A 21-year-old man who has sex with men presents to a sexual health clinic to get screening for sexually transmitted infections. He says that a sex partner was recently diagnosed with hepatitis B virus (HBV) infection and asks about his risk of acquiring hepatitis B through sex with this partner. This 21-year-old has never received any doses of hepatitis B vaccine. Which one of the following statements is TRUE regarding sexual transmission of HBV to a partner who does not have immunity to HBV? HBV is never transmitted through sexual contact Urine has higher quantities of HBV than semen Semen and vaginal secretions are considered potentially infectious Most cases of transmission occur with sex practices that result in fecal-oral contact