Why Dr. Kent Brantly Couldn't Donate Blood to Thomas Eric Duncan

— -- Thomas Eric Duncan, the first person in the United States to be diagnosed with Ebola and who later died, didn't receive a blood transfusion from a physician who survived the virus because their blood types didn't match.

Dr. Kent Brantly told ABC News today that his blood type is A+, while Duncan's family has said his blood type was B+, making them incompatible for a transfusion of whole blood or plasma. Blood transfusions from someone who successfully battled the virus are believed to possibly be beneficial to Ebola patients.

Had Duncan received a blood transfusion from Brantly, it would have caused hemolysis - the breakdown of red blood cells - according to Dr. Christopher Stowell, director of Transfusion Medicine at Massachusetts General Hospital.

Brantly was caring for sick Ebola patients with the aid group Samaritan's Purse in Monrovia, Liberia, when he became the first American diagnosed with Ebola in late July. He said he has since given blood plasma to Ashoka Mukpo, Dr. Richard Sacra and Nina Pham.

Brantly said he hasn't been asked to donate blood plasma to Amber Vinson, the second health worker who tested positive for the virus after treating Duncan.

Duncan died last Wednesday at a hospital in Dallas where he was being treated. According to Texas Health Presbyterian Hospital, where Duncan was being treated, Duncan did not receive any kind of blood transfusion because his blood type was not compatible with any of the donors.