Fulminant babesiosis treated with clindamycin, quinine, and whole-blood exchange transfusion

BACKGROUND: Babesiosis is an increasingly recognized parasitic infection wi th manifestations that range from a subclinical or mild flu-like illness to life-threatening disease. Risk factors that may be associated with a more severe clinical course include immunosuppression, splenectomy, and advanced age. The most effective chemotherapeutic regimen, clindamycin plus quinine , is sometimes ineffective in cases of severe disease. CASE REPORT: A previously healthy, 58-year-old man was infected by Babesia microti, presumably through a tick bite. He developed fulminant disease cha racterized by severe hemolytic anemia, disseminated intravascular coagulati on, acute renal failure, and respiratory failure. There was no history of s plenectomy or immunodeficiency. He was given oral clindamycin (300 mg/4x/da y) 2 days before admission. Oral quinine (650 mg/3x/day) was added upon hos pitalization. There was no clinical improvement despite antibiotic therapy with clindamycin and quinine. On the second hospital day, a whole-blood exc hange transfusion was performed to simultaneously lower the parasite load a nd replace the patient's plasma. With an automated blood cell separator, 87 percent of the patient's total blood volume was exchanged. As replacement fluid, 6.7 L of packed RBCs reconstituted with FFP (average Hct, 33%) was u sed. The patient's Hct increased from 26.9 percent before the exchange to 2 8.3 percent after the exchange. The percentage of parasitized RBCs decrease d from 13.8 percent just before exchange to 4.2 percent immediately after e xchange. There was rapid clinical improvement after the whole-blood exchang e transfusion. The patient's subsequent clinical course was marked by a dis appearance of the parasitemia and continued slow, general improvement. Ther apy with clindamycin was continued for 14 days after the exchange transfusi on and quinine for 17 days. CONCLUSION: In cases of severe babesiosis, prompt institution of whole-bloo d exchange transfusion, in combination with appropriate antimicrobial thera py, can be life-saving.