Neurovirulence of herpes simplex virus types 1 and 2 isolates in diseases of the central nervous system

Eur J Clin Microbiol Infect Dis. 1990 Oct;9(10):751-7. doi: 10.1007/BF02184688.


Herpes simplex virus (HSV) isolates derived from the central nervous system of ten patients with HSV-1-induced encephalitis, one patient with multiple sclerosis, and 14 patients with HSV-2-induced meningitis were investigated for neurovirulence by assaying the LD50 after nose and intracerebral (i.c.) inoculation of mice. HSV-1 encephalitis strains were significantly more virulent after nose inoculation (i.e. neuroinvasive) when compared with HSV-1 isolates from patients with oral lesions only, whereas HSV-2 meningitis strains were significantly more virulent after i.c. inoculation when compared with HSV-2 isolates from patients with genital lesions only. No correlation between high neurovirulence (defined as low LD50 for both routes of infection) and replication in cell cultures of neuronal and non-neuronal cell lines was found, but the weakly neurovirulent HSV-1 strain isolated from a patient with multiple sclerosis gave low replication yields. After nose inoculation, a highly neuroinvasive HSV-1 laboratory reference strain replicated to high titers in nose tissue, the trigeminal ganglia and brainstem, while a strain with low neuroinvasiveness but high i.c. virulence replicated less well in the brainstem. Neuroinvasiveness of the virus strain might be one factor of relevance in the pathogenesis of HSV-1 encephalitis in man.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Encephalitis / etiology
  • Encephalitis / microbiology*
  • Humans
  • Lethal Dose 50
  • Meningitis / etiology
  • Meningitis / microbiology*
  • Mice
  • Multiple Sclerosis / etiology
  • Multiple Sclerosis / microbiology*
  • Simplexvirus / isolation & purification
  • Simplexvirus / pathogenicity*
  • Simplexvirus / physiology
  • Species Specificity
  • Virulence
  • Virus Replication