A new research from the Annenberg Public Policy Center (APPC) at the University of Pennsylvania found that Americans’ knowledge of sexually transmitted infections (STDs) is somewhat lacking. While the vast majority of adults know the most common STDs and the most common means of transmission, there is still a lot of confusion about lesser-known infections, vaccines, and whether sitting on a toilet seat is dangerous (it’s not).
The survey was conducted in April 2026. It asked a representative sample of 1,639 US adults to answer questions about STDs. It found that many people in the US (47%) know someone who has ever been diagnosed with an STD. In fact, most people (72%) who knew someone with an STD reported knowing two or more people who had been diagnosed. This is not surprising given that it is estimated that 1 in 2 people in the United States will develop an STD in their lifetime.
People in the US appear to be familiar with the most common infections as 95% of respondents correctly identified genital herpes as an STD followed by gonorrhea (94%), HIV (92%), syphilis (91%), chlamydia (89%) and HPV or human papillomavirus (75%). While most of these responses were similar to a 2024 survey, there was a six-point jump in the number of people who knew HPV could be sexually transmitted.
People were understandably less familiar with some of the less common STDs. Only 35% of respondents knew that mpox can be sexually transmitted and only 13% knew that the Zika virus, which is mainly spread by mosquitoes, can also be sexually transmitted.
The good news is that 93% of people understood that STDs can be spread even without symptoms, and 87% rejected the myth that only people with multiple sex partners get STDs.
STDs are spread through sexual contact, not toilet seats
Respondents were also mostly correct about how STDs are transmitted. Almost all respondents (97%) identified vaginal sex as a common means of transmission, 94% said anal sex, 91% said genital-to-genital contact, 89% said oral sex, and 80% knew that some STDs could be transmitted from mother to child during pregnancy or childbirth.
There was some confusion about whether kissing and toilet seats could transmit STDs. Almost half of the respondents (49%) identified kissing as a route of transmission of STDs in general. Kissing carries a risk of herpes simplex virus type 1 (HSV-1) which causes blisters or “canker sores” in the mouth. It is not considered dangerous for most other STDs.
Similarly, 20% of respondents were concerned that sitting on a toilet seat immediately after being used by someone who had an STD could be dangerous. This is not true. The germs that cause most STDs are very fragile and cannot survive outside the body on surfaces such as toilets or doorknobs.
There are vaccines to prevent STDs
Respondents were also asked about which STDs could be prevented with vaccines. The responses show that this is an area where more training is needed. We currently only have vaccines for HPV (the virus that causes genital warts and cervical cancer), hepatitis A, hepatitis B and mpox.
While 68% of people correctly said that there is a vaccine that can protect against HPV and cervical cancer, only 42% knew that there is a vaccine for mpox. Unfortunately, the survey also found that 14% of people in the US believe that the HPV vaccine leads teenagers to engage in risky sexual behavior. While that may sound small, it’s an increase from just 10% in 2024. There have been numerous studies he did all that dispel this myth; Youth who get the HPV vaccine are no more likely to be sexually active or have multiple partners than their unvaccinated peers.
For most sexually transmitted diseases, the majority of respondents either admitted they were unsure if there was a vaccine or mistakenly believed a vaccine already existed: HIV (53%), genital herpes (54%), gonorrhea (58%), chlamydia (60%), syphilis (61%) and Zika (81%). We do not have vaccines for any of these STDs.
There were also some interesting gaps in knowledge about HIV treatment. A majority of respondents (83%) knew that HIV medication can control the progression of the disease, but only 45% knew that most people in the United States who have HIV do not develop AIDS.
“Gaps in STI information can have real consequences. If people don’t understand how STIs are transmitted, they may not protect themselves and their partners. If they don’t know which STI tests to get, they may not find out they have an infection or get the treatment they need,” said Rebecca Karpinski, ASHA interim president and CEO. “Access to education and care are the keys to addressing the STD epidemic in this country. This research shows that more work needs to be done,” he added.
