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 New Hampshire, the transmission of sexually transmitted diseases (STDs) is addressed under the state's public health laws rather than as a specific criminal offense. Under New Hampshire Revised Statutes Annotated (RSA) 141-C, individuals who know they are infected with an STD have a legal duty to inform their partners before engaging in sexual activity. Failure to do so can result in misdemeanor charges. Additionally, RSA 141-C:20 requires health care providers to report cases of certain STDs to the Division of Public Health Services. While New Hampshire does not have a specific criminal statute for the transmission of STDs, individuals who intentionally or recklessly transmit an STD to another person could potentially be charged under general criminal laws, such as assault. Furthermore, a person who negligently transmits an STD without informing their partner may face civil liability and be sued for damages.