NCBI Bookshelf. Dahlia Saleh ; Sandeep Sharma. Authors Dahlia Saleh 1 ; Sandeep Sharma 2. Herpes simplex virus type 1 HSV-1 is a member of the Alphaherpesviridae subfamily. Its structure is composed of linear dsDNA, an icosahedral capsid that is to nm in diameter, with a spikey envelope.
Fragmentary evidence has accumulated to suggest a connection between the HSV-1 and oral cancer and precancer. HSV-2 is a sexually transmitted infection that causes genital herpes. Review Management of non-genital herpes simplex virus infections in immunocompetent patients. Expression of late genes occurs last; this group of genes Female porn star molds encode proteins that form the virion particle. Epidemiologically, it is important to note that herpes encephalitis is the leading cause of lethal encephalitis in the United States, and ocular HSV infection is a common cause of blindness in the United States. Reprinted with permission from Chumley H. Multinucleated keratinocytes may contain Cowdry A inclusions, which are eosinophilic nuclear inclusions that can also be seen in Oral herpes simplex virus iii herpesviruses such as varicella-zoster virus VZV and cytomegalovirus CMV. Envelope glycoprotein. This is a rare condition, occurring in an estimated 10 out of everybirths globally, but can lead to lasting neurologic Oral herpes simplex virus iii or death.
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Birth-acquired herpes is a potentially life-threatening condition caused by the herpes simplex virus. These tests are generally expensive. HSV type 2 normally affects the genital area, but may also occur in the mouth. Southfield Michigan Works. Learn how to tell if you have…. You may need any of the following to help manage symptoms:. So caution is important. SafeKids-Oakland County Herpes simplex is a common viral infection. Subscribe to our newsletters.
The sexual transmission of some types of HSV is also possible.
- The herpes simplex virus, also known as HSV, is an infection that causes herpes.
- Oral herpes as the name suggests occur on mouth and are also known as Herpes labialis, fever blisters or cold sores.
- This material must not be used for commercial purposes, or in any hospital or medical facility.
- Herpes Simplex III.
Herpes simplex virus 1 and 2 HSV-1 and HSV-2 , also known by their taxonomical names Human alphaherpesvirus 1 and Human alphaherpesvirus 2 , are two members of the human Herpesviridae family , a set of viruses that produce viral infections in the majority of humans. They can be spread when an infected person begins shedding the virus.
Many of those who are infected never develop symptoms. Sometimes, the viruses cause mild or atypical symptoms during outbreaks. As neurotropic and neuroinvasive viruses , HSV-1 and -2 persist in the body by hiding from the immune system in the cell bodies of neurons.
After the initial or primary infection, some infected people experience sporadic episodes of viral reactivation or outbreaks. In an outbreak, the virus in a nerve cell becomes active and is transported via the neuron's axon to the skin, where virus replication and shedding occur and cause new sores.
In another study, 73 subjects were randomized to receive valaciclovir 1 g daily or placebo for 60 days each in a two-way crossover design. A daily swab of the genital area was self-collected for HSV-2 detection by polymerase chain reaction, to compare the effect of valaciclovir versus placebo on asymptomatic viral shedding in immunocompetent, HSV-2 seropositive subjects without a history of symptomatic genital herpes infection.
Both viruses may also be transmitted vertically during childbirth. The risk is considerable when the mother is infected with the virus for the first time during late pregnancy. An example of this is herpetic whitlow , which is a herpes infection on the fingers.
This was a common affliction of dental surgeons prior to the routine use of gloves when conducting treatment on patients. Animal herpes viruses all share some common properties. The structure of herpes viruses consists of a relatively large, double-stranded, linear DNA genome encased within an icosahedral protein cage called the capsid , which is wrapped in a lipid bilayer called the envelope. The envelope is joined to the capsid by means of a tegument. This complete particle is known as the virion.
These genes and their functions are summarized in the table below. Early gene expression follows, to allow the synthesis of enzymes involved in DNA replication and the production of certain envelope glycoproteins.
