Sexually transmitted diseases, or STDs, are relatively common infections transmitted through sexual contact, such as sexual intercourse, caused by bacteria, viruses, or parasites. STDs can be spread through vaginal, anal, or oral sex, and those are infected can have no symptoms.
Because STDs can show no symptoms and can lead to serious health problems if untreated, getting tested for STDs is important and, luckily, easy to do. Most STDs are easy to treat as well.
In the United States, the most common STD is HPV (human papillomavirus), affecting over 79 million Americans, most teens and young adults. While HPV is usually harmless and can go away on its own, it can sometimes lead to cancer. Other common types of STDs in the U.S. are chlamydia, gonorrhea, and syphilis. All three of these STDs are bacterial infections that are easily treatable.
Other types of STDs include genital warts, Hepatitis B, herpes, HIV/AIDS, scabies, pubic lice, molluscum contagiosum, and trichomoniasis (“trich”).
The Centers for Disease Control and Prevention (CDC) estimates 20 million new STD infections every year. Despite vast and numerous resources and information on STDs and easy access to condoms and STD testing, STDs continue to rise in the U.S.
STD rates vary between states. This can be caused by variations in the availability or use of contraception (condoms), the presence or lack of sex education, and cultural norms regarding the use of condoms or getting tested.
Mississippi has the second-highest rate of chlamydia, the highest rate of gonorrhea, and the sixth-highest rate of syphilis in the United States. The rate per 100,000 people for each of these STDs is 750.0, 427.7, and 28.1, respectively. State health officials say that Mississippi’s diluted health structure is the main factor in the high rates of STDs, decreasing residents’ access to care.
Alaska has the highest rate of chlamydia in the U.S. According to the CDC’s 2021 Surveillance Report, there were 5,571 cases of chlamydia in Alaska in 2021. This is a rate of about 760.4 cases per 100,000 people. Alaska also has the tenth-highest rate of gonorrhea in the country of 269.8 cases per 100,000 people. Alaska has reportedly ranked first in the country for chlamydia since 2001 and gonorrhea is becoming an increasingly concerning issue. Health officials in Alaska believe the rate is so high because of a combination of unprotected sex and less access to health care services or resources for prevention.
Louisiana has the third-highest rate of chlamydia of 730.1 cases per 100,000 people. Louisiana also has the third-highest rate of gonorrhea of 354.5 cases per 100,000 people. Louisiana had been making progress, seeing the rate of cases of gonorrhea and syphilis fall between 2017 and 2018, but they have again risen in recent years.
South Carolina has the fourth-highest chlamydia rate and the fifth-highest gonorrhea rate in the U.S. South Carolina’s chlamydia rate is 702.7 cases per 100,000 people and its gonorrhea rate is 309.2 cases per 100,000 people. Of South Carolina's approximately 5 million residents, 53,365 STD cases were reported in 2021. Columbia has one of the highest rates of STDs of any city in the United States.
Alabama has the sixth-highest rate of chlamydia and the fourth-highest rate of gonorrhea in the United States. The chlamydia rate in Alabama is 625.2 cases per 100,000 and the gonorrhea rate is 321.3 cases per 100,000.
Vermont overall has the lowest STD rates in the United States. Vermont’s chlamydia rate is 141.0 cases per 100,000, the lowest in the country. Vermont’s gonorrhea and syphilis rates are also the lowest in the country at 21.1 cases per 100,000 people and 1.4 cases per 100,000 people, respectively. Health officials in Vermont have expressed concerns, however, as Vermont is seeing an increase in STDs in recent years, following the nationwide trend.
Like its neighbor Vermont, New Hampshire has relatively low STD rates across the board. New Hampshire’s chlamydia is the second-lowest in the U.S. at 217.9 cases per 100,000 people. The gonorrhea rate is the second-lowest at 44.2 cases per 100,000. The syphilis rate is the third-lowest in the country. While rates still remain low, New Hampshire's STD rates have increased significantly in recent years. For example, from 2015 to 2017 alone, the chlamydia rate in New Hampshire increased by 42.1%.
Like its neighbors Vermont and New Hampshire, Maine has relatively low rates for chlamydia and gonorrhea. Maine’s chlamydia rate is 245.7 cases per 100,000 people, the third-lowest in the U.S., and its gonorrhea rate is 33.7 cases per 100,000 people, the second-lowest. Maine has seen some improvement in its low STD rates since 2018.
West Virginia has the fourth-lowest rate of chlamydia in the United States with 293.1 cases per 100,000 people. West Virginia also has the sixth-lowest gonorrhea rate of 91.9 cases per 100,000. Like many other states, West Virginia has also seen a rise in the number of cases, and STDs should still be a cause for concern, especially among young people.
Wyoming has the seventh-lowest chlamydia rate, the fifth-lowest gonorrhea rate, and the second-lowest syphilis rate. Wyoming’s chlamydia rate is 359.0 cases per 100,000 people, its gonorrhea rate is 90.4 cases per 100,000, and its syphilis rate is 2.8 cases per 100,000. Wyoming has seen a decrease in its syphilis cases, after seeing a huge increase between 2012 and 2018.
Syphilis Primary & Secondary Cases
Syphilis Primary/Secondary Case Rate
Syphilis Congenital Cases
Syphilis Congenital Case Rate