What is Hepatitis A?

What is Hepatitis A?

What is Hepatitis A?

Hepatitis A is a viral liver disease caused by the hepatitis A virus (HAV). Hepatitis A virus is an undeveloped RNA virus and is considered a picornavirus. Humans are the only natural host of this virus.(1) The hepatitis A virus is very stable and can remain present for several months in most environments. The virus, however, can be killed by high temperatures (above 85°) or by solutions such as chlorine or formalin.(2-3)

Hepatitis A is contracted orally and is typically acquired by contact with human fecal waste, generally through consumption of contaminated food and/or water.(4) Sources of contamination may include raw shellfish, fruits and vegetables, and ice.(5)

Hepatitis A replicates in the liver and can be found in the bloodstream within 10 to 12 days of exposure. The virus is excreted from the biliary system in the feces of a contaminated individual.(6) An infected individual can spread hepatitis A to others for one to two weeks before becoming symptomatic.(7-8) Virus excretion may persist longer in children than in adults, however, by the third week of illness, most infected individuals no longer excrete the virus in the stool.(9)

Symptoms of hepatitis A appear on average four weeks (two to seven weeks) after exposure. Symptoms often come on suddenly and include fatigue, abdominal and/or joint pain, loss of appetite, fever, nausea, jaundice, dark urine, clay-colored bowel movements, and diarrhea. Young children are often asymptomatic and show no clinical signs of infection.(10) Most infected individuals recover completely within two months, but approximately 10 to 15 percent of infected individuals may have persistent symptoms for up to six months.(11)

Hepatitis A infection does not cause chronic liver disease(12) and people who recover from the disease develop lifelong immunity.(13)

Is hepatitis A contagious?

Hepatitis A is contagious and spreads from person to person through exposure to oral contact with the feces of an infected person.1 (14) Infection can occur following exposure to water or food contaminated with the virus. Sources of contamination can include raw shellfish, vegetables, fruit and even contaminated ice.(15) Transmission of the virus through blood is very rare.(16) Hepatitis A thrives in areas without adequate sanitation and where personal hygiene habits are poor.(17) Contaminated water sources can also be a source of transmission. Hepatitis A can infect drinking water through several sources, including malfunctioning sewer systems, pollution from stormwater runoff, and sewage overflows.(18) Wells can also be contaminated if they are shallow or if floodwaters have submerged them for long periods of time.(19)

Hepatitis A is endemic in many areas of the world, including Africa, the Middle East, the Western Pacific, Asia, and Central and South America.(20) People traveling to developing countries with high or intermediate levels of hepatitis A are at increased risk of contracting the virus and developing the infection.(21)

Since 2016, several states have reported hepatitis A outbreaks linked primarily to people experiencing homelessness and among individuals who use drugs.(22) Between the end of 2016 and January 6, 2023, more than 44.700 cases were reported, resulting in 27.332 hospitalizations and 421 deaths.(23) It is believed that the increased number of hospitalizations and deaths that have occurred during this ongoing epidemic can be attributed to cofactors such as pre-existing health conditions, hepatitis B and C co-infections, age, and additional risk behaviors found in this particular population.(24)

This article is summarized and translated by National Vaccine Information Center.

IMPORTANT NOTE: Corvelva invites you to get in-depth information by reading all the sections and links, as well as the manufacturer's product leaflets and technical data sheets, and to speak with one or more trusted professionals before deciding to vaccinate yourself or your child. This information is for informational purposes only and is not intended as medical advice.

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