Congo said on Thursday that Ebola had reached three new health zones, bringing the outbreak total to 676 confirmed cases and 136 deaths. The outbreak has also crossed into neighboring Uganda.

“There are still many blind spots in some areas that are high risk,” Olivier le Polain, a WHO epidemiologist based in Beni, eastern Congo, said.

Le Polain said surveillance systems needed to be strengthened in affected regions, adding that a shortage of isolation beds remained a major challenge. Only 250 beds were available across the three affected provinces, he said.

The outbreak involves the rare Bundibugyo strain of Ebola, for which there is currently no approved treatment or vaccine. Health workers said the disease went undetected for weeks, leaving responders struggling to contain its spread.

The WHO has not yet issued projections on the possible scale of the outbreak, Le Polain said.

The warning came after the US Centers for Disease Control and Prevention said the outbreak could potentially reach levels comparable to the 2014-2016 Ebola epidemic in West Africa, which killed more than 11,000 people.

Health officials said efforts to control the current outbreak are being complicated by limited medical resources and challenges in identifying cases early.

The U.S. Department of Health and Human Services (HHS) said on Wednesday that the country’s specialized treatment network remains ready to respond to the ongoing Ebola outbreak in the Democratic Republic of Congo (DRC), where the World Health Organization has reported 344 confirmed cases and 60 deaths.

The issue has gained prominence after the U.S. State Department said American citizens exposed to Ebola but not showing symptoms would be quarantined at a facility under construction at Kenya’s Laikipia Air Base. The department has also pledged to prevent travelers infected with Ebola from entering the United States.

Public health specialists have increasingly urged the U.S. government to bring infected Americans back to the United States for treatment rather than relying on overseas facilities. Opposition to the Kenyan quarantine center has intensified following protests that resulted in at least two deaths, while a Kenyan court has ordered construction work halted.

The United States invested heavily in Ebola preparedness after the 2014 West African outbreak, spending hundreds of millions of dollars to strengthen treatment capacity and establish a national network of specialized facilities capable of handling highly contagious pathogens.

Reuters contacted the 13 hospitals and universities participating in the National Emerging Special Pathogens Training and Education Center network. Nine confirmed they are currently prepared to receive and treat patients exposed to Ebola.

The network includes institutions such as the University of Nebraska Medical Center, Emory University in Atlanta, Bellevue Hospital in New York and Cedars-Sinai Medical Center in Los Angeles. Four institutions, including Emory, did not respond to requests for comment.

“The United States’ investment in preparedness remains a critical component of national health security,” HHS spokesperson Emily Hilliard said, adding that participating hospitals are equipped to evaluate, isolate and treat patients with high-consequence infectious diseases while supporting broader outbreak response efforts.

Under federal requirements, designated treatment centers must be capable of caring for at least two patients exposed to contagious viral hemorrhagic fevers such as Ebola. Facilities are required to conduct quarterly training exercises, maintain laboratory testing capabilities and stock protective equipment.

The U.S. Centers for Disease Control and Prevention has dozens of personnel deployed in the DRC and has said members of the U.S. Public Health Service Corps could be sent to support operations at the proposed Kenyan facility. American healthcare workers and aid personnel also continue to serve in the region through international relief organizations.

Several healthcare officials, including former CDC leaders, argued in an open letter this week that medical evacuation to established U.S. treatment centers would pose fewer risks than housing exposed Americans at a newly constructed overseas quarantine site.

A former CDC official familiar with the response effort said concerns surrounding the Kenya plan could complicate efforts to recruit American personnel for outbreak response missions.

The official said some prospective volunteers fear they could be left overseas if exposed to the virus, potentially undermining confidence in government support for public health workers deployed to epidemic zones.