April is Sexually Transmitted Infections awareness month, so what better time to explore the most common STI that Alpha Center sees and treats?
What is Chlamydia?
Chlamydia (kluh-mi-dee-uh) is a common STI caused by a bacterial infection called Chlamydia trachomatis, and affects people of all ages, biological sex or gender identity. This infection is passed through vaginal, oral, or anal sex.
April is Sexually Transmitted Infections Awareness Month, so what better time to explore the most common STI that Alpha Center sees and treats?
What is Chlamydia?
Chlamydia (kluh-mi-dee-uh) is a common STI caused by a bacterial infection called Chlamydia trachomatis, and affects people of all ages, biological sex or gender identity. This infection is passed through vaginal, oral, or anal sex.
How Common is Chlamydia?
Chlamydia is the most commonly reported STI in both Colorado and the larger United States. At Alpha Center, it’s the most common STI that we see, and it’s the one that we are also able to treat! It’s important to note that because Chlamyia is so often asymptomatic, the number of cases that are undiagnosed is much higher. In total, Larimer County reported 275 cases to the CDC in 2023.
How is Chlamydia spread?
Chlamydia trachomatis is spread through unprotected vaginal, oral, or anal sex with someone who already has the infection, through semen or vaginal fluids. It can also be spread through non-sexual transmission, such as through sharing sex toys or manual stimulation of infected genitalia. If a pregnant woman has chlamydia, her baby can get the infection through the birth process.
If you have had chlamydia in the past, you are not immune to re-infection if you have unprotected sex with someone who is currently infected – in fact, you’re actually at higher risk of getting re-infected.
Who is at risk for becoming infected?
- Teens and Young Adults: Over half of reported cases in Colorado (55.8%) are in individuals aged 15 to 24, and the rate of infection is higher in women than in men.
- Women: In Colorado (2022), women were diagnosed with 61.6% of reported cases, or were 1.6x more likely to be infected than men. This rate of diagnosis could be in part because of an increase in screening recommendations, and thus males with chlamydia are less likely to be diagnosed or reported.
- Men who have sex with Men (MSM): Compared to men who have sex with women, Chlamydia occurs disproportionately in men who have sex with men.
- Black and Non-Hispanic Individuals: Non-Hispanic Black populations are more likely to become infected.
The higher rate of transmission is more because of a lack of access to prevention (sex education, condoms, and/or dental dams) and care than it is about sexual behavior.
Symptoms of Chlamydia
Symptoms vary depending on the individual and the location of the infection.Up to 70-75% of individuals will not experience any symptoms of Chlamydia. If they do, symptoms will likely take a few weeks to notice. For most, if symptoms appear, it will be between one and three months of exposure.
Signs in Women:
Symptoms in women often mimic the symptoms of other infections such as a urinary tract infection or cervicitis. These can include:
- White, yellow or gray discharge from the vagina which may have a foul odor
- Increased urination
- Pain or a burning sensation during urination
- Painful periods
- Pain during sexual intercourse
- Itching or burning around the vagina
- Dull pain in your lower abdomen
- Pus in the urine
Signs in Men:
Chlamydia’s symptoms are most often located in the urethra and mimic the signs of other urethral infections. These can include:
- Mucusy or clear, watery discharge from the penis
- Pain or burning sensations while urinating
- Burning or itchy around the testicles or penis
- Pain and swelling of testicles
Other symptoms of chlamydia
Chlamydia can also infect the anus, mouth, or eyes.
- Anus: pain, discomfort, bleeding, or mucusy discharge
- Throat: Potentially a sore throat, but this is less common
- Eyes: redness, pain and discharge, similar to conjunctivitis
How Can I Prevent Getting Chlamydia?
Abstinence is the only way to ensure that you are not exposed to an STI or experience unplanned pregnancy. The CDC says that sex is safest in a long-term, mutually monogamous relationship where both parties have been tested and cleared for STI infections. If you have sex outside of a relationship, make sure to use protection the right way, every time, and to get tested at least yearly for STIs.
If you are on birth control to prevent pregnancy, keep in mind that it does not protect from STIs and condoms should still be used.
Why Should I Be Tested for Chlamydia?
As nearly 80% of chlamydia infections are asymptomatic, and if it’s not bothering you, you may think you don’t need testing or treatment. This is not the case! The CDC recommends STI testing between every 3-12 months, depending on your risk factors and number of sexual partners.
Complications of Untreated Infection
If you are biologically female, untreated Chlamydia can lead to Pelvic Inflammatory Disease, pregnancy complications if you’re pregnant (or the transmission of the infection to your baby during birth), and infertility. In biological males, untreated infections can lead to reduced fertility and/or Epididymitis, an infection of the testicles and epididymis (the tube that carries the semen to the urethra) that causes pain and swelling in the testicles.
No matter your biological sex, untreated chlamydia infections can spread to your bloodstream and cause reactive arthritis, and increase your chances of contracting HIV.
What is Pelvic Inflammatory Disease?
When left untreated, Pelvic Inflammatory Disease is a serious complication that arises when STIs are left untreated and spread to the uterus and other reproductive organs. Symptoms of PID may include pain, fever, burning sensation with urination, bleeding in between menstrual cycles, and pain and/or bleeding during sex. Left untreated, 1 in 8 women who experience PID will have fertility issues. Untreated PID can also cause the formation of scar tissue in and around the fallopian tubes, ectopic pregnancy, and long term pelvic pain.
Complications in Pregnancy
In pregnancy, Chlamydia infections are associated with lower birth rate, premature delivery, and can cause eye infections.