Expression of late genes occurs last; this group of genes predominantly encode proteins that form the virion particle. Entry of HSV into a host cell involves several glycoproteins on the surface of the enveloped virus binding to their transmembrane receptors on the cell surface. Many of these receptors are then pulled inwards by the cell, which is thought to open a ring of three gHgL heterodimers stabilizing a compact conformation of the gB glycoprotein, so that it springs out and punctures the cell membrane.
At first, complementary receptors on the virus and the cell surface bring the viral and cell membranes into proximity. Interactions of these molecules then form a stable entry pore through which the viral envelope contents are introduced to the host cell.
The virus can also be endocytosed after binding to the receptors, and the fusion could occur at the endosome. In the case of a herpes virus, initial interactions occur when two viral envelope glycoprotein called glycoprotein C gC and glycoprotein B gB bind to a cell surface particle called heparan sulfate. Next, the major receptor binding protein, glycoprotein D gD , binds specifically to at least one of three known entry receptors.
The nectin receptors usually produce cell-cell adhesion, to provide a strong point of attachment for the virus to the host cell.
The interaction of these membrane proteins may result in a hemifusion state. After the viral capsid enters the cellular cytoplasm , it is transported to the cell nucleus. Once attached to the nucleus at a nuclear entry pore, the capsid ejects its DNA contents via the capsid portal.
The capsid portal is formed by 12 copies of portal protein, UL6, arranged as a ring; the proteins contain a leucine zipper sequence of amino acids , which allow them to adhere to each other. In the host cell, TAP transports digested viral antigen epitope peptides from the cytosol to the endoplasmic reticulum, allowing these epitopes to be combined with MHC class I molecules and presented on the surface of the cell.
Viral epitope presentation with MHC class I is a requirement for activation of cytotoxic T-lymphocytes CTLs , the major effectors of the cell-mediated immune response against virally-infected cells.
Following infection of a cell, a cascade of herpes virus proteins, called immediate-early, early , and late, is produced. In the case of HSV-1, no protein products are detected during latency, whereas they are detected during the lytic cycle. The early proteins transcribed are used in the regulation of genetic replication of the virus. The viral genome immediately travels to the nucleus, but the VHS protein remains in the cytoplasm.
The late proteins form the capsid and the receptors on the surface of the virus. Here, concatemers of the viral genome are separated by cleavage and are placed into formed capsids. HSV-1 undergoes a process of primary and secondary envelopment. The primary envelope is acquired by budding into the inner nuclear membrane of the cell.
This then fuses with the outer nuclear membrane, releasing a naked capsid into the cytoplasm. The virus acquires its final envelope by budding into cytoplasmic vesicles. HSVs may persist in a quiescent but persistent form known as latent infection, notably in neural ganglia.
LAT regulates the host cell genome and interferes with natural cell death mechanisms. By maintaining the host cells, LAT expression preserves a reservoir of the virus, which allows subsequent, usually symptomatic, periodic recurrences or "outbreaks" characteristic of nonlatency.
Whether or not recurrences are symptomatic, viral shedding occurs to infect a new host. A protein found in neurons may bind to herpes virus DNA and regulate latency. When bound to the viral DNA elements, histone deacetylation occurs atop the ICP4 gene sequence to prevent initiation of transcription from this gene, thereby preventing transcription of other viral genes involved in the lytic cycle. The whole sequence is then encapsuled in a terminal direct repeat.
The herpes simplex 1 genomes can be classified into six clades. This suggests that the virus may have originated in East Africa. It has also been reported that HSV-1 and HSV-2 can have contemporary and stable recombination events in hosts simultaneously infected with both pathogens. All of the cases are HSV-2 acquiring parts of the HSV-1 genome, sometimes changing parts of its antigen epitope in the process.
Another analysis has estimated the mutation rate in the herpes simplex 1 genome to be 1. The herpes viruses establish lifelong infections thus cannot be eradicated from the body. Treatment usually involves general-purpose antiviral drugs that interfere with viral replication, reduce the physical severity of outbreak-associated lesions, and lower the chance of transmission to others. Studies of vulnerable patient populations have indicated that daily use of antivirals such as aciclovir  and valaciclovir can reduce reactivation rates.
