The World Health Organization (WHO) has updated its fact sheet on Hepatitis A.

Background Information:

Hepatitis A is a liver disease caused by the hepatitis A virus.

The virus is primarily spread when an uninfected (and unvaccinated) person ingests food or water that is contaminated with the faeces of an infected person.

The disease is closely associated with unsafe water or food, inadequate sanitation and poor personal hygiene.

Unlike hepatitis B and C, hepatitis A infection does not cause chronic liver disease and is rarely fatal, but it can cause debilitating symptoms and fulminant hepatitis (acute liver failure), which is often fatal.

The hepatitis A virus is one of the most frequent causes of foodborne infection.

Hepatitis A viruses persist in the environment and can withstand food-production processes routinely used to inactivate and/or control bacterial pathogens.

Key Messages:

Transmission

The hepatitis A virus is transmitted primarily by the faecal-oral route; that is when an uninfected person ingests food or water that has been contaminated with the faeces of an infected person.

In families, this may happen though dirty hands when an infected person prepares food for family members. Waterborne outbreaks, though infrequent, are usually associated with sewage-contaminated or inadequately treated water.

Symptoms

The incubation period of hepatitis A is usually 14–28 days.

Symptoms of hepatitis A range from mild to severe, and can include

• fever,
• malaise,
• loss of appetite,
• diarrhoea,
• nausea,
• abdominal discomfort,
• dark-coloured urine and
• jaundice (a yellowing of the skin and whites of the eyes). 

Not everyone who is infected will have all of the symptoms.

Who is at risk? 

Anyone who has not been vaccinated or previously infected can get infected with hepatitis A virus.

Risk factors in intermediate and high endemicity areas include:

• poor sanitation;
• lack of safe water;
• use of recreational drugs;
• living in a household with an infected person;
• being a sexual partner of someone with acute hepatitis A infection; and
• travelling to areas of high endemicity without being immunized.

Diagnosis

Cases of hepatitis A are not clinically distinguishable from other types of acute viral hepatitis.

Specific diagnosis is made by the detection of HAV-specific Immunoglobulin G (IgM) antibodies in the blood.

Treatment

There is no specific treatment for hepatitis A.

Recovery from symptoms following infection may be slow and may take several weeks or months.

Most important is the avoidance of unnecessary medications. Acetaminophen / Paracetamol and medication against vomiting should not be given.

Hospitalization is unnecessary in the absence of acute liver failure.

Prevention

Improved sanitation, food safety and immunization are the most effective ways to combat hepatitis A.

The spread of hepatitis A can be reduced by:

• adequate supplies of safe drinking water;
• proper disposal of sewage within communities; and
• personal hygiene practices such as regular hand-washing with safe water.

Several injectable inactivated hepatitis A vaccines are available internationally. 

No vaccine is licensed for children younger than 1 year of age. In China, a live oral vaccine is also available.

Useful Links:

Link to the updated fact sheet:

http://who.int/mediacentre/factsheets/fs328/en/

Link to the WHO position paper on Hepatitis A vaccines:

Click to access wer8728_29.pdf

Link to the ‘Global Policy report on the prevention and control of viral hepatitis in WHO member states’:

http://apps.who.int/iris/bitstream/10665/85397/1/9789241564632_eng.pdf?ua=1