Part 1: The Investigators will test for active HBV infection using a rapid point-of-care HBsAg test. In addition, as a service to clients who have not had an HIV test in the past year (as recommended by Ministry of Health), for 20% of participants (selected randomly at household level), the Investigators will also collect a dried blood spot using finger prick method to perform HBcAb test, an epidemiologic test for lifetime exposure to HBV.