Ebola Outbreak in Congo Passes 10,000 Confirmed Cases as Experts Question Containment

The number crossed 10,000 this week: confirmed Ebola cases in Congo, with nearly half of those infected now dead. The milestone has sharpened a question among health experts about whether authorities are losing their grip on the outbreak.

The weekly picture is steady but not improving. Congo has been reporting about 400 to 500 new confirmed cases each week, and the figure appears to be holding. Dr. Boghuma Titanji, an infectious disease specialist at Emory University, called it good news that cases are not rising exponentially, at least for now. But she added that they are not coming down either. In her words, the plateau sits at a very, very high set point.

Part of the difficulty is that responders cannot see the whole chain of infection. Fewer than a quarter of new cases come from people already known to have been in contact with an infected person, which means transmission is continuing along routes health authorities have not mapped. Contact tracing is limited, and so is cooperation with affected communities. Health workers sometimes spend more time persuading locals to work with them than providing care. Katie Thomas-Canfield, the International Rescue Committee's Ebola response director, said testing, care and tracing only work if responders go door to door, village by village.

The outbreak has already crossed borders. About 30 confirmed cases have turned up in other countries, and France, Kenya, Nigeria and Uganda have all reported cases tied to Congo. Justin Lessler, a University of North Carolina researcher who studies outbreak dynamics, said the risk of more cases abroad grows if the outbreak is not brought under control. He put the direct risk to the United States at very close to zero, noting that travel restrictions like those imposed by the U.S. make it harder for the virus to leave Africa, and that in many places health officials could quickly isolate a traveler and trace contacts. His larger worry is poor, conflict-stricken places with weak health systems, South Sudan among them. The viruses that cause Ebola disease spread through contact with bodily fluids such as vomit, blood and semen.

On Wednesday, at a virtual summit of African health ministers, Africa CDC Director-General Dr. Jean Kaseya said the continent is not winning the fight and must do more now that the disease has reached multiple African countries. He wrote on X that the ministers agreed to prepare every country, coordinate across borders and keep borders open while watching them closely.

The scale is already historic. Ebola has been recorded in dozens of outbreaks since 1976, and the largest and deadliest, in West Africa from 2014 to 2016, caused 28,000 infections and more than 11,000 deaths. The current outbreak ranks second, and in the time since it was declared it has produced at least three times the cases and deaths of the West African one. Officials declared it in May, but medical evidence suggests infections began months earlier. One reason for the delay is that earlier outbreaks were almost all caused by the Ebola virus, so initial testing targeted it, while the illness was actually caused by the related but different Bundibugyo virus. Armed conflict, gaps in the health system, mistrust, misinformation and global aid cuts have compounded the problem. Conditions vary across Congo, which is why cases can be stable or falling in some places and climbing in others.

Experts disagree on where this goes. Some warn it could become the worst Ebola outbreak in history; others do not expect that. Dr. Wendy Armstrong, president of the Infectious Diseases Society of America, expects things to get worse and said the outbreak is very far from being controlled. Alessandro Vespignani, a Northeastern University disease modeler, said there has not been the weekly decay in cases needed to see the light at the end of the tunnel.

Projections are being redone. In May, when the Africa CDC was reporting 400 confirmed cases, the U.S. CDC published computer-model scenarios in which cases over three months could range from 10,000 to more than 20,000. The agency is updating that work but declined to let The Associated Press interview its scientists about the trend.

Experts expect the outbreak to continue through the end of the year. Titanji is hopeful about 2027, since vaccines are being tested against the Bundibugyo virus and she is optimistic an effective one could be available within 12 months. No vaccine was available early in the West African outbreak. What to watch now is whether weekly cases begin to fall and whether the updated models arrive.