By Andrew Ward for Financial Times.

Bill Gates says there could be one benefit from the Ebola epidemic that has killed more than 11,000 people in west Africa since 2014. “It may serve as a wake-up call,” says the Microsoft founder. “We must prepare for future epidemics of diseases that may spread more effectively than Ebola.”

His charitable foundation, the Bill & Melinda Gates Foundation, has been at the heart of the global fight against slower-burning health scourges such as HIV and malaria. However, few things worry him as much as the risk of a sudden global infectious disease outbreak.

A clear plan should be in place before an epidemic erupts — and exercises carried out to test it for flaws.

“There is a significant chance that an epidemic of a substantially more infectious disease [than Ebola] will occur sometime in the next 20 years,” he wrote in a paper in the New England Journal of Medicine earlier this year. “Of all the things that could kill more than 10m people around the world, the most likely is an epidemic stemming from either natural causes or bioterrorism.”