Microbiology & infectious diseases
Viruses
HSV1 / HSV2
Author: Christopher S. Hale, M.D.
Last author update: 1 February 2014
Last staff update: 18 October 2021
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: HSV1 / HSV2
Table of Contents
Definition / general | Etiology | Laboratory | Treatment | Gross description | Molecular / cytogenetics description | Additional referencesCite this page: Hale C. HSV1 / HSV2. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/microbiologyHSV12.html. Accessed December 22nd, 2024.
Definition / general
- Alpha subfamily of Herpesviridae = Herpes simplex virus-1, herpes simplex virus-2, and herpes B virus (a zoonotic pathogen found in primates)
- Herpes simplex virus-1 = Human herpes virus-1 (HHV1)
- Herpes simplex virus-2 = Human herpes virus-2 (HHV2)
- See also topics in these chapters: Penis and scrotum, Vulva
Etiology
- HSV1: more often "oral herpes" (gingivostomatitis, fever, lymphadenopathy), although increasingly a cause of genital infections
- HSV2: "genital herpes" (vesicles, fever, lymphadenopathy, dysuria)
- Neonatal herpes: maternal to infant transmission of HSV1 or 2 → CNS, skin, ocular, systemic infection
- Meningitis or encephalitis: severe complication of HSV1 or HSV2 infection, often involves temporal lobe, often fatal
- Ocular infection: conjunctivitis / uveitis / retinitis
- Esophageal infection
- Cutaneous infections:
- Herpes gladiatorum: cutaneous herpes infection affecting wrestlers, transmitted through contact
- Herpetic whitlow: infection of fingertip
- Eczema herpeticum: "Kaposi varicelliform eruption" sometimes used as synonym; disseminated cutaneous herpes infection with overlapping features of atopic dermatitis (PLoS Med 2004;1:e17)
Laboratory
- Culture conditions:
- Culture less sensitive than molecular, but near 100% specific if confirmatory tests run
- Must collect in viral transport medium (VTM)
- Richards viral transport and HH medium best transport media when transport is > 1 day or if low levels of virus (Diagn Microbiol Infect Dis 1994;19:137)
- Transport specimen cold, but not frozen
- Avoid swabs with wooden shafts or calcium alginate heads (J Infect Dis 1982;145:399)
- Culture techniques include growth in standard eukaryotic cell lines such as Hep-2 or human diploid fibroblasts (Diagn Microbiol Infect Dis 1991;14:373)
- Infected cell cultures may be examined for characteristic viral cytopathic effects (inclusions, multinucleation, etc.)
- Newer molecular techniques increasingly preferred (PCR, multiplex PCR) over viral culture (Clin Microbiol Rev 2008;21:716)
- Serology (change in titer, IgM to IgG switch) may assist in determining exposure or time course of disease
- Direct fluorescent antibody (DFA) kits
- Enzyme immunoassay (EIA) kits
- Tzanck smear:
- A Giemsa or Wright stain used for morphologic identification of viral cytopathic effects
- Cytopathic effects include the "3 Ms:" molding of nuclei, multinucleation, and margination of chromatin to the periphery of the nucleus
- Cannot distinguish HSV1, HSV2, and Varicella Zoster Virus by Tzanck smear
Treatment
- DNA synthesis inhibitors (acyclovir and others) often used for treatment / suppresion (CDC: Gential Ulcers [Accessed 18 October 2021])
- Long term suppression therapy reduces risk of transmission (Expert Rev Anti Infect Ther 2009;7:559)
- Resistance to DNA synthesis inhibitors is increasing; consider combination therapy (Curr Opin Infect Dis 2013;26:551)
Gross description
- Infected cells show focal lysis, multinucleation (ASM: Cytopathic Effects of Viruses [Accessed 18 October 2021])
Molecular / cytogenetics description
- Molecular identification techniques (nucleic acid amplification testing) replacing traditional diagnostics in some settings (Curr Issues Mol Biol 2007;9:87)
- PCR: most sensitive method of detecting HSV infections, used for CSF / ocular / neonatal infections
Additional references
