Marie Bakikula, a caregiver at a UNICEF-supported nursery in Mongbwalu in the Democratic Republic of Congo, works at an emergency nursery for Ebola orphans. Marie Ruwet/AFP/via Getty Images hide caption

Marie Ruwet/AFP/via Getty Images

The fastest spreading Ebola outbreak in history has surpassed another grim milestone. More than 10,000 people have been infected since the outbreak was first declared in May, according to the latest government figures from the Democratic Republic of Congo.

"It's a milestone that we're all surprised to be passing this quickly," says Katie Thomas-Canfield, interim Ebola response director for the International Rescue Committee. "10,000 people affected by Ebola in such a short period is really staggering," she says, noting that at this point in the West Africa outbreak of 2014-2016, only about 4,000 people had been infected.…