Authorities in West Africa have confirmed the region’s first known case of Marburg virus after at least one person in Guinea died of the hemorrhagic fever disease, the World Health Organization said Monday.

Health officials said they were trying to track down everyone who might have come into contact with the patient, who had sought medical treatment in Gueckedou.

The case was reported in the same part of Guinea where the 2014-2016 Ebola epidemic started and ultimately killed at least 11,325 people. A much smaller outbreak of Ebola earlier this year also hit the same area near Guinea’s borders with Sierra Leone and Liberia, leaving 12 dead.

The Marburg virus belongs to the same family as Ebola, and previously outbreaks have erupted elsewhere across Africa in Angola, Congo, Kenya, South Africa and Uganda.

The new West African case was confirmed by a laboratory in Guinea and again by the Institut Pasteur in nearby Senegal, according to WHO.

“The potential for the Marburg virus to spread far and wide means we need to stop it in its tracks,” said Dr. Matshidiso Moeti, WHO’s regional director for Africa. “We are working with the health authorities to implement a swift response that builds on Guinea’s past experience and expertise in managing Ebola, which is transmitted in a similar way.”

Marburg outbreaks start when an infected animal, such as a monkey or a fruit bat, passes the virus to a human. The virus then spreads from human to human by contact with an infected person’s body fluids.

Marburg symptoms include high fever and muscle pains, and some patients later bleed through body openings such as the eyes and ears. There is no approved drug or vaccine for Marburg, but rehydration and other supportive care can improve a patient’s chances of survival.

Case fatality rates have been as high as 88% in previous outbreaks, but WHO said the figure has varied based on the strain and how cases were managed.

Source: Voice of America