The virus, which is called hepatitis B virus (HBV), can cause lifelong infection, cirrhosis (scarring) of the liver, liver cancer, liver failure, and death.

"HIV stands for human immunodeficiency virus. HIV is the virus medical researchers believe causes AIDS. (Medical researchers believe that HIV is causative agent of AIDS).

Syphilis is a sexually transmitted bacterial infection caused by the bacterium Treponema Pallidum. Syphilis is passed from person to person through direct contact with syphilis sore.

Chlamydia is a common sexually transmitted disease caused by the bacteria Chlamydia trachomatis.