Hepatitis F virus

Last updated

Hepatitis F is a hypothetical virus linked to viral hepatitis. Several hepatitis F candidates emerged in the 1990s; however, none of these claims were substantiated. [1] [2] [3]

In 1994, Deka et al. reported that novel viral particles had been discovered in the stool of post-transfusion, non-hepatitis A, non-hepatitis B, non-hepatitis C, non-hepatitis E patients. [4] Injection of these particles into the bloodstream of Indian rhesus monkeys caused hepatitis, and the virus was named hepatitis F or Toga virus. Further investigations failed to confirm the existence of the virus, and it was delisted as a cause for infectious hepatitis. [3] [5]

A subsequently-discovered virus thought to cause hepatitis was named Hepatitis G, though its role in hepatitis has not been confirmed and it is now considered synonymous with GB virus C. It is an "orphan virus" with no causal links to any human disease. [6]

Related Research Articles

<span class="mw-page-title-main">Virology</span> Study of viruses

Virology is the scientific study of biological viruses. It is a subfield of microbiology that focuses on their detection, structure, classification and evolution, their methods of infection and exploitation of host cells for reproduction, their interaction with host organism physiology and immunity, the diseases they cause, the techniques to isolate and culture them, and their use in research and therapy.

<span class="mw-page-title-main">Hepatitis C</span> Human viral infection

Hepatitis C is an infectious disease caused by the hepatitis C virus (HCV) that primarily affects the liver; it is a type of viral hepatitis. During the initial infection period, people often have mild or no symptoms. Early symptoms can include fever, dark urine, abdominal pain, and yellow tinged skin. The virus persists in the liver, becoming chronic, in about 70% of those initially infected. Early on, chronic infection typically has no symptoms. Over many years however, it often leads to liver disease and occasionally cirrhosis. In some cases, those with cirrhosis will develop serious complications such as liver failure, liver cancer, or dilated blood vessels in the esophagus and stomach.

Hepatitis D is a type of viral hepatitis caused by the hepatitis delta virus (HDV). HDV is one of five known hepatitis viruses: A, B, C, D, and E. HDV is considered to be a satellite because it can propagate only in the presence of the hepatitis B virus (HBV). Transmission of HDV can occur either via simultaneous infection with HBV (coinfection) or superimposed on chronic hepatitis B or hepatitis B carrier state (superinfection).

<span class="mw-page-title-main">Hepatitis E</span> Human disease caused by Orthohepevirus A

Hepatitis E is inflammation of the liver caused by infection with the hepatitis E virus (HEV); it is a type of viral hepatitis. Hepatitis E has mainly a fecal-oral transmission route that is similar to hepatitis A, although the viruses are unrelated. In retrospect, the earliest known epidemic of hepatitis E occurred in 1955 in New Delhi, but the virus was not isolated until 1983 by Russian scientists investigating an outbreak in Afghanistan. HEV is a positive-sense, single-stranded, nonenveloped, RNA icosahedral virus and one of five known human hepatitis viruses: A, B, C, D, and E.

<i>Hepadnaviridae</i> Family of viruses

Hepadnaviridae is a family of viruses. Humans, apes, and birds serve as natural hosts. There are currently 18 species in this family, divided among 5 genera. Its best-known member is hepatitis B virus. Diseases associated with this family include: liver infections, such as hepatitis, hepatocellular carcinomas, and cirrhosis. It is the sole accepted family in the order Blubervirales.

<i>Adenoviridae</i> Family of viruses

Adenoviruses are medium-sized, nonenveloped viruses with an icosahedral nucleocapsid containing a double-stranded DNA genome. Their name derives from their initial isolation from human adenoids in 1953.

<span class="mw-page-title-main">Viral hepatitis</span> Liver inflammation from a viral infection

Viral hepatitis is liver inflammation due to a viral infection. It may present in acute form as a recent infection with relatively rapid onset, or in chronic form, typically progressing from a long-lasting asymptomatic condition up to a decompensated hepatic disease and hepatocellular carcinoma (HCC).

<span class="mw-page-title-main">Hepatitis C virus</span> Species of virus

The hepatitis C virus (HCV) is a small, enveloped, positive-sense single-stranded RNA virus of the family Flaviviridae. The hepatitis C virus is the cause of hepatitis C and some cancers such as liver cancer and lymphomas in humans.

<i>Orthohepevirus A</i> Species of virus

The hepatitis E virus (HEV) is the causative agent of hepatitis E. It is of the species Orthohepevirus A.

Virus-like particles (VLPs) are molecules that closely resemble viruses, but are non-infectious because they contain no viral genetic material. They can be naturally occurring or synthesized through the individual expression of viral structural proteins, which can then self assemble into the virus-like structure. Combinations of structural capsid proteins from different viruses can be used to create recombinant VLPs. Both in-vivo assembly and in-vitro assembly have been successfully shown to form virus-like particles. VLPs derived from the Hepatitis B virus (HBV) and composed of the small HBV derived surface antigen (HBsAg) were described in 1968 from patient sera. VLPs have been produced from components of a wide variety of virus families including Parvoviridae, Retroviridae, Flaviviridae, Paramyxoviridae and bacteriophages. VLPs can be produced in multiple cell culture systems including bacteria, mammalian cell lines, insect cell lines, yeast and plant cells.

GB virus C (GBV-C), formerly known as hepatitis G virus (HGV) and also known as human pegivirus – HPgV is a virus in the family Flaviviridae and a member of the Pegivirus, is known to infect humans, but is not known to cause human disease. Reportedly, HIV patients coinfected with GBV-C can survive longer than those without GBV-C, but the patients may be different in other ways. Research is active into the virus' effects on the immune system in patients coinfected with GBV-C and HIV.

