For health professionals: Hepatitis A

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What health professionals need to know about hepatitis A

The hepatitis A virus is a member of the Picornaviridae family and Hepatovirus genus. It is an icosahedral, non-enveloped, positive-sense ribonucleic acid virus.

There have been 7 hepatitis A genotypes identified (I-VII), 4 of which are of human origin (I, II, III and VII).

Clinical manifestations

Hepatitis A only causes acute hepatitis and is not associated with chronic liver disease. However, individuals with pre-existing liver disease may suffer severe complications.

Most individuals infected with hepatitis A develop non-specific constitutional signs and symptoms followed by gastrointestinal symptoms.

The disease course typically lasts less than 2 months.

In rare cases, hepatitis A can cause severe cases of fulminant hepatitis with fatal outcomes in otherwise healthy adults.


A number of techniques have been employed to detect hepatitis A virus, including:

  • immunoblotting
  • radioimmunoassay
  • dot-blot gold filtration
  • real-time polymerase chain reaction (RT-PCR)
  • enzyme-linked immunosorbent assays (ELISA)


Vaccination can prevent the onset of symptoms in those exposed if given within 2 weeks of exposure.

No specific treatment for hepatitis A virus infection has been shown to be effective.

However, the following treatments are recommended:

  • bed rest
  • balanced nutrition
  • avoidance of alcohol or other hepatotoxins

Prevention and control

Hepatitis A is one of the most common vaccine-preventable illnesses in travellers. The vaccine is recommended for persons 1 year of age and older who are at increased risk of:

  • infection
  • severe hepatitis A

All persons who wish to decrease their risk of becoming infected with the hepatitis A virus should be vaccinated. Hepatitis A vaccines have demonstrated at least 90% to 97% effectiveness in preventing clinical illness.

In particular, the following groups are recommended to be vaccinated for hepatitis A prevention:

  • travellers to or immigrants from hepatitis A-endemic areas
  • household or close contacts of children adopted from hepatitis A-endemic countries
  • populations or communities at risk of hepatitis A outbreaks or in which hepatitis A is highly endemic
    • for example, some Indigenous communities
  • military personnel and humanitarian relief workers likely to be posted to areas with high rates of hepatitis A

Additional at-risk groups recommended to be vaccinated include:

  • persons with lifestyle risks for infection, including:
    • men who have sex with men
    • those who use illicit drugs (injectable and non-injectable)
  • zoo keepers, veterinarians and researchers who handle non-human primates
  • people with hemophilia A or B receiving plasma-derived replacement clotting factors
  • workers involved in research on the hepatitis A virus or the production of the hepatitis A vaccine
  • persons who have chronic liver disease from any cause, including persons infected with hepatitis B or C
    • these persons may be at risk of more severe disease if infection occurs

Hepatitis A surveillance in Canada

You must report hepatitis A cases to your local medical officer of health.

Health professionals in Canada play a critical role in identifying and reporting cases of hepatitis A. Refer to the surveillance section for more information on surveillance in Canada.

Consult the national case definition for additional information.

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