What are Sexually Transmitted Infections (STI)?

Sexually transmitted infections (STIs) are some of the most common infections found in the United States. More than 19 million men and women are affected each year.

Although STIs are more prevalent among people aged 15-24 years, they affect persons of all ages and from all backgrounds. Some STIs affect certain populations more:

  • Gonorrhea affects Blacks and African Americans 18 times more than it does whites.
  • Women tend to have more severe health consequences from infection with STIs than men. Women often do not show symptoms of STIs; however, they can be at greater risk for major complications. 
  • Many people with STIs have no symptoms, but they can still transmit to others.
  • Many STIs can be treated effectively so it is important to get tested!

Frequently Asked Questions

How will I know if I have an STI?

Most STIs have no signs or symptoms. You or your partner could be infected and not know it. The only way to know your STD status is to get tested. Having an STI, such as herpes, syphilis, or gonorrhea, may make it easier to get HIV. It’s important to get tested to protect your health and the health of your partner. CDC recommends sexually active gay and bisexual men get tested for:

  • HIV at least once a year;
  • Syphilis;
  • Hepatitis B;
  • Hepatitis C;
  • Chlamydia and gonorrhea of the rectum if you’ve had receptive anal sex (been a “bottom”) in the past year;
  • Chlamydia and gonorrhea of the penis if you have had insertive anal sex (been a “top”) or received oral sex in the past year;
  • Gonorrhea of the throat if you’ve performed oral sex (i.e., your mouth on your partner’s penis, vagina, or anus) in the past year;
  • Sometimes, your healthcare provider may suggest a herpes test.

Source: https://www.cdc.gov/std/life-stages-populations/stdfact-msm.htm

How do healthcare providers test for STDs?

There’s not a single test for all STDs — each STD has its own test. Based on what’s learned from your interview or exam, providers may take one or more of the following samples:
  • blood sample
  • urine sample
  • swab of the inside throat, genitals, or anus

Your provider can help you figure out which tests you need, and will likely perform a physical exam as well to check for warts, sores, rashes, irritation, or discharge.

How often should you get tested for STDs?

It all depends on your age, risk factors, and sexual behavior. Testing should happen once a year as a part of routine healthcare. If something has changed in your sexual practices, you should get tested. If you have symptoms of an STD, get tested immediately.

How is chlamydia spread and how can I reduce my risk of getting it?

You can get chlamydia by having vaginal, anal, or oral sex with someone who has chlamydia. If your sex partner is male you can still get chlamydia even if he does not ejaculate (cum). If you’ve had chlamydia and were treated in the past, you can still get infected again. This can happen if you have unprotected sex with someone who has chlamydia. If you are pregnant, you can give chlamydia to your baby during childbirth.

The only way to avoid STIs including chlamydia is to not have vaginal, anal, or oral sex. If you are sexually active, you can do the following things to lower your chances of getting chlamydia:

  • Be in a long-term mutually monogamous relationship with a partner who has been tested and has negative STD test results;
  • Use latex condoms the right way every time you have sex.

For more information on chlamydia: https://www.cdc.gov/std/chlamydia/stdfact-chlamydia.htm

How is genital herpes spread?

You can get genital herpes by having vaginal, anal, or oral sex with someone who has the disease. If you do not have herpes, you can get infected if you come into contact with the herpes virus in:

  • A herpes sore;
  • Saliva (if your partner has an oral herpes infection) or genital secretions (if your partner has a genital herpes infection);
  • Skin in the oral area if your partner has an oral herpes infection, or skin in the genital area if your partner has a genital herpes infection.

You can get herpes from a sex partner who does not have a visible sore or who may not know he or she is infected. It is also possible to get genital herpes if you receive oral sex from a sex partner who has oral herpes.

You will not get herpes from toilet seats, bedding, or swimming pools, or from touching objects around you such as silverware, soap, or towels. If you have additional questions about how herpes is spread, consider discussing your concerns with a healthcare provider.

For more information on genital herpes: https://www.cdc.gov/std/herpes/stdfact-herpes.htm

How do I know if I have gonorrhea?

