Varicella Zoster Virus (VZV / HHV-3)

VZV infects a variety of human and animal cell types in vitro and gives rise to 2 distinct clinical syndromes:

Varicella (Chicken pox) - (nothing to do with chickens or pox!). Infection normally occurs in childhood (~90% - more?), via respiratory tract or conjunctiva. After multiplication at the inoculation sites, virus spreads to bloodstream and reticuloendothelial system. Secondary multiplication involves skin and mucosa, producing vesicles filled with very high titres of infectious virus! Complications are rare, but may include CNS infection.
Zoster (Shingles) - After primary infection, virus persists in sensory ganglia of CNS. It is not clear if this is a latent or a persistent infection, but 'reactivation' after many years leads to infection and tissue damage to dermatosome served by infected ganglia - most serious when cranial nerves are involved, affecting face/head - can lead to blindness.
Therapy - acyclovir.
Medscape Article "Current Management of Herpes Zoster "