An unknown simian virus recently killed off nearly half the human population of a remote jungle town
Because the disease spread at an alarming rate-victims usually exhibited signs within 8 hours of exposure, and many died within 36 hours-the simian virus, if an outbreak occurs again, is likely to cause more deaths than has any other previous virus
The Zairean strain of the Ebola virus, known as Zaire ebolavirus, has a mortality rate of nearly 75%.