Sheik Umar Khan, 39, the head doctor fighting the Ebola virus in Sierra Leone, has contracted the deadly virus. So far, the hemorrhagic fever has killed 206 people in Sierra Leone and more than 600 across West Africa. Khan, who has been called a national hero for his work, has treated more than 100 Ebola victims since the outbreak. He is reported to be alive and receiving treatment at a ward run by Doctors Without Borders. Ebola has no cure or vaccine and kills up to 90 percent of those infected.