A Marburg fever outbreak in Equatorial Guinea that is thought to have begun back in January has been officially confirmed. The World Health Organization has convened in an “urgent meeting” to discuss the situation.

Experts claim that every day counts and warned others virtually on Tuesday to try to chart a course for what they want to. Marburg virus was responsible for the growing cluster of people sick with hemorrhagic-fever-like illness and was only confirmed on Monday, according to a report by STAT News. To date, nine people have died; all were epidemiologically linked. Another 16 people with some symptoms are in quarantine.

Marburg virus disease (MVD) is a rare but severe hemorrhagic fever which affects both people and non-human primates. MVD is caused by the Marburg virus, a genetically unique zoonotic (or, animal-borne) RNA virus of the filovirus family. The six species of Ebola virus are the only other known members of the filovirus family. –Centers for Disease Control and Prevention

Marburg outbreaks are rare. This is the first one Equatorial Guinea has recorded. While there have been four in the past decade in Ghana, Guinea, and Uganda (which had two), the last Marburg outbreak with cases that numbered in the double digits was in 2012. And even that one only recorded 15 cases.

“I cannot emphasize enough the requirement for speed for doing any trials,” John Edmunds, an epidemiologist from the London School of Hygiene and Tropical Medicine, said during the meeting, which was organized by the World Health Organization.

Nancy Sullivan, director of Boston University’s National Emerging Infectious Diseases Laboratories feels that this could become an even bigger outbreak because of travel in and out of Equatorial Guinea.

“The difficulty with predicting where the outbreak will go is that there is more movement in and out of Equatorial Guinea than we have in some of the more remote locations,” said Sullivan, who led the team that designed one of the Marburg vaccines that could be tested if authorities in Equatorial Guinea agree to conduct a clinical trial. “And while the [ministry of health] has done a great job tracking cases, I think we would be foolish to assume that no cases have gone undetected.”

According to a separate report by Reuters, Cameroonian authorities detected two suspected cases of Marburg disease on Monday in Olamze, a commune on the border with Equatorial Guinea, the public health delegate for the region, Robert Mathurin Bidjang, said on Tuesday.

“On the 13th of February, we had two suspected cases. These are two 16-year-old children, a boy and a girl, who have no previous travel history to the affected areas in Equatorial Guinea,” Bidjang said at a meeting in Cameroon’s capital Yaounde.

The case-fatality rate for MVD (Marburg Virus Disease) is between 23-90%.