In many states it is a criminal offense to intentionally or recklessly transmit a sexually transmitted disease (STD or venereal disease) to another person. Examples of such diseases include HIV/AIDS, syphilis, gonorrhea, chlamydia, genital herpes, human papillomavirus (HPV), genital warts, and hepatitis B.

Laws vary from state to state, and in some states these laws include other infectious or communicable diseases. In some states there is a specific criminal offense for transmission of sexually transmitted or communicable diseases, and in other states criminal prosecutors charge the defendant with a more general crime like assault.

Laws regarding criminal liability for the intentional or reckless transmission of sexual or other infectious or communicable diseases are generally located in a state’s statutes—often in the penal or criminal code, or the health and safety code.

A person who negligently transmits a sexually transmitted disease to another person through sexual contact—without informing the other person of the offender’s infection before the sexual contact—may also be subject to civil liability for money damages in a lawsuit.

In Washington State, it is a criminal offense to knowingly transmit an STD. Under RCW 70.24.080, it is illegal for a person who knows that they are afflicted with a sexually transmitted disease to expose another person to that disease. This law applies to diseases such as HIV/AIDS, syphilis, gonorrhea, chlamydia, genital herpes, HPV, genital warts, and hepatitis B. The transmission of HIV specifically can be prosecuted under RCW 9A.36.011, which addresses the assault in the first degree, if the transmission was intentional. Additionally, individuals who negligently transmit an STD without informing their partner of their infection may face civil liability and be sued for damages. The laws are designed to protect public health and encourage individuals to take responsibility for preventing the spread of STDs.