In addition to these, risk factors for anti-HBc positivity included age (aOR=1.04; 95% CI 1.04 to 1.05), imprisonment ever in life (aOR=2.53; 95% CI 1.41 to 4.56), and poor knowledge on infectious diseases (aOR=1.32; 95% CI 1.05 to 1.67), while living in Yerevan (vs provinces) was protective (aOR=0.74; 95% CI 0.59 to 0.93). This evidence concerns the gene KRT88P and infectious disease.