Staggering Ebola Predictions

The WHO says more than 20,000 people could be infected by November, while the CDC estimates the epidemic will strike some 500,000 people by the end of January.

Sep 23, 2014
Tracy Vence

WIKIMEDIA, PLOS BIOLOGYMore than 20,000 people are likely to have been infected with Ebola by November 2, the World Health Organization (WHO) Ebola Response Team predicted in the New England Journal of Medicine today (September 23). Extrapolating data from the beginning of the outbreak and accounting for the increased pace of infections, the team noted that “transmission has to be a little more than halved to achieve control of the epidemic and eventually to eliminate the virus from the human population.”

Meanwhile, at the current rate of transmission and without any further aid, scientists from the US Centers for Disease Control and Prevention (CDC) estimate that “the Ebola epidemic sweeping West Africa could infect up to 500,000 people by the end of January,” The Washington Post reported (via Bloomberg News). The Post also noted that the CDC prediction, which is still under development and set to be released next week, is subject to change. “One of the scary things about this outbreak is that all the general models of the past have been broken,” microbiologist John Connor of Boston University School of Medicine told the newspaper.

Update (September 23): In a Morbidity and Mortality Weekly Report article issued after this post was published, the CDC presented a worst-case scenario prediction that—assuming transmission “trends continue without additional interventions,”and correcting for under-reporting—as many as 1.4 million people could be infected with Ebola by January 20, 2015. “It is still possible to reverse the epidemic,” CDC Director Thomas Frieden said in a statment. “Once a sufficient number of Ebola patients are isolated, cases will decline very rapidly—almost as rapidly as they rose.”