Herpes simplex encephalitis

Herpes simplex encephalitis
Other namesHerpes encephalitis,
Herpesviral encephalitis
Coronal T2-weighted MR image shows high signal in the temporal lobes including hippocampal formations and parahippogampal gyrae, insulae, and right inferior frontal gyrus. A brain biopsy was performed and the histology was consistent with encephalitis. PCR was repeated on the biopsy specimen and was positive for HSV
SpecialtyInfectious diseases Edit this on Wikidata

Herpes simplex encephalitis (HSE), or simply herpes encephalitis, is encephalitis due to herpes simplex virus. It is estimated to affect at least 1 in 500,000 individuals per year,[1] and some studies suggest an incidence rate of 5.9 cases per 100,000 live births.[2]

About 90% of cases of herpes encephalitis are caused by herpes simplex virus-1 (HSV-1), the same virus that causes cold sores. According to a 2006 estimate, 57% of American adults were infected with HSV-1,[3] which is spread through droplets, casual contact and sometimes sexual contact, though most infected people never have cold sores. The rest of cases are due to HSV-2, which is typically spread through sexual contact and is the cause of genital herpes.

Two-thirds of HSE cases occur in individuals already seropositive for HSV-1, few of whom (only 10%) have history of recurrent orofacial herpes, while about one third of cases results from an initial infection by HSV-1, predominantly occurring in individuals under the age of 18.[1] Approximately half of individuals who develop HSE are over 50 years of age.[4]

The most common cause for encephalitis in children and adults is HSV-1. However, encephalitis found in newborns and immunocompromised individuals is mainly caused by HSV-2.[5]

  1. ^ a b Whitley RJ (September 2006). "Herpes simplex encephalitis: adolescents and adults". Antiviral Research. 71 (2–3): 141–148. doi:10.1016/j.antiviral.2006.04.002. PMID 16675036.
  2. ^ Kropp RY, Wong T, Cormier L, Ringrose A, Burton S, Embree JE, Steben M (June 2006). "Neonatal herpes simplex virus infections in Canada: results of a 3-year national prospective study". Pediatrics. 117 (6): 1955–1962. doi:10.1542/peds.2005-1778. PMID 16740836. S2CID 9632498.
  3. ^ Xu F, Sternberg MR, Kottiri BJ, McQuillan GM, Lee FK, Nahmias AJ, et al. (August 2006). "Trends in herpes simplex virus type 1 and type 2 seroprevalence in the United States". JAMA. 296 (8): 964–973. doi:10.1001/jama.296.8.964. PMID 16926356.
  4. ^ Whitley RJ, Gnann JW (February 2002). "Viral encephalitis: familiar infections and emerging pathogens". Lancet. 359 (9305): 507–513. doi:10.1016/S0140-6736(02)07681-X. PMID 11853816. S2CID 5980017.
  5. ^ Ak, Ajith Kumar; Mendez, Magda D. (2023), "Herpes Simplex Encephalitis", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID 32491575, retrieved 2023-10-02