Source / episode info

• **Episode:**2
• **Title:**Divine Intervention Episode 2 (Viral Cases A).
• **Published:**2018-03-14
• Source:Episode page

One-liner

This episode reviews high-yield viral infections including Herpesviruses (HSV/VZV), Cytomegalovirus (CMV) and Epstein-Barr Virus (EBV), emphasizing unique clinical presentations, congenital imaging patterns, and specific antiviral drug mechanisms.

High-yield summary

• JC Virus & PML: Progressive Multifocal Leukoencephalopathy (PML) is a demyelinating process caused by JC virus reactivation, classically seen in severely immunocompromised HIV patients (CD4 < 50) or those on immunosuppressive agents like alemtuzumab.
• CMV vs Toxoplasmosis Calcifications: Periventricular calcifications are highly suggestive of congenital CMV infection; diffuse/cortical calcifications favor toxoplasmosis.
• Herpesvirus Localization: HSV-1 typically affects the trigeminal ganglia, while HSV-2 classically involves the sacral ganglia. VZV lesions follow a dermatomal pattern and can reactivate as shingles.
• EBV & Burkitt's Lymphoma: EBV is associated with B cell infections and latency; its presence in lymphoma often correlates with the t(8;14) translocation, leading to a "starry sky" appearance on histology.
• HIV Pharmacology: Maraviroc blocks CCR5 (a chemokine receptor), while Enfuvirtide acts as a fusion inhibitor by blocking GP41. NRTIs (e.g., Lamivudine) inhibit the viral RNA-dependent DNA polymerase.

Learning objectives

• Differentiate between the clinical presentations and congenital imaging findings of CMV, Toxoplasmosis, and other TORCH infections.
• Identify the key viral associations for opportunistic CNS infections (e.g., JC virus -> PML).
• Correlate specific anatomical locations with Herpesvirus types (HSV-1 vs HSV-2) and understand their respective ganglia tropisms.
• Understand the mechanism of action and clinical use of antiviral drugs (e.g., acyclovir, ganciclovir, enfuvirtide).
• Recognize high-yield viral syndromes based on exposure history or specific physical exam findings (e.g., Botulism, Lassa fever).

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