<span class="mw-page-title-main">Astrovirus</span> Family of viruses

Astroviruses (Astroviridae) are a type of virus that was first discovered in 1975 using electron microscopes following an outbreak of diarrhea in humans. In addition to humans, astroviruses have now been isolated from numerous mammalian animal species and from avian species such as ducks, chickens, and turkey poults. Astroviruses are 28–35 nm diameter, icosahedral viruses that have a characteristic five- or six-pointed star-like surface structure when viewed by electron microscopy. Along with the Picornaviridae and the Caliciviridae, the Astroviridae comprise a third family of nonenveloped viruses whose genome is composed of plus-sense, single-stranded RNA. Astrovirus has a non-segmented, single stranded, positive sense RNA genome within a non-enveloped icosahedral capsid. Human astroviruses have been shown in numerous studies to be an important cause of gastroenteritis in young children worldwide. In animals, Astroviruses also cause infection of the gastrointestinal tract but may also result in encephalitis, hepatitis (avian) and nephritis (avian).

<span class="mw-page-title-main">Hepatitis B</span> Human viral infection

Hepatitis B is an infectious disease caused by the Hepatitis B virus (HBV) that affects the liver; it is a type of viral hepatitis. It can cause both acute and chronic infection.

<span class="mw-page-title-main">Virus</span> Infectious agent that replicates in cells

A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898, more than 11,000 of the millions of virus species have been described in detail. The study of viruses is known as virology, a subspeciality of microbiology.

<span class="mw-page-title-main">Hepatitis C virus nonstructural protein 2</span>

Nonstructural protein 2 (NS2) is a viral protein found in the hepatitis C virus. It is also produced by influenza viruses, and is alternatively known as the nuclear export protein (NEP).

<i>Hepatitis B virus</i> Species of the genus Orthohepadnavirus

Hepatitis B virus (HBV) is a partially double-stranded DNA virus, a species of the genus Orthohepadnavirus and a member of the Hepadnaviridae family of viruses. This virus causes the disease hepatitis B.

A neutralizing antibody (NAb) is an antibody that defends a cell from a pathogen or infectious particle by neutralizing any effect it has biologically. Neutralization renders the particle no longer infectious or pathogenic. Neutralizing antibodies are part of the humoral response of the adaptive immune system against viruses, intracellular bacteria and microbial toxin. By binding specifically to surface structures (antigen) on an infectious particle, neutralizing antibodies prevent the particle from interacting with its host cells it might infect and destroy.

The transmission of hepadnaviruses between their natural hosts, humans, non-human primates, and birds, including intra-species host transmission and cross-species transmission, is a topic of study in virology.

Aichivirus A formerly Aichi virus (AiV) belongs to the genus Kobuvirus in the family Picornaviridae. Six species are apart of the genus Kobuvirus, Aichivirus A-F. Within Aichivirus A, there are six different types including human Aichi virus, canine kobuvirus, murine kobuvirus, Kathmandu sewage kobuvirus, roller kobuvirus, and feline kobuvirus. Three different genotypes are found in human Aichi virus, represented as genotype A, B, and C.

<i>Ground squirrel hepatitis virus</i> Species of virus

Ground squirrel hepatitis virus, abbreviated GSHV, is a partially double-stranded DNA virus that is closely related to human Hepatitis B virus (HBV) and Woodchuck hepatitis virus (WHV). It is a member of the family of viruses Hepadnaviridae and the genus Orthohepadnavirus. Like the other members of its family, GSHV has high degree of species and tissue specificity. It was discovered in Beechey ground squirrels, Spermophilus beecheyi, but also infects Arctic ground squirrels, Spermophilus parryi. Commonalities between GSHV and HBV include morphology, DNA polymerase activity in genome repair, cross-reacting viral antigens, and the resulting persistent infection with viral antigen in the blood (antigenemia). As a result, GSHV is used as an experimental model for HBV.

References

  1. Uchida, T. (1993). "Genetic Variations of the Hepatitis B Virus and Their Clinical Relevance". Microbiol. Immunol. 37 (6): 425–39. doi: 10.1111/j.1348-0421.1993.tb03233.x . PMID   7694049.
  2. Fagan, E. A. (1994). "Acute Liver Failure of Unknown Pathogenesis: The Hidden Agenda". Hepatology. 19 (5): 1307–12. doi:10.1002/hep.1840190532. PMID   8175156. S2CID   267133.
  3. 1 2 Bowden, S. (2001). "New Hepatitis Viruses: Contenders and Pretenders". J. Gastroenterol. Hepatol. 16 (2): 124–31. doi: 10.1046/j.1440-1746.2001.02405.x . PMID   11207890.
  4. Deka N, Sharma MD, Mukerjee R (1994). "Isolation of the novel agent from human stool samples that is associated with sporadic non-A, non-B hepatitis". J. Virol. 68 (12): 7810–5. doi:10.1128/JVI.68.12.7810-7815.1994. PMC   237242 . PMID   7966570.
  5. Kelly, D., Skidmore, S. (2002). "Hepatitis C-Z: recent advances". Arch. Dis. Child. 86 (5): 339–43. doi:10.1136/adc.86.5.339. PMC   1751087 . PMID   11970925.
  6. Lefrère J. J., Laperche, S., Roudot-Thoraval, F. (April 2008). "Hepatitis G Virus: A Suitable Marker of in vivo Efficacy for Pathogen Inactivation". Vox Sang. 95 (1): 76–8. doi:10.1111/j.1423-0410.2008.01050.x. PMID   18393946. S2CID   10193248.