New strain of Ebola identified
WASHINGTON (Reuters) - A new strain of Ebola virus has infected 51 people and killed 16 in an area near Uganda's border with Democratic Republic of Congo, U.S. health experts said on Thursday.
Analysis of samples taken from some of the victims show it is a previously unknown type of Ebola, a team at the U.S. Centers for Disease Control and Prevention said.
"This virus didn't behave as would be expected of some of the known strains," Dr. Tom Ksiazek, current chief of the CDC's special pathogens branch, said in a telephone interview.
"That tipped us off that this is probably a novel or new strain of Ebola."
Ugandan health officials have said the virus appears to be unusually mild, but Ksiazek said it is not yet clear if this is the case. He said experts need to check to see how many diagnosed patients are still alive.
Ebola is a hemorrhagic fever, meaning it can cause internal and external bleeding. Victims often die of shock but symptoms can be vague, including fever, muscle pain and nausea.
There are four identified strains, Ksiazek said. The two strains that cause the most human disease are the Zaire and Sudan strains, named after the countries in which they first appeared.
A strain called Reston caused an outbreak in a primate facility in the Washington, D.C. suburb of the same name while a single human case in Ivory Coast was caused by the Cote d'Ivoire strain.
The Zaire strain killed 80 percent of victims, while the Sudan strain had just over a 50 percent mortality rate.
The new strain would be the fifth identified. Ksiazek said it had not yet been named.
The CDC said nine researchers were helping in the response to the Uganda outbreak and another team was waiting for an official invitation from Uganda's government before heading there to help.
(Reporting by Maggie Fox, editing by Will Dunham and John O'Callaghan)