The deadly Ebola virus has been treated successfully in monkeys using a new technology, researchers say.

U.S. government researchers and a small Canadian biotech company, Tekmira Pharmaceuticals of Vancouver, developed the treatment, which they say is the first to help monkeys exposed to the Zaire strain of Ebola virus. It is the most lethal strain of Ebola and kills up to 90 per cent of the people it infects. 

Ebola viruses, which are native to Africa, can cause serious hemorrhagic fevers that threaten humans and monkeys, and even endangered gorilla populations. There are currently no treatments for Ebola or other hemorrhagic fever viruses.

Thomas Geisbert and colleagues at the Boston University School of Medicine in Massachusetts used small interfering genetic material — called RNA or siRNAs — that can block the action of a gene. The treatment prevents the Ebola virus from replicating while the immune system gears up to fight it.

Tests on four rhesus monkeys infected with high doses of Ebola all survived after receiving injections of siRNAs for seven days, the researchers report in Saturday's issue of the medical journal The Lancet.

"These data show the potential of RNA interference as an effective post-exposure treatment strategy for people infected with Ebola virus, and suggest that this strategy might also be useful for treatment of other emerging viral infections," the study's authors concluded.

The treatment could be used on humans infected with Ebola within five years, Geisbert said.

Further funding and experiments are needed to show how long the treatment lasts. Before getting U.S. Food and Drug Administration approval, researchers need to show it does not harm people and works in at least two animal species, such as guinea pigs and non-human primates.

"The specialty of hemorrhagic viruses is in desperate need of approved countermeasures against Ebola-virus infections," Heinz Feldmann of Rocky Mountain Laboratories in Hamilton, Mont., wrote in a journal commentary.

Feldmann also called for experimental approaches such as Giesbert's to be approved as investigational new therapies that are ready to use in emergencies.