Spectrum of Pediatric Babesia Infection: A Retrospective Case Series

Introduction: Babesiosis is a tick-borne infection, primarily reported in the Northeastern and northern Midwest states. Asymptomatic or mildly symptomatic infection is common in healthy individuals, but severe disease can occur in those with impaired splenic function or other immunosuppression. Older adults and infants may also develop severe disease. There are little data reported about Babesia infection in children. Methods: Children younger than 18 years were identified in a search of patients diagnosed with babesiosis in the MaineHealth medical record between January 1, 2010, and September 30, 2024. Charts were reviewed by standardized data extraction. Results: The 19 cases ranged in age from 4 weeks to 17 years, with an average age of 7.4 years. All children were previously healthy and had not received a prior blood transfusion. Two children required hospitalization, both of whom were young infants who required blood transfusions and did well on atovaquone and azithromycin. Most children were identified from a diagnostic panel that detects multiple tick-borne infections. Except in 1 case, babesiosis was not suspected when testing was done. Discussion: In this retrospective series, older children with positive test results for Babesia recovered with or without anti-babesial treatment. Tick panels were frequently done because of signs of Lyme disease. Most children (74%) were treated for babesiosis after getting a positive test result, and many had concurrent Lyme disease. Conclusions: Babesiosis is an uncommon infection detected in children. Testing for babesiosis should be considered in infants and children who are immunosuppressed and have a compatible illness. More targeted use of tick panels is recommended.