A Pediatric Coinfection with Babesia microti and Plasmodium falciparum

Introduction: Babesiosis and malaria are diseases caused by intraerythrocytic protozoan parasites. Both parasites are spread by arthropod vectors—Babesia spp by ticks and Plasmodium spp by mosquitoes—and share similar clinical and diagnostic characteristics. The geographic distributions of these 2 pathogens are historically distinct. Coinfections that lead to concurrent babesiosis and malaria are rare. Clinical Findings: A prepubescent child presented with symptoms of malaria 2 weeks after returning from a trip to Central Africa and was subsequently hospitalized for assessment and treatment. Clinical Course: The patient had anemia and thrombocytopenia on admission with steady decreases in leukocytes, erythrocytes, hemoglobin, and hematocrit reported through day 5 of hospitalization. Initial polymerase chain reaction testing revealed coinfection with Babesia microti and Plasmodium falciparum. A blood smear sent to the Centers for Disease Control and Prevention identified Babesia sp. and P. falciparum in the blood, confirming coinfection that led to concurrent babesiosis and malaria. The patient recovered and was discharged home. Conclusions: Patients who spend time in both mosquito and tick habitats are at risk of coinfection with multiple parasites. Clinicians should consider babesiosis testing for patients with malaria who may have spent time in tick habitats where Babesia spp are endemic.