UC Berkeley, College of Letters and Science, United States. Electronic address: tang.t@berkeley.edu UC Irvine School of Medicine, Department of Pathology and Laboratory Medicine, United States. Electronic address: minhhat1@uci.edu
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.
