The transmission of a sexually transmitted disease (STD) from a person who knows or should know they have the disease to another person who is not informed of that fact before engaging in sexual contact with the infected person may result in both civil liability (for money damages) and criminal liability (for penalties).

Laws vary from state to state and some states have both civil and criminal statutes (laws enacted by the state legislature) that specifically address the transmission of sexually transmitted diseases. In other states civil lawsuits may be filed and criminal prosecutions may be made under traditional legal theories such as negligence in a civil lawsuit and battery (harmful or offensive physical contact without consent) in a criminal prosecution.

In Massachusetts, the transmission of a sexually transmitted disease (STD) by an individual who knows or should have known about their infection to an uninformed partner can lead to both civil and criminal consequences. Under Massachusetts law, civil liability may arise if the transmission is deemed negligent, meaning the infected person failed to exercise reasonable care to prevent the spread of the STD. This could result in a lawsuit for monetary damages. On the criminal side, Massachusetts General Laws Chapter 265, Section 37 provides that anyone who 'knowingly' transmits an STD could be charged with a crime. The term 'knowingly' implies that the person was aware of their infection at the time of transmission. Criminal charges could range from misdemeanors to felonies, depending on the circumstances and the specific STD transmitted. It is important for individuals to be aware of their health status and to communicate openly with sexual partners about any potential risks. An attorney can provide guidance on the specifics of the law and representation in the event of litigation or criminal charges.