After a week without new Ebola cases, a study has reported how much worse the epidemic could have been without the supply of treatment beds. At the same time, it reveals the price of response delay, with half of Sierra Leone's cases declared as preventable with swifter action.
The Ebola epidemic of 2013-15 was by far the worst in history, with 11,300 deaths far exceeding all previous cases combined. As a result, the world was desperately underprepared for a crisis of this scale. Nevertheless, a paper in the Proceedings of the National Academy of Sciences concludes that Sierra Leone would have had an additional 56,600 cases were it not for the treatment beds.
The conclusion is based on mathematical modeling comparing transmission rates in the 12 districts of Sierra Leone where Ebola cases emerged. Between them, the governments of the U.K. and Sierra Leone provided 2,700 beds, 1,500 of which went to small, localized Holding and Community Care Centers. By comparing the decline in transmission where these beds were available to areas where they were not, the authors conclude they proved extremely effective.
“As well as the humanitarian value of providing treatment and care to sick patients, there is a secondary benefit to expanding bed capacity that is more difficult to quantify; by isolating the ill and removing them from the community, further infections might be prevented,” the paper argues.
Transmission rates peaked in November 2014, when Sierra Leone was reporting 500 new cases a week. Clearly something worked to reduce this rate to zero, but the authors acknowledge that it is hard to disentangle the benefits provided by the beds from effects like “behavior changes, community engagement, improved case finding, and an increase in safe burials.” However, substantial differences between bed availability in different regions gave the authors enough data that even the lower confidence limit for the cases prevented was 48,000.
The disruption caused by Ebola created numerous secondary effects as vaccination programs and other health systems broke down. Consequently, the deaths averted by the beds program probably far exceed the numbers directly from Ebola itself.
The outbreak began in Guinea in December 2013, providing plenty of time for a response before its peak almost a year later. Co-author Professor John Edmunds of the London School of Hygiene and Tropical Medicine said in a statement, “Our analysis suggests putting treatment beds in place just one month earlier could have further reduced the size of the outbreak and potentially saved thousands of more lives. The way we prepare for, and respond to, future outbreaks of Ebola and other infectious diseases needs to be strengthened."
At the height of the outbreak, politicians and commentators in wealthy countries advocated banning flights from ebola-affected regions. Such a move would have made it virtually impossible to deliver these beds, or any other form of support.