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.

Numbers about sexually transmitted infections can feel abstract. They are also useful. They show where testing is most needed, how Houston compares with Texas, and why a routine test is a normal part of health care here.

This guide gathers the most recent published figures for Houston and Harris County. It covers chlamydia, gonorrhea, syphilis and HIV. Every number is paired with its year and its source. The guide also explains how to read the figures, because the year, the geography and the source all change what a number means.

Key takeaways

In 2022, Texas DSHS reported 656.9 chlamydia cases per 100,000 people in Harris County, compared with 519.9 for Texas as a whole.
For gonorrhea in 2022, DSHS reported 270.6 per 100,000 in Harris County and 207.0 statewide.
Harris County recorded 1,082 primary and secondary syphilis cases and 5,670 syphilis cases at all stages in 2022, according to DSHS.
The Houston Health Department reported 1,343 new HIV diagnoses in Houston/Harris County in 2023, a rate of 27.5 per 100,000.
Higher rates often reflect how much testing happens as well as how much infection there is. More testing finds more cases that would otherwise go unnoticed.
Testing is free or sliding-scale at several Houston clinics, and chlamydia, gonorrhea, syphilis and HIV can all be tested for. Bacterial STIs are curable with treatment from a clinician, and HIV is treatable.

In this guide

How to read STD rates
Chlamydia, gonorrhea and syphilis in Harris County
HIV in Houston and Harris County
STD rates by state and by city: how Houston compares
What shapes the numbers
Texas rules that touch testing
Free and low-cost testing in Houston
Sources

How to read STD rates

A case count is the number of infections reported to public health. A rate divides that count by the population, usually per 100,000 people. Rates matter because Harris County is large. A big county will have a big count even if its rate is average.

Reported cases are not all infections

The CDC notes that many chlamydia and gonorrhea infections cause no symptoms. A person without symptoms may never be tested, so that infection never becomes a reported case. Reported numbers are therefore a floor, not a full count.

In Texas, labs and clinicians report certain conditions to the state. The Texas Department of State Health Services (DSHS) lists chlamydia, gonorrhea, syphilis at all stages, chancroid, HIV and AIDS as notifiable conditions in its 2026 list. Reporting is how these figures exist at all.

Years and sources are not interchangeable

The latest published figures do not all cover the same year. The most recent DSHS STD surveillance report with county tables covers 2022. The Houston Health Department's HIV figure covers 2023. CDC's HIV release tables cover 2024. DSHS also notes that prior-year numbers may change as data are updated.

For that reason, this guide does not mix sources inside one comparison. Where a comparison is made, both numbers come from the same source and the same year. Where two figures cannot be compared fairly, the guide says so.

Chlamydia, gonorrhea and syphilis in Harris County

Houston sits mostly in Harris County, and the county is the unit the state reports. These are the 2022 figures from the Texas DSHS STD Surveillance Report, set beside the DSHS statewide figures for the same year.

Infection (2022, Texas DSHS)	Harris County	Texas
Chlamydia	31,406 cases; 656.9 per 100,000	156,131 cases; 519.9 per 100,000
Gonorrhea	12,935 cases; 270.6 per 100,000	62,174 cases; 207.0 per 100,000
Syphilis, primary and secondary	1,082 cases (county rate not published in the report's county tables)	4,655 cases; 15.5 per 100,000
Syphilis, all stages	5,670 cases (county rate not published in the report's county tables)	25,991 cases; 86.6 per 100,000

Chlamydia

Harris County's chlamydia rate of 656.9 per 100,000 in 2022 was about 26 percent higher than the Texas rate of 519.9, using DSHS figures for both. The county's 31,406 cases made up roughly one in five of the state's reported cases.

Chlamydia is a bacterial infection. The CDC STI Treatment Guidelines (2021) describe it as curable with antibiotics prescribed by a clinician. Because it often has no symptoms, testing is the only way to find out.