Some men with gonorrhea may have no symptoms at all. However, men who do have symptoms, may have:

  • A burning sensation when urinating;
  • A white, yellow, or green discharge from the penis;
  • Painful or swollen testicles (although this is less common).

Most women with gonorrhea do not have any symptoms. Even when a woman has symptoms, they are often mild and can be mistaken for a bladder or vaginal infection. Women with gonorrhea are at risk of developing serious complications from the infection, even if they don’t have any symptoms.

Symptoms in women can include:

  • Painful or burning sensation when urinating;
  • Increased vaginal discharge;
  • Vaginal bleeding between periods.

Rectal infections may either cause no symptoms or cause symptoms in both men and women that may include:

  • Discharge;
  • Anal itching;
  • Soreness;
  • Bleeding;
  • Painful bowel movements.

You should be examined by your doctor if you notice any of these symptoms or if your partner has an STD or symptoms of an STD, such as an unusual sore, a smelly discharge, burning when urinating, or bleeding between periods.

For more information on gonorrhea.

Why does having an STI put me more at risk for getting HIV?

If you get an STI, you are more likely to get HIV than someone who is STI-free. This is because the same behaviors and circumstances that may put you at risk for getting an STI also can put you at greater risk for getting HIV. In addition, having a sore or break in the skin from an STI may allow HIV to more easily enter your body. If you are sexually active, get tested for STIs and HIV regularly, even if you don’t have symptoms.

For more information on STIs and HIV.

What is PID and how to you get it?

Pelvic inflammatory disease (PID) is an infection of a woman’s reproductive organs. It is a complication caused by untreated infections.

Can STIs be spread through oral sex?

Many STDs, as well as other infections, can be spread through oral sex. Anyone exposed to an infected partner can get an STD in the mouth, throat, genitals, or rectum. The risk of getting an STD from oral sex, or spreading an STD to others through oral sex, depends on several things, including

  • The particular STD.
  • The sex acts practiced.
  • How common the STD is in the population to which the sex partners belong.
  • The number of specific sex acts performed.

In general:

  • It may be possible to get some STDs in the mouth or throat from giving oral sex to a partner with a genital or anal/rectal infection, particularly from giving oral sex to a partner with an infected penis.
  • It also may be possible to get certain STDs on the penis (and possibly the vagina, anus or rectum) from getting oral sex from a partner with a mouth or throat infection.
  • It’s possible to have an STD in more than one area at the same time, for example in the throat and the genitals.
  • Several STDs that may be transmitted by oral sex can then spread throughout the body (i.e., syphilis, gonorrhea, and intestinal infections).
  • Anilingus (or oral sex involving the anus) can transmit hepatitis A and B, intestinal parasites like Giardia, and bacteria like E. coli and Shigella.
  • STDs can be spread to a sex partner even when the infected partner has no signs or symptoms.  If you are infected with an STD, you might not know it because many STDs may have no symptoms.

For more information on STIs and oral sex: https://www.cdc.gov/std/healthcomm/stdfact-stdriskandoralsex.htm

How can STIs affect me and my unborn baby?

STIs can complicate your pregnancy, and may have serious effects on both you and your developing baby. Some of these problems may be seen at birth; others may not be discovered until months or years later. In addition, it is well known that infection with an STI can make it easier for a person to get infected with HIV. Most of these problems can be prevented if you receive regular medical care during pregnancy. This includes tests for STIs starting early in pregnancy and repeated close to delivery, as needed.

For more information on STIs during pregnancy: https://www.cdc.gov/std/pregnancy/stdfact-pregnancy.htm

What does syphilis look like?

Syphilis is divided into stages (primary, secondary, latent, and tertiary), with different signs and symptoms associated with each stage.

  • Primary syphilis: a sore or sores at the original site of infection; these sores usually occur on or around the genitals, around the anus or in the rectum, or in or around the mouth; and are usually (but not always) firm, round, and painless.
  • Secondary syphilis: skin rash, swollen lymph nodes, and fever.
  • Tertiary syphilis: associated with severe medical problems affecting the heart, brain, and other organs.

