The Ebola outbreak in the Democratic Republic of the Congo and Uganda could lead to more than 20,000 cases and over 2,000 deaths in a worst-case scenario, according to a report published Friday by the Centers for Disease Control and Prevention.
Subscribe to read this story ad-free
Get unlimited access to ad-free articles and exclusive content.
That scenario — modeled using data through May 24, when about 50 deaths had been reported — assumes that only 20% of Ebola patients isolate and that access to vaccines and treatments is limited, the agency said. The outbreak is caused by a rare type of Ebola called Bundibugyo that currently has no available vaccines or treatments.
Even in a more optimistic scenario, with around 70% of cases isolating, the report found that there remains about a 1 in 5 chance that the outbreak could surpass 10,000 cases within three months.
Dr. Krutika Kuppalli, an infectious diseases physician at UT Southwestern Medical Center in Texas and a former World Health Organization medical officer, called the projections “concerning.”
“Under certain scenarios, the current Bundibugyo Ebola outbreak could grow into one of the largest Ebola outbreaks ever recorded,” she wrote in an email.
Still, “one of the most important takeaways from this CDC analysis is that the future of this outbreak is still very much within our control,” Kuppalli said.
“The findings should serve as a call to action for the international community,” she said.
There have been 397 confirmed cases and 65 deaths in the outbreak, according to the World Health Organization.
On a call with reporters Friday, Jason Asher, the director of the CDC’s Center for Forecasting and Outbreak Analytics, stressed that this modeling “is not a forecast; it is a planning tool.” The models are limited by questions that remain about the Bundibugyo strain, how many people are in isolation and how widely the outbreak could spread in the months ahead.
“Our models today are built on current data and our understanding of current conditions,” Asher said. “They’re designed to support action, not to generate alarm.”
Lawrence Gostin, the director of the World Health Organization Collaborating Center for National and Global Health Law, said he welcomed the CDC’s risk assessment.
“The CDC has been missing in action in the current Ebola response,” Gostin said in an interview.
He said that the CDC’s projections during the 2014-2016 West Africa Ebola outbreak helped galvanize the response. “This report is a step in the right direction,” he said.
That outbreak was the largest on record, with more than 28,000 cases and more than 11,000 deaths.
It remains unclear how many Ebola cases are going undetected in Congo and Uganda. The initial response to the outbreak was hampered in part because standard Ebola tests did not pick up the Bundibugyo strain. Further complicating matters, the epicenter of the outbreak, Ituri province, is a conflict zone.
Dr. Satish Pillai, who is leading the CDC’s Ebola response, said on the Friday call that while the Ebola response remains “fluid,” the percentage of cases being detected and isolated appears to be on the lower end.
“This is a dynamic situation,” said Pillai, who added that Friday’s report is meant to highlight the need to marshal resources to contain the outbreak.
A separate CDC report, also published Friday, found that the risk to the general U.S. population remains low.
“We released this dedicated assessment, not because the risk is high, but because we know that there is concern about the outbreak,” Pillai said.
To date, no Ebola cases linked to the outbreak have been reported in the U.S. Dr. Peter Stafford, an American surgeon who contracted Ebola while working in Congo, was evacuated to Germany for treatment. His wife and four children, who were exposed to the virus, were also flown to Germany, while another doctor, Patrick LaRochelle, was taken to the Czech Republic for monitoring.