Details on the outbreak

Ebola disease, which was first discovered in the DRC in 1976, is caused by a group of viruses called orthoebolaviruses, which are primarily found in sub-Saharan Africa. The disease is rare but often severe, as around half of cases are fatal.

The disease spreads through contact with the bodily fluids of an infected person or corpse, which can occur through surfaces that have been contaminated with blood, feces, or vomit, according to CDC.

Symptoms of Ebola start with fever, aches, pains, and fatigue but eventually develop into diarrhea, vomiting, and unexplained bleeding. Symptoms can start within two to 21 days after contact.

The most recent outbreak was confirmed by African health officials on Friday. A species of orthoebolavirus called Bundibugyo is behind the outbreak, which health officials have less experience dealing with as there have only been two documented Bundibugyo outbreaks in the past and there are no licensed vaccines or therapeutics for this species of virus.

As of Saturday, there have been eight confirmed cases, 246 suspected cases, and 80 suspected deaths in the Ituri province of the DRC, which borders South Sudan and Uganda. This site was the location of the second largest Ebola outbreak in history, which occurred between 2018 and 2020 and led to 3,470 cases and 2,287 deaths.

Two cases have been reported in Kampala, the capital of Uganda, and involved people who had been in the DRC. It's believed the two patients did not have any links to each other, which suggests at least two introductions of the virus into Uganda. WHO said on Sunday there is currently no indication of any ongoing transmission in Uganda.

Some Americans are among those potentially exposed to Ebola in the DRC, and at least one individual with symptoms may need to be evacuated, according to two people familiar with the Trump administration's Ebola response who spoke to the Washington Post.

The Americans involved, including a family with children, have been working with a nonprofit in the outbreak area, the people told the Post. One individual noted multiple planning scenarios are being discussed for the medical evacuation of the symptomatic individual.

CDC said on Sunday that it's supporting partners "actively coordinating the safe withdrawal of a small number of Americans who are directly affected" by the outbreak.

Satish Pillai, CDC's Ebola response incident manager, said the agency is also mobilizing to send personnel and is "identifying deployers" to travel early this week. "We're actively moving to get people into the field," Pillai said.

In a statement, the International Panel for Pandemic Preparedness and Response said Tedros' quick actions were prudent.

"His decision to proceed ahead of convening a formal Emergency Committee reflects the gravity of the situation and the need for immediate global mobilization," they said.

Infectious disease experts noted this most recent outbreak could be difficult to contain given it's caused by the Bundibugyo virus.

"It is unfolding in exactly the kind of environment where containment becomes extraordinarily difficult," said Anne Rimoin, an epidemiologist and director of the Center for Global Health Security at the University of California, Los Angeles's Jonathan and Karin Fielding School of Public Health.

"This is a highly mobile region. People move constantly for work, trade, family, mining, transport, medical care, and survival," she said, adding that cases connected to cities like Kampala and other major population centers immediately raise the complexity of the response as they're connected to urban networks with roads, buses, clinics, markets, border crossings, and international flights.

"Ebola containment depends on speed and precision," Rimoin said. "You have to identify cases quickly, isolate patients safely, trace contacts rapidly, and interrupt transmission chains before they expand. All of that becomes much harder in places dealing with fragile health infrastructure, conflict, displacement, mistrust, overcrowding, and limited laboratory capacity."