( CNN ) -- A doctor who has played a key role in fighting the Ebola outbreak in Sierra Leone is infected with the disease , according to that country 's Ministry of Health . Dr. Sheik Humarr Khan is being treated by the French aid group Medecins Sans Frontieres -- also known as Doctors Without Borders -- in Kailahun , Sierra Leone , Tim Shenk , an agency spokesman , told CNN . Until falling ill , Khan had been overseeing Ebola treatment and isolation units at Kenema Government Hospital , about 185 miles east of the capital Freetown . Citing patient confidentiality , Shenk declined to provide additional details about Khan 's condition . The Ministry of Health took to Facebook to deny reports the doctor had died . The ministry `` wishes the general public and all partners working in the healthcare sector to know that . ... Khan is still alive and responding to treatment contrary to social media report of his demise , '' according to a Facebook post . Sanjay Gupta : 'It only took moments ' Sierra Leone has had 427 confirmed cases of Ebola and 144 deaths , according to figures released Wednesday by the health ministry . That puts it , along with Guinea , at the center of an outbreak of the virus that has steadily spread through western Africa since it began earlier this year . More than 1,000 people have contracted Ebola in Sierra Leone , Guinea and Liberia , according to the World Health Organization . Ebola typically kills 90 % of those infected , but the death rate in this outbreak has dropped to roughly 60 % thanks to early treatment . What is Ebola , and why does it kill ? Officials believe that the Ebola outbreak has taken such a strong hold in West Africa due to the proximity of the jungle -- where the virus originated -- to Conakry , which has a population of 2 million . Since symptoms do n't immediately appear , the virus can easily spread as people travel around the region . Once the virus takes hold , many die in an average of 10 days as the blood fails to clot and hemorrhaging occurs . The disease is n't contagious until symptoms appear . Symptoms include fever , headache and fatigue . At that point , the Ebola virus is spread via bodily fluids . Get the fast facts on Ebola . Health workers are at especially high risk , since they are in close contact with infected people and their bodily fluids . Adding to the danger , in the initial stages of infection doctors may mistake an Ebola infection for another , milder illness . Aside from his work on Ebola , Khan also serves as the lead physician of the hospital 's Lassa Fever Program , another fearsome tropical disease . The hospital 's official biography page states Khan took on that job when his predecessor died of Lassa Fever . I survived Ebola , but villagers shunned me .
Dr. Sheik Humarr Khan is being treated in Kailahun , Sierra Leone . The Ebola outbreak has killed more than 11,300 people and infected nearly 11,000 since it began last year. Khan had been overseeing Ebola treatment and isolation units .