Tick-borne babesiosis parasite infecting blood supply, CDC says

(CBS) Little ticks are causing big trouble for the U.S. blood supply. A new study shows that people have contracted an infection known as babesiosis after receiving transfusions of blood contaminated with the tick-borne parasite that causes the potentially deadly disease.

There have been 159 cases of transfusion-related babesiosis between 1979 and 2009, according to the study, which was published online in the Annals of Internal Medicine. So far, transfusion-related babesiosis has been identified in 19 states.

There's no FDA-approved test that can spot the infection in people before they donate blood. So what can be done to protect patients who need blood transfusions?

"We want clinicians to become more aware of babesiosis, including the small possibility of transmission via blood transfusion," study Dr. Barbara Herwaldt, a CDC epidemiologist, said in a written statement. She said doctors should consider babesiosis if a patient develops unexplained fever or anemia after receiving a transfusion.

In addition, the CDC says blood donors can help keep the Babesia parasite out of the blood supply by taking steps to avoid tick bites. The ticks that carry the microscopic parasite - black-legged or deer ticks - can be as small as a poppy seed.

Babesiosis can cause fever, chills, sweats, headaches, body aches and other flu-like symptoms. These typically occur within a week or two. The disease can be life-threatening in people whose immune system has been weakened by cancer, AIDS or another medical condition, as well as those who have no spleen or a spleen that works abnormally, who have liver or kidney disease, and elderly people.

There is no vaccine to prevent the disease, though antibiotics and other medicines can be used to treat it.

The CDC has more on babesiosis.