GENEVA -- The Ebola outbreak in West Africa has killed more than 1,200 people since it began in December 2013, the World Health Organization said Tuesday.

More than 2,200 have been sickened, according to the UN health agency's latest numbers.

Authorities have struggled to contain the outbreak, which started in Guinea and has spread to Liberia, Sierra Leone and Nigeria. There are quarantines and travel restrictions for the sick and those in contact with them, sometimes including whole villages and counties, but officials warned that the restrictions have sometimes hampered food deliveries.

The UN World Food Program has said that it is preparing to deliver food to 1 million people over the next three months.

"I think now there is a high vigilance in all countries," Fadela Chaib, a spokeswoman for WHO, told reporters in Geneva. "I can't remember the last time we fed 1 million people in a quarantine situation."