Babesiosis can be transmitted by blood transfuion. Vulnerable infants are at risk for more severe illness.


Risk factors for clinical babesiosis:

(1) blood donor from a region endemic for Babesia microti

(2) premature infant


The incubation period may be 1 to 9 weeks following the transfusion.


Clinical presentation:

(1) unexplained fever

(2) history of recent blood transfuion

(3) variable thrombocytopenia, anemia or pancytopenia

(4) variable hepatosplenomegaly

(5) variable tachypnea, apnea or respiratory failure

(6) variable heart failure

(7) variable DIC

(8) variable renal failure

(9) variable multi-organ failure (MOF)


Asymptomatic infections are relatively common.


The diagnosis can be made by examination of a peripheral blood smear. If the smear is negative then PCR should be performed if there is a significant risk of infection.


If a donor is implicated as the source of babesia, then all products derived from a donation should be quarantined and transfusion recipients evaluated.


To read more or access our algorithms and calculators, please log in or register.