Suspected Typhus in a Pediatric Patient with Fever of Unknown Origin

Murine typhus, caused by Rickettsia typhi, is an increasingly recognized but frequently underdiagnosed cause of pediatric febrile illness in endemic regions of the southern United States. Nonspecific symptoms and limitations of early serologic testing often delay diagnosis and treatment. We report the case of a previously healthy 12-year-old girl from South Texas who presented with five days of fever, headache, rash, gastrointestinal symptoms, leukopenia, normocytic anemia, elevated inflammatory markers, and mild transaminitis, with significant flea exposure. Initial rickettsial serologies were negative, and respiratory PCR was positive for rhinovirus/enterovirus; however, the overall clinical and epidemiologic picture raised strong concern for murine typhus. Empiric doxycycline therapy was initiated, resulting in rapid defervescence and clinical improvement. This case underscores the importance of considering murine typhus in children with fever and cytopenias in endemic areas, recognizing the limitations of early serologic testing, and initiating prompt empiric doxycycline to reduce morbidity and prevent complications.