Case Report: Pediatric Rickettsia felis encephalitis-a rare case and literature review

Rickettsia felis (R. felis), an obligate intracellular bacterium, has been reported to cause human encephalitis. Clinical reports of R. felis encephalitis remain rare, particularly in children. Herein, we present a pediatric case and review the relevant literature.

A previously healthy 9-year-old boy initially presented with fever and headache. Following admission, he developed hyperpyrexia and somnolence. Cranial magnetic resonance imaging revealed a left temporal lobe lesion with ipsilateral temporoparietal meningeal enhancement, and electroencephalography showed background slowing. Metagenomic next-generation sequencing of cerebrospinal fluid detected a high abundance of R. felis sequences, whereas autoantibody testing for central nervous system autoimmune diseases was negative. Based on these findings, a diagnosis of R. felis encephalitis was established. The child fully recovered and was discharged after receiving doxycycline-based antimicrobial therapy combined with glucocorticoids, intravenous immunoglobulin, and intracranial pressure management.

This rare case highlights that R. felis infection should be included in the differential diagnosis of encephalitis. Metagenomic next-generation sequencing is recommended for early etiological diagnosis to facilitate timely and effective clinical intervention.