vomiting and diarrhea. The virus can often spread out of control, as it did during a 2015 outbreak in West Africa.
The Health Ministry in Congo confirmed on Wednesday that four people had contracted the disease in the remote town of Mangina in North Kivu, about 100 miles from the border with Uganda, where the latest outbreak is believed to have started.
The first case to raise alarm was a 65-year-old woman who had been hospitalized with fever and later discharged, but who then died in late July, Dr. Salama said. She was buried in a manner that health officials said was unsafe, and seven members of her immediate family have also died.
Dr. Salama said suspected cases had been identified in the city of Beni, in North Kivu, and in neighboring Ituri Province, to the north. He said the authorities were trying to track down contacts in 10 locations across an area of about 150 square miles.
One nurse has also died, and two others are believed to be infected, Dr. Salama said.
For health officials, the lack of security in the region adds a daunting hazard to the already formidable challenges of operating in remote locations spread across huge distances and in dense forest with poor roads and communications.