Apheresis for babesiosis: Therapeutic parasite reduction or removal of harmful toxins or both?

Babesiosis is a potentially life-threatening illness caused by intraerythrocytic protozoan parasites of the genus Babesia that are transmitted most commonly by Ixodes ticks, and rarely from blood transfusion or congenitally. Clinical presentations of babesiosis include asymptomatic infection, mild to moderate disease, or severe disease. Antibiotics such as atovaquone plus azithromycin or clindamycin and quinine can be used effectively to treat this disease in most cases, however in high risk populations, the mortality rate can be as high as 20% despite therapy. Therapeutic exchange transfusion has been used in severe babesiosis and is of apparent therapeutic benefit. It is not entirely clear through what mechanism therapeutic exchange transfusion may help patients. Data suggests that in addition to parasite load reduction, it is possible that therapeutic exchange transfusion removes toxins generated by babesia infection. There are many remaining questions that need to be addressed regarding exchange transfusion for babesiosis. J. Clin. Apheresis 31:454-458, 2016.