Babesiosis rare in U.S. transfusions

ATLANTA, Sept. 6 (UPI) -- U.S. health officials say 159 cases of transfusion-related babesiosis -- a blood disease caused by tick-borne parasites -- were recorded in the past 30 years.

Researchers at the Centers for Disease Control and Prevention in Atlanta and colleagues say of the total number of transfusion-related babesiosis cases recorded from 1979 to 2009, 77 percent occurred from 2000 to 2009.

Dr. Barbara Herwaldt, a CDC medical epidemiologist who was the study's lead author, says the malaria-like disease is a potentially fatal but treatable complication of blood transfusion. However, severe consequences, such as multi-organ failure and death, are most often seen in people without a spleen, the elderly and those with a weak immune system, the researchers say.

The study authors say prevention strategies, including development of a screening test, are needed because even those infected can feel fine.

"We want clinicians to become more aware of babesiosis, including the small possibility of transmission via blood transfusion," Herwaldt says in a statement. "If a patient develops unexplained fever or hemolytic anemia after a transfusion, babesiosis should be considered as a possible cause, regardless of the season or U.S. region."

Babesiosis is spread most commonly by ticks, and Herwaldt says people who unknowingly become infected through the bite of a tiny tick -- about the size of a poppy seed -- can transmit the parasite via blood transfusion. Therefore, prevention of tick-borne infection can help safeguard the blood supply, Herwaldt adds.