Abstract
BACKGROUND: Rickettsia japonica infection is a rare disease, it is rare to report critical and severe case caused by this disease in Zhejiang Province, China. PATIENT CONCERNS: We report a patient who initially sought medical attention due to fever and developed coma and convulsions during treatment. The patient did not develop typical eschar and rash. Eventually, the patient needed to be treated in the intensive care unit due to acute respiratory failure. DIAGNOSES: The patient was diagnosed with Rickettsia japonica bloodstream infection by metagenomic next-generation sequencing (mNGS). OUTCOMES: Due to the critical illness, the patient was transferred to the intensive care unit, received doxycycline and other treatments, and rapidly recovered and discharged. CONCLUSION: The patient developed a critical illness after being infected with Rickettsia, when the medical history is unclear and clinical symptoms and signs are atypical, it is necessary to use mNGS examination for diagnosis.