Abstract We present a case of a co-infection of babesiosis and Lyme disease. 89-year-old female with a medical history of hypertension, mitral valve prolapse, and cognitive impairment was admitted to the emergency department after a fall. Laboratory tests revealed markedly elevated creatine kinase (CK) levels at 3, 217 U/L, thrombocytopenia with a platelet count of 125 x 10⁹/L, elevated liver enzymes (AST 134 U/L and ALT 114 U/L), and significantly high total bilirubin at 134 µmol/L. Imaging, including CT scans of the head, cervical spine, abdomen, and pelvis, showed no acute structural abnormalities. A peripheral blood smear identified intra-erythrocytic rings, suggesting babesiosis. The initial parasitemia was 12%, and the patient was started on Azithromycin and Atovaquone with a decrease in parasitemia to 6. 6%. After 48 hours of treatment, a rebound increase in parasitemia to 10%, worsening anemia, and pulmonary edema were noted prompting exchange transfusion. Serological tests for Lyme disease were positive, while Anaplasma, Ehrlichia, and Rickettsia serologies were negative. Treatment for Lyme disease was initiated with doxycycline. Her hospital course was complicated with acute hypoxic respiratory failure due to pneumonia and acute kidney injury (AKI) which was further exacerbated by acute diastolic heart failure. Following improvement in liver function tests, thrombocytopenia, and anemia, she was discharged to a subacute rehabilitation facility with a 14-day course of antibiotics per Infectious disease recommendations. Outpatient follow-up was arranged to monitor her recovery and manage her ongoing health issues. The diagnosis of babesiosis can be challenging due to its symptom overlap with other febrile illnesses and the variability in clinical presentation. In our case, the patient presented with a fall, and her review of systems was limited in the setting of cognitive impairment. High suspicion in endemic areas with the detection of intra-erythrocytic rings on a peripheral blood smear remains key for diagnosis. There is a strong correlation between the degree of parasitemia and morbidity with previous studies reporting severe outcomes and complications if parasitemia is between 4 and 10%. Red cell exchange transfusion (RCE) has been shown to reduce parasite burden with some studies questioning its superiority over microbiological treatment. In our case, there was a transient reduction in parasitemia with a rebound increase and worsening clinical status necessitating RCE. This case underscores the diagnostic and therapeutic challenges posed by the co-infection of babesiosis and Lyme disease, particularly in elderly patients with multiple comorbidities. This abstract is funded by: SELF
Misra et al. (Fri,) studied this question.