The Ebola outbreak is still spreading far beyond the region where it began.

More than 3,500 new cases have been reported across West Africa, according to the World Health Organization (WHO), which says the toll could be as high as 10,000 cases by the end of the week.

It is the worst-ever outbreak in West Africa.

In West Africa itself, the WHO reported that there are now nearly 300,000 suspected cases, which include about half a million confirmed cases and about 1.3 million probable cases.

The WHO said this number is likely to be higher, and it warned of “unprecedented” growth in the next 24 hours, though the exact number is unclear.

The outbreak has also prompted the U.S. to call for an end to the “immediate quarantine” imposed by the WHO and other international organizations, saying the measures were preventing “a substantial reduction” in the number of cases.