Hepatitis B (HBV) is a vaccine-preventable infection. People who have not been vaccinated, however, may become infected through contact with the body fluids of an HBV-infected person.
While the early stages of HBV infection may be characterized by non-specific symptoms in some, many people are asymptomatic. Consequently, people living with acute HBV may progress to chronic illness and remain undiagnosed for years until advanced liver disease and liver cancer have developed.
Early diagnosis through HBV screening, and early treatment of HBV infections, is necessary to reduce the risk of complications among those affected.
Hepatitis B in British Columbia
British Columbia (BC) reported five new cases of acute HBV in 2016; a record low attributable to province-wide childhood vaccination programs that have been in place for over two decades. However, more than a thousand new cases of chronic HBV are reported each year.
In BC, 50% of people living with chronic HBV and decompensated cirrhosis or liver cancer are diagnosed late in the course of their infection; many are diagnosed alongside or after diagnosis with advanced liver disease. This highlights the need for more effective HBV screening programs.
Purpose of research
Differences in the demographics and risk behaviors of people diagnosed with acute or chronic HBV infections may impact the public health interventions targeted at either population.
Using data from the BC Hepatitis Testers Cohort, we assessed the characteristics of individuals diagnosed with acute or chronic HBV infection between 1990 and 2015. We identified the factors associated with acute or chronic HBV infection to inform prevention and screening programs in BC.
- 46,498 of the 1,058,056 (4.4%) study participants were HBV-positive, of which 2,015 (4.3%) were diagnosed with acute HBV, and 44,483 (95.7%) with chronic HBV.
- Acute HBV infection, indicative of viral transmission, was diagnosed predominantly among males (71%), people between the ages of 25 and 34 (32%), White individuals (78%), socioeconomically disadvantaged people, and individuals with a history of substance use (alcohol dependence or injection drug use) or co-infection with HIV or hepatitis C.
- Individuals diagnosed with chronic HBV infection were predominantly older, East Asian (60%), with no history of substance use or co-infection.
- After adjusting for confounding variables, East Asians had 12 times greater odds of being diagnosed with chronic HBV infection than Whites, and these odds increased with increasing socioeconomic deprivation.
These findings highlight distinct risk patterns for individuals with acute and chronic HBV infection and underscore the need for different strategies to prevent, diagnose and treat HBV within these groups.
Optimal care for acute HBV requires the integration of HBV prevention, screening, and treatment programs with programs for mental health, addiction and other blood-borne infections. In contrast, managing chronic HBV requires screening programs for early diagnosis and treatment among at-risk ethnic groups, including foreign-born East and South Asians, with low prevalence of traditional risk factors.
For more information
This study was recently published in World Journal of Gastroenterology:
Binka M, Butt ZA, Wong S, Chong M, Buxton JA, Chapinal N, Yu A, Alvarez M, Darvishian M, Wong J, McGowan G, Torban M, Gilbert M, Tyndall M, Krajden M, Janjua NZ. Differing profiles of people diagnosed with acute and chronic hepatitis B virus infection in British Columbia, Canada. World J Gastroenterol. 2018 Mar 21;24(11):1216-1227. doi: 10.3748/wjg.v24.i11.1216.
This study was supported by the Canadian Institutes of Health Research and the BC Centre for Disease Control.