All Topics  
Varicella zoster virus

 
Varicella Zoster Virus

 
   Email Print
   Bookmark   Link
 

 

Varicella zoster virus
 
 
  Topics Varicella zoster virus Topic Home

Varicella zoster virus (VZV) is one of eight herpes viruses
Herpesviridae

The Herpesviridae are a large family of DNA viruses that cause diseases in animals, including humans. The members of this family are also known as herpesviruses....
 known to infect humans (and other vertebrates). It commonly causes chicken-pox in children and both shingles and postherpetic neuralgia
Postherpetic neuralgia

Postherpetic neuralgia is a neuralgia caused by the varicella zoster virus. Typically, the neuralgia is confined to a dermatomic area of the skin and follows an outbreak of herpes zoster in that same dermatomic area....
 in adults.

cella zoster virus is known by many names, including: chickenpox virus, varicella virus, zoster virus, and human herpes virus type 3 (HHV-3).

ary VZV infection results in chickenpox
Chickenpox

Chickenpox or chicken pox is a highly contagious illness caused by primary infection with varicella zoster virus . It generally begins with a vesicular skin rash appearing in two or three waves, mainly on the body and head rather than the hands and becoming itchy raw pockmarks, small open sores which heal mostly without scarring....
 (varicella), which may rarely result in complications including encephalitis
Encephalitis

Not to be confused with syphilis, although that can cause encephalitis as well.Encephalitis is an Acute inflammation of the brain.Encephalitis with meningitis is known as meningoencephalitis....
 or pneumonia
Pneumonia

Pneumonia is an Inflammation illness of the lung. Frequently, it is described as lung parenchyma/alveolus inflammation and abnormal alveolar filling with fluid ....
.






Discussion
Ask a question about 'Varicella zoster virus'
Start a new discussion about 'Varicella zoster virus'
Answer questions from other users
Full Discussion Forum



Encyclopedia


Varicella zoster virus (VZV) is one of eight herpes viruses
Herpesviridae

The Herpesviridae are a large family of DNA viruses that cause diseases in animals, including humans. The members of this family are also known as herpesviruses....
 known to infect humans (and other vertebrates). It commonly causes chicken-pox in children and both shingles and postherpetic neuralgia
Postherpetic neuralgia

Postherpetic neuralgia is a neuralgia caused by the varicella zoster virus. Typically, the neuralgia is confined to a dermatomic area of the skin and follows an outbreak of herpes zoster in that same dermatomic area....
 in adults.

Nomenclature

Varicella zoster virus is known by many names, including: chickenpox virus, varicella virus, zoster virus, and human herpes virus type 3 (HHV-3).

Human disease

Primary VZV infection results in chickenpox
Chickenpox

Chickenpox or chicken pox is a highly contagious illness caused by primary infection with varicella zoster virus . It generally begins with a vesicular skin rash appearing in two or three waves, mainly on the body and head rather than the hands and becoming itchy raw pockmarks, small open sores which heal mostly without scarring....
 (varicella), which may rarely result in complications including encephalitis
Encephalitis

Not to be confused with syphilis, although that can cause encephalitis as well.Encephalitis is an Acute inflammation of the brain.Encephalitis with meningitis is known as meningoencephalitis....
 or pneumonia
Pneumonia

Pneumonia is an Inflammation illness of the lung. Frequently, it is described as lung parenchyma/alveolus inflammation and abnormal alveolar filling with fluid ....
. Even when clinical symptoms of chickenpox have resolved, VZV remains dormant in the nervous system
Nervous system

The nervous system is a Neural network of specialized cells that communicate information about an animal's surroundings and itself. It processes this information and causes reactions in other parts of the body....
 of the infected person (virus latency
Virus latency

Virus latency is the ability of a pathogenic virus to lie dormancy within a cell, denoted as the lysogenic part of the viral life cycle. A latent viral infection is a type of persistent viral infection which is distinguished from a chronic viral infection....
), in the trigeminal
Trigeminal nerve

The trigeminal nerve is responsible for sensation in the face. Sensory information from the face and body is processed by parallel pathways in the central nervous system....
 and dorsal root ganglia
Dorsal root ganglion

In anatomy and neurology, the dorsal root ganglion is a nodule on a dorsal root that contains cell bodies of neurons in afferent nerve spinal nerves....
. In about 10-20% of cases, VZV reactivates later in life producing a disease known as herpes zoster
Herpes zoster

Herpes zoster , commonly known as shingles, is a viral disease characterized by a painful skin rash with blisters in a limited area on one side of the body, often in a stripe....
 or shingles. Serious complications of shingles include postherpetic neuralgia
Postherpetic neuralgia

Postherpetic neuralgia is a neuralgia caused by the varicella zoster virus. Typically, the neuralgia is confined to a dermatomic area of the skin and follows an outbreak of herpes zoster in that same dermatomic area....
, zoster multiplex, myelitis, herpes ophthalmicus, or zoster sine herpete.

