This page is general health information, not medical advice. It cannot tell you whether you have an infection. A clinician can, and the testing options on this site are a good place to start.

If you live in Columbia, you may want to know how common sexually transmitted infections are here. This guide gathers the most recent published figures for Richland County and South Carolina, explains how to read them, and points to free and low-cost testing close to home.

Numbers about STIs describe communities. They do not describe any one person, and they say nothing about anyone's character. Anyone who is sexually active, of any gender or orientation, can get an STI, and testing is the way to know.

Key Takeaways

The most recent county figures found for Richland County are from 2021: chlamydia 1,344.2, gonorrhea 577.6 and primary and secondary syphilis 22.9 cases per 100,000 people (Stacker's analysis of CDC county data).
The most recent state figures found are from 2023: chlamydia 612.1, gonorrhea 222.4 and primary and secondary syphilis 17.3 per 100,000 people.
South Carolina ranked 9th in the nation for gonorrhea and 19th for primary and secondary syphilis in 2023, according to FITSNews citing CDC data.
The county and state figures come from different years, so they should not be compared head to head.
Published HIV diagnosis rates and congenital syphilis counts for Richland County were not available in the sources reviewed.
Many infections cause no symptoms. Only a test can show what is going on, and several Columbia clinics offer free or sliding-scale testing.

How STD rates are measured, and why they are not the same as risk
Richland County figures
South Carolina figures and national rank
STD rates by state and by city: what can be compared
What shapes the numbers
South Carolina rules that matter for testing
Free and low-cost testing in Columbia

How STD Rates Are Measured, and Why They Are Not the Same as Risk

An STD rate is the number of reported cases in a year divided by the population, then expressed per 100,000 people. Using a rate lets a county of several hundred thousand people be compared fairly with a state of several million.

Cases are counted when they are diagnosed and reported

South Carolina law requires physicians to report certain infectious diseases to the county health department. This comes from S.C. Code Ann. § 44-29-10 in the South Carolina Code of Laws. The state health department, the South Carolina Department of Public Health (DPH), compiles those reports. The CDC then publishes national and county tables, including its AtlasPlus tool.

That means a rate reflects infections that were found and reported. It does not capture infections that were never tested for.

Why a higher rate does not always mean more infection

The CDC STI Treatment Guidelines (2021) note that many chlamydia and gonorrhea infections cause no symptoms. When more people are screened, more infections are found. A county with strong testing access can show a higher reported rate than a county with less testing, even if actual infection levels are similar.

So a high number can signal that the health system is finding infections. It can also signal that infections are spreading. The figures alone cannot say which.

A note on the sources

The county figures in this guide come from Stacker's analysis of CDC county data. That is a secondary source, because the official DPH county tables could not be read when this page was researched. The state figures come from America's Health Rankings (data attributed to CDC AtlasPlus) and from FITSNews, which cites CDC 2023 data. Check the live CDC and DPH pages if you need exact current numbers for a report or grant application.

Richland County Figures

Columbia is in Richland County. The most recent county-level figures found are for 2021.

Infection (Richland County, 2021)	Rate per 100,000 people	Reported cases
Chlamydia	1,344.2	5,623
Gonorrhea	577.6	2,416
Primary and secondary syphilis	22.9	96

Source: Stacker, analysis of CDC county data, 2021. This is a secondary source.

Chlamydia

Chlamydia is the most commonly reported of the three. Stacker's analysis of CDC data lists 5,623 cases in Richland County in 2021, or 1,344.2 per 100,000 people. Chlamydia is a bacterial infection, and the CDC says it is curable with treatment from a clinician.

Gonorrhea

The same analysis lists 2,416 gonorrhea cases in 2021, a rate of 577.6 per 100,000. Gonorrhea is also bacterial and curable with treatment from a clinician. The CDC advises that clinicians choose treatment based on current guidance, which is one reason to see a provider rather than guess.

Primary and secondary syphilis

Stacker's analysis lists 96 cases of primary and secondary syphilis in 2021, a rate of 22.9 per 100,000. These are the early stages of the infection. Syphilis is curable with treatment from a clinician, and the CDC notes that early treatment prevents longer-term problems.

HIV and congenital syphilis

The sources reviewed did not include a Richland County rate for new HIV diagnoses or a count of congenital syphilis. For those figures, check CDC AtlasPlus and the DPH surveillance reports on the DPH sexually transmitted diseases page. HIV is not curable, but the CDC says it is treatable, and people who take HIV treatment as prescribed can stay healthy.

South Carolina Figures and National Rank

The most recent statewide figures found are for 2023.

