Chlamydia - Symptoms, Transmission and Treatment

Chlamydia is the most common sexually transmitted disease in the world. Chlamydia patients usually do not develop symptoms, but when they do, the clinical picture is very similar to that of gonorrhea, and it is impossible to distinguish them only by symptoms.

Chlamydia trachomatis
Chlamydia trachomatis

What is chlamydia?

Chlamydia is a sexually transmitted disease caused by a bacterium called Chlamydia trachomatis. Not all people infected with chlamydia have symptoms, and the infection may go undetected for many years. Patients with asymptomatic chlamydia become permanent sources of contamination, which is why chlamydia is the most common STD in the world. Whoever transmits chlamydia may not know that it is contaminated and whoever has become infected may not know who got it.

It is estimated that 5% of the adult population and 10% of the sexually active adolescent population are infected with Chlamydia trachomatis. Chlamydia infection is more common in young people, people who have had multiple partners in the past few years, or people who do not use condoms during sex.


The Chlamydia trachomatis can be transmitted in two ways: through sexual contact (anal, vaginal or oral) or from mother to child during the passage of the baby through the birth canal during childbirth.

As in gonorrhea, in adults and adolescents transmission is exclusively through sexual intercourse. No chlamydia is found in public restrooms or swimming pools. Kissing is also not a form of chlamydia transmission.

Transmission through towels or underwear has not yet been proven, but it is theoretically possible if there is contact with fresh contaminated secretions. For example, if a woman with