Hepatitis A is an acute, self-limited liver infection caused by the hepatitis A virus (HAV). The virus has a worldwide distribution and is endemic in Central and South America, Africa, India, the Middle East and Asia.
Seroprevalence rates for HAV are low in Canada. In Ontario, overall incidence of HAV has declined since 2002. In 2017, there were 63 cases reported to Toronto Public Health, with an incidence of 2.2 cases per 100,000 persons. The majority of infections (63 per cent) occurred in males.
Remember to report all suspect or confirmed cases of hepatitis A infection for Toronto residents to Toronto Public Health’s Surveillance Unit at 416-392-7411 during work hours (8:30 a.m. to 4:30 p.m., Monday to Friday) or 3-1-1 after hours.
Clinical Signs & Symptoms
- Symptoms of hepatitis A may begin with a prodrome that lasts one to seven days, including:
- fever
- malaise
- anorexia
- nausea
- abdominal pain
- Adults may then develop jaundice, dark urine, pale stools, pruritis and hepatomegaly. Fulminant hepatitis and liver failure are uncommon but can occur.
- Children are usually asymptomatic or have a very mild infection. Adults tend to present with more severe disease.
Transmission
- Humans are the main reservoir for hepatitis A virus (HAV). Transmission occurs predominantly via the fecal-oral route.
- HAV can be acquired by:
- direct contact with infected individuals
- ingestion of contaminated food and/or water
- sexual activity that includes direct oral-anal contact
- drug-sharing (including intravenous drug use)
- blood-borne transmission is less common
- The incubation period is 15-50 days (on average it is 28-30 days).
- Persons with HAV are infectious from two weeks before the onset of clinical illness to one week after the onset of jaundice.
Diagnosis
All patients with suspected Hepatitis A (HAV) should have confirmatory serologic testing (both anti-HAV IgM and IgG):
- IgM antibodies are detectable five to10 days after infection is acquired.
- IgM antibodies indicate acute infection; they can be falsely positive if patients have been recently vaccinated (within two weeks).
- The presence of IgG antibodies indicates immunity/previous infection.
Infection Prevention and Control (IPAC)
- Patient education should emphasize:
- proper hand hygiene practices
- limiting food-handling activities and sharing of common food items during the infectious period
- availability of post-exposure prophylaxis for exposed contacts
- Any individual with suspected or confirmed hepatitis A virus (HAV) who is employed in one of the following areas should be advised to refrain from these activities until the diagnosis is ruled out:
- food handlers
- childcare staff or attendees
- health care workers
- An occupational history is critical in anyone with suspected HAV.
- If HAV is confirmed, the infected individual should not return to these activities until 14 days after the onset of symptoms, or seven days after the onset of jaundice, whichever is earlier.
- Infection prevention and control (IPAC) considerations for inpatients:
- Adults with hepatitis A infection should be managed using routine practices.
- Children and incontinent or non-compliant adults should be managed using contact precautions and in a single room.
- Duration of precautions:
- less than three years of age: for the duration of hospital stay
- greater than three years of age: one week from symptom onset
More Information
Provincial Infectious Diseases Advisory Committee (PIDAC) Routine Practices and Additional Precautions in All Health Care Settings
Post-Exposure Prophylaxis (PEP)
- Toronto Public Health will provide health care providers with post-exposure prophylaxis (PEP) for contacts as indicated.
- PEP consists of one dose of hepatitis A vaccine (combined vaccines are not recommended), immunoglobulin or both.
- One dose of hepatitis vaccine is indicated for healthy children over six months of age and adults.
- Immunoglobulin should be provided, in addition to hepatitis A vaccine, for:
- adults over 50 years
- immunocompromised patients
- patients with chronic liver disease
- Infants less than six months should receive immunoglobulin only.
- PEP should be provided as soon as possible and within 14 days of exposure.