Morphology


VZV is closely related to the herpes simplex virus
Herpes simplex virus

Herpes simplex virus 1 and 2 are two species of the herpes virus family, Herpesviridae, which cause infections in humans. Eight members of herpes virus infect humans to cause a variety of illnesses including cold sores, chickenpox or varicella, shingles or herpes zoster , cytomegalovirus , and various cancers, and can cause brain...
es (HSV), sharing much genome
Genome

In classical genetics, the genome of a diploid organism including eukarya refers to a full set of chromosomes or genes in a gamete; thereby, a regular somatic cell contains two full sets of genomes....
 homology. The known envelope glycoproteins (gB, gC, gE, gH, gI, gK, gL) correspond with those in HSV, however there is no equivalent of HSV gD. VZV also fails to produce the LAT (latency-associated transcripts) that play an important role in establishing HSV latency (herpes simplex virus
Herpes simplex virus

Herpes simplex virus 1 and 2 are two species of the herpes virus family, Herpesviridae, which cause infections in humans. Eight members of herpes virus infect humans to cause a variety of illnesses including cold sores, chickenpox or varicella, shingles or herpes zoster , cytomegalovirus , and various cancers, and can cause brain...
). VZV virons are spherical and 150-200 nm in diameter. Their lipid
Lipid

Lipids are broadly defined as any fat-soluble , naturally-occurring molecule, such as fats, oils, waxes, cholesterol, sterols, fat-soluble vitamins , monoglycerides, diglycerides, phospholipids, and others....
 envelope encloses the nucleocapsid of 162 capsomeres arranged in an icosahedral form. Its DNA
DNA

Deoxyribonucleic acid is a nucleic acid that contains the genetics instructions used in the development and functioning of all known living organisms and some viruses....
 is a single, linear, double-stranded molecule, 125,000 nt long. The capsid is surrounded by a number of loosely associated proteins known collectively as the tegument; many of these proteins play critical roles in initiating the process of virus reproduction in the infected cell. The tegument is in turn covered by a lipid envelope studded with glycoproteins that are displayed on the exterior of the virion.

The virus is very susceptible to disinfectants, notably sodium hypochlorite
Sodium hypochlorite

Sodium hypochlorite is a chemical compound with the chemical formula NaClO. Sodium hypochlorite solution, commonly known as bleach, is frequently used as a disinfectant or a bleaching agent....
. Within the human body it can be treated by a number of drugs and therapeutic agents including aciclovir
Aciclovir

Aciclovir or acyclovir , chemical name acycloguanosine, is a guanosine nucleic acid analogues antiviral drug, marketed under trade names such as Cyclovir, Herpex, Acivir, Zovirax and Zovir ....
, zoster-immune globulin
Zoster-immune globulin

Zoster-immune globulin is a globulin fraction of pooled blood plasma extracted from human donors who have recovered from infection by herpes zoster. ZIG is used in the prevention and treatment of chickenpox....
 (ZIG), and vidarabine
Vidarabine

Vidarabine is an anti-viral drug which is active against herpes simplex and varicella zoster viruses....
.

Vaccine

A live attenuated VZV Oka/Merck strain vaccine
Vaccine

A vaccine is a biological preparation that establishes or improves immunity to a particular disease.Vaccines can be prophylaxis , or Medication ....
 is available and is marketed in the United States under the trade name Varivax. It was developed by Merck, Sharp & Dohme
Merck & Co.

Merck & Co., Inc. , also known as Merck Sharp & Dohme or MSD outside the USA and Canada, is one of the largest pharmaceutical companies in the world....
 in the 1980s from the Oka strain virus isolated and attenuated by Michiaki Takahashi and colleagues in the 1970s. It was submitted to the U.S. Food and Drug Administration
Food and Drug Administration

The U.S. Food and Drug Administration is an Government agency of the United States Department of Health and Human Services and is responsible for regulating and supervising the safety of foods, dietary supplements, Medications, vaccines, Biopharmaceutical, blood transfusion, medical devices, Electromagnetic radiation-emitting devices, veteri...
 for approval in 1990 and was approved in 1995. Since then, it has been added to the recommended vaccination schedules for children in Australia
Australia

Australia, officially the Commonwealth of Australia, is a country in the southern hemisphere comprising the Australia of the world's smallest continent, the major island of Tasmania, and numerous list of islands of Australia in the Indian Ocean and Pacific Oceans....
, the United States
United States

The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
, and many other countries. Varicella vaccination has raised concerns in some that the immunity induced by the vaccine may not be lifelong, possibly leaving adults vulnerable to more severe disease as the immunity from their childhood immunization wanes. Vaccine coverage in the United States in the population recommended for vaccination is approaching 90%, with concomitant reductions in the incidence of varicella cases, and hospitalizations and deaths due to VZV. So far, clinical data has proved that the vaccine is effective for over 10 years in preventing varicella infection in healthy individuals and when breakthrough infections do occur, illness is typically mild.. In 2007, the ACIP recommended a second dose of vaccine before school entry to ensure the maintenance of high levels of varicella immunity.

In 2006, the FDA approved Zostavax
Zostavax

Zostavax is a live vaccine developed by Merck & Co. which has been shown to reduce the incidence of herpes zoster by 51.3% in a pivotal phase III study of 38,000 adults aged 60 and older who received the vaccine....
 for the prevention of shingles. Zostavax is a more concentrated formulation of the Varivax vaccine, designed to elicit an immune response in older adults whose immunity to VZV wanes with advancing age.

See also

  • Progressive outer retinal necrosis
    Progressive outer retinal necrosis

    Progressive outer retinal necrosis , also known as Varicella zoster virus retinitis , is an aggressive, Necrosis inflammation of the eye's retina caused by herpes varicella zoster virus....
  • Simian varicella virus
    Simian varicella virus

    The Simian Varicella Virus or SVV infects primates and shares clinical, pathological, immunological, and virological features with varicella-zoster virus infection of humans....


External links