Transfusion transmitted babesiosis: A systematic review of reported cases

Transfus Apher Sci. 2020 Oct;59(5):102843. doi: 10.1016/j.transci.2020.102843. Epub 2020 Jun 5.


Background: Transfusion transmitted babesiosis (TTB) has a high mortality rate but may go unrecognized, particularly in non-endemic areas. We therefore conducted a systematic review to better characterize clinical aspects of TTB.

Methods: A literature search was conducted in PubMed and CINAHL databases, from which 25 eligible articles describing 60 TTB patients met criteria for data extraction.

Results: Symptom evaluation was provided for 25 implicated donors: 18/25 (72%) were asymptomatic while 7/25 (28%) had mild flu-like symptoms but were asymptomatic at time of donation. It was common for a single donor or donation to infect multiple patients. Where reported, species included B. microti - 54/60 (90%), B. duncani - 3/60 (5%), and B. divergens-like/MO-1 - 1/60 (2%). Most TTB patients (44/60, 73%) resided in endemic states, while most TTB deaths 6/9 (67%) occurred in non-endemic states. Severity of hemolysis was proportional to degree of parasitemia. Mortality in our series was 9/60 (15%); most deaths occurred at extremes of the age spectrum: 6/9 non-survivors were aged >55 years, 2/9 were <1 year, only 1/9 was 2-54 years. Number of comorbidities was higher among non-survivors (median = 4) compared to survivors (median = 1).

Conclusions: All implicated donors (for which symptoms data were reported) resulting in TTB infections were asymptomatic at the time of donation, and it was common for a single donor or donation to infect multiple patients. Mortality of TTB appeared highest among those with more comorbidities and in non-endemic states. Heightened awareness of this diagnosis is key in its recognition.

Keywords: Babesia; Pathogen reduction; Transfusion transmitted babesiosis.

Publication types

  • Systematic Review

MeSH terms

  • Babesiosis / etiology*
  • Babesiosis / mortality
  • Babesiosis / physiopathology
  • Female
  • Humans
  • Male
  • Survival Analysis
  • Transfusion Reaction / complications*