Sexually Transmitted Diseases

Sexually transmitted diseases (STDs) are infections transmitted from an infected person to an uninfected person through sexual contact. STDs can be caused by bacteria, viruses, or parasites. Examples include gonorrhea, genital herpes, human papillomavirus infection, HIV/AIDS, chlamydia, and syphilis

Why Is the Study of Sexually Transmitted Diseases a Priority for NIAID?

STDs are an important global health priority because of their devastating impact on women and infants and their inter-relationships with HIV/AIDS. STDs and HIV are linked by biological interactions and because both infections occur in the same populations. Infection with certain STDs can increase the risk of getting and transmitting HIV as well as alter the way the disease progresses. In addition, STDs can cause long-term health problems, particularly in women and infants. Some of the health complications that arise from STDs include pelvic inflammatory disease, infertility, tubal or ectopic pregnancy, cervical cancer, and perinatal or congenital infections in infants born to infected mothers.


A cornerstone of public health is disease prevention. Tools to prevent STDs, such as vaccines, topical microbicides, and behavioral interventions, are a vital part of protecting the public against infectious diseases. Gardasil, a vaccine against the four most common strains of human papillomavirus (HPV), is an exciting accomplishment in the field of STDs. However, the work to develop safe and effective vaccines against other STDs continues. Most notably are the ongoing clinical trials to evaluate an investigational vaccine to prevent genital herpes.


Early and rapid diagnosis of STDs increases the chance to limit effects of the disease. Left untreated, STDs, such as gonorrhea, syphilis, chlamydia, genital herpes, and human papillomavirus, can lead to devastating and sometimes long-term complications. These complications include blindness, bone deformities, brain damage, cancer, heart disease, infertility, birth defects, mental retardation, and even death.


There are many different kinds of STDs, and the types of treatment are as varied as their symptoms. NIAID supports the development and licensure of vaccines, topical microbicides, and drug treatments, such as antibiotics and antifungals, for the microbes that cause STDs. No STD is harmless. Even the curable ones can cause serious consequences if left untreated. HIV is of particular concern as biological evidence demonstrates the increased likelihood of acquiring and transmitting HIV when STDs are present.