Seroprevalences of hepatitis B virus and hepatitis C virus among participants of an Asian health fair in the Lower Mainland, British Columbia

BACKGROUND: The seroprevalences of hepatitis B virus (HBV) and hepatitis C virus (HCV) are 0.4% and 0.8%, respectively, in Canada, but varying rates have been reported in different populations. OBJECTIVES: To determine the seroprevalences of HBV and HCV among attendees of an Asian health fair in the Lower Mainland, British Columbia, as well as to correlate questionnaire answers regarding vaccination status to serological profiles. METHODS: Attendees at an Asian health fair were invited to participate in the present study on a voluntary basis. They provided answers to a questionnaire including ethnicity and vaccination status. Blood was then drawn for HBV and HCV serology. Active HBV was defined as HBV surface antigen (HBsAg) positive while HCV seroprevalence was defined as HCV antibody reactive. Previous exposure to HBV was defined as HBV core antibody (anti-HBc) positive and HBsAg negative. Nonimmunity was defined as anti-HBc negative and HBV surface antibody negative. Only those with correct demographic information matched to serological results were included in the study. RESULTS: There were 192 consenting attendees of the fair, of whom 112 were included in the study. Of the participants, 91% were Chinese. Active HBV infection was found in three participants (2.7% [95% CI 0.6% to 7.6%]) and HCV infection was found in two participants (1.8% [95% CI 0.2% to 6.3%]). More than 40% of participants had been previously exposed to HBV (42% [95% CI 33% to 51%]). Almost 20% demonstrated nonimmunity to HBV (19% [95% CI 12% to 27%]). There was significant discordance when questionnaire answers regarding vaccination status were compared with serological profiles. CONCLUSION: The seroprevalences of HBV and HCV in this cohort were 2.7% and 1.8%, respectively – higher than nationally reported rates. Our results highlight that the lack of knowledge of HBV infection and vaccination status remains a significant clinical issue in the Asian community of British Columbia.