Human hepatitis A virus (HAV) is a member of the family Picornaviridae and the genus Hepatovirus. It is a small, non-enveloped, single-stranded RNA virus that specifically infects the liver. HAV is the etiological agent of hepatitis A, which is an acute infectious disease characterized by inflammation and dysfunction of the liver.
HAV is highly contagious and is primarily transmitted through the fecal-oral route. This means that the virus is commonly contracted through ingestion of contaminated food or water, or by close contact with an infected individual. The virus can also be transmitted through certain sexual practices and through intravenous drug use.
Upon entering the body, the virus primarily replicates in hepatocytes, the main functional cells of the liver, leading to inflammation and liver damage. The incubation period for HAV infection ranges from 15 to 50 days, with symptoms typically manifesting within 4 weeks of exposure.
Symptoms of hepatitis A include fatigue, fever, loss of appetite, nausea, vomiting, abdominal pain, and jaundice. However, in some cases, particularly in young children, the disease may occur without noticeable symptoms. Most people who contract hepatitis A experience a complete recovery within a few weeks to several months. However, in rare cases, the infection can progress to a severe form, leading to liver failure, which can be life-threatening.
Prevention of HAV infection primarily involves proper sanitation practices, such as handwashing with soap and water, and vaccination. The hepatitis A vaccine provides long-lasting protection against the virus and is recommended for individuals at increased risk of HAV infection, including travelers to high-risk areas, men who have sex with men, and individuals with chronic liver disease.
