Characteristics, management and outcome of Herpes Simplex and Varicella-Zoster virus encephalitis: a multicentre prospective cohort study

Clin Microbiol Infect. 2024 Jul;30(7):917-923. doi: 10.1016/j.cmi.2024.03.017. Epub 2024 Mar 26.

Abstract

Objective: To characterize differences between Herpes Simplex virus encephalitis and Varicella-Zoster virus encephalitis (HSVE and VZVE) and other aetiologies of infectious encephalitis (IE), and to investigate the impact of time-to-aciclovir (ACV) start, ACV dose and duration on outcome.

Methods: We compared 132 HSVE, 65 VZVE and 297 other IE enrolled in a prospective cohort (ENCEIF). We estimated associations between time-to-ACV start, dose or duration and outcome through adjusted odds ratio (aOR) using logistic regression analysis.

Results: Prevalence of immunodepression differed among aetiologies: 15/65 (23%) for VZVE, 13/132 (10%) for HSVE and 30/297 (10%) for other IE (p <0.05), as was presence of seizure at admission: 27/132 (20%) for HSVE, 4/65 (6%) for VZVE and 43/297 (14%) for other IE (p <0.05). Poor outcome at hospital discharge (Glasgow outcome scale ≤3) differed among the three groups: 40/127 (31%) for HSVE, 12/65 (18%) for VZVE and 38/290 (13%) for other IE (p <0.05). Time-to-ACV start was associated with outcome in HSVE (aOR 3.61 [1.25-10.40]), but not in VZVE (aOR 0.84 [0.18-3.85]). Increased ACV dose was not associated with outcome among HSVE (aOR 1.25 [0.44-3.64]) nor VZVE (aOR 1.16 [0.24-5.73]).

Discussion: HSVE and VZVE are distinct in clinical presentation, outcome and prognostic factors. The impact of early ACV initiation was more apparent for HSVE than for VZVE; however, this could be because of VZVE's smaller sample size and lower outcome rate leading to low statistical power or because of potential distinct IE pathophysiology.

Keywords: Acyclovir; Herpes Simplex virus; Infectious encephalitis; Outcome; Varicella-Zoster virus.

Publication types

  • Multicenter Study

MeSH terms

  • Acyclovir* / administration & dosage
  • Acyclovir* / therapeutic use
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Antiviral Agents* / therapeutic use
  • Encephalitis, Herpes Simplex* / drug therapy
  • Encephalitis, Varicella Zoster* / drug therapy
  • Female
  • Herpesvirus 3, Human
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Treatment Outcome
  • Young Adult

Substances

  • Antiviral Agents
  • Acyclovir