What is hepatitis A?

Hepatitis A is an inflammation of the liver caused by the hepatitis A virus (HAV). The virus spreads through contaminated food or water and through direct contact with an infected person. Common symptoms of a hepatitis A infection can include fatigue, fever, loss of appetite, nausea and vomiting, dark urine and jaundice.

Hepatitis A can be prevented with vaccination and by taking care to avoid contact with infected people. Hepatitis A does occur in developed countries, but is more common in developing countries. Travellers from Australia or other developed nations can be at risk if not vaccinated. 

Jaundice

A yellowing of the skin, the whites of the eyes and the mucous membranes, due to an accumulation of bilirubin in the blood. Often a symptom of liver problems.

Vaccination

The practice of administering a vaccine, a solution containing a microorganism (that causes a specific disease) in a dead or weakened state, or parts of it, for the purpose of inducing immunity in a person to that microorganism.

Causes

Hepatitis A is caused by the hepatitis A virus (HAV). It leads to inflammation and damage to the liver and digestive system. The virus moves between people via the faecal-oral route - meaning that you catch it when you accidentally come in contact with an infected person's stools (faeces). This can occur in the following situations:

  • Drinking water or eating food contaminated with human faeces. Uncooked shellfish from water polluted with human sewage is especially notorious for harbouring hepatitis A;
  • Sex with an infected person, particularly with oral-anal contact;
  • Direct contact with an infected person's faeces, such as when changing nappies, and;
  • Touching a surface or object that was previously touched by an infected person who has not washed their hands well.

Digestive system

The series of organs within the body that contribute to the digestion of food. It begins at the mouth and ends at the anus, and includes the stomach, small and large intestines as well as the pancreas, gallbladder and liver.

Risk factors

People at particular risk of infection include:

  • Sexual partners of people with hepatitis A. There is a higher risk in men who have sex with men;
  • People sharing a household with a person with hepatitis A;
  • People who live in, or have travelled to, countries where sanitation is poor and hepatitis A is common, and;
  • Childcare and healthcare workers.

Street food vendor.Poor sanitation can transmit hepatitis A. 

Signs and symptoms

Many people who have been infected with hepatitis A are not aware of it. About 30% of infected adults and up to 90% of infected children show no signs or symptoms at all. [1 ] Symptoms are generally worse in older children and adults. Young children can have hepatitis A and pass it on without experiencing any symptoms. If symptoms do appear, they typically do so after an incubation period of 2-6 weeks.

Symptoms of hepatitis A may include:

  • Fatigue;
  • Loss of appetite;
  • Nausea and vomiting;
  • In smokers, a distaste for cigarettes;
  • Dark urine;
  • Muscle and joint pain;
  • Itchy skin;
  • Jaundice - a yellowing of the skin and/or eyes (this only appears in one out of five people);
  • Fever;
  • Pain in the abdomen, and;
  • Diarrhoea.

Symptoms normally clear up within a few weeks, but the virus can persist for 2 to 3 months.

Jaundice

A yellowing of the skin, the whites of the eyes and the mucous membranes, due to an accumulation of bilirubin in the blood. Often a symptom of liver problems.

1. Shetty N. Tang J.W. and Andrews J. (2009) Infectious disease: Pathogenesis Prevention and Case Studies (1st edition). Chichester UK: Wiley-Blackwell.

Methods for diagnosis

Since the symptoms of hepatitis A are very similar to those of the more serious types of hepatitis (hepatitis B and hepatitis C), it is important to diagnose it correctly. Your doctor may suspect a hepatitis A infection based on your symptoms and your recent medical history. Hepatitis A can then be diagnosed by blood tests. These tests can measure liver function and detect the presence of virus particles and antibodies, which the body's immune system produces in response to the virus.

The hepatitis A virus can often be hard to detect soon after infection has occurred. It may take several weeks before the presence of virus particles, or the body's immune reaction to them, are reliably picked up by blood tests.

