In settings in which a universal anti-HDV antibody testing approach is not feasible because laboratory capacity or other resources are limited, testing for anti-HDV may be given priority in specific populations of HBsAg-positive individuals, including the following: • people born in HDV-endemic countries, regions and areas; • people with advanced liver disease, those receiving HBV treatment and those with features suggesting HDV infection (such as low HBV DNA with high ALT levels); and • people considered to have increased risk of HDV infection, including haemodialysis recipients, people living with hepatitis C or HIV, people who inject drugs, sex workers and men who have sex with men