Hepatitis B surveillance in Canada: 2005-2012

Abstract

Objective: To describe surveillance trends by age, sex and infection status of Hepatitis B (HB) virus in Canada between 2005 and 2012. Methods: Data on acute and chronic HB cases reported to the Canadian Notifiable Disease Surveillance System were compiled at the national level to examine trends by age and sex over time. Time trends are presented from 2005 to 2012, corresponding to the availability of data differentiated by acute and chronic infection status. Results: The rate of reported acute HB infections decreased from 1.0 to 0.6 per 100,000 between 2005 and 2012. Both sexes showed rate decreases over this time, although acute HB rates were consistently higher among males than females. The rate of reported chronic HB infections decreased from 14.1 to 12.0 per 100,000 between 2009 and 2012. These results are based on data in which infection status was specified. The proportion of unspecified cases in any given year may somewhat alter the results. Conclusion: This is the first time that trends in reported cases and corresponding rates of HB in Canada have been examined by acute and chronic infection status using national surveillance data. Canada continues to have a downward trend in HB rates across Canada, most notably in acute HB cases. Increasing national capacity to differentiate between acute and chronic HB will facilitate a more thorough understanding of trends in transmission and of the burden of HB infection in Canada.