Antibodies

A protein molecule produced by the immune system. Antibodies bind specifically to foreign substances to neutralise them or target them for destruction.

Immune system

The organs and cells involved in protecting the body against infection.

1. Shetty N. Tang J.W. and Andrews J. (2009) Infectious disease: Pathogenesis Prevention and Case Studies (1st edition). Chichester UK: Wiley-Blackwell.

Types of treatment

There is no specific treatment for hepatitis A; treatment focuses on supporting your body's immune system as it handles the infection and easing the burden on your liver. Treatment measures include:

  • Rest;
  • Good nutrition, with a preference for small, frequent meals;
  • Plenty of fluids, and;
  • Avoiding alcohol.

Medication

Hepatitis A treatment does not require medication. However, if the symptoms affect your quality of life, your doctor may prescribe medications to relieve pain or ease nausea, as long as they do not harm your liver.

Immune system

The organs and cells involved in protecting the body against infection.

1. Shetty N. Tang J.W. and Andrews J. (2009) Infectious disease: Pathogenesis Prevention and Case Studies (1st edition). Chichester UK: Wiley-Blackwell.

Potential complications

The hepatitis A virus normally goes away by itself after a couple of months, with the symptoms usually only lasting a few weeks. The body develops immunity to the virus and you are unlikely to catch it again. In rare cases, the symptoms may persist for up to six months.

Relapse

In about 10% of cases, hepatitis A will not be completely cleared from the body and symptoms will flare up again after several weeks. [2]  This is known as a relapse.

Cholestasis

Cholestasis is an uncommon complication of hepatitis A that affects mostly older people. It is caused by blockage of the small ducts in the liver, which leads to bile accumulating in the liver. It can last for months and is characterised by jaundice, high fever, itching, weight loss and diarrhoea with pale stools. Cholestasis normally goes away on its own.

Liver failure

Very rarely, a hepatitis A infection can lead to liver failure, a serious condition in which the liver sustains significant damage and cannot operate normally. If that occurs, a liver transplant may be required. This complication is more common in older people who either have other liver problems or have a weak immune system.

Bile

A fluid made in the liver and stored in the gall bladder.

Immune system

The organs and cells involved in protecting the body against infection.

Jaundice

A yellowing of the skin, the whites of the eyes and the mucous membranes, due to an accumulation of bilirubin in the blood. Often a symptom of liver problems.

2. Matheny S.C. and Kingery J.E. (2012). Hepatitis A. American Family Physician 86:1027–1034.

Prognosis

Unlike other types of hepatitis, hepatitis A does not develop into a chronic condition. The acute phase of the disease typically goes away on its own after a few weeks.

2. Matheny S.C. and Kingery J.E. (2012). Hepatitis A. American Family Physician 86:1027–1034.

Prevention

Vaccination

The best protection is a vaccine against hepatitis A. In many countries, children are now vaccinated against hepatitis A at an early age. Vaccinations are available for unvaccinated adults and older children who intend to travel to areas where hepatitis A is common.

It is important to note that the vaccine does not protect against other types of hepatitis.

Vaccination.The best protection against hepatitis A is a vaccination. 

Passive immunisation

A different kind of hepatitis A vaccine can be given just before or just after exposure to hepatitis A. Known as passive immunisation, this vaccine consists of antibodies against the hepatitis A virus. It is effective only for a few weeks.

Avoiding exposure

Since hepatitis A spreads through contaminated water and food, a good way of avoiding infection is practising good food-handling measures and avoiding eating uncooked food from dubious sources.

Antibodies

A protein molecule produced by the immune system. Antibodies bind specifically to foreign substances to neutralise them or target them for destruction.

Vaccinations

The practice of administering a vaccine, a solution containing a microorganism (that causes a specific disease) in a dead or weakened state, or parts of it, for the purpose of inducing immunity in a person to that microorganism.

2. Matheny S.C. and Kingery J.E. (2012). Hepatitis A. American Family Physician 86:1027–1034.