[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Microbiology](https://durgical.com/en/microbiology/) › [Human herpesviruses](https://durgical.com/en/microbiology/groups/human-herpesviruses/) › Herpes simplex virus 2 [Microbiology](https://durgical.com/en/microbiology/) · [Human herpesviruses](https://durgical.com/en/microbiology/groups/human-herpesviruses/) # Herpes simplex virus 2 - Virus - Enveloped - Contact - Exam priority: high A sexually transmitted virus that causes recurrent genital herpes and can infect a newborn during birth. Updated 2026-11-01 Also called: HSV-2, genital herpes ## Key points - Latency in the sacral ganglia. - Neonatal herpes: the highest risk is maternal primary infection late in pregnancy. - Active genital lesions at the start of labor: an indication for cesarean delivery. - Neonatal herpes: contact precautions until lesions are dry and crusted. ## At a glance **Shape** Icosahedral with tegument and envelope **Genome** Linear double-stranded DNA **Envelope** Enveloped **Family** Herpesviridae (alphaherpesvirus) **Size** About 150 to 200 nm ## Morphology - Same structure as HSV-1, with which it shares much of its genome - Multinucleated giant cells with intranuclear inclusions in lesion scrapings ## Transmission - Sexual contact, often from a person without symptoms - Perinatal: passage through a birth canal shedding virus **Reservoir:** Humans ### Isolation precautions What the care team adds to standard precautions. **Contact** Gown and gloves; dedicated equipment. For C. difficile, soap-and-water hand washing. ## Virulence factors - Latency in the sacral ganglia - Recurs and sheds in the genital area more often than HSV-1 - Genital ulcers raise the risk of acquiring and passing on HIV ## Diseases it causes - Primary and recurrent genital herpes - Neonatal herpes (skin, eye and mouth; central nervous system; disseminated) [Congenital (TORCH) infections: syphilis, toxoplasmosis, CMV and Zika →](https://durgical.com/en/conditions/congenital-infections-syphilis-toxoplasmosis-cmv-and-zika/) - Aseptic meningitis ## Clinical picture - Painful genital vesicles and ulcers, with inguinal lymphadenopathy - The first episode can be severe, with fever, dysuria and neurologic involvement - Neonatal risk is high when the mother acquires infection near delivery and low with known recurrent herpes ## Diagnosis - PCR (NAAT) of the lesion, typed as HSV-1 or HSV-2 - Type-specific serology when there are no lesions; IgM testing is not recommended - In the newborn: PCR of surface swabs, blood and cerebrospinal fluid ## Treatment Acyclovir, valacyclovir or famciclovir for the first episode, recurrences or suppression; intravenous acyclovir in the newborn. Resistant strains are usually resistant to valacyclovir and often to famciclovir; foscarnet is then used. Drug class only; doses and regimens are set by the clinician from the current guideline. In Pharmacology: - [Aciclovir](https://durgical.com/en/pharmacology/aciclovir/) - [Valaciclovir](https://durgical.com/en/pharmacology/valaciclovir/) - [Famciclovir](https://durgical.com/en/pharmacology/famciclovir/) - [Foscarnet](https://durgical.com/en/pharmacology/foscarnet/) ## Prevention - Condoms and avoiding sex during active lesions - Antiviral suppression late in pregnancy for mothers with recurrent herpes - Cesarean delivery if genital lesions are present at the start of labor - Contact precautions for a newborn with herpes and for disseminated or severe primary mucocutaneous disease ## Memory aid Type 2 lives downstairs: sacral ganglia, genitals and the birth canal. ## Test yourself Think of the answer, then tap the question to see it. ## When in pregnancy is genital HSV infection most dangerous for the newborn? When the mother acquires it near delivery, because she has not yet passed protective antibodies to the baby. ## Which precautions apply to a newborn with neonatal herpes? Standard precautions plus contact precautions until the lesions are dry and crusted. ## What is the preferred test for a genital ulcer suspected to be herpes? PCR (nucleic acid amplification) of lesion fluid, with typing of the virus. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/microbiology/herpes-simplex-virus-2/) ## Related - [Herpes simplex virus 1](https://durgical.com/en/microbiology/herpes-simplex-virus-1/) - [Human papillomavirus](https://durgical.com/en/microbiology/human-papillomavirus/) ## Related conditions - [Congenital (TORCH) infections: syphilis, toxoplasmosis, CMV and Zika](https://durgical.com/en/conditions/congenital-infections-syphilis-toxoplasmosis-cmv-and-zika/) ## What the colours mean **Gram-positive** Thick peptidoglycan wall: stains purple. **Gram-negative** Thin wall with an outer membrane: stains pink. **Acid-fast** Lipid-rich wall (mycobacteria): Ziehl–Neelsen stain. **Contact** Gown and gloves; dedicated equipment. For C. difficile, soap-and-water hand washing. **Droplet** Surgical mask within about a metre; single room. **Airborne** N95 respirator and a negative-pressure room. [← Back to the group: Human herpesviruses](https://durgical.com/en/microbiology/groups/human-herpesviruses/) Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given. Sources: [Herpes simplex virus](https://www.who.int/news-room/fact-sheets/detail/herpes-simplex-virus) (WHO, 2024); [Herpes - STI Treatment Guidelines](https://www.cdc.gov/std/treatment-guidelines/herpes.htm) (CDC, 2021); [Appendix A: Type and Duration of Precautions Recommended for Selected Infections and Conditions](https://www.cdc.gov/infection-control/hcp/isolation-precautions/appendix-a-type-duration.html) (CDC, 2024). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/microbiology/herpes-simplex-virus-2/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/microbiology/herpes-simplex-virus-2/