A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Facebook Twitter LinkedIn Syndicate Emerging Infectious Disease journal ISSN: 1080-6059 Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.
A 79-year-old man in China sought care for fever and syncope and was diagnosed with myelodysplastic syndrome. Bone marrow showed hemophagocytosis and macrophages resembling typhoid cells, but cultures excluded Salmonella infection. Targeted next-generation sequencing identified Orientia tsutsugamushi , and a concealed popliteal eschar was found. Scrub typhus can produce typhoid-like bone marrow morphology.
Scrub typhus remains a major cause of acute undifferentiated fever across the Asia-Pacific region. Approximately 1 million cases are reported annually ( 1 ). The diagnosis is straightforward when the classic triad of fever, rash, and eschar is present, but atypical manifestations, particularly in older or immunocompromised patients, can lead to delays in diagnosis ( 2 ).
Although the clinical overlap between typhoid fever and scrub typhus has long been recognized, the 2 diseases have not previously been linked at the level of bone marrow pathology. Typhoid cells (i.e., macrophages with distinctive eosinophilic granular cytoplasm) historically have been considered a hallmark of Salmonella bacterial infection in bone marrow ( 3 , 4 ). Whether other intracellular pathogens can produce morphologically identical cells has not been systematically examined. Furthermore, scrub typhus has undergone dramatic geographic expansion in China, where incidence increased >20-fold during 2006–2023, and the disease has spread from its historical focus in southern China to previously nonendemic northern provinces, including Shandong ( 3 , 5 ). We report a patient in whom bone marrow morphology strongly suggested typhoid fever but the actual pathogen proved to be O. tsutsugamushi bacteria. We obtained written informed consent from the patient for publication of this report and accompanying images.
A 79-year-old man, who was retired farmer from rural Shandong Province, came to the emergency department in October 2025 with 4 days of spiking fevers up to 39.5°C and rigors. Over the preceding month, he had experienced 4 syncopal episodes; each time he regained consciousness within minutes but had headache and dizziness afterward. He spent most of his days tending a backyard garden and had a long history of drinking ≈60 mL of liquor daily. He kept no animals and had not traveled recently.
On arrival, he looked pale. His temperature was 38.3°C, pulse 92, and blood pressure 136/78 mm Hg. The conjunctivae were blanched. Heart sounds were regular without murmurs, the lungs were clear, and the abdomen was soft with no organomegaly. Neurologic examination and electrocardiogram results were unremarkable. Cranial computed tomography showed only mild left anterior cerebral artery stenosis, insufficient to explain his syncopal episodes. Chest and abdominal computed tomography showed scattered lymphadenopathy in the anterior mediastinum and both inguinal regions (largest node 1.4 cm).
Laboratory studies revealed pancytopenia and multiorgan dysfunction: white cells 3,690 cells/μL (reference range 3,500–9,500 cells/μL); hemoglobin 8.5 g/dL (reference 13.0–17.5 g/dL); mean corpuscular volume 106.8 fL (reference 82–100 fL); platelets 84,000…