A health worker, wearing Personal Protective Equipment (PPE), and a woman pose on September 7, 2014 inside the high-risk area at Elwa hospital in Monrovia, which is run by the non-governmental  international organization Medecins Sans Frontieres (Doctors without Borders -- MSF). US President Barack Obama said in an interview aired on September 7 the US military would help in the fight against fast-spreading Ebola in Africa, but warned it would be months before the epidemic slowed. The tropical virus, transmitted through contact with infected bodily fluids, has killed 2,100 people in four countries since the start of the year -- more than half of them in Liberia.   AFP PHOTO / DOMINIQUE FAGET        (Photo credit should read DOMINIQUE FAGET/AFP/Getty Images)
WHO declares West Africa Ebola-free
01:45 - Source: CNN

Story highlights

The patient got sick at a town in Sierra Leone

Health officials are tracing anyone who may have had contact with the deceased

CNN  — 

Sierra Leone has reported a death from the Ebola virus – a major setback hours after global experts said the outbreak was over in West Africa.

The patient got sick at a town bordering Guinea, said Sidi Tunis, a spokesman at an Ebola response center in Sierra Leone.

Health officials are tracing anyone who may have had contact with the deceased.

The new case was confirmed Friday, hours after the World Health Organization gave the region an all-clear.

It made the proclamation after Liberia, Sierra Leone and Guinea halted the chain of transmission simultaneously for the first time

The clearance was notable because it meant the three nations hardest hit by the Ebola outbreak had reported zero cases for at least 42 days.

Caution urged

Despite the clearance, health experts urged caution and vigilance, saying there may be some flare-ups.

And like Liberia, the virus has also resurfaced in Sierra Leone.

Liberia was first declared free of Ebola transmission in May, but the virus returned twice after that, with the latest case in November.

Before this week, Sierra Leone was declared free of Ebola transmission in November while Guinea got its clearance last month.

Forty-two days is twice the incubation period of the virus, a WHO requirement for a nation to be declared free of transmission.

Thousands killed

The Ebola epidemic killed about 11,300 people and infected 28,600 others, mostly in the three nations. It has devastated families, communities and economic systems since it emerged in late 2013 .

Evidence shows the virus can remain in the semen of male survivors for as long as a year. In rare instances, it can be transmitted to sexual partners.

Journalist Umaru Fofana contributed to this report