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 Connecticut, 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 Connecticut law, an individual may face civil liability if they negligently or intentionally transmit an STD to a partner without disclosing their infection, allowing the partner to seek monetary damages. This falls under the legal theory of negligence, where the infected person had a duty to inform their partner and failed to do so, resulting in harm. On the criminal side, Connecticut General Statutes Section 53a-65 defines assault in the second degree, which includes the intentional transmission of an STD as a form of assault. This can be prosecuted as a felony, with potential penalties including imprisonment. It is important for individuals to be aware of their health status and to communicate openly with sexual partners about any known STDs to avoid legal repercussions and to promote public health.