Follow-up of a Rickettsia felis encephalitis: Some new insights in clinical and imaging features

Abstract Rickettsia felis infection is a cause of unspecified encephalitis. However, the incidence of it was underestimated due to the intracellular feature of the pathogen and insufficient understanding of its clinical picture. Here we report a case of Rickettsia felis infection in a 26-year-old female who manifested with only certain neurological symptoms. With the lack of specific systemic inflammatory symptoms, the diagnosis was initially misdiagnosed as brain glioma. However, brain tissue biopsy showed prominent peri-vascular inflammatory infiltration which indicated inflammatory diseases. The spinal fluid Metagenomic Next-Generation Sequencing (mNGS) was taken after ruling out other common infectious and autoimmune diseases. The results suggested Rickettsia felis infection which was also supported by Weil Felix reaction in the serum. After the diagnosis was corrected as Rickettsia felis encephalitis, the patient was successfully treated with doxycycline and had a good prognosis in one-year follow up.