SHM Converge Scientific Abstract ePoster Gallery-How to Suspect Tick-Borne Infections Without an Obvious Bite Mark?

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A 75-year-old woman presented with four days of fatigue and persistent fever. Initial outpatient testing showed leukopenia, and repeat studies revealed worsening leukopenia and thrombocytopenia, prompting emergency referral. She had no past medical history, took no medications, and had no obvious tick bite history or visible bite marks, though she often visited fields and bamboo thickets.<br /><br />On admission, she was febrile, tachycardic, and had marked leukopenia and thrombocytopenia. There was no lymphadenopathy, rash, or clear localizing source of infection. She was treated as febrile neutropenia, but the fever persisted. By hospital day 6, she developed altered mental status and disseminated intravascular coagulation. Bone marrow aspiration on day 7, performed because of persistent fever, splenomegaly, and progressive thrombocytopenia, confirmed hemophagocytic syndrome. Further testing identified severe fever with thrombocytopenia syndrome (SFTS) virus in serum, throat swab, and urine.<br /><br />She was managed in the ICU with multidisciplinary care. Her platelet count improved by day 8 and fever subsided to low grade, but severe hyperactive delirium persisted until day 13 and required intravenous sedation. She was later transferred to the general ward and discharged on day 38.<br /><br />This case highlights that SFTS can be difficult to diagnose when there is no obvious tick bite mark or exposure history. In endemic areas, clinicians should suspect SFTS in patients with persistent fever, leukopenia, thrombocytopenia, splenomegaly, and liver dysfunction, even without visible bite marks. Prolonged delirium may also be part of the severe disease spectrum.

Asset Subtitle

Yasue Hashimoto

Meta Tag

Author List Hirofumi Mikami, Koki Takeda, Tatsuya Fujikawa, Yasue Hashimoto

Category Clinical Vignettes

Concept Severe Fever with Thrombocytopenia Syndrome

Concept HLH-MAS

Concept Fever

Concept Leukopenia

Concept Thrombocytopenia

Distinguished Non-Finalist

Presenter Organization Mitoyo General Hospital

Presenting Author Yasue Hashimoto

Track Adult

Keywords

severe fever with thrombocytopenia syndrome

SFTS virus

leukopenia

thrombocytopenia

persistent fever

hemophagocytic syndrome

disseminated intravascular coagulation

delirium

tick-borne disease

splenomegaly

Severe Fever with Thrombocytopenia Syndrome

HLH-MAS

Fever

Leukopenia

Thrombocytopenia