Herpesviridae is a large family of DNA viruses that cause infections and certain diseases in animals, including humans.[1][2][3] The members of this family are also known as herpesviruses. The family name is derived from the Greek word ἕρπειν (herpein 'to creep'), referring to spreading cutaneous lesions, usually involving blisters, seen in flares of herpes simplex 1, herpes simplex 2 and herpes zoster (shingles).[4] In 1971, the International Committee on the Taxonomy of Viruses (ICTV) established Herpesvirus as a genus with 23 viruses among four groups.[5] As of 2020, 115 species are recognized, all but one of which are in one of the three subfamilies.[6] Herpesviruses can cause both latent and lyticinfections.
Nine herpesvirus types are known to primarily infect humans,[7] at least five of which – herpes simplex viruses 1 and 2 (HSV-1 and HSV-2, also known as HHV-1 and HHV-2; both of which can cause orolabial herpes and genital herpes), varicella zoster virus (or HHV-3; the cause of chickenpox and shingles), Epstein–Barr virus (EBV or HHV-4; implicated in several diseases, including mononucleosis and some cancers), and human cytomegalovirus (HCMV or HHV-5) – are extremely widespread among humans. More than 90% of adults have been infected with at least one of these, and a latent form of the virus remains in almost all humans who have been infected.[8][9][10] Other human herpesviruses are human herpesvirus 6A and 6B (HHV-6A and HHV-6B), human herpesvirus 7 (HHV-7), and Kaposi's sarcoma-associated herpesvirus (KSHV, also known as HHV-8).[7]
In total, more than 130 herpesviruses are known,[11] some of them from mammals, birds, fish, reptiles, amphibians, and mollusks.[7] Among the animal herpesviruses are pseudorabies virus, the causative agent of Aujeszky's disease in pigs, and bovine herpesvirus 1, the causative agent of bovine infectious rhinotracheitis and pustular vulvovaginitis.
| Herpesviridae | |
|---|---|
 | |
Virus classification | |
| (unranked): | Virus |
| Realm: | Duplodnaviria |
| Kingdom: | Heunggongvirae |
| Phylum: | Peploviricota |
| Class: | Herviviricetes |
| Order: | Herpesvirales |
| Family: | Herpesviridae |
| Subfamilies and genera | |
See text | |
Human herpesvirus types[edit]
Below are the distinct viruses in this family known to cause disease in humans.[21][22][23]
| Name | Synonym | Subfamily | Primary Target Cell | Syndrome | Site of Latency | Means of Spread |
|---|---|---|---|---|---|---|
| HHV‑1 | Herpes simplex virus-1 (HSV-1) | α (Alpha) | Mucoepithelial | Oral and/or genital herpes, herpetic gingivostomatitis, pharyngitis, eczema herpeticum, herpetic whitlow, herpes simplex keratitis, erythema multiforme, encephalitis, as well as other herpes simplex infections | Neuron | Close contact (oral or sexually transmitted infection) |
| HHV-2 | Herpes simplex virus-2 (HSV-2) | α | Mucoepithelial | Oral and/or genital herpes, herpetic gingivostomatitis, pharyngitis, eczema herpeticum, herpetic whitlow, herpes simplex keratitis, erythema multiforme, Mollaret's meningitis, as well as other herpes simplex infections | Neuron | Close contact (oral or sexually transmitted infection) |
| HHV-3 | Varicella zoster virus (VZV) | α | Mucoepithelial | Chickenpox and shingles | Neuron | Respiratory and close contact (including sexually transmitted infection) |
| HHV-4 | Epstein–Barr virus(EBV) Lymphocryptovirus | γ (Gamma) | B cells and epithelial cells | Epstein-Barr virus-associated lymphoproliferative diseases, a large group of benign, pre-malignant, and malignant diseases including Epstein-Barr virus-positive reactive lymphoid hyperplasia, severe mosquito bite allergy, Epstein-Barr virus-positive reactive lymphoid hyperplasia, Infectious mononucleosis, Burkitt's lymphoma, Epstein–Barr virus-positive Hodgkin lymphoma, extranodal NK/T cell lymphoma, nasal type, Epstein–Barr virus-associated aggressive NK cell leukemia, CNS lymphoma in AIDS patients, post-transplant lymphoproliferative syndrome (PTLD), nasopharyngeal carcinoma, HIV-associated hairy leukoplakia | B cell | Close contact, transfusions, tissue transplant, and congenital |
| HHV-5 | Cytomegalovirus(CMV) | β (Beta) | Monocytesand epithelial cells | Infectious mononucleosis-like syndrome,[24] retinitis | Monocyte, and ? | Saliva, urine, blood, breast milk |
| HHV-6A and 6B | Roseolovirus | β | T cells and ? | Sixth disease (roseola infantum or exanthem subitum) | T cells and ? | Respiratory and close contact? |
| HHV-7 | β | T cells and ? | drug-induced hypersensitivity syndrome, encephalopathy, hemiconvulsion-hemiplegia-epilepsy syndrome, hepatitis infection, postinfectious myeloradiculoneuropathy, pityriasis rosea, and the reactivation of HHV-4, leading to "mononucleosis-like illness" | T cells and ? | ? | |
| HHV-8 | Kaposi's sarcoma-associated herpesvirus (KSHV), a type of Rhadinovirus | γ | Lymphocyte and other cells | Kaposi's sarcoma, primary effusion lymphoma, some types of multicentric Castleman's disease | B cell | Close contact (sexual), saliva? |
Zoonotic herpesviruses[edit]
In addition to the herpesviruses considered endemic in humans, some viruses associated primarily with animals may infect humans. These are zoonotic infections:
| Species | Type | Synonym | Subfamily | Human Pathophysiology |
|---|---|---|---|---|
| Macaque monkey | CeHV-1 | Cercopithecine herpesvirus 1, (monkey B virus) | α | Very unusual, with only approximately 25 human cases reported.[25] Untreated infection is often deadly; sixteen of the 25 cases resulted in fatal encephalomyelitis. At least four cases resulted in survival with severe neurologic impairment.[25][26] Symptom awareness and early treatment are important for laboratory workers facing exposure.[27] |
| Mouse | MuHV-4 | Murid herpesvirus 68(MHV-68) | γ | Zoonotic infection found in 4.5% of general population and more common in laboratory workers handling infected mice.[28] ELISA tests show factor-of-four (x4) false positive results, due to antibody cross-reaction with other herpesviruses.[28] |
Animal herpesviruses[edit]
In animal virology, the best known herpesviruses belong to the subfamily Alphaherpesvirinae. Research on pseudorabies virus (PrV), the causative agent of Aujeszky's disease in pigs, has pioneered animal disease control with genetically modified vaccines. PrV is now extensively studied as a model for basic processes during lytic herpesvirus infection, and for unraveling molecular mechanisms of herpesvirus neurotropism, whereas bovine herpesvirus 1, the causative agent of bovine infectious rhinotracheitis and pustular vulvovaginitis, is analyzed to elucidate molecular mechanisms of latency. The avian infectious laryngotracheitis virus is phylogenetically distant from these two viruses and serves to underline similarity and diversity within the Alphaherpesvirinae.[2][3]
Research[edit]
Research is currently ongoing into a variety of side-effect or co-conditions related to the herpesviruses. These include:
https://en.wikipedia.org/wiki/Herpesviridae#Human_herpesvirus_types
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