Hepatitis A remains a significant public health concern due to its high transmissibility and potential severity for all travellers. This article provides essential guidance on prevention, management, and reporting protocols to mitigate the spread and impact of hepatitis A.

Characteristics of Hepatitis A

Hepatitis A infection is caused by the hepatitis A virus (HAV), a highly contagious virus transmitted predominantly via the fecal-oral route through contaminated food, water, or close personal contact. Anyone without immunity from previous vaccination or infection can be infected and typically presents after an incubation period of around one month (with a range of 15 to 50 days) following exposure. Clinical severity can vary widely from asymptomatic illness — seen in 70% of children under 6 years old — to a severely disabling disease lasting several months.

Onset of illness in adults is usually abrupt, presenting with fever, malaise, anorexia, nausea, abdominal discomfort, followed within a few days by jaundice.

Prolonged, relapsing hepatitis for up to 1 year occurs in around 15% of cases, though chronic infection is not known to occur. While most individuals recover completely, severe cases — especially in older adults or those with pre-existing liver disease — may progress to fulminant hepatitis. The case fatality rate is approximately 0.5% but can reach 2.6% in adults over 60 years of age.

Controlling the spread of hepatitis A can be particularly challenging not only due to frequent asymptomatic illness especially in the pediatric population, but also because maximum infectivity is thought to occur during the incubation period before any symptoms develop.

Local Epidemiology

OPH receives an average of 10 reports of hepatitis A in Ottawa residents each year (2019-2023). In 2023, 75% of Ottawa cases were related to travel to hepatitis A-endemic countries. See the CDC Yellow book for more details about hepatitis A endemicity.

Outbreaks of hepatitis A have occurred in Ontario, affecting:

• people who are homeless/underhoused,
• men who have sex with men,
• people who use drugs, and
• Children in childcare and elementary school settings and staff assisting children with toileting.

Natural History of Illness

Persons are infectious beginning about 2 weeks before symptom onset and are considered no longer infectious 7 days after the onset of jaundice. Asymptomatic infection in children still presents risk of transmission of HAV to others.

Consider hepatitis A when assessing acute onset illness with nausea, anorexia, fever, malaise, and/or abdominal pain with jaundice or elevated serum aminotransferase levels.

Testing and Reporting

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 antibodies in the blood (in acute infection initially IgM and then IgM and IgG are detectable; if IgM is non-reactive and only IgG is reactive, this would be consistent with immunity from past infection or immunization).

Information on laboratory testing is available from Public Health Ontario's web page: Hepatitis A – Serology. Please indicate diagnostic testing for acute hepatitis A infection with testing for both IgM and IgG antibodies.

• Please call Ottawa Public Health immediately at 613-580-2424, ext. 24224, to report any suspect or confirmed cases of hepatitis A.
• After hours, call 311 and ask to speak to Public Health.

Pre-exposure prophylaxis for hepatitis A

The Canadian Immunization Guide recommends pre-exposure prophylaxis for anyone at increased risk of infection, including people travelling to countries with intermediate or high hepatitis A endemicity (see the CDC Yellow book for more details about hepatitis A endemicity).

Individuals visiting an endemic country to visit friends and family, stay in rural areas or places with inadequate sanitary facilities, or attend large events may be at increased risk. Pre-departure counselling on hand hygiene, food and water precautions, and vaccination can reduce the risk of infection and dispel myths about transmission.

In Ontario, publicly funded hepatitis A vaccines can be used for pre-exposure prophylaxis of individuals who meet high risk eligibility criteria, including individuals who use injection drugs, individuals with chronic liver disease (including hepatitis B and C), and men who have sex with men. See the Publicly Funded Immunization Schedules for Ontario for more detail.

Outside of the publicly funded program, hepatitis A vaccination for pre-exposure prophylaxis must otherwise be obtained from a travel clinic or at a pharmacy with a prescription and may be covered by some private health insurance plans.

Post-exposure prophylaxis for hepatitis A

Post-exposure prophylaxis, when recommended, normally consists of hepatitis A vaccine (and possibly human immunoglobulin) as soon as possible within 14 days of last exposure to the virus to help reduce the risk of progression to clinical illness.

OPH recommends that household and close-contact exposed persons who are ≥50 years of age or persons of any age who are immune-compromised or have chronic liver disease receive both hepatitis A vaccine and human immunoglobulin (Ig). There are some exceptions, such as a low-risk exposure.

The recommendation for the addition of Ig in older persons attempts to reconcile differences in guidance from the Canadian Immunization Guide which recommends human Ig as part of post-exposure prophylaxis for susceptible adults ≥60 years of age, and the Provincial Infectious Disease Advisory Committee (PIDAC) which recommends human Ig for susceptible (i.e., non-immune) adults ≥50 years of age. (The US Advisory Committee on Immunization Practices uses >40 years for their post-exposure prophylaxis recommendation to offer Ig in addition to hepatitis A vaccine (Table 4 at https://www.cdc.gov/mmwr/volumes/69/rr/rr6905a1.htm#T4_up.) OPH recommends Ig alongside vaccine for post-exposure prophylaxis of those ≥50 years of age to provide immediate protection for those who may present a less rapid or robust response to immunization.

The OPH case management team supports the risk assessment, provides post-exposure prophylaxis recommendations, and coordinates Ig/vaccine delivery.

The initial dose of hepatitis A vaccine for post-exposure prophylaxis is publicly funded and can be ordered from OPH. For long-term protection against hepatitis A, a second dose of hepatitis A vaccine would be required 6 to 12 months (up to 36 months, depending on the vaccine received) after the first dose; second doses are not publicly funded and can be obtained at a pharmacy with a prescription.

Physician and NP Resources

• To report any suspect or confirmed cases of hepatitis A, or if you have any questions about hepatitis A case management, please contact the OPH Infectious Diseases Program reporting line at 613-580-2424 ext. 24224. After hours, call 311 and ask to speak to Public Health.
• Order vaccines from Ottawa Public Health (OPH)
• Hepatitis A vaccines: Canadian Immunization Guide, Health Canada.
• Publicly Funded Immunization Schedules for Ontario, Public Health Ontario
• CDC Yellow Book- Hepatitis A, Center for Disease Control and Prevention

Patient Resources

• What is Hepatitis A?, Ottawa Public Health
• Hepatitis A- CATIE (focus on hepatitis A as a sexually transmitted infection), Canada’s Source for HIV and Hepatitis C information
• Hepatitis A - World Health Organization (WHO) – Key facts and overview, available in Arabic, Chinese, Russian & Spanish, World Health Organization
• Hepatitis A vaccination for pre-exposure prophylaxis may be covered by some private health insurance plans.
• Plan for your health before and during travel, Health Canada.

Sandra Petersen RN, BScN, CCHN(C), CIC Nursing Project Officer
Ottawa Public Health