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 really counts of people who were tested, diagnosed and reported to the county. This guide walks through the latest San Diego figures, explains how to read them, and shows where free and low-cost testing is available in the city.

One note up front. The most recent county numbers published in the sources we could read are for 2024. State and national comparisons need a different source, and we point you to it below rather than guess.

Contents

How to read STD rates
San Diego County numbers for 2024
Syphilis and congenital syphilis
HIV: what the sources do and do not show
STD rates by state and by city: how to compare
What shapes the numbers
Free and low-cost testing in San Diego
Common questions
Sources

Key takeaways

Times of San Diego, reporting County of San Diego Health and Human Services Agency data, says chlamydia cases fell 7.4% in San Diego County, from 17,720 in 2023 to 16,414 in 2024.
The same report lists gonorrhea at 6,021 cases in 2024, down 9.5% from 6,651 in 2023.
Primary and secondary syphilis fell 35.8%, from 481 cases to 309. Congenital syphilis was reported in 31 babies in 2024, and three were stillbirths or neonatal deaths, the most since 2019.
These are counts of reported cases, not rates per 100,000 people. Counts and rates are different measures, and only rates are fair for comparing places.
Many infections cause no symptoms, so only a test can show whether someone has one.
Free and low-cost testing is available in the city. See the clinic section below, and confirm hours and eligibility by phone.

How to read STD rates

Before the San Diego figures, it helps to know what a number is measuring. Three terms come up again and again.

Cases versus rates

A case count is the number of infections reported in a place and a year. A rate divides that count by the population, usually per 100,000 people. A big county will almost always have more cases than a small one. Rates make the comparison fairer.

The San Diego numbers in this guide are counts. The article we relied on does not show the rate per 100,000, so we do not state one here.

Reported cases are not all infections

The CDC explains that many people with chlamydia, gonorrhea and other STIs have no symptoms. A person who never gets tested may never be counted. That means case counts reflect two things at once: how many infections there are, and how much testing is happening.

A drop in cases can mean fewer infections. It can also mean fewer tests. Public health agencies look at several measures together for this reason.

Diagnosed and reported are not the same as new

A reported case is an infection that a lab or clinician sent to the health department. Reports are usually grouped by the year the infection was diagnosed. They do not always show when the infection began.

San Diego County numbers for 2024

Times of San Diego published a report on March 2, 2026, describing the 2024 STI numbers compiled by the County of San Diego Health and Human Services Agency, HIV, STD and Hepatitis Branch. The county figures cover San Diego County as a whole, not just the city limits.

Infection	2023 cases	2024 cases	Change
Chlamydia	17,720	16,414	Down 7.4%
Gonorrhea	6,651	6,021	Down 9.5%
Primary and secondary syphilis	481	309	Down 35.8%
Congenital syphilis	36	31	Down 5 cases

Source: Times of San Diego, March 2, 2026, reporting County of San Diego HHSA data for 2023 and 2024.

Chlamydia

Chlamydia is a bacterial infection and the most commonly reported of the three bacterial STIs in the county. The report lists 16,414 cases in 2024. That is 1,306 fewer than the 17,720 reported in 2023.

The CDC says chlamydia is curable with antibiotics prescribed by a clinician. Because it often has no symptoms, the CDC 2021 STI Treatment Guidelines recommend routine screening for some groups. These include sexually active women under 25 and older women with risk factors. They also include men who have sex with men, who are advised to be screened at least yearly at the sites of sexual contact.

Gonorrhea

The county reported 6,021 gonorrhea cases in 2024, down 9.5% from 6,651 in 2023. That is 630 fewer cases.

Gonorrhea is also a bacterial infection that a clinician can treat and cure. The CDC notes that antibiotic resistance in gonorrhea is a concern, which is one reason treatment choices are left to a clinician. Treatment recommendations change over time as resistance patterns change.

What the declines do and do not tell us

Three infections fell in the same year. That is encouraging. The sources we read do not say why, and we will not guess. Public health agencies usually avoid reading too much into a single year, so the more useful question is whether the decline holds in 2025 and 2026.

It is also worth remembering that these are still thousands of people. Declining numbers do not mean testing matters less.

Syphilis and congenital syphilis

Syphilis gets special attention from public health agencies. It can be treated and cured with antibiotics from a clinician, but it can cause serious harm if it goes unfound for years. During pregnancy it can be passed to a baby.

Primary and secondary syphilis

These are the early stages, when the infection is most easily passed on and most often reported. Times of San Diego, citing the county, lists 309 cases in 2024, down 35.8% from 481 in 2023. That is 172 fewer cases, the largest percentage drop of the infections in the report.

Congenital syphilis

Congenital syphilis happens when syphilis passes from a pregnant person to the baby. The county reported 31 cases in 2024, down from 36 in 2023. The same report says three of the 2024 cases were stillbirths or neonatal deaths, the most since 2019.

Congenital syphilis is preventable. The CDC recommends that pregnant people be tested for syphilis, and the USPSTF also recommends syphilis screening for pregnant people. Whether California law requires a specific number of prenatal syphilis tests is something we could not confirm for this guide. A prenatal care provider or the California Department of Public Health can answer that.

If you are pregnant or planning a pregnancy, a clinician can explain which tests apply to you and when.

HIV: what the sources do and do not show

This guide does not include a current county or California count for new HIV diagnoses. The sources we could read did not publish one, and we will not fill the gap with an estimate. The County of San Diego HIV, STD and Hepatitis Branch and the California Department of Public Health are the places to look for current HIV surveillance data.

What we can say comes from the CDC. HIV is not curable, but it is treatable. With treatment, people with HIV can live long and healthy lives. The CDC recommends that everyone from age 13 to 64 be tested for HIV at least once, and that people with more risk be tested more often.

Prevention tools available in San Diego

Several local providers list HIV prevention services:

Family Health Centers of San Diego says PrEP is available at all of its primary care clinics. PrEP may be covered by insurance or available at low or no cost.
UC San Diego Health's Owen Clinic runs a PrEP clinic for HIV-negative patients. Appointments are by phone at 619-543-3995. The Owen Clinic page does not mention STI testing, so it is a PrEP and HIV care option rather than an STI testing site.
CDC directory listings show PrEP navigation at the County Central Public Health Center, the San Diego LGBT Community Center and Planned Parenthood on College Avenue.

PEP, a short course of medicine a clinician can prescribe after a possible exposure, is listed at both Hillcrest Family Health Center clinics. Ask a clinician as soon as possible after a possible exposure, because timing matters.

STD rates by state and by city: how to compare

Many people look up STD rates by state or STD rates by city to see how their own area compares. It is a reasonable question, but the answer needs care.

Why counts do not compare well

The San Diego County figures above are counts. A county of this size will report far more cases than a small county. To compare places fairly you need a rate per 100,000 people for the same year, the same infection and the same definition of the area.

Where to find rates by state

The CDC publishes national and state surveillance data, including rate tables and an interactive tool called AtlasPlus. The California Department of Public Health publishes state-level STD surveillance. The sources we could open for this guide did not include California's state totals or rates, so we do not quote any. Use the CDC and state sources directly for the latest year.

Where to find rates by city

City-level rates are less common than county or state rates. In California, the county health department is the usual source. For San Diego, that is the County of San Diego Health and Human Services Agency. The numbers in this guide are county-wide, which is also the area the county health department reports on.

A few cautions when comparing

Check the year. Surveillance data are usually published months or years after the period they cover.
Check whether the number is a count or a rate.
Remember that more testing finds more infections, so a higher rate can sometimes reflect more screening.
Remember that reporting rules and lab practices differ between places.

A ranking of places does not tell any one person about their own health. A test does.

What shapes the numbers

The sources we read do not explain the 2024 declines in San Diego County, so this section describes general factors the CDC discusses, not conclusions about San Diego.

Testing access

Because so many infections have no symptoms, the number of infections found depends on how many people get tested. Clinics that offer walk-in, evening or free testing make it easier for people to find and treat infections early.

Treatment and partner care

When a clinician treats an infection, partners may need treatment too, or the infection can pass back and forth. California law helps here. Under Health and Safety Code section 120582, a physician who diagnoses chlamydia, gonorrhea or certain other STIs may provide antibiotics to the patient's sexual partners without examining them. Nurse practitioners, nurse-midwives and physician assistants may also do so. This is called expedited partner therapy, or EPT. Ask a clinician whether it applies to your situation.

Prevention tools

Condoms, regular testing, vaccines for hepatitis A and B and HPV, and PrEP for HIV all play a part. In 2024 the CDC also issued guidance on doxycycline taken after sex (doxy-PEP). The CDC recommends that clinicians discuss it with gay and bisexual men and transgender women who have had a bacterial STI in the past year. It is available only by prescription, and a clinician decides whether it is right for a person. The Night Clinic at Hillcrest Family Health Center lists DoxyPEP among its services.

Health care access and stigma

People who fear judgment or cost may put off testing. Clear information, confidential care and low-cost options reduce those barriers. Nobody needs a particular reason or history to be tested. Testing is routine health care.

Young people

California Family Code section 6926 lets a minor 12 or older consent to diagnosis and treatment of certain infectious diseases, including sexually transmitted ones, and to care related to preventing an STD. The statute says parents are not liable for payment. The Guttmacher Institute lists no parental notification requirement for California. Clinics can explain how their own billing and privacy practices work.

Free and low-cost testing in San Diego

If these numbers have you wondering about your own health, testing is how you find out. A test can show whether an infection is present. If one is found, a clinician can discuss treatment or management. For a full side-by-side look at costs and options, see our guide to where to get tested in San Diego and what it costs.

The clinics below come from published listings. Hours and eligibility can change, so call before you go.

County of San Diego Central Public Health Center sexual health clinic

The address is 5101 Market St, San Diego, CA 92114. The CDC directory prints Suite 200, though one county search result suggests Suite 2000, so confirm the suite when you call. The phone number is (619) 229-5400.

The CDC GetTested listing says a free STI test and a free HIV test are listed. It also says the clinic accepts insurance, Medicaid and Medicare, and charges based on income. It lists testing for HIV, hepatitis B and C, herpes, chlamydia, gonorrhea and syphilis, as well as HPV and mpox vaccines and PrEP navigation. The listing says appointments are required, but other county material suggests walk-in service. Call to confirm which applies. The listing does not give hours.

Hillcrest Family Health Center (daytime)

This Family Health Centers of San Diego clinic is at 4094 4th Avenue, San Diego, CA 92103. Hours are Monday to Friday, 8:00 a.m. to 5:00 p.m. The clinic's page says walk-ins are welcome and that it may be able to waive fees or help with insurance enrollment. Call (619) 515-2300 for appointments or (619) 515-2545 for information. Services include STI screening and treatment, HIV services, PrEP and PEP.

The Night Clinic at Hillcrest Family Health Center

The Night Clinic is at the same address, 4094 4th Avenue. Its page lists Monday to Thursday, 5:00 to 9:00 p.m., and does not list Friday. It describes free and confidential HIV testing and low-cost STI tests, with fees that may be waived or insurance enrollment help. Services include PrEP, PEP, DoxyPEP and hepatitis testing. The page lists free parking and says walk-ins are welcome. Phone numbers are (619) 515-2545 and (619) 515-2300.

San Diego LGBT Community Center (The Center)

The Center is at 3909 Centre Street, San Diego, CA 92103, phone 619-692-2077. The CDC NPIN listing shows Monday to Friday, 10:00 a.m. to 8:00 p.m., and Saturday, 10:00 a.m. to 4:00 p.m., with a note to call for STD and HIV testing hours. It lists no fee for services, with eligibility to be confirmed by contacting the organization. Testing includes chlamydia, gonorrhea, syphilis, rapid HIV and rapid hepatitis C, plus PrEP navigation. The listing says appointments are not required, but a separate news report gave an appointment contact, so a phone call is the safest step.

Planned Parenthood College Avenue Sarah Weddington Center

This center is at 4575 College Ave, San Diego, CA 92115, phone (888) 743-7526. The CDC GetTested listing says no appointment is required and lists insurance, Medicaid and sliding scale payment, plus PrEP for people without insurance. Tests include rapid HIV and blood HIV tests, herpes, chlamydia, gonorrhea and syphilis, with hepatitis B and HPV vaccines. The listing does not give hours.

Testing at home

Family Health Centers of San Diego lists at-home or mail-in testing through programs called TakeMeHome and Don't Think, Know. Its page does not state eligibility or cost. If an at-home result is positive, the page lists (619) 876-4462 to call. Check with the program about eligibility and cost before relying on it.

Finding more options

The CDC's GetTested locator lets you look up testing sites by ZIP code. The County of San Diego also has a sexual health services page that you can check for current clinic details.

When to test: window periods

A test needs time after an exposure to show a result. The CDC says HIV nucleic acid tests can detect HIV 10 to 33 days after exposure. Antigen and antibody tests done on a blood draw from a vein can detect it 18 to 45 days after exposure. Antigen and antibody tests with a finger prick take 18 to 90 days, and antibody-only rapid tests take 23 to 90 days. A clinician can tell you which test fits your timing and whether a repeat test makes sense.

For other infections, window periods differ. Ask the clinic what applies to the tests you are considering.

Common questions

Are STD rates in San Diego going up or down?

For 2024, the county figures reported by Times of San Diego fell for chlamydia, gonorrhea, primary and secondary syphilis, and congenital syphilis compared with 2023. One year is only one data point, so the next reports will show whether the trend continues.

Does a lower rate mean I can skip testing?

No. Rates describe a population. They cannot tell you whether you have an infection. Only a test can show that, and a clinician can help you decide which tests fit your situation.

Is testing confidential?

Clinics follow health privacy rules, and the Hillcrest Night Clinic describes its HIV testing as free and confidential. Ask any clinic how it handles billing statements and results if privacy is a concern.

Can I be prosecuted for having HIV?

California Health and Safety Code section 120290, as amended in 2017, covers any infectious or communicable disease, not HIV alone. Intentional transmission requires knowledge, specific intent to transmit, conduct posing a substantial risk, and actual transmission. Taking practical means to prevent transmission, such as using condoms, negates intent. Anyone with questions about the law should speak with a lawyer or a legal aid group.

What if I cannot pay?

Several of the clinics above list free testing, sliding scale fees, or fee waivers. Call and ask about options before assuming you cannot afford care.

STD Rates in San Diego: What the Latest Data Shows