Recent Advances in Varicella-Zoster Virus Infection

View larger version (12K): [in a new window]   Figure 1. Structure of the varicella-zoster virus genome and position of selected genes. The genome is arranged in unique long (U L ), unique short (U S ), terminal repeat long (TR L ), terminal repeat short (TR S ), and internal repeat (IR) regions. Selected immediate-early (IE), early (E), late (L), and latency-associated genes are shown. ssDNA = single-stranded DNA.

View larger version (75K): [in a new window]   Figure 2. Dermatologic manifestations of varicella and zoster. A. A child with varicella who had onset of rash 2 weeks after his sibling (C) had zoster. The rash is in different stages of evolution, with some vesicles, macules, and papules. The rash is generalized and, in this early stage, mainly on the trunk. B. The thigh of a child recovering from varicella complicated by necrotizing fasciitis due to group A streptococci. C. A child with zoster. The rash is unilateral in the distribution of the third and fourth thoracic dermatomes. D. Verrucous lesions on the foot of an HIV-positive child with progressive varicella who had been treated for several months with antiviral drugs without resolution of the lesions (reproduced with permission from Srugo and colleagues [27]). E. A vesicular lesion on the thumb (Ea) and papular lesions on the face (Eb) of a child who had previously received varicella vaccine. F. A generalized maculopapular rash in a child who had received varicella vaccine 9 days previously.

View larger version (22K): [in a new window]   Figure 3. Approximate peak serum blood levels of antiviral drugs and the 50% effective dose (ED 50 ) in vitro concentrations required to inhibit replication of the herpes simplex virus (HSV) or the varicella-zoster virus (VZV/). Although intracellular drug triphosphate concentrations are more relevant, this schematic provides some explanation for the advantages of intravenous acyclovir (ACV), oral valacyclovir (VCV), and oral famciclovir (FCV) relative to standard high-dose (800 mg) oral acyclovir (ACV). id = per day; IV = intravenous; PO = oral; Q8h = every 8 hours.