Among the 279 participants, 19 (6.8%; 95% CI 4.4–10.4) were HIV co-infected, 1.4% (4/279, 95% CI 0.5–3.8) had chronic hepatitis B infection (HBsAg positive) and 9.3% (26/279, 95% CI 6.4–13.4) had serological marker of exposure to hepatitis B virus infection (total anti-HBc positive). The gene discussed is KRT88P; the disease is chronic hepatitis B virus infection.