Ebola transmissions over in Liberia, enters 90-day watch

More than 4,800 people have died in Liberia since the outbreak began in West Africa in late 2013. The country celebrated what it thought was the end of Ebola in May, but then six more cases emerged the following month.

That started the clock over — 42 days or two incubation periods of 21 days — before Liberia could return to being free of transmission. On Thursday, officials announced they had made it without any more cases.