Gonorrhea

DSHS reported 270.6 gonorrhea cases per 100,000 in Harris County for 2022, against 207.0 for Texas. That is about 31 percent higher than the statewide rate. The county's 12,935 cases were roughly one fifth of the state's 62,174.

Gonorrhea is also bacterial and curable with treatment from a clinician. The CDC guidelines note that treatment recommendations are updated over time as the bacteria change, which is one reason treatment is always chosen by a clinician.

Syphilis

Syphilis is counted in two ways. Primary and secondary syphilis are the earlier stages. The all-stages figure also includes later and latent stages that may have no visible signs.

DSHS counted 1,082 primary and secondary cases in Harris County in 2022, about 23 percent of the state's 4,655. For all stages, Harris County had 5,670 of Texas's 25,991 cases, about 22 percent. DSHS did not publish a Harris County rate for syphilis in its county tables, so this guide does not calculate one.

Syphilis is curable with treatment from a clinician, and earlier treatment prevents later complications. It matters especially in pregnancy. CDC's 2023 state surveillance tables list 930 congenital syphilis cases in Texas, a rate of 238.6 per 100,000 live births. Congenital syphilis can be prevented when syphilis is found and treated during pregnancy, which is why Texas law calls for repeat screening (see below).

HIV in Houston and Harris County

HIV is counted by new diagnoses. This is the number of people first diagnosed in a given year, not the number of people living with HIV. Two recent sources describe Houston-area diagnoses. They differ in year, geography and population base, so they are shown side by side rather than compared.

Measure	Figure	Source and year
New HIV diagnoses, Houston/Harris County	1,343; 27.5 per 100,000	Houston Health Department, HIV in the Houston Area: 2026 Epidemiologic Supplement (2023 data)
New HIV diagnoses, Harris County	1,262; 30.7 per 100,000 people aged 13 and older	CDC HIV Surveillance Data Release Tables (2024 data)
New HIV diagnoses, Texas	5,016; 16.0 per 100,000, all ages	CDC HIV Surveillance Data Release Tables (2024 data)

Why these rows are not a trend line

It is tempting to read 1,343 and 1,262 as a drop. That would be a mistake. The first figure covers the Houston/Harris County area in 2023 and comes from the city health department. The second covers Harris County in 2024 and comes from CDC. They count slightly different places in different years with different methods.

The 2024 county and state rates also use different denominators. CDC's Harris County rate is per 100,000 people aged 13 and older. The Texas rate is per 100,000 people of all ages. A rate based on a smaller group of people runs higher by design, so 30.7 and 16.0 should not be set against each other as a like-for-like gap.

A true year-on-year change needs the same source, geography and population base for both years. The published figures gathered here do not offer that for Harris County, and this guide does not invent one. The Houston Health Department's epidemiologic supplement and CDC's AtlasPlus are the places to look when a newer matched pair is released.

What is different about HIV

HIV is not curable, but it is treatable. A clinician can prescribe antiretroviral therapy that keeps HIV well managed. HIV prevention has also changed. PrEP and nPEP are medicines a clinician prescribes to lower the chance of getting HIV. The Houston Health Department offers PrEP and nPEP at its health centers, and clinics listed later in this guide offer them too.

STD rates by state and by city: how Houston compares

People often search for STD rates by state or STD rates by city to see where they live on a list. Rankings are easy to find and easy to misread. Here is how to use them well.

Compare like with like

A fair comparison uses the same infection, the same year, the same source and the same denominator. Harris County's 2022 DSHS figures can be compared with Texas's 2022 DSHS figures, as in the table above. They should not be compared with a 2023 CDC state figure, because the two sources count and round differently.

For reference, here are the statewide Texas figures from CDC's 2023 state ranking tables, which stand on their own as a separate set:

Chlamydia: 150,056 cases, 491.9 per 100,000 (CDC, 2023).
Gonorrhea: 53,793 cases, 176.4 per 100,000 (CDC, 2023).
Primary and secondary syphilis: 4,562 cases, 15.0 per 100,000 (CDC, 2023).