Infection (South Carolina, 2023)	Rate per 100,000 people	Reported cases	National rank
Chlamydia	612.1	32,889	Not found in sources reviewed
Gonorrhea	222.4	11,950	9
Primary and secondary syphilis	17.3	927	19

Sources: America's Health Rankings, with data attributed to CDC AtlasPlus, 2023 (chlamydia rate); FITSNews, Nov. 25, 2024, citing CDC 2023 data (chlamydia case count, gonorrhea and syphilis figures and ranks). FITSNews is a secondary source.

What the rank means

A national rank of 9 for gonorrhea means eight states had higher rates in 2023 according to FITSNews. A rank of 19 for primary and secondary syphilis places South Carolina in the upper-middle part of the national list. Ranks shift from year to year and depend on how each state tests and reports.

Year-on-year change

A true year-on-year comparison needs the same geography and the same source for consecutive years. The sources reviewed give Richland County for 2021 and South Carolina for 2023, and no paired earlier or later year for either. Because of that, this page does not state whether Columbia's rates rose or fell. To see trends, open CDC AtlasPlus, choose the infection, pick South Carolina or Richland County, and view the multi-year chart.

STD Rates by State and by City: What Can Be Compared

People often look for STD rates by city. Here is how the data is actually organized.

State rates

The CDC publishes STD rates by state every year, which is why national rankings like those above exist. State rates are the most reliable way to compare South Carolina with other states, as long as the same year and infection are used.

County rates

For most places, the smallest area with stable published numbers is the county. That is why the best local figures for Columbia are the Richland County numbers. Part of the Columbia area extends into neighboring counties. Coverage of Lexington County was not found in the sources reviewed, so this page does not give a figure for it.

City rates

City-level rates are less common because small populations make yearly numbers jump around. When a source does give a city number, check how it defines the city and what year it covers. For decisions about your own health, a city or county rate matters less than your own situation, which a clinician can talk through with you.

Comparing across places and years

Compare the same infection.
Compare the same year.
Compare rates, not raw case counts.
Remember that testing levels affect what gets counted.

For example, Richland County's 2021 chlamydia rate (1,344.2) is higher than South Carolina's 2023 rate (612.1). Because the years differ, that gap is not a clean comparison. A same-year pull from CDC AtlasPlus would be needed.

What Shapes the Numbers

The sources reviewed do not give a local explanation for Columbia's rates, and this guide does not guess at one. These are the general factors the CDC describes.

Infections without symptoms

The CDC STI Treatment Guidelines (2021) explain that chlamydia, gonorrhea and syphilis can be present without noticeable symptoms. Someone can pass an infection on without knowing it. This is why screening matters even when you feel well.

How much testing happens

The U.S. Preventive Services Task Force (USPSTF) recommends chlamydia and gonorrhea screening for sexually active women 24 and younger, and for older women at increased risk. It also recommends HIV screening for adolescents and adults ages 15 to 65, and syphilis screening for people at increased risk. More screening finds more infections, which raises reported rates and lowers the chance of complications.

Access to care

Cost, transportation, clinic hours and worry about privacy can all keep people from getting tested. Free and sliding-scale options, walk-in hours and the legal protections for minors described below all make testing easier to reach.

Prevention tools

The CDC supports several prevention tools. Condoms lower the chance of many infections. HIV pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) are prescribed by a clinician. In 2024 the CDC issued guidance on doxycycline post-exposure prophylaxis (doxy-PEP), which a clinician may discuss for certain people at higher risk of bacterial STIs. The CAN Community Health clinic page lists doxy-PEP among its services. DPH also keeps a South Carolina PrEP Provider Directory on its PrEP page.

South Carolina Rules That Matter for Testing

Minors and consent

South Carolina Code § 63-5-350 says health services of any kind may be given to minors of any age without a parent or guardian's consent when an authorized provider considers them necessary. Section 63-5-340 covers minors 16 and older. Neither section names STDs, and the state has no STD-specific minor consent law that could be confirmed. The Guttmacher Institute lists South Carolina as a state where minors may consent to STI testing and treatment, with no age limit and no parental-notification rule shown. If you are under 18, ask the clinic about its own policies when you book.

Partner treatment

The CDC's page on the legal status of expedited partner therapy (EPT) in South Carolina says the state has no EPT-specific law. The SC Board of Medical Examiners interprets § 40-47-113(B) to allow EPT for chlamydia and gonorrhea. EPT lets a clinician provide treatment for a patient's partner without a separate visit. Wording may have changed since it was last reviewed, so ask your clinician whether it applies to you.

Reporting

Under S.C. Code § 44-29-10, physicians report infectious diseases on the DPH list to the county health department. This is how the rates above are produced. The text of the DPH reportable list could not be confirmed for this page, so check with DPH for the current list.

Pregnancy

S.C. Code § 44-29-120 requires a physician attending a pregnant woman to take a blood sample at the first examination, or within three days after, and have it tested for syphilis, rubella, Rh factor and hemoglobin. A person may be exempt by sworn affidavit of religious objection. A third-trimester or delivery syphilis test was not found in that section. If you are pregnant, ask your prenatal provider which tests are planned.

Free and Low-Cost Testing in Columbia

The best response to any set of statistics is a test. A negative result gives peace of mind, and a positive result opens the door to treatment. Bacterial STIs and trichomoniasis are curable with treatment from a clinician. HIV and herpes are not curable but are treatable and manageable.

For a full breakdown of locations and what each visit may cost, see our guide to STD testing in Columbia, where to get tested and what it costs. You can also browse the local testing list. A summary of options follows. Hours and fees can change, so call before you go.

CAN Community Health, Columbia

1911 Hampton St., Columbia, SC 29201. Phone (803) 849-8430. The clinic page lists free testing, including free rapid and home HIV testing. It lists tests for HIV, chlamydia, gonorrhea, syphilis, herpes, hepatitis B, hepatitis C and trichomoniasis, with treatment on site. It accepts Medicare, Medicaid and most insurance, and says sliding-scale fees and grant funding may be available. Walk-ins are accepted during regular hours: Monday to Thursday 8:30 a.m. to 5:30 p.m. and Friday 8:30 a.m. to 12:30 p.m. Thursday extended hours and some Saturday hours are offered on select dates. The CDC directory listing says an appointment is required, so call to confirm.

PALSS (Palmetto AIDS Life Support Services)

2638 Two Notch Rd, Ste 108, Columbia, SC 29204. Phone (803) 779-7257. The CDC NPIN listing shows free HIV, hepatitis B, hepatitis C and STI tests, and it also says sliding scale and insurance or Medicaid are accepted. Listed hours are Monday to Friday 8:30 a.m. to 5:00 p.m., with walk-in testing Tuesday 3 to 8 p.m. and Thursday 3 to 7 p.m., and walk-in only on the 1st and 3rd Saturday 10 a.m. to 2 p.m. The CDC GetTested listing says an appointment is required, so confirm by phone.

Planned Parenthood South Atlantic, Columbia Health Center

2712 Middleburg Dr, Ste 107, Columbia, SC 29204. Phone (803) 256-4908. The CDC NPIN listing shows tests for chlamydia, gonorrhea, hepatitis B, herpes, rapid HIV and syphilis, and says insurance and Medicaid are accepted. It lists hours of Monday 9 a.m. to 5 p.m., Tuesday 9 a.m. to 3 p.m., Wednesday 9 a.m. to 5 p.m., Thursday 10 a.m. to 6 p.m. and Friday 9 a.m. to 2 p.m. The listing says an appointment is required, but you can walk in during open hours to book or ask about same-day availability. Ask the center about cost and eligibility.

Cooperative Health, Five Points

The Five Points Walk-In Center is at 1228 Harden St, Ste A, Columbia, SC 29204. Phone (803) 722-1565. CDC GetTested lists HIV, hepatitis C, chlamydia, gonorrhea and syphilis tests, with insurance, Medicaid, Medicare and sliding scale accepted, and no appointment required. The listing does not give hours. Cooperative Health's Waverly Family Practice, at 1228 Harden St, Ste C, phone (803) 748-1181, also offers these tests, but by appointment.

AHF Healthcare Center, Columbia

4100 N Main St, Suite 102, Columbia, SC 29203. Phone (803) 223-9895. CDC GetTested lists a free HIV test, plus rapid HIV, chlamydia, gonorrhea and syphilis tests. It says an appointment is required. For eligibility for tests other than HIV, contact the organization.

Richland County Health Department (SC DPH)

2000 Hampton St., Columbia, SC 29204. DPH says STD, HIV and hepatitis C services continue at this site and that it may later move to the former Columbia Place Mall site. The DPH page does not give a clinic phone number, hours or fees. To make an appointment, call the DPH Care Line at 1-855-472-3432. The DPH STD/HIV Hotline is 1-800-322-2437.

Free at-home HIV testing

The DPH In-Home HIV Testing Program offers a free HIV self-test kit to South Carolina residents age 17 or older, one kit every 90 days. You request it through an online survey on the DPH Home HIV Testing Program page. Questions can go to [email protected] or 1-800-322-2437. A clinician can explain what a self-test result means and when a follow-up test is helpful. For how long after an exposure a test can detect an infection, the CDC publishes the window periods for each infection, and a clinic can walk you through them.

Finding more options

The CDC's GetTested directory lets you look up testing sites by ZIP code. Use it alongside the clinics above, since listings and hours can change.

What to expect at a visit

Testing is usually a urine sample, a swab or a blood draw, depending on which tests you and the clinician choose. You can ask any questions about privacy, cost and results timing. If a test finds an infection, a clinician can prescribe treatment and talk about partners. Nothing about getting tested says anything about you as a person. It is routine health care.

STD Rates in Columbia: What the Latest Data Shows