The virus interacts with the components and receptors of lipoproteins , which may lead to the development of Alzheimer's disease. A retrospective study from Taiwan on 33, patients found that being infected with herpes simplex virus increased the risk of dementia 2.
However, HSV-infected patients who were receiving anti-herpetic medications acyclovir, famciclovir, ganciclovir, idoxuridine, penciclovir, tromantadine, valaciclovir, or valganciclovir showed no elevated risk of dementia compared to patients uninfected with HSV. Multiplicity reactivation MR is the process by which viral genomes containing inactivating damage interact within an infected cell to form a viable viral genome.
MR was originally discovered with the bacterial virus bacteriophage T4, but was subsequently also found with pathogenic viruses including influenza virus, HIV-1, adenovirus simian virus 40, vaccinia virus, reovirus, poliovirus and herpes simplex virus.
When HSV particles are exposed to doses of a DNA damaging agent that would be lethal in single infections, but are then allowed to undergo multiple infection i. HSV-1, upon infecting host cells, induces inflammation and oxidative stress. Modified Herpes simplex virus is considered as a potential therapy for cancer and has been extensively clinically tested to assess its oncolytic cancer killing ability. Herpes simplex virus is also used as a transneuronal tracer defining connections among neurons by virtue of traversing synapses.
However, it prevents atherosclerosis which histologically mirrors atherosclerosis in humans in target animals vaccinated. From Wikipedia, the free encyclopedia. Species of virus. This article is about the virus. For information about the disease caused by the virus, see Herpes simplex. This article is about the human viruses. For for the genus of animalian simplex viruses, see Simplexvirus. Main article: Herpes simplex. Play media. Please expand the article to include this information.
Further details may exist on the talk page. May Main article: Oncolytic herpes virus. Main article: Viral neuronal tracing. Sherris Medical Microbiology 4th ed. McGraw Hill. Pediatr Rev. World Health Organization. December 11, Retrieved September 22, Genital herpes is common in the United States. Infectious Diseases in Obstetrics and Gynecology. Retrieved J R Soc Interface. J Clin Invest. Sex Transm Dis.
Annual Review of Medicine. New England Journal of Medicine. Retrieved 16 July Virus Res. Virus Genes.
Shortcuts Address Telephone Alerts. Southfield Area Chamber of Commerce. Your doctor may check your body for sores and ask you about some of your symptoms. Michigan Advocacy Center. They may also transmit the virus to others. You may also need any of the following:.
Oral herpes simplex virus iii. What are oral herpes simplex virus infections?
Herpes Simplex Type 1 - StatPearls - NCBI Bookshelf
NCBI Bookshelf. Dahlia Saleh ; Sandeep Sharma. Authors Dahlia Saleh 1 ; Sandeep Sharma 2. Herpes simplex virus type 1 HSV-1 is a member of the Alphaherpesviridae subfamily. Its structure is composed of linear dsDNA, an icosahedral capsid that is to nm in diameter, with a spikey envelope. In general, the pathogenesis of HSV-1 infection follows a cycle of primary infection of epithelial cells, latency primarily in neurons, and reactivation.
HSV-1 is responsible for establishing primary and recurrent vesicular eruptions, primarily in the orolabial and genital mucosa. HSV-1 infection has a wide variety of presentations, including orolabial herpes, herpetic sycosis HSV folliculitis , herpes gladiatorum, herpetic whitlow, ocular HSV infection, herpes encephalitis, Kaposi varicelliform eruption eczema herpeticum , and severe or chronic HSV infection.
Antiviral therapy limits the course of HSV infection. The major risk factor for herpetic sycosis is close shaving with a razor blade in the presence of an acute orolabial infection.
It has been postulated that these mutations inhibit normal interferon-based responses. The major risk factor for eczema herpeticum is skin barrier dysfunction. This can be seen in atopic dermatitis, Darier disease, Hailey-Hailey disease, mycosis fungoides, and all types of ichthyosis.
