A Russian researcher has died after pricking herself with a needle containing the deadly Ebola virus.
The accident happened earlier this month when Ms Antonina Presnyakova was conducting research on Ebola, a virus for which no vaccine or remedy exists, said a spokeswoman for the Vektor State Research Centre of Virology outside Novosibirsk in central Siberia.
She said efforts to save Ms Presnyakova failed and she died on May 19th at a special hospital located on the territory of the centre.
Research and medical personnel who were in contact with Ms Presnyakova during her treatment will remain under medical observation for three weeks, she said.
The spokeswoman denied a report that the centre was slow to inform the World Health Organisation (WHO) about the incident, reporting it only last week. She said the case was reported immediately to both the Russian Health Ministry and the WHO.
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.
Ebola is spread by contact with body fluids, including sweat 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.