Viral hepatitis is a major source of morbidity and mortality around the world. Acute hepatitis, chronic liver disease, and hepatocellular cancer are all possible outcomes. A number of DNA viruses have been linked to viral hepatitis. These include the hepatitis B and C viruses, as well as the hepatitis E virus.
The Hepatitis B virus (HBV) is a DNA virus that causes viral hepatitis. It is most usually transmitted from mothers to newborns during pregnancy (perinatal transmission) or horizontally (exposure to infected blood). Infection with Hepatitis B can result in severe liver damage and even liver cancer.Chronic hepatitis B infection can go undetected for decades until it causes liver problems such as cirrhosis or liver failure. The Hepatitis B virus enters the cell via binding to a particular protein on the cell's surface known as nucleotide transfer protein (NTP). A hepatitis B virus DNA polymerase inserts its pre-genomic RNA into the capsid once inside the cell. To create the (+) DNA strand, the pgRNA undergoes reverse transcription. After that, it is transformed into covalently closed circular DNA (cccDNA). This cccDNA serves as a template for the synthesis of viral mRNA by a host RNA polymerase. The hepatitis B virus then replicates and infects new cells, resulting in the production of additional viral particles. The Hepatitis C virus (HCV) causes the disease. Blood-to-blood contact is used to propagate this single-stranded RNA virus. A speck of blood, which is imperceptible to the naked eye, can contain hundreds of HCV particles. Hepatitis C is most commonly transmitted through needlesticks or other blood-related equipment used to manufacture or inject narcotics. The hepatitis C virus can also be spread from an infected woman to her unborn child during pregnancy or through sex-to-sex contact. These transmission modes are less prevalent. The hepatitis C virus is a leading cause of liver disease and can result in life-threatening conditions such as liver failure, cirrhosis, and malignancy. Antiviral medications are particularly effective in treating it. However, diagnosis and treatment are difficult to obtain. Hepatitis E virus (HEV) is the leading cause of intestinal hepatitis globally. It is typically transmitted through fecal-oral contact, although it can also be transferred through person-to-person contact and blood transfusions. HEV is a single-stranded, positive-sense RNA virus with a diameter of 27–34 nm that belongs to the Hepeviridae family. It contains four genotypes that are harmful to mammals. Pigs, deer, rabbits, and humans are the most common HEV hosts. Other mammals, such as dogs and cats, may also be susceptible to infection. HEV infection causes an acute illness that typically lasts a few weeks. Hepatitis E can cause severe hepatitis and fulminant hepatitis in rare cases, necessitating hospitalization and treatment. It can be more severe in those who have an immune system that is weakened or in pregnant women. Pregnant women who contract hepatitis E are at increased risk of miscarriage, fulminant liver failure, and death. Hepatitis is an inflammation of the liver caused by a variety of factors, such as viruses, other illnesses, alcohol, and medications. It can be self-limiting or lead to fibrosis (scarring), cirrhosis, or liver cancer. The most prevalent cause of hepatitis is viral infection. Each of the five hepatitis viruses causes a somewhat different type of liver damage. Viral hepatitis is liver inflammation caused by infection with one of these five types of viruses, another virus, an autoimmune illness, or medicines that harm the liver. A lack of appetite, nausea, vomiting, and fever are the most typical symptoms. The hepatitis F virus was discovered in 1994 and is thought to be responsible for some cases of hepatitis that spread through contaminated food or water. This virus has also been linked to post-transfusion hepatitis in children who have had liver transplants. The explanation for this is uncertain; however, it could be related to how hepatitis F impacts blood coagulation.
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