• The WHO on Friday confirmed a third case of Ebola in the Democratic Republic of the Congo.
• The number of people who might have been exposed to the virus has risen from over 70 on Monday to 182 as of Friday, a WHO official said.
• The WHO is "still unclear around the original community source" of the first Ebola case, they said, but hope to understand whether the new cases are associated with the last Butembo outbreak.

The World Health Organization on Friday confirmed a third case of Ebola in the Democratic Republic of the Congo as health officials race to vaccinate residents and contain the potential outbreak.

Earlier this week, the global health agency confirmed that a woman died of the disease in Butembo, a city in North Kivu Province and an epicenter of a previous Ebola outbreak that was declared over in June. The WHO has since confirmed two more cases, including another person who has died, Dr. Mike Ryan, executive director of the WHO's health emergencies program, said Friday.

The number of people who might have been exposed to the virus has risen from over 70 on Monday to 182 as of Friday, Ryan said. He added that all but three of those people have been contacted and more than half of them were previously vaccinated against Ebola during prior outbreaks.

"We're seeing some benefits of the previous vaccination, but obviously we have to look at the length of time that vaccine protects," he said.

He added that new shipments of vaccine arrived in Butembo this week. Ultracold-chain storage equipment is being set up in Butembo and personnel are being trained, Ryan said.

The DRC also has other therapeutics, including Ebola monoclonal anitbody treatments, in the capital, Kinshasa, and another city, Mbandaka, Ryan said, adding that they will be airlifted into North Kivu over the weekend. The DRC has enough vaccine for 16,000 people in the country, Ryan said, but it's not clear how much has arrived in Butembo.

The WHO is "still unclear around the original community source" of the first Ebola case, Ryan said, adding that the DRC's National Institute of Biomedical Research is sequencing samples of the virus at its main lab in Kinshasa to determine whether the new cases are associated with the last Butembo outbreak. Ryan said results are expected over the weekend.

The Ebola outbreak that was declared over in June lasted for nearly two years. It was the second-largest in the world and by the time it ended there were 3,481 total cases and 2,299 deaths, according to the WHO.

The WHO noted that outbreak response efforts in North Kivu Province have been especially difficult because of ongoing violent conflicts in the area, which is occupied by over 100 different armed groups, according to Human Rights Watch.

Ryan said the WHO is working with nongovernmental organizations, the DRC government, and other United Nations agencies, such as UNICEF, to respond to the new Ebola cases.

Unlike the highly infectious coronavirus, which can be spread by people who don't have symptoms, Ebola is thought to mainly spread through people who are already visibly sick. The virus spreads through direct contact with the blood or body fluids of people who are sick or who died of the disease, according to the U.S. Centers for Disease Control and Prevention.

Ebola has an average case fatality rate of 50%, though it can vary by outbreak, according to the WHO.

"Obviously, two cases and now a third may not seem like many, many cases in the light of what we see globally with Covid, but we've been on the alert waiting for the return of Ebola in eastern Congo, and we'll do everything in our power to support the government in the response," Ryan said.