Even as Regional West African governments sharpened their efforts to tackle the virus, it has taken its toll on a number of health care workers. To date several nurses and other health care workers have died and the most prominent doctor fighting the disease in Sierra Leone Sheik Umar Khanwas himself became infected. Also, a top physician from Liberia who was treating patients is listed among the casualties.

Meanwhile, two Americans working in Sierra Leone with the non-profit Samaritan Purse have been diagnosed with the virus. Kent Brantley, a doctor from Fort Worth, Texas, and Nancy Writebol, an aid worker from Charlotte, North Carolina are being treated for the disease.

Ebola, which has no treatment or cure, causes fever, sore threat, vomiting, diarrhea, and internal and external bleeding. It can spread via blood and other bodily fluids, or indirectly via contact with infected bedding, utensils or even air. Mortality rates run in excess of 60 percent although more than 90 percent of those infected could die from the disease.