The signs and symptoms of primary and secondary syphilis can be mild, and they might not be noticed. During the latent stage, there are no signs or symptoms. A doctor can usually diagnose tertiary syphilis with the help of multiple tests. Left untreated, syphilis can result in blindness, loss of hearing, and heart disease.

For more information on syphilis: https://www.cdc.gov/std/syphilis/stdfact-syphilis.htm

How common is syphilis among men who have sex with men?

Between 2018 and 2019, the number of reported primary and secondary (P&S) cases in the United States increased by 11%, and there were 38,992 P&S syphilis cases reported in 2019. Most (47%) of these cases were among MSM only and men who have sex with both men and women.

For more information on syphilis in men who sex have sex men: https://www.cdc.gov/std/syphilis/stdfact-msm-syphilis.htm

What is congenital syphilis and how can it affect me and my baby?

Congenital syphilis (CS) is a disease that occurs when a mother with syphilis passes the infection on to her baby during pregnancy. CS can have major health impacts on your baby. How CS affects your baby’s health depends on how long you had syphilis and if — or when — you got treatment for the infection.

CS can cause:

  • Miscarriage (losing the baby during pregnancy),
  • Stillbirth (a baby born dead),
  • Prematurity (a baby born early),
  • Low birth weight, or
  • Death shortly after birth.

Up to 40% of babies born to women with untreated syphilis may be stillborn, or die from the infection as a newborn. For babies born with CS, CS can cause:

  • Deformed bones,
  • Severe anemia (low blood count),
  • Enlarged liver and spleen,
  • Jaundice (yellowing of the skin or eyes),
  • Brain and nerve problems, like blindness or deafness,
  • Meningitis, and
  • Skin rashes.

For more information on congenital syphilis: https://www.cdc.gov/std/syphilis/stdfact-congenital-syphilis.htm

What is trichomoniasis and how do you get it?

Trichomoniasis (or “trich”) is a very common sexually transmitted infection (STI). It is caused by infection with a protozoan parasite called Trichomonas vaginalis. Although symptoms of the disease vary, most people who have the parasite cannot tell they are infected.

The parasite passes from an infected person to an uninfected person during sex. In women, the most commonly infected part of the body is the lower genital tract (vulva, vagina, cervix, or urethra). In men, the most commonly infected body part is the inside of the penis (urethra).

During sex, the parasite usually spreads from a penis to a vagina, or from a vagina to a penis. It can also spread from a vagina to another vagina. It is not common for the parasite to infect other body parts, like the hands, mouth, or anus.

It is unclear why some people with the infection get symptoms while others do not. It probably depends on factors like a person’s age and overall health. Infected people without symptoms can still pass the infection on to others.

For more information about trichomoniasis: https://www.cdc.gov/std/trichomonas/stdfact-trichomoniasis.htm

For overall health facts, check out our Overall Fact Source:


STIs are preventable if you know about them and how to protect yourself and others.

Get Protected: Condoms are very effective at preventing disease transmission.


Some people have no signs or symptoms of STIs, so it is important to get routine testing if you are sexually active.

It is even more important if you are experiencing anything out of the ordinary, (itching, burning, bleeding, sores, etc.)

Find a Testing Site Near You


Most STIs are treatable. It is important to seek medical care if you or your partner has an STI.

Disease Intervention Specialists (DIS)

DIS are public health professionals with skills in interviewing, counseling, educating, and referring clients and their partners to treatment and services. We work to prevent the spread of disease in the community, specifically sexually transmitted conditions. DIS interview all newly diagnosed syphilis and HIV cases in Connecticut so that appropriate treatment is administered and partners who have been exposed can get tested and treated as needed. We also educate clients and their partners about ways to reduce their risks of getting infected again and provide information about PrEP. Leave it to us DIS to notify your partners without revealing any information about you.

CT Department of Public Health shares what “Leave it to us” is all about

Tell Your Partner

If would prefer to notify partners yourself, try TYP to send a text to their mobile phone: tellyourpartner.org