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.

People look up STD rates for many reasons. Some are curious about their city. Some are comparing places before a move. Some want context for a decision about their own sexual health. This guide covers what is publicly reported for Boston, what is not, and how to read the numbers fairly.

It also ends where it should: with free and low-cost testing in Boston, which is the most useful thing any rate can point you toward.

Key takeaways

The most recent county figures available to us are from 2021. For Suffolk County, which contains Boston, they show a chlamydia rate of 807.8 per 100,000 people (6,230 cases) and a gonorrhea rate of 298.0 per 100,000 (2,298 cases).
Suffolk County ranked first in Massachusetts for chlamydia in that 2021 CDC county data, as republished by Boston 25 News and Stacker in March 2024.
Suffolk County is larger than the city of Boston, so these are not city-only numbers.
We could not confirm current Boston or Massachusetts figures for syphilis, HIV, or statewide chlamydia and gonorrhea. This guide says so plainly and shows where to look them up.
A rate describes a population, not any one person. Only a test can tell you about your own status.
Free and low-cost testing exists across Boston, including Boston Medical Center, Fenway Health, Codman Square Health Center and the Multicultural AIDS Coalition.

What is in this guide

The latest numbers for Boston and Suffolk County
How to read STD rates, by state and by city
What we could not confirm, and where to find it
What shapes the numbers
Who is advised to test, and how often
Free and low-cost testing in Boston
Massachusetts rules on consent, privacy and partner treatment
Sources

The latest numbers for Boston and Suffolk County

The most recent local figures we could verify are for 2021. They are CDC county-level data for Suffolk County, Massachusetts, as republished by Boston 25 News and Stacker on March 18, 2024. That is a secondary source, so the CDC's own tools remain the place to confirm them.

Infection	Rate per 100,000 people	Reported cases	Year	Geography
Chlamydia	807.8	6,230	2021	Suffolk County, MA
Gonorrhea	298.0	2,298	2021	Suffolk County, MA

According to the same CDC county data, Suffolk County had the highest chlamydia rate of any county in Massachusetts in 2021.

What Suffolk County means for Boston

Suffolk County contains Boston, but it is larger than the city. A county rate is a useful signal for the Boston area. It is not a count of Boston residents alone.

What these figures cannot tell you

Two limits matter here.

First, the figures are for one year. With a single year, we cannot report a year-on-year change, and we will not guess at one.

Second, the numbers count reported cases. They do not count every infection. Chlamydia and gonorrhea often cause no symptoms, so many infections go unfound unless someone is tested. The CDC says in its surveillance reporting that reported cases are an undercount of all infections.

How to read STD rates, by state and by city

Searches for STD rates by state and STD rates by city lead to tables that look easy to compare. A few ideas make them easier to read fairly.

What a rate per 100,000 means

A rate puts places of different sizes on the same scale. If a rate is 807.8 per 100,000, that is about 808 reported cases for every 100,000 residents in that year. The rate does not say how many people carry an infection at a given moment. It says how many cases were reported.

More testing can mean higher rates

A place that tests more people finds more infections. A higher reported rate can therefore reflect strong access to testing, not only more infections. A county with many clinics and active screening can look worse on paper than one where people have few places to go.

This is one reason to be careful with rankings. A first-place ranking, like Suffolk County's for chlamydia in 2021, is not a verdict on the people who live there.

Why city, county and state numbers differ

City, county and state figures cover different populations. A city rate can be higher or lower than the county around it. A state rate blends cities, suburbs and rural areas. When you compare STD rates by city, check that both figures use the same year, the same infection and the same kind of geography.

Where to look up rates yourself

The CDC publishes county and state data in AtlasPlus. The Boston Public Health Commission lists its infectious disease work on its Infectious Diseases page.

What we could not confirm, and where to find it

A complete picture of STD rates in Boston would include syphilis and HIV, and statewide figures for comparison. We could not verify these for this guide.

Syphilis. We could not confirm a current primary and secondary syphilis rate or a congenital syphilis count for Suffolk County or Massachusetts.
HIV. We could not confirm a current figure for new HIV diagnoses in Boston or Massachusetts.
Statewide chlamydia and gonorrhea. We could not confirm state-level rates to set beside the county numbers.

