STD Rates by Country 2026

An STD, or sexually transmitted disease, is a bacterial, viral, or parasitic infection usually transmitted through unprotected vaginal, oral, or anal sex. However, STDs can also spread via non-sexual interactions, such as passing from mother to child during pregnancy, breastfeeding, or childbirth; between drug users who share syringes; or from donor to recipient via infected blood donations. Often referred to as STIs, or sexually transmitted infections, STDs often display few or no symptoms, making diagnosis and treatment unlikely. Although all STIs can be treated, some can be cured entirely while others require ongoing management. Consequently, health agencies typically encourage prevention, especially through the use of protection when engaging in sexual activity, and regular STD testing.

While the severity of symptoms varies from one STD to the next, some infections can be serious indeed—particularly for women. The World Health Organization points out that STDs can lead to neurological disease, cardiovascular disease, infertility, stillbirth, ectopic pregnancies, liver cancer, cervical cancer, and (in the case of the sexually transmitted HIV virus) AIDS. Factors that contribute to rising STD rates include drug use, poverty, and the public stigma associated with STDs and non-monogamous sexual conduct. Conversely, awareness campaigns, the use of condoms, and access to sexual health education are known to decrease the prevalence of STDs.

Global STD Rates

STD infection rates vary widely by disease and country, but have seen an overall increase in recent years. The World Health Organization estimates that more a million new curable STD infections are created every day. STD rates can be difficult to determine in underdeveloped and developing countries because of the lack of access to health care and dearth of available STD testing—situations which often lead to high STD infection rates as well. By comparison, developed countries tend to have more comprehensive health care systems, so STI testing is much more common and infection rates are much lower. For example, HIV/AIDS infects nearly 27% of people in underdeveloped Eswatini, but only .10% in well-developed Norway.

The Centers for Disease Control and Prevention (CDC) provides resources on STI prevention, testing, and treatment. Its HPV overview describes human papillomavirus as a very common infection. Most HPV infections go away on their own within two years, but some persist and can cause cancer; other HPV types can cause genital warts. Vaccination helps protect against HPV-related cancers. Other common STIs include trichomoniasis, chlamydia, gonorrhea, and syphilis, with treatment depending on the infection.

STDs in the United States, Australia, and South Africa

The United States has some of the highest STD rates in the developed world. The United States had a gonorrhea rate of 123 per 100,000 people in 2015—the highest in the developed world at the time—which increased to 179 cases per 100,000 people in 2021. The U.S. also posted the third-highest rate for chlamydia in the developed world with 475 per 100,000 people in 2015, which increased to 490 per 100,000 in 2021. STD rates increase in the United States for many reasons, including decreased condom use among vulnerable groups such as young people and men who partner sexually with other men. Additionally, state and local programs have experienced budget cuts, resulting in clinic closures, decreased screenings and care, and reduced patient follow-up.

STD rates in the U.S. vary widely from state to state. In 2019, the states with the highest STD rates were Mississippi, Alaska, and Alabama for gonorrhea, Alaska, Mississippi, and Louisiana for Chlamydia, and Nevada, New Mexico, and Mississippi for primary and secondary syphilis.

For newer U.S. trends, the CDC’s STI statistics page provides provisional 2024 surveillance data for chlamydia, gonorrhea, and syphilis. These reported case counts are a different measure from estimates of all STI infections. Comparisons should identify the infection, reporting year, and whether the data are provisional; changes in testing and reporting can also affect recorded case counts.

In Australia, STD cases have risen significantly over the past two decades. Experts attribute the rise to more widespread testing, increasing popularity of online dating, high tourist numbers, and a lack of condom usage, despite people being educated on their effectiveness. South Africa is ranked first in the world overall for the highest STD rates and has the third highest rate of HIV per 100,000 people of 16,049. STD rates in South Africa are driven by a complex mix of biological, economic, and societal factors, with the country facing ongoing challenges in prevention, education, and access to care.