While the American Red Cross screens donated blood for a host of infectious diseases like HIV, hepatitis, and West Nile Virus, it doesn’t test for a tickborne illness that’s more common in Massachusetts than in other states. As a result, those who get transfusions in the state are vulnerable to getting infected with Babesia, a parasite that attacks red blood cells, according to a study published today in the Annals of Internal Medicine.
It’s carried by the same deer ticks that carry Lyme disease — which thankfully doesn’t appear to pose a blood transfusion risk even though it’s also not screened for in blood donors. Babesia, however, has been transmitted through donated blood and when left untreated, can cause a wide range of symptoms from mild infections that resolve on their own to life-threatening anemia, liver or kidney failure.
No question, the risk of getting Babesia from a blood transfusion is low: The study authors from the US Centers for Disease Control and Prevention identified 162 cases of transfusion-related Babesia from 1979 to 2009; the first case was reported in Boston.
But that’s probably an under-reporting since doctors often misdiagnose the infection or don’t associate it with a blood transfusion. And the frequency of infections via transfusion are increasing, with just 4 percent of the cases reported during the first 11 years of the study and 77 percent reported from 2000 to 2009.
Massachusetts had 12 transfusion-related cases of Babesia from 2005 to 2009 compared with two in a period from 2000 to 2004.
Since there’s no test available to screen the blood for the parasite, it “has become the infectious agent most frequently transmitted by blood transfusion in the United States,’’ wrote David Leiby, a microbiologist from the American Red Cross laboratory in Rockville, Md. in an editorial that accompanied the study.
The study authors emphasized that doctors should be aware of the possibility of this infection from blood donation and should investigate Babesia diagnoses in any patients given blood transfusions who later wind up with hemolytic anemia, a condition where iron deficiency is caused by the destruction of red blood cells.
Treatment usually involves a combination of anti-parasitic and antibiotic medications administered for seven to 10 days.