Interim Northern Ontario and Indigenous Immunization Strategy for Hepatitis A
Interim Northern Ontario and Indigenous Immunization Strategy for Hepatitis A
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Quick facts
Ontario is recommending an interim immunization strategy for people living in and visiting Northern Ontario and parts of Manitoba, to support the prevention and control of hepatitis A.
To date, Ontario has identified four cases of hepatitis A that have been genetically linked to the ongoing Manitoba outbreak.
Overall, hepatitis A cases in Halton are relatively low, and the majority are travel related. The most recent locally acquired case occurred in 2025.
Report suspected/confirmed cases of hepatitis A immediately to Public Health by calling 311 or 905-825-6000.
Key messages for healthcare providers
Manitoba outbreak update and expansion of Ontario’s targeted outbreak vaccination strategy:
The initial outbreak that primarily affected the Northern Manitoba area, has now expanded to other areas of Manitoba, most notably in Winnipeg among the homeless and underhoused populations.
Ontario recommends, as part of an interim immunization strategy, that individuals six months and older receive one dose of publicly funded hepatitis A vaccine if they are from the following groups:
Individuals who live, work, travel to, or receive visitors from ANY Indigenous community in Manitoba
Individuals in Northern Ontario communities that are on or in close proximity to the border with Manitoba
Individuals who are homeless or underhoused AND are going to or spending time anywhere in Manitoba
Individuals who work or volunteer or provide services in shelters, encampments, or similar settings in Winnipeg
Hepatitis A is an acute viral infection that is most commonly transmitted through the fecal-oral route, including person to person spread or exposure to contaminated food or water.
Symptoms are often abrupt and may include fever, malaise, abdominal discomfort, loss of appetite, fatigue, nausea, and jaundice. Symptoms typically develop 28 to 30 days after exposure but can take as long as 50 days.
Hepatitis A virus (HAV) IgM testing is used to assess for recent or acute infection and should generally be reserved for individuals with symptoms consistent with hepatitis A infection or those with a relevant exposure history.
HAV IgG testing is used to assess immunity from previous infection or vaccination.