The increased risk is also associated with mutations in the filaggrin gene, which is seen in atopic dermatitis and ichthyosis vulgaris. Pharmaceutical risk factors for eczema herpeticum include the use of topical calcineurin inhibitors such as pimecrolimus and tacrolimus.
Non-primary initial infection is defined as infection with one HSV subtype in patients who already have antibodies to the other HSV type i. Approximately 1 in newborns in the United States experience a neonatal herpes simplex virus infection, resulting from HSV exposure during vaginal delivery. Women with recurrent genital herpes have a low risk of vertically transmitting HSV to their neonate.
However, women who acquire a genital HSV infection during pregnancy have a higher risk. Epidemiologically, it is important to note that herpes encephalitis is the leading cause of lethal encephalitis in the United States, and ocular HSV infection is a common cause of blindness in the United States.
HSV-1 begins to replicate at the site of infection mucocutaneous and then proceeds to travel by retrograde flow down an axon to the dorsal root ganglia DRG. It is in the DRG that latency is established. This latency period allows the virus to remain in a non-infectious state for a variable amount of time before reactivation.
HSV-1 is sly in its ability to evade the immune system via several mechanisms. Normally, these CD1d molecules are transported to the cell surface, where the antigen is presented resulting in the stimulation of natural killer T-cells, thus promoting immune response.
When CD1d molecules are sequestered intercellularly, the immune response is inhibited. HSV-1 has several other mechanisms by which it down-regulates various immunologic cells and cytokines. Classic, though not pathognomonic, histologic findings for HSV infection include ballooning degeneration of keratinocytes and multinucleated giant cells. Multinucleated keratinocytes may contain Cowdry A inclusions, which are eosinophilic nuclear inclusions that can also be seen in other herpesviruses such as varicella-zoster virus VZV and cytomegalovirus CMV.
There is no pathognomonic histologic finding for HSV-1 infection, and therefore, clinical correlation is crucial during histopathologic evaluation. It is important to note that HSV-1 infection is frequently asymptomatic. When symptoms do occur, there is a wide range of clinical presentations including orolabial herpes, herpetic sycosis HSV folliculitis , herpes gladiatorum, herpetic whitlow, ocular HSV infection, herpes encephalitis, Kaposi varicelliform eruption eczema herpeticum , and severe or chronic HSV-1 infection.
In children, symptomatic orolabial HSV-1 infections often present as gingivostomatitis that leads to pain, halitosis, and dysphagia. In adults, it can present as pharyngitis and a mononucleosis-like syndrome. Symptoms of a primary orolabial infection occur between three days and one week after the exposure. Patients will often experience a viral prodrome consisting of malaise, anorexia, fevers, tender lymphadenopathy, localized pain, tenderness, burning, or tingling prior to the onset of mucocutaneous lesions.
Primary HSV-1 lesions usually occur on the mouth and lips. Patients will then demonstrate painful grouped vesicles on an erythematous base. These vesicles exhibit a characteristic scalloped border. These vesicles may then progress to pustules, erosions, and ulcerations.
Within 2 to 6 weeks, the lesions crust over and symptoms resolve. Symptoms of recurrent orolabial infection are typically milder than those of primary infection, with a hour prodrome of tingling, burning, and itch. Recurrent orolabial HSV-1 infections classically affect the vermillion border of the lip as opposed to the mouth and lips as seen in primary infection. Initial or recurrent HSV-1 infections may affect the hair follicle, and when this occurs, it is termed herpetic sycosis HSV folliculitis.
This will present on the beard area of a male with a history of close razor blade shaving. Lesions exist on a spectrum ranging from scattered follicular papules with erosion to large lesions involving the entire beard area. Herpetic sycosis is self-limited, with a resolution of eroded papules within 2 to 3 weeks.
Lesions of herpes gladiatorum will be seen on the lateral neck, side of the face, and forearms within 4 to 11 days after exposure. A high suspicion for this diagnosis is crucial in athletes, as this is commonly misdiagnosed as bacterial folliculitis. HSV-1 infection can also occur on the digits or periungual, causing herpetic whitlow.