These are not directly comparable to the Harris County 2022 numbers, so no change from 2022 to 2023 is calculated. DSHS and CDC statewide counts also differ slightly for the same infection.

City and county are not the same

Houston spans parts of three counties: Harris, with small portions in Fort Bend and Montgomery. Published STD data are usually by county. When a source says "Houston," check whether it means the city, Harris County or the Houston/Harris County area. A "city" rate may be a county rate under another label.

A high rate is not a verdict

A county can rank high because it tests more, reports more completely or has a large, young, mobile population. A county can rank low because few people are tested. Rate tables describe the health system as much as they describe any group of people. Nothing in a ranking says anything about an individual's risk, and it should never be read as a judgment about a community.

The CDC's AtlasPlus tool lets readers look up county and state data for chlamydia, gonorrhea, syphilis and HIV, and it is the best place to check for newer releases.

What shapes the numbers

No single factor explains a county's rate. Public health agencies point to several that work together.

How much testing happens

Screening finds infections that cause no symptoms. The CDC STI Treatment Guidelines (2021) recommend yearly chlamydia and gonorrhea screening for sexually active women under 25 and for older women with risk factors. The guidelines also recommend regular screening for gay, bisexual and other men who have sex with men, based on exposure. The USPSTF makes similar screening recommendations for people at increased risk. More screening means more diagnoses are reported, which can push a rate up even as more infections are caught and treated.

Access to care

Cost, transportation, clinic hours and insurance all affect whether a person gets tested and treated. A long wait for care lets infections go on longer and can pass them to others. Free and sliding-scale clinics exist to close that gap, and the final section lists them.

Infections with no symptoms

Chlamydia, gonorrhea and syphilis can all be present without noticeable signs. People who feel fine may not seek care. A routine test is the way to learn anything. A clinician or a lab result is the only thing that can tell a person about their own status.

Newer prevention tools

In 2024 the CDC issued guidance on doxycycline post-exposure prophylaxis, called doxy-PEP. It is for certain groups, including gay, bisexual and other men who have sex with men and transgender women who have had a bacterial STI in the past year. A clinician decides whether it fits and prescribes it. Legacy Community Health lists doxy-PEP among its Montrose services.

Texas rules that touch testing

A few state laws shape what happens around testing in Houston. These come from Texas statutes and state agencies. Check with the clinic or the health department for how they apply to your situation.

Reporting

Under the DSHS Texas Notifiable Conditions list for 2026, chlamydia and gonorrhea are reported within one week. Primary and secondary syphilis is reported within one work day, and syphilis at other stages, including congenital, within one week. Acute HIV is reported within one work day and non-acute HIV within one week. These reports go to public health, which uses them to produce the figures in this guide.

Minors and consent

Texas Family Code Section 32.003 lets a minor of any age consent to diagnosis and treatment of a reportable infectious disease. That covers reportable STIs and HIV, and parent or guardian consent is not necessary. The same section allows a physician to tell a parent or guardian about treatment, with or without the minor's consent. A provider therefore cannot promise that parents will never be told. Houston Health Department also notes that Texas SB 1188, effective September 1, 2025, gives parents and guardians access to a minor's electronic health record, such as MyChart. Teens who have questions should ask the clinic about its privacy practices before the visit.

Pregnancy

Texas Health and Safety Code Section 81.090 calls for a syphilis, HIV and hepatitis B test at the first prenatal visit. It calls for syphilis and HIV tests in the third trimester, not earlier than the 28th week. It also calls for syphilis and hepatitis B tests on admission for delivery. The patient may object to the HIV tests, but not to the syphilis tests.

Partner treatment

CDC's legal-status page for expedited partner therapy (EPT) says Texas has no EPT statute. Its basis is Texas Administrative Code rules. Physicians may prescribe STD medication for partners of an established patient without seeing the partner, and pharmacists may fill those prescriptions. Whether a clinician uses EPT is a clinical decision, so ask the clinic.

