An HIV-positive patient (CD4 count 80 cells/µL) has been febrile for 3 weeks with splenomegaly and markedly elevated alkaline phosphatase. Blood cultures grow small gram-negative bacilli after 5 days on BACTEC system. Warthin-Starry silver stain of liver biopsy shows bacilli within blood vessel walls. What is the diagnosis?
- A Visceral leishmaniasis (Kala-azar) caused by Leishmania donovani
- B Disseminated Mycobacterium avium complex (MAC) infection
- C Cat scratch disease (localized form) caused by Bartonella henselae
- D Bacillary angiomatosis/peliosis hepatis caused by Bartonella henselae or Bartonella quintana ✓
Explanation
Bacillary angiomatosis (BA) is caused by Bartonella henselae or B. quintana in severely immunocompromised HIV patients (CD4 <100 cells/µL). Peliosis hepatis (blood-filled cavities in liver) with elevated ALP is characteristic of Bartonella hepatic involvement. Warthin-Starry silver stain demonstrates pleomorphic bacilli within vascular lesions — the histopathological hallmark. Bartonella grows slowly on blood/chocolate agar or in BACTEC. Cat scratch disease is the self-limited form in immunocompetent hosts. Leishmania would show amastigotes in macrophages, not vascular bacilli.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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