(AP)—Authorities say the top doctor treating Ebola in Sierra Leone has died from the disease.
Dr. Shek Umar had been hospitalized in quarantine since he contracted the virus that has killed more than 670 people across West Africa this year.
His death Tuesday was confirmed by chief medical officer Dr. Brima Kargbo.
Health workers have been especially vulnerable to contracting Ebola, which is spread through bodily fluids such as saliva, sweat, blood and urine. Two American health workers are currently being hospitalized with Ebola in neighboring Liberia.
The Ebola outbreak is the largest in history with deaths blamed on the disease in Sierra Leone, Liberia, Guinea and also Nigeria.
The disease has no vaccine and no specific treatment, with a fatality rate of at least 60 percent.
Explore further: 5 things to know about Ebola outbreak in W. Africa