If sodomy is committed by force, the passive partner may suffer painful injuries. Sodomy committed by force, threat of force, or impairment of victim's ability to decide through drugs or alcohol or with an under-age child is considered to be a crime parallel to rape. Unprotected anal sex is the riskiest kind of sex for transmitting sexually transmitted diseases, including AIDS. HIV, the virus that causes AIDS, can pass across an anus-lining even if it is intact. The risk is even greater in circumstances where dildos or fisting (in which the hand is used as the organ of anal penetration) may have torn the lining. In addition, the rectum is home to lots of infectious bacteria that can subsequently cause burning and urethritis of the inserted penis. Damage to the lining of the rectum may also provide access for many infectious agents into the blood stream.