Herpetic whitlow presents as deep blisters that may secondarily erode. A common misdiagnosis is an acute paronychia or blistering dactylitis. Herpetic whitlow can also lead to lymphadenopathy of the epitrochlear or axillary lymph nodes in association with lymphatic streaking, mimicking bacterial cellulitis.
Primary ocular HSV presents with keratoconjunctivitis that can be unilateral or bilateral. There can be associated eyelid tearing, edema, photophobia, chemosis swelling of the conjunctiva , and preauricular lymphadenopathy. It is common for patients to experience recurrence, and in these cases, it is usually unilateral. Ocular HSV is a common cause of blindness in the United States when it manifests as keratitis or a branching dendritic corneal ulcer which is pathognomonic for ocular HSV.
It primarily affects the temporal lobe of the brain leading to bizarre behavior and focal neurological deficits localized to the temporal lobe.
Patients may have a fever and altered mental status as well. Kaposi varicelliform eruption, or eczema herpeticum, presents as an extensive spreading of HSV infection in the setting of a compromised skin barrier e.
Patients will display 2 to 3 mm punched-out erosions with hemorrhagic crusts in widespread distribution.
There may be secondary impetigo with Staphylococcus or Streptococcus species. Neonatal herpes virus presents at day 5 to 14 of life and favors the scalp and the trunk. It may present with disseminated cutaneous lesions and involvement of oral and ocular mucosa. Central nervous system CNS involvement may occur and manifest as encephalitis with lethargy, poor feeding, bulging fontanelle, irritability, and seizures. In the immunocompromised patient population, HSV infection can result in severe and chronic infection.
It is not uncommon for patients to have respiratory or gastrointestinal tract involvement and present with dyspnea or dysphagia. However, serology remains the gold standard. The DFA assay, however, can distinguish between the 2 entities. For the treatment of orolabial herpes, the current recommendation is oral valacyclovir 2 grams twice daily for one day.
If the patient has frequent outbreaks, chronic suppression is warranted. For immunocompromised patients with severe and chronic HSV, treatment is aimed at chronic suppression. The differential diagnosis of orolabial HSV-1 infection includes aphthous stomatitis, Stevens-Johnson syndrome, erythema multiforme EM major, and herpangina. These entities can be distinguished from orolabial herpes by history and physical exam findings.
The differential diagnosis of herpetic whitlow includes blistering dactylitis and acute or chronic paronychia. The majority of the time, HSV-1 infection follows a chronic course of latency and reactivation. Herpes type 1 infections are best managed by a multidisciplinary team that includes the primary provider, pediatrician, nurse practitioner, infectious disease specialist and the internist.
The key to treatment is starting the antiviral within 24 hours of symptoms. To access free multiple choice questions on this topic, click here. This book is distributed under the terms of the Creative Commons Attribution 4.
Turn recording back on. National Center for Biotechnology Information , U. StatPearls [Internet]. Search term. Affiliations 1 Sampson Regional Medical Center. Histopathology Classic, though not pathognomonic, histologic findings for HSV infection include ballooning degeneration of keratinocytes and multinucleated giant cells. Differential Diagnosis The differential diagnosis of orolabial HSV-1 infection includes aphthous stomatitis, Stevens-Johnson syndrome, erythema multiforme EM major, and herpangina.
Enhancing Healthcare Team Outcomes Herpes type 1 infections are best managed by a multidisciplinary team that includes the primary provider, pediatrician, nurse practitioner, infectious disease specialist and the internist.
Questions To access free multiple choice questions on this topic, click here. References 1. Herpesvirus: an underestimated virus. Folia Microbiol. Genotyping of herpes simplex virus type 1 by whole-genome sequencing. Jiang Y, Leib D. Preventing neonatal herpes infections through maternal immunization. Future Virol.
Clin J Sport Med. Notes from the field: outbreak of skin lesions among high school wrestlers--Arizona, MMWR Morb.