2019 Jun 27. doi: 10.1111/trf.15425. [Epub ahead of print]

Characteristics of transfusion-transmitted Babesia microti, American Red Cross 2010-2017.



Babesia microti, a red blood cell (RBC) parasite transmitted naturally to vertebrate hosts by ixodid ticks, is endemic to the northeastern and upper midwestern United States, with the geographic range of infected ticks expanding. B. microti is a blood safety issue with >200 transfusion-transmissions reported.


The American Red Cross’s Hemovigilance program investigated hospital-reported transfusion-transmitted babesiosis (TTB) cases. Follow-up samples from involved donors were tested for B. microti antibodies and parasite DNA, the latter by real-time polymerase chain reaction (PCR). Test-positive donors were permanently deferred from future donations.


B. microti-positive donors were implicated in 77 of 143 suspect TTB cases investigated from 2010 through 2017. In four cases, two positive donors were identified for a total of 81 positive donors. In three cases, a RBC unit was split and components transfused multiple times to the same pediatric recipient. RBCs were the transmitting product in all cases. At follow-up, all involved donors were antibody positive; 25 donors were also PCR positive. Positive donations were collected throughout the year, peaking in the summer. Most donors (78) were resident of, or traveled to (2), an endemic state. One donor resided in a non-endemic state without relevant travel history. One fatality listed babesia as a contributing factor. No implicated donation was screened by an investigational protocol.


Babesiosis remains a blood safety issue. Prior to FDA-licensed screening test availability and final FDA Guidance, blood collectors in endemic states investigationally tested none, a portion, or all collections. Future expanded testing will reduce the frequency of TTB cases.



This clearly shows there were more than 200 Babesia transfusion-transmissions reported. It also shows you don’t have to reside in an endemic area or travel to an endemic area to get it. The article also clearly points out that the geographic range of ticks is expanding, which means the pathogens they carry will as well.

More on Babesia:

Babesia, as well as Lyme is under reported. Research hardly exists on those with both. We desperately need to know what concurrent infection is doing to patients. It only makes logical sense that their cases are more severe and of greater duration, yet mainstream research and medicine doesn’t blink at this issue:

Going back to 1998, it was known that when a patient has Lyme and Babesia, Lyme is found three-times more frequently in the blood, causing greater symptoms, disease severity, and duration of illness:

What happens when a patient has Lyme, Babesia, and Bartonella and maybe a few viruses thrown in for good measure?  Nobody’s studied this, yet it is common scenario in Lyme-land:

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