A health worker takes the temperature of U.S. Marines arriving to take part in Operation United Assistance on Oct. 9, 2014 near Monrovia, Liberia.
Photo by John Moore/Getty

US pulls troops from Ebola-affected West Africa

The U.S. military is pulling most of its troops from Ebola-affected Liberia, and more than half of them are already out, the Defense Department said Tuesday night.

The troops started moving in last fall, when Ebola cases were spreading out of control. Now, Liberia is managing just a handful of new cases, although health officials caution the epidemic could reignite at any moment.

“At the height of the epidemic, there were 2,800 DoD [Department of Defense] personnel deployed to West Africa,” the department said in a statement.

“Given the success of the U.S. response to the crisis, the majority of DoD personnel in West Africa will now return home. Today, around 1,500 of them are already back to their duty stations and nearly all will return by April 30.”

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All troops must sit out a 21-day quarantine period to make sure they haven’t somehow been infected with Ebola.

The World Health Organization says more than 22,000 people have been infected and more than 9,000 have died in the epidemic, which spread from Guinea to Sierra Leone and Liberia starting about a year ago.

The U.S. pledged to move troops in to help its traditional ally Liberia, while British troops have been in Sierra Leone and France has helped French-speaking Guinea. WHO, nonprofit groups and other countries have also sent aid and personnel.

“To support the some 10,000 civilian responders that remain on the ground in West Africa, the Department of Defense will leave behind important assets that can help health workers stem potential outbreaks in the future,” the department added.

“In addition, DoD will identify 100 personnel who will maintain a continued presence in the region working to strengthen the disease preparedness and surveillance capacity of the national governments,” it said.

Read more on NBCNews.com.

Africa, Ebola, Liberia and Sierra Leone

US pulls troops from Ebola-affected West Africa