Liver cirrhosis caused by hepatitis B, if not treated with standard antiviral therapy, is very likely to test positive for the hepatitis B virus. HBV-DNA is a good indicator of the hepatitis B virus; if HBV-DNA tests positive, then it is contagious. The main transmission routes of hepatitis B include mother-to-child transmission, blood and body fluid transmission, and sexual transmission between spouses, though this route carries a relatively lower risk. Why is this the case? Firstly, the spouse may already have hepatitis B surface antibodies, which are protective antibodies providing immunity against hepatitis B. Secondly, when adults are infected with hepatitis B, most can acutely clear the virus, preventing the chronic manifestation of the disease.