Scientists have confirmed that a new strain of Ebola is responsible for killing 16 Ugandans close to the border with the Democratic Republic of Congo, Reuters reports.
The virus, which has infected 51, is described as "unusually mild" by Ugandan health officials. Symptoms of Ebola hemorrhagic fever range from fever, vomiting, and diarrhoea to internal and external bleeding, depending on the strain.
Tom Ksiazek of the US Centres for Disease Control and Prevention, which identified the virus from genetic samples taken from victims, said: "This virus didn't behave as would be expected of some of the known strains. That tipped us off that this is probably a novel or new strain of Ebola."
Dr Sam Okware, head of Uganda's national hemorrhagic fever task force, confirmed: "It's definitely a different strain. There's not much bleeding - most died of fever."
The extent of the Ebola outbreak is unknown. Okware said: "From the beginning we've been isolating cases... but we can't say it's contained. There may be other people in those villages unknown to us."
Uganda's last Ebola epidemic was in 2000, when it claimed just over half of 425 people infected. Earlier this year, an outbreak in the Democratic Republic of Congo infected 264, killing 187.
The new strain brings the total of known Ebola varieties to five. The two responsible for most human infections are the Zaire and Sudan strains - the first to be identified in 1976 - with 80 and 50 per cent mortality rates, respectively. The Cote d'Ivoire strain has so far infected just one person in Ivory Coast, while the Reston strain "caused an outbreak in a primate facility in the Washington, DC suburb of the same name". ®