[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Microbiology](https://durgical.com/en/microbiology/) › Human herpesviruses [Microbiology](https://durgical.com/en/microbiology/) · [Viruses](https://durgical.com/en/microbiology/#d-virus) # Human herpesviruses - Viruses Enveloped DNA viruses that, after the first infection, stay latent for life and can reactivate. Updated 2026-11-01 ## What they are There are eight human herpesviruses (HSV-1, HSV-2, VZV, EBV, CMV, HHV-6, HHV-7 and HHV-8); here HHV-6 and HHV-7 share a page. All carry linear double-stranded DNA and an envelope taken from the nuclear membrane. Their hallmark is latency: the virus persists in neurons or immune cells and returns when cell-mediated immunity falls. ## What they share - Linear double-stranded DNA, icosahedral capsid, tegument and envelope - Replicate and assemble in the nucleus: intranuclear inclusions and multinucleated giant cells - Alpha (HSV-1, HSV-2, VZV): latency in sensory ganglia, fast cycle - Beta (CMV, HHV-6, HHV-7): slow cycle and enlarged cells (cytomegaly); CMV persists in myeloid cells, salivary glands and kidney - Gamma (EBV, HHV-8): latency in B cells, oncogenic potential ## Key points - Latency: HSV-1 in the trigeminal ganglion, HSV-2 in sacral ganglia, VZV in dorsal root and cranial nerve ganglia, EBV in B cells, CMV in monocytes. - Nucleoside analogues (acyclovir, valacyclovir) need the viral thymidine kinase of HSV and VZV; ganciclovir depends on the CMV UL97 kinase. - Foscarnet and cidofovir do not need activation by the viral kinase: they are the fallback for resistance. - Varicella and disseminated zoster need airborne and contact precautions; most other herpesviruses need standard precautions only. - Oncogenic viruses worth knowing: HPV (cervix, anus, oropharynx), HBV and HCV (hepatocellular carcinoma), EBV (Burkitt, nasopharynx, Hodgkin), HHV-8 (Kaposi sarcoma) and HTLV-1 (adult T-cell leukemia/lymphoma). ## Microorganisms in this group - [**Herpes simplex virus 1** The virus behind cold sores; it sleeps in the nerves of the face and rarely causes severe encephalitis. Exam priority: high](https://durgical.com/en/microbiology/herpes-simplex-virus-1/) - [**Herpes simplex virus 2** A sexually transmitted virus that causes recurrent genital herpes and can infect a newborn during birth. Exam priority: high](https://durgical.com/en/microbiology/herpes-simplex-virus-2/) - [**Varicella-zoster virus** The virus of childhood chickenpox that, years later, can reactivate as shingles (herpes zoster) in one dermatome. Exam priority: high](https://durgical.com/en/microbiology/varicella-zoster-virus/) - [**Epstein–Barr virus** A virus spread by saliva that causes infectious mononucleosis and is linked to some lymphomas and carcinomas. Exam priority: medium](https://durgical.com/en/microbiology/epstein-barr-virus/) - [**Cytomegalovirus** A very common virus that usually goes unnoticed but is the main congenital infection and causes severe disease in the immunocompromised. Exam priority: medium](https://durgical.com/en/microbiology/cytomegalovirus/) - [**Human herpesviruses 6 and 7** Herpesviruses that cause roseola in infants: several days of high fever and, as it breaks, a pink rash. Exam priority: medium](https://durgical.com/en/microbiology/human-herpesviruses-6-and-7/) - [**Human herpesvirus 8** A herpesvirus that causes Kaposi sarcoma, mainly in people with AIDS or after an organ transplant. Exam priority: medium](https://durgical.com/en/microbiology/human-herpesvirus-8/) ## Test yourself Think of the answer, then tap the question to see it. ## Where does varicella-zoster virus stay latent? In the sensory dorsal root and cranial nerve ganglia; when it reactivates it causes herpes zoster in the matching dermatome. ## Which herpesviruses are oncogenic? The gammaherpesviruses: EBV (Burkitt lymphoma, nasopharyngeal carcinoma, Hodgkin) and HHV-8 (Kaposi sarcoma, primary effusion lymphoma). ## Why does foscarnet work against acyclovir-resistant HSV? It inhibits the viral DNA polymerase directly, without needing phosphorylation by thymidine kinase, the enzyme that usually mutates. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/microbiology/groups/human-herpesviruses/) [← All of microbiology](https://durgical.com/en/microbiology/) 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); [Clinical Overview of Shingles (Herpes Zoster)](https://www.cdc.gov/shingles/hcp/clinical-overview/index.html) (CDC, 2024); [Clinical Overview of CMV and Congenital CMV](https://www.cdc.gov/cytomegalovirus/hcp/clinical-overview/index.html) (CDC, 2024); [Clinical Overview of Epstein-Barr Virus (EBV)](https://www.cdc.gov/epstein-barr/hcp/clinical-overview/index.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/groups/human-herpesviruses/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/microbiology/groups/human-herpesviruses/