Chlamydia in 2025 – Impact on Fertility, Symptoms & Effective Prevention

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Zappelphilipp Marx•
Chlamydia bacteria under a microscope

Chlamydia is the most common curable sexually transmitted infection (STI). The World Health Organization estimates that there were about 129 million new infections worldwide in 2020 WHO. Germany has no mandatory reporting system, so exact figures are lacking; experts put the number at roughly 300,000 cases per year RKI estimate. The issue: Most people have no symptoms – allowing long-term complications such as infertility to develop unnoticed.

Chlamydia Explained: Causes & Transmission

The infection is caused by the bacterium Chlamydia trachomatis, which targets the mucous membranes of the urethra, cervix, rectum, and throat. Transmission is almost always via unprotected vaginal, anal, or oral sex. During delivery, an infected mother can also pass the bacterium to her baby, causing conjunctivitis or pneumonia in newborns.

Symptom Check: How “Silent” Is Chlamydia?

According to the CDC, infections are asymptomatic in about 70–95 percent of women and roughly 50 percent of men. When symptoms do occur, they usually appear 1–3 weeks after exposure – by then the bacteria may have spread further.

Chlamydia in Women – Typical Symptoms & Long-Term Effects

Early warning signs (if any):

  • unusual, often watery-pus-like or foul-smelling discharge
  • intermenstrual or post-coital bleeding
  • pain during intercourse (dyspareunia)
  • burning while urinating (dysuria)
  • lower-abdominal or back pain

Potential long-term consequences if untreated:

  • PID (Pelvic Inflammatory Disease) – infection spreads to uterus and fallopian tubes
  • Salpingitis – scarring of the tubes leading to blockage
  • Infertility – reported in up to 40 percent of untreated cases
  • higher risk of ectopic pregnancy, preterm birth, or miscarriage

Chlamydia in Men – What’s Different?

Possible acute symptoms:

  • clear to pus-like urethral discharge
  • burning or pain when urinating
  • swelling or pain in the testes or epididymis

Typical complications (rare but possible):

  • Epididymitis – inflammation of the epididymis with pain and fever
  • prostatitis or urethral strictures
  • reduced sperm quality, leading to fertility issues
  • Reactive arthritis (Reiter’s syndrome) – joint, eye, and skin inflammation

Note: Even symptom-free men can transmit the infection – both partners must always be treated.

Untreated Chlamydia: Shared Risks

  • chronic pelvic or lower-abdominal pain
  • infertility in women; impaired fertility in men
  • conjunctivitis or pneumonia in newborns

Prevention That Really Works

  • Condoms – highly effective when used consistently and correctly
  • Routine testing – CDC recommends yearly screening for sexually active women up to 25, and risk-based testing thereafter
  • limit the number of sexual partners or agree on shared testing intervals
  • clean sex toys after each use or cover them with a fresh condom
  • pregnant individuals should be tested for chlamydia in the first trimester

Treatment Today – Why Doxycycline Has Replaced Azithromycin

Chlamydia is almost always curable with antibiotics. Updated guidelines favor doxycycline for seven days over a single dose of azithromycin because studies show rising azithromycin resistance and slightly better efficacy for doxycycline. True laboratory resistance to tetracyclines or macrolides remains rare.

Diagnostics & Testing Basics

Test types

  • NAAT / PCR – very reliable; results in 1–2 days
  • Rapid test – results in about 20 minutes, but far less accurate (screening only)

Specimen options

  • women: vaginal swab (self-taken or clinician) or first-catch morning urine
  • men: first-catch urine; urethral swab if symptomatic

When to Seek Medical Advice

The WHO defines infertility as the absence of pregnancy after 12 months of unprotected intercourse (after six months if the woman is over 35). Common causes include untreated chlamydia, endometriosis, and hormonal disorders.

  • unexplained discharge, burning, or bleeding → get tested immediately
  • new relationship without up-to-date STI status → both partners should test
  • positive result → treat both partners and abstain from sex for seven days

Takeaway

Chlamydia is common, often silent – but highly treatable. Regular testing, consistent condom use, and prompt antibiotics dramatically reduce the risk of severe complications like infertility. Invest in your sexual health – prevention is far easier than treating late-stage damage.

Disclaimer: Content on RattleStork is provided for general informational and educational purposes only. It does not constitute medical, legal, or other professional advice; no specific outcome is guaranteed. Use of this information is at your own risk. See our full Disclaimer.

Frequently Asked Questions (FAQ)

Chlamydia is a bacterial sexually transmitted infection (STI) caused by Chlamydia trachomatis. It’s common, often silent, but completely curable with antibiotics.

Most women notice nothing. Possible clues are unusual discharge, spotting, burning while urinating, pain during sex, or lower-abdominal cramps.

Men may have a clear or pus-like drip from the penis, burning urination, or swollen tender testicles—but about half stay symptom-free.

Mainly through unprotected vaginal, anal, or oral sex. It can also pass from mother to baby during delivery.

Yes—untreated infection raises the risk of preterm birth and can cause eye or lung infections in newborns. Prenatal screening is standard care.

In women it can scar fallopian tubes; in men it can lower sperm quality. Either way, untreated infection may end in infertility.

Any time you have a new partner, symptoms, a partner who tests positive, or if you’re pregnant. The CDC recommends yearly screening for sexually active women under 25.

NAAT/PCR is the gold standard: sensitivity and specificity exceed 95 percent, with results in one to two days. Rapid antigen tests give results in 15-20 minutes but are far less accurate.

Women provide a self- or clinician-collected vaginal swab or first-catch urine. Men provide first-catch urine; a urethral swab is added if symptoms are present.

First-line therapy is doxycycline 100 mg twice daily for seven days. A single 1 g dose of azithromycin is an alternative but less favored due to rising resistance.

Cure rates are excellent if the full course is taken and all partners are treated simultaneously.

Untreated infection can progress to pelvic inflammatory disease (PID), chronic pain, ectopic pregnancy, or impaired fertility in both sexes.

Absolutely. Partners from the past 60 days need testing and treatment to avoid ping-pong reinfection.

You’re considered noninfectious seven days after starting doxycycline (or seven days after an azithromycin dose). Avoid sex during that window.

Yes. Prior infection offers no lasting immunity. Consistent condom use and regular STI checks remain essential.

When used correctly every time, condoms sharply cut the risk of chlamydia, gonorrhea, HIV, and other STI—still the cornerstone of safer sex.

Pelvic inflammatory disease is an ascending infection of the uterus, tubes, and ovaries. Up to 30 percent of untreated female chlamydia cases can evolve into PID.

Yes. The bacteria can infect the throat and rectum. Barriers like condoms and dental dams help prevent transmission.

Not yet. Several protein- and mRNA-based candidates are in clinical trials, but no vaccine is currently approved.

Co-testing for gonorrhea, syphilis, HIV, and trichomoniasis is wise because coinfections are common and can worsen outcomes.