SHM Converge Scientific Abstract ePoster Gallery-Incorporating Anaplasmosis in the Differential: A Summer Case Report

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This case report highlights the importance of considering anaplasmosis in patients with persistent, unexplained fevers, especially in tick-endemic regions like Pennsylvania during summer months.<br /><br />An 81-year-old man was hospitalized repeatedly over two months for presumed worsening diverticulitis after presenting with left lower quadrant pain and diarrhea. Despite multiple courses of broad-spectrum antibiotics, including ciprofloxacin, metronidazole, piperacillin-tazobactam, and amoxicillin-clavulanic acid, his fevers persisted and his abdominal pain improved. By his fourth admission in July, he had high fevers, fatigue, sweats, chills, weight loss, cough, and mental status changes. Imaging showed only stable diverticulitis and no pneumonia. Laboratory findings revealed progressive thrombocytopenia and acute kidney injury, along with elevated inflammatory markers.<br /><br />Because of the treatment-resistant fevers and falling platelets, clinicians broadened the differential to include tick-borne disease and started doxycycline. Testing supported anaplasmosis: Anaplasma IgG was elevated, peripheral smear showed rare neutrophils with inclusion bodies, and PCR detected Anaplasma phagocytophilum. Tests for Babesia, Ehrlichia, and Lyme disease were negative. The patient improved rapidly, with fevers resolving within 48 hours of doxycycline initiation and platelet counts improving by day 3. He was discharged on a 14-day course of doxycycline.<br /><br />The report emphasizes that anaplasmosis commonly presents with nonspecific symptoms such as fever, myalgia, malaise, and headache, which can mimic other illnesses. In Pennsylvania, where tick-borne disease incidence has risen substantially, anaplasmosis should remain on the differential for patients with recurrent fevers and thrombocytopenia, particularly in the summer months when blacklegged ticks are most active.

Asset Subtitle

Stevie L. Muscarella

Meta Tag

Author List Kayla E. Fresco, Kirsten Gimbel, Sarah Al-Obaydi, Stevie L. Muscarella

Category Clinical Vignettes

Concept Anaplasmosis

Concept Tick-Borne Disease

Concept Fever

Concept Thrombocytopenia

Concept Doxycycline

Distinguished Non-Finalist

Presenter Organization Penn State College of Medicine, Hershey Medical Center

Presenting Author Stevie L. Muscarella

Track Adult

Keywords

anaplasmosis

tick-borne disease

persistent fever

thrombocytopenia

Pennsylvania

summer months

doxycycline

Anaplasma phagocytophilum

blacklegged ticks

acute kidney injury

Anaplasmosis

Tick-Borne Disease

Fever

Thrombocytopenia

Doxycycline