About one in five people in the United States over age 12 — approximately 45 million individuals — are infected with HSV-II, the virus that causes genital herpes. Around 50-80 percent of the adult population has oral herpes, which most people contract through nonsexual contact in childhood.
While most cases of Zika virus are acquired via mosquito bites, this emerging virus can be transmitted sexually, and the CDC reports that the numbers of such cases are growing in subtropical regions of the Americas.
Trichomoniasis is one of the most common sexually transmitted diseases, mainly affecting 16-to-35-year old females.
Syphilis has been called "the great imitator" because many of its signs look like other diseases. It is also difficult to know if someone has syphilis because a person might not have any symptoms at all.
This disease has bothered humans for thousands of years, but it seems to come and go in unexplainable cycles. Scabies used to be very rare in America, but now it is coming back again.
Pubic lice are often spread through sexual contact, though genital contact or sexual intercourse is not necessary for transmission. In a few cases, pubic lice have been spread through contact with bed linens, towels, or clothes because lice can live for 24 hours off a human body.
"Pelvic inflammatory disease" is shorthand for any serious bacterial infection of the reproductive organs that are housed in the pelvis: the uterus, uterine lining, fallopian tubes, and/or ovaries. These infections usually start in the vagina and, when left untreated, can progressively infect other reproductive organs. 20% of PID cases are found in teens, who often are afraid or unable to get reproductive health care. PID can result in permanent infertility and chronic pain.
As many as one in ten Americans have HPV, and some studies show that at least one-third of all sexually active young adults have genital HPV infections. It is often stated that more than half of all college-age women wil become infected with HPV during their college career.
In the United States, approximately 75% of all reported gonorrhea is found in people age 15 to 29.
One member of a group of herpes-type viruses, CMV is transmitted through body fluids, sexually and nonsexually, and from mother to infant during birth. CMV is also incredibly dangerous for people who are immunocompromised or people with HIV.