Tick-borne Parasite Infecting U.S. Blood Supply

CDC says that tick-borne parasite Babesia being transmitted through blood transfusions

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) A parasite spread by deer ticks that can lead to a fatal malaria-like illness is becoming increasingly prevalent, causing concern over the safety of the U.S. blood supply.

Cases of babesia, a tick-borne parasite of red blood cells transmitted through blood transfusions, have increased exponentially in recent years, a recently released 31-year study from the U.S. Centers for Disease Control and Prevention revealed.

"Use repellents that contain at least 20 percent Deet to avoid tick bites."

Babesiosis was first reported in 1979, the year the first known case occurred, but now 159 transfusion-related cases have been reported. About 77 percent of those cases were reported between 2000 and 2009.

There is currently no U.S. Food and Drug Administration-approved screening test available for prospective blood donors. While cases of babesiosis can be severe and symptoms may include fever, chills, organ failure and death, some cases are so mild that would-be blood donors wouldn't even know they were ill.

Individuals most at risk include the elderly, those with weakened immune systems and people who do not have a spleen. Though the disease is potentially life-threatening, it is treatable. However, cases can be easy to miss and it is often misdiagnosed as malaria.

The parasite is spread through the blood supply after individuals unknowingly bitten by an infected tick donate blood that is later transfused into another patient.  Most cases so far have occurred in seven states where the infected ticks are often found, including Connecticut, Massachusetts, Minnesota, New Jersey, New York, Rhode Island, and Wisconsin.

Cases tend to be higher during the warm months of the year. But in total, cases have been identified in 19 states and have occurred year–round.

Government study authors are urging the development of a screening test, and some manufacturers already are working to design a screening  test that could garner FDA approval.

The study and an accompanying editorial were published in the Annals of Internal Medicine.

Reviewed by: 
Review Date: 
September 6, 2011
Last Updated:
September 7, 2011