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 Iowa, the transmission of a sexually transmitted disease (STD) by an individual who knows, or should know, they are infected to an uninformed partner can lead to both civil and criminal consequences. Under Iowa Code §709C, it is a criminal offense to knowingly expose another person to a human immunodeficiency virus (HIV) without the individual's consent. This can result in serious criminal penalties, including prison time. Additionally, individuals may face civil liability for negligently or intentionally transmitting an STD to a partner. In civil cases, the infected person could be sued for damages based on theories of negligence, battery, or intentional infliction of emotional distress. It is important for individuals to be aware of their health status and to disclose any communicable or infectious diseases to potential sexual partners to avoid legal repercussions.