HIV and the law

CDC's 2023 analysis places Texas in the category with no HIV-specific or STD-specific criminal exposure law. General criminal laws can still apply in some situations. Anyone with questions about this should talk with a legal aid organization or a clinic's counselor.

Free and low-cost testing in Houston

Rates matter most when they lead to action. A test is a short visit, and several Houston clinics offer free or sliding-scale testing. For a fuller local list with costs, see the guide to STD testing in Houston and what it costs.

Houston Health Department

The Houston Health Department runs STD and HIV services at three sites. Costs are on a sliding scale. The department's phone line for all three is 832-393-4220.

Northside Health Center, 8504 Schuller Rd., Houston, Texas 77093.
Sharpstown Health Services, 6201 Bonhomme Rd., 3rd Floor, South Tower, Houston, Texas 77036.
Sunnyside Health and Multi-Service Center, 4410 Reed Rd., Houston, Texas 77051.

The department says it accepts walk-ins as capacity permits and encourages appointments from September 1, 2026. PrEP and nPEP are by appointment at 832-395-9800. Calling ahead is a good idea.

Harris County Public Health Antoine Clinic

The clinic at 5815 Antoine Dr., Houston, TX 77091, offers testing for HIV, syphilis, gonorrhea and chlamydia, plus PrEP and STI treatment. Harris County Public Health lists these services as free, and walk-ins are welcome. The listed hours are Monday to Thursday 8am to 7pm, closed Friday, and every other Saturday 8am to 2pm. The page itself says to confirm before visiting. The phone number is 832-927-7350.

Legacy Community Health, Montrose

Legacy is at 1415 California St., Houston, TX 77006, phone (832) 548-5100. HIV, syphilis and hepatitis C testing are free and available on a walk-in basis. A full STI panel is by appointment. Legacy also lists express STI testing for uninsured people without symptoms. The clinic does not publish prices for the full panel, so ask when calling. Legacy says its services are open to all regardless of ability to pay.

Avenue 360 Health & Wellness

Avenue 360 lists free walk-in rapid HIV, hepatitis C and syphilis testing at its Heights site (2150 West 18th Street, Suite 300, Houston, TX 77008) and its Midtown site (2920 Fannin St., Houston, TX 77002), Monday to Friday, 8:30am to 4:30pm. The phone number for both is (713) 426-0027. Avenue 360's testing page describes rapid syphilis testing rather than a full STI panel.

The Montrose Center

This LGBTQ+ community center is at 401 Branard Street, Houston, Texas 77006, phone 713-529-0037. It lists free walk-in rapid HIV, hepatitis C and syphilis testing, Monday to Thursday, 9AM to 2PM. It does not list a full STI panel or PrEP.

Testing at a place you choose

Harris County Public Health's Testing123 program sends staff to a location you choose in Harris or Montgomery County for free HIV and syphilis testing. Text (281) 962-8378. Texas DSHS also lists a free mail-order self-collection program for anyone in Texas aged 13 and older, covering HIV, syphilis, gonorrhea and chlamydia, at testfortexas.org. Together TakeMeHome provides free HIV self-tests to U.S. residents aged 17 and older. For a broader search by ZIP code, the CDC's GetTested locator lists testing sites.

What to expect at a visit

A clinic visit usually starts with a short talk about what tests make sense, then a urine sample, swab or blood draw. Results can take from minutes for rapid tests to several days for others. If a test is positive for a bacterial STI, a clinician prescribes treatment that cures it. If an HIV test is positive, the clinic can connect a person to care and treatment that keeps HIV well managed. The CDC lists window periods, the time after exposure before a test can detect an infection, for each test. Ask a clinician which applies to you and whether to retest.

Getting tested is a routine act of health care. It says nothing about who someone is, and every gender, orientation and relationship type is welcome at the clinics above.

STD Rates in Houston: What the Latest Data Shows