When Passing On an Infection Becomes a Lawsuit

Can you sue someone for giving you an STI?

Sometimes. In general, a person who transmits an STI can face a civil lawsuit, most commonly under a negligence or battery theory, and a smaller set of situations fall under state criminal laws. Whether any of that leads anywhere depends on your jurisdiction and the specific facts. The single most important fact is usually whether the person knew they were infected and did not tell you.

most cases turn on whether the person knew and failed to disclose

None of this is legal advice, and outcomes are not something a page can predict. A lawyer licensed in your state is the person who can weigh a real case, and the companion guide on sti disclosure law walks through the statutes in more detail. What this page can do is explain the medical facts that shape those cases, because the law and the biology are tangled together here.

The hinge of most cases: did they know?

Liability usually turns on knowledge and disclosure, and that is exactly where the medicine complicates the law. Many common STIs are frequently silent. Chlamydia is often asymptomatic, which is a major reason it spreads quietly 1Ref 1Centers for Disease Control and Prevention (2024).About Chlamydia.That chlamydia is a common bacterial STI that is frequently asymptomatic, which allows it to spread without the infected person's awareness., and syphilis moves through a long latent stage in which a person feels completely well 2Ref 2Centers for Disease Control and Prevention (2024).About Syphilis.That syphilis progresses through stages, including a latent phase in which an infected person has no symptoms.. Someone who never had symptoms and never tested may genuinely not have known they carried an infection.

This is why the asymptomatic sti majority matters so much to these disputes: a person cannot fail to disclose what they had no way to know. Concealing a diagnosis you were aware of is a very different situation, legally and morally, from unknowingly passing on something invisible. Most of the contested ground in an STI case sits in the space between those two.

Herpes, disclosure, and 'even without symptoms'

Herpes drives a large share of STI lawsuits, and the reason is biological. Genital herpes has no cure, it can be transmitted even when there is no visible sore, and daily suppressive antiviral therapy lowers but does not eliminate the risk of passing it on 3Ref 3Centers for Disease Control and Prevention (2024).About Genital Herpes.That genital herpes has no cure, can be transmitted even without visible symptoms, and that daily suppressive antiviral therapy reduces the risk of transmission.. So 'I wasn't having an outbreak' is not the same as 'I couldn't have transmitted it.'

That gap between symptoms and transmissibility is what both disclosure conversations and disclosure law wrestle with. A person who has been told they have herpes carries knowledge that a person who has never been tested does not, and knowledge is the fact that these cases most often hinge on. It is also why the honest, non-legal takeaway is about testing and telling, not about winning or losing a suit.

What tends to strengthen or weaken a claim

Legal outcomes here are fact-specific, but a few themes recur. Cases tend to be stronger when there is documented knowledge, such as a prior positive test, followed by nondisclosure, and weaker when knowledge cannot be shown at all. These are factors courts commonly weigh, not a formula, and how they apply varies from state to state.

Causation is its own hurdle. Proving that one particular partner was the source is genuinely difficult, especially with infections that can sit silent for months or years before they are detected. A person may have carried an infection before the relationship began without ever knowing. Because so much of this depends on timing and evidence that is hard to pin down, a lawyer's early assessment of the facts usually matters more than any general rule.

Damages are another dimension. In civil cases, what a person can recover typically depends on demonstrable harm, which ranges widely with the infection and its consequences. A curable bacterial infection treated promptly looks very different from a lifelong viral one, both medically and in how a court might weigh it. This is one more reason these cases are so fact-dependent, and why a lawyer's read on your particular situation is worth more than any rule of thumb found online.

Knowing your status changes the picture

Testing is the factual pivot for both your health and the disclosure question, because you cannot disclose or protect a partner from something you have not detected. National guidance reflects this: the US Preventive Services Task Force gives its strongest, Grade A recommendation to syphilis screening for people at increased risk 4Ref 4US Preventive Services Task Force (2022).Syphilis Infection in Nonpregnant Adolescents and Adults: Screening.That the USPSTF gives a Grade A recommendation to screen for syphilis in asymptomatic, nonpregnant adolescents and adults who are at increased risk., and the CDC sets population-specific screening intervals for chlamydia, gonorrhea, HIV, and more 5Ref 5Centers for Disease Control and Prevention (2021).STI Screening Recommendations.That the CDC sets population-specific STI screening recommendations, including annual chlamydia and gonorrhea screening for sexually active women under 25 and defined intervals for other groups..

Because symptoms are unreliable, waiting for sti symptoms in men or sti symptoms in women to appear is not a substitute for testing. Screening matters even more around stis in pregnancy, where an untreated infection can pass to a newborn, a distinct and serious context. Knowing your status early converts uncertainty into information you can act on: treatment, telling partners, and a record that you took responsibility.

Criminal laws are a separate track

Beyond civil suits, a number of states have criminal statutes that can apply to STI exposure or transmission, historically focused on HIV nondisclosure. These laws vary widely from one state to the next, several have been reformed or repealed in recent years, and they operate on a different standard than a civil lawsuit does. This page cannot tell you what your own state's statute says or how it would be applied.

That is a question for a lawyer and for the disclosure-law guide, which covers criminal-exposure law in more depth. One situation stands apart from all of this: if a sexual encounter was non-consensual, it is not first a legal-strategy question but a medical and safety emergency, with time-sensitive options described in the box below.

For the criminal statutes specifically, the disclosure-law guide tracks how they differ by state, and the broad direction of reform has been away from laws written before effective treatment existed. Still, a trend is not your own state's current statute, which is why a criminal-exposure question has only one reliable answer: one from a lawyer licensed where the events happened.