How many people have STDs?

According to the Centers for Disease Control and Prevention (CDC), sexually transmitted infections (STIs) are very common in the United States. A recent CDC analysis estimated that in 2018 there were about 26 million new STIs and nearly 68 million total infections, meaning roughly 1 in 5 people in the U.S. was living with an STI on any given day.  Most of these infections were due to chlamydia, trichomoniasis, genital herpes, and HPV.

In 2024, more than 2.2 million cases of chlamydia, gonorrhea, and syphilis were reported. While this represents a 9% decline in STI morbidity compared to 2023 (and the third consecutive year of decreases), there is still more work to do. Compared to a decade ago, the overall STI case burden in the U.S. remains 13% higher and reported congenital syphilis cases increased again last year for the 12th year in a row.

STIs can affect anyone, but adolescents and young adults ages 15–24 account for nearly half of all new STIs each year, despite being a smaller share of the population.

In addition, gay, bisexual, and other men who have sex with men are disproportionately affected by HIV, accounting for about 69% of new HIV diagnoses in 2018, and they experience higher rates of syphilis compared with other men and women.