The Massachusetts Department of Public Health publishes surveillance reports, but we were not able to read them for this guide, so we do not quote them. For the latest numbers, use CDC AtlasPlus, the state health department, or the Boston Public Health Commission.

The Boston Public Health Commission's Infectious Disease Bureau can be reached at 617-534-5395. The Mayor's Health Line, at 617-534-5050, offers free, confidential, multilingual health information and referral, according to the City of Boston.

What shapes the numbers

No single cause explains STD rates in any place. Public health agencies, including the CDC, describe several factors that work together.

Whether infections are found

Many bacterial STIs cause no symptoms. They are found mainly through screening. Places and groups with more screening report more cases.

Access to care

Cost, clinic hours, transportation, language and fear of being judged can all keep people from testing. When people cannot reach care, infections can go unfound and untreated, and can pass to others without anyone knowing.

Partner treatment and follow-up

Reinfection is common when a partner is not treated at the same time. Massachusetts law supports partner treatment for chlamydia, which is covered below.

Public health capacity

The CDC has noted in its national reporting that strained public health programs and clinic capacity affect how quickly infections are found and treated. We have no Boston-specific figure on this, so we draw no local conclusion.

Biology and testing methods

Some infections, such as syphilis, can have long stretches without noticeable signs. Newer lab methods can find infections that older tests missed. A change in a reported rate can partly reflect a change in how people are tested.

Who is advised to test, and how often

Rates describe a city. Screening advice describes what helps individuals. These recommendations come from the CDC STI Treatment Guidelines (2021) and the USPSTF. A clinician can tell you which apply to you.

Chlamydia and gonorrhea

The CDC recommends yearly chlamydia and gonorrhea screening for sexually active women under 25, and for older women with risk factors such as a new partner or a partner with other partners. The CDC also recommends at least yearly screening for sexually active gay, bisexual and other men who have sex with men. More frequent screening may be advised depending on risk. Sites of testing can include the throat and rectum as well as urine, depending on sexual practices.

HIV

The CDC recommends that everyone from 13 to 64 be tested for HIV at least once, and more often if there is ongoing risk. The USPSTF recommends HIV screening for people from 15 to 65. For timing after a possible exposure, the CDC says a lab blood test for HIV antigens and antibodies can usually detect HIV 18 to 45 days after exposure. Other test types have different windows, so ask the clinic which test it uses.

Syphilis, hepatitis C and pregnancy

The USPSTF recommends syphilis screening for people at increased risk and for all pregnant people. The CDC recommends hepatitis C testing at least once for adults. People who are pregnant should ask their prenatal care provider about the full set of recommended screenings.

Doxy-PEP and prevention

In 2024 the CDC issued guidance on doxycycline as post-exposure prevention (doxy-PEP) for certain groups. It applies to gay, bisexual and other men who have sex with men, and transgender women, who have had a bacterial STI in the past year. It is a clinician's prescription decision. Fenway Health lists doxy-PEP among its services. PrEP and PEP, which are HIV prevention options, are listed at Boston Medical Center, Fenway Health, Codman Square Health Center and others below.

What treatment looks like

Chlamydia, gonorrhea, syphilis and trichomoniasis are curable with treatment from a clinician. HIV and herpes are not curable but are treatable and manageable. HPV often clears on its own, and a vaccine can prevent the types that most often cause problems. A clinician decides on any treatment.

Free and low-cost testing in Boston

The list below comes from clinic pages and the CDC GetTested directory. Hours and services can change, so call before you go. The City of Boston also has a page called Getting Tested for STIs. For a fuller walk-through of costs and what happens at a visit, see our guide to where to get tested in Boston and what it costs.

Boston STD Clinic at Boston Medical Center

The clinic is at 725 Albany St., 9th Floor, Suite 9C (BMC Shapiro Center), Boston, MA 02118. The phone is 617-414-2803. The clinic page says routine testing for HIV, chlamydia, gonorrhea, syphilis and hepatitis C is free, and that cost assistance is available for people without insurance. PrEP and PEP are listed too.

Appointments are made by phone, or through MyChart for established patients. The page does not say whether walk-ins are accepted. Listed hours are Monday, Wednesday and Friday 9 a.m. to 4 p.m., and Tuesday and Thursday 9 a.m. to 7 p.m. The page also lists Tuesday with the shorter days, so confirm by phone. Details are on the clinic page.

Fenway Health Sexual Health Clinic

Fenway Health is in the Ansin Building, 1340 Boylston Street, 4th floor, Boston, MA 02215. The clinic line is 617-267-0159, and the main line is 617-267-0900. Walk-in hours, first come first served, are Tuesday 1 to 7 p.m., Wednesday 3 to 7 p.m., Thursday 3 to 7 p.m. and Friday 9 a.m. to 12 p.m. Monday 9 a.m. to 4 p.m. is by appointment only. Check-in closes 30 minutes before the end time. Results take 3 to 5 business days.

The clinic bills insurance if you have it. Uninsured patients can be seen free through grant funding. The page does not mention a sliding scale. Services include HIV and hepatitis C testing, PrEP, PEP and doxy-PEP. The page is aimed at gay, bisexual and other men who have sex with men, transgender and gender diverse people, and their partners. Details are on the Fenway Health page.

X-Clinic at Codman Square Health Center

The X-Clinic is at 637 Washington St., Dorchester, MA 02124. The phone is 617-822-8350. Express visits, for people with no symptoms and no known exposure, are walk-in during operating hours. Telehealth and appointments are also offered. The center accepts all insurance, uses a sliding fee schedule, and offers testing and treatment regardless of citizenship status. Teen testing is confidential. Rapid HIV testing, PrEP and PEP are listed.

Two Codman pages list different schedules, so call to confirm hours. Coverage help is at 617-822-8162. Details are on the X-Clinic page.

TrueCare@MAC testing, Multicultural AIDS Coalition

The Multicultural AIDS Coalition is at 9 Palmer Street, Roxbury, MA 02119. The phone is 617-442-1622. Testing is free, and an appointment is optional. Testing hours are Monday, Tuesday, Thursday and Friday 10:30 a.m. to 4 p.m., Wednesday 12:30 to 6 p.m., and Saturday 11:30 a.m. to 3 p.m. Sunday is not listed. HIV, hepatitis C and STD testing are listed. See the MAC site.

Other listings from the CDC GetTested directory

Boston Public Health Commission, 774 Albany St, Boston, MA 02118, 617-534-3976. The directory lists free HIV, hepatitis C, chlamydia, gonorrhea and syphilis tests. It does not list hours or confirm walk-ins. This is a separate provider from Boston Medical Center, which is on the same street.
Planned Parenthood League of Massachusetts, Greater Boston Health Center, 1055 Commonwealth Ave, Boston, MA 02215, 617-295-7235. Appointment required. The directory lists insurance, Medicaid, Medicare and a sliding scale, plus PrEP navigation and HPV vaccine.
DotHouse Health, 1353 Dorchester Avenue, Dorchester, MA 02122, 617-288-3230. The directory lists appointment required, Medicaid, Medicare and sliding scale fees, with English, Portuguese and Spanish. Codman's resource list mentions walk-in testing through urgent care at the same number, so ask when you call.

To search for other options by address, use the CDC's GetTested directory.

What to ask when you call

Is the visit free, or what is the fee if I have no insurance?
Do you take walk-ins, or do I need an appointment?
Which infections are included in the standard panel?
How will I get my results, and how long will it take?

Massachusetts rules on consent, privacy and partner treatment

Testing as a minor

Under Massachusetts General Laws chapter 112, section 12F, a minor who reasonably believes they are at risk of exposure through sexual activity may consent to care to diagnose or treat the disease, or to HIV prevention if sexually active, without a parent's consent. The records are confidential between the minor and the provider, except that a provider must notify a parent or guardian if the minor's life or limb is seriously endangered. The City of Boston tells people 13 or older that they can get a confidential STI test without parental permission.

Reporting and privacy

Massachusetts law requires certain diseases to be reported to local boards of health and the state health department. Under chapter 111, section 119, these reports and records are not public. They can be disclosed only by judicial order or to officials whose duties entitle them to see them.

Partner treatment

Chapter 111, section 121B directs the state health department to set rules that let clinicians prescribe medication for the partners of patients diagnosed with chlamydia, sometimes called expedited partner therapy. The CDC's page on the legal status of expedited partner therapy in Massachusetts lists chlamydia under the state regulation. Ask a clinician whether this applies in your situation.

STD Rates in Boston: What the Latest Data Shows