Case Presentation: 82 year-old female with prior history of hypertension visiting from rural Wisconsin who presented to a Georgia hospital emergency room with cough, exertional dyspnea, fever, and fatigue. Temperature 40 degrees Celsius with other vital signs normal. Lung exam with expiratory crackles bilateral lung fields. Cardiac and skin exam were normal. Hematology labs with white blood cells 4900/mcL, Hemoglobin 6.3 g/dL, and platelet count of 40000/mcL. Chemistries showed AST 146 units/L, ALT 97units/L, LDH 780 units/L, and creatinine 1.2 g/dL, Chest Xray showed a right middle lobe opacity. She was started on empiric antibiotics for community acquired pneumonia. Due to pancytopenia, peripheral smear was performed and revealed presence of schistocytes and parasites. PCR testing confirmed Babesia microti and she was diagnosed with severe babesiosis with an initial parasitemia of 19% with positive IgM Lyme antibodies suggesting Lyme co-infection. She was subsequently treated with azithromycin, atovaquone, and doxycycline with marked clinical improvement. Despite her high grade parasitemia, evidence of severe hemolytic anemia, and acute renal failure, she improved with antibiotics and supportive blood transfusions without the need for adjunctive red cell exchange.
Discussion: Data from the CDC show that a total of 1,834 cases of babesiosis were reported in 2020 in the US, and zero cases were diagnosed in the state of Georgia. Treatment options for babesiosis depend on the clinical status of the patient. In patients with high-grade parasitemia (>10%) or one or more of the following: severe hemolytic anemia and/or severe pulmonary, renal, or hepatic compromise, IDSA guidelines provide a weak recommendation for consideration of exchange transfusion. While exchange transfusion is known to decrease parasitemia, there are significant adverse effects to consider including transfusion reactions, worsening of thrombocytopenia, and complications associated with venous access devices. Given these adverse effects, after infectious disease and hematology consultations, the decision was made to proceed with supportive therapy. It is likely that the patient had been co-infected with babesia and Lyme for several months, given her high-grade parasitemia, however, despite her older age and severe infection, she was discharged after five days of supportive therapy alone. Her parasitemia responded well to treatment and was almost undetectable after one week.
Conclusions: This report illustrates a case of babesia in a nonendemic region and addresses the lack of necessity of adjunctive red cell exchange in severe babesiosis. Given that it is already a weak recommendation, these findings provide further evidence that red cell exchange is not a necessary treatment for babesiosis, even when there is a co-infection with another illness among older adults.