If you are still considering your options for an unplanned pregnancy, make sure that STI testing is a part of your pre-abortion screening. Untreated STIs at the time of an abortion or birth puts you at higher risk for Pelvic Inflammatory Disease when the cervix is not fully closed (this study found a 63% rate of women with chlamydia at the time of their surgical termination went on to develop PID).
How often Should I be Tested for Chlamydia?
If you are sexually active, the CDC recommends testing annually for both Chlamydia and Gonorrhea. If you have multiple or anonymous partners, you should consider testing every three to six months. Alpha Center provides testing for Chlamydia, Gonorrhea, HIV, and Syphilis up to two times a year at no cost to you, and testing for chlamydia and gonorrhea during a pre-abortion screening. Treatment can be provided in-clinic for Chlamydia. Referrals are offered for other positive results as it requires treatment beyond the clinic’s scope of care.
What Can I Expect at My STI Testing Appointment with Alpha Center?
Your STI appointment at Alpha Center will take roughly 45 minutes. You’ll first meet with a nurse to go over your sexual health history and risk factors. Then, both males and females will get a blood test to check for HIV and Syphilis. Males will give a urine sample for Chlamydia and Gonorrhea, and females will perform a vaginal self swab. We will call you with results within a week’s time, and if your result is positive we will have you return for treatment.
Schedule an appointment by calling 970.239.2272 or by chatting with our schedulers online!
What is Treatment for Chlamydia?
Alpha Center treats Chlamydia with a one-time dose of azithromycin, an antibiotic. After three months, Alpha Center can see you for a follow-up test to make sure that you haven’t been re-infected after treatment, as reinfection is common.
Your current partner should also come in for testing, and if they test positive, they will receive treatment.
After your antibiotics, you should not have sex again until 7 days have passed or symptoms have resolved to avoid spreading the infection to your partner.
Outlook
If caught and treated early, Chlamydia infections are treatable and curable and should not lead to further complications.
Frequently Asked Questions about Chlamydia
What is Chlamydia?
Chlamydia is a common sexually transmitted infection (STI) caused by the bacteria Chlamydia trachomatis. It is a bacterial infection that can affect individuals of any age, biological sex, or gender identity. It is typically transmitted through vaginal, oral, or anal sex.
How common is Chlamydia in Colorado?
Chlamydia is the most frequently reported STI in both Colorado and the United States. In 2023, Larimer County reported 275 cases to the CDC. Because the infection is often asymptomatic, the actual number of local cases is estimated to be much higher.
What are the symptoms of Chlamydia?
Approximately 70-75% of people do not experience any symptoms. If symptoms do occur, they usually appear 1 to 3 months after exposure and may include:
- In Women: Abnormal vaginal discharge, painful urination, or pain during intercourse.
- In Men: Clear or watery discharge from the penis, burning during urination, or testicular pain.
- Other areas: It can also cause symptoms in the rectum (pain/discharge), throat, or eyes (redness/pain).
How is Chlamydia treated?
Chlamydia is treatable and curable with a course of antibiotics. At Alpha Center, we typically provide a one-time dose of azithromycin. To prevent re-infection, sexual partners should also be tested and treated, and you should abstain from sexual activity for 7 days after completing treatment.
Can Chlamydia cause infertility?
Yes. If left untreated, Chlamydia can lead to Pelvic Inflammatory Disease (PID) in biological females, which can cause permanent damage to the fallopian tubes and lead to infertility or ectopic pregnancy. In biological males, untreated infection can lead to epididymitis, which may also reduce fertility.
Where can I get tested for Chlamydia in Fort Collins?
Alpha Center provides no-cost testing for Chlamydia and Gonorrhea for residents in the Fort Collins area. Our appointments take about 45 minutes and include a consultation with a nurse. You can schedule an appointment by calling 970.239.2272.
How often should I be tested for STIs?
The CDC recommends that sexually active individuals be tested annually. However, if you have increased risk factors, it is safer to be screened every 3 to 6 months. Alpha Center can provide free testing up to twice a year. If you need to be screened more often than that, we are happy to provide you with referrals.
Sources:
- Centers for Disease Control: About Chlamydia (January 2025)
- Centers for Disease Control: STI Statistics (2024)
- Cleveland Clinic: Chlamydia (February 2023)
- Mayo Clinic: Chlamydia trachomatis (n.d)
- NHS: Chlamydia (October 2024)
- Medline Plus: Chlamydia Infections (May 2024)
- Colorado Department of Public Health & Environment: Sexually Transmitted Infections in Colorado (2023)
- Testing.com: STD testing in Colorado (2022)
- Frontiers in Bioengineering and Biotechnology: A pilot clinical validation study of a self-collected vaginal swab device for the detection of chlamydia trachomatis in women (October 2022)
- Centers for Disease Control: About Pelvic Inflammatory Disease (PID) (December 2023)
- Centers for Disease Control: Condom Use: An Overview (January 2024)
- World Health Organization: Chlamydia (November 2025)
- National Library of Medicine: Significance of cervical Chlamydia trachomatis infection in postabortal pelvic inflammatory disease (September 1982)
- National Library of Medicine: Health gains from screening for infection of the lower genital tract in women attending for termination of pregnancy (July 1993)
- Medical News Today: What is Pelvic Inflammatory Disease? (June 2023)
- Center for Urogynecology and Advanced Laparoscopic Surgery: What You Need to Know About Asymptomatic Chlamydia (n.d.)
Authored by Kristen Long for Alpha Center. Medically reviewed by Meghan Downing, RN, Nurse Manager.
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