In addition to the dead, 14 other people are infected with the hemorrhagic fever, WHO said. The U.N. agency said a known form of the virus was responsible for the outbreak.

On Saturday, WHO said it believed a new, milder strain of Ebola could have caused the outbreak. This was wrong, said Dick Thompson, spokesman for the U.N. health agency.

"The reason was that initial lab tests were very confusing," Thompson said.

Meanwhile, a Russian researcher has died after sticking herself with a needle containing the deadly Ebola virus, her organization said Tuesday.

The accident occurred on May 5, when Antonina Presnyakova was conducting research on Ebola, a virus for which no vaccine or remedy exists, said Natalia Skultetskaya, a spokeswoman for the Vektor State Research Center of Virology and Biotechnology outside Novosibirsk in central Siberia.

Skultetskaya said that efforts to save Presnyakova failed and she died on May 19 at a special hospital located on the territory of the center. Research and 카지노사이트 - http://www.lakikataberna.com/ medical personnel who were in contact with Presnyakova during her treatment will remain under medical observation for three weeks, she said in a telephone interview.

Skultetskaya denied a report in The New York Times that the center was slow to inform the World Health Organization - http://www.stockhouse.com/search?searchtext=Health%20Organization about the incident, reporting it only last week. She said the case was reported immediately to both the Russian Health Ministry and the WHO.

"We received all the necessary medical assistance," Skultetskaya said. "On the WHO's advice, we had a conference call involving a doctor who treated Ebola patients in Africa."

The incident was the third case of accidental contraction of a deadly virus at Vektor, which served as a top biological weapons laboratory in Soviet times.

One Vektor researcher accidentally contracted the Marburg virus and died in 1988, while another worker contracted the same virus and survived in 1990, Skultetskaya said.

In a 1996 incident at another Russian biological research center, the Defense Ministry's Virology Center in Sergiyev Posad near Moscow, a worker accidentally contracted the Ebola virus and died, Skultetskaya said.

Ebola is spread by contact with body fluids, including sweat - https://www.rewards-insiders.marriott.com/search.jspa?q=including%20sweat and saliva. Outbreaks of the disease are rare, and no one knows where the virus lives when it is not infecting humans. The disease usually kills its victims so fast that it also destroys the host for the virus.

Skultetskaya said Vektor was conducting research on the Ebola and Marburg viruses to develop vaccines for the lethal diseases.