Varicella-Zoster Virus
One-Sentence Definition
Varicella-zoster virus (VZV) is a neurotropic alpha-herpesvirus causing primary varicella (chickenpox) and reactivation zoster (shingles), preventable by live-attenuated or recombinant subunit vaccines.
Taxonomy & Morphology
- Human herpesvirus 3; dsDNA; envelope; latent in sensory ganglia
- Related: HSV — similar latency/reactivation biology
Virulence Highlights
- Respiratory spread (varicella) → viremia → vesicular rash
- Latency in dorsal root ganglia → zoster with dermatomal rash
- Immunocompromised: disseminated disease, visceral involvement
Clinical Syndromes
- Primary varicella (often childhood)
- Herpes zoster — painful dermatomal vesicles; postherpetic neuralgia
- Disseminated zoster in immunosuppression
- CNS: meningitis/encephalitis (less common than HSV Encephalitis)
Diagnosis
- Clinical often sufficient for typical zoster
- PCR on vesicle fluid/CSF when atypical or severe
- Serology: IgG immunity vs acute (context-dependent)
Treatment / Prevention
- Antivirals (acyclovir/valacyclovir) for zoster/complicated varicella
- Vaccines: childhood varicella; shingles vaccine (recombinant preferred in older adults)
- Isolation for susceptible contacts (airborne + contact)
Genomics & Surveillance
- Clade tracking in research; vaccine strain vs wild-type differentiation occasionally relevant
Related Notes
- HSV · Vaccination · MOC - Virology
- Disease links: immunocompromised CNS disease → CNS Infections
Active Recall
- Where does VZV establish latency?
- Live vs recombinant zoster vaccine — key difference?
- PCR sample of choice in zoster?