Seroprevalence of hepatitis B and C virus infections: Results from the 2007 to 2009 and 2009 to 2011 Canadian Health Measures Survey.

Background: Chronic hepatitis B (HBV) and C (HCV) virus infections can lead to liver failure, liver cancer, and death. In Canada, prevalence studies of HBV and HCV have been limited to regional and special populations.

Data And Methods: Data are from cycles 1 (2007 to 2009) and 2 (2009 to 2011) of the Canadian Health Measures. Socio-demographic, health and lifestyle information was obtained via a household questionnaire; blood samples collected at mobile examination centres were used to identify present and resolved HBV infections, vaccine-induced HBV immunity, and HCV infections.

Results: The seroprevalence of present HBV infection among the population aged 14 to 79 was 0.4%, representing an estimated 111,800 individuals. Another 4.2% had evidence of a previous HBV infection. Nearly 30% had vaccine-induced HBV immunity. The seroprevalence of HCV infection was 0.5%, representing an estimated 138,600. More than half of people with laboratory-confirmed HBV and 70% with laboratory-confirmed HCV were unaware of their infections.

Interpretation: This is the first Canadian study to report laboratory-confirmed seroprevalence of HBV and HCV infections based on a nationally representative household sample. Substantial percentages of younger Canadians have vaccine-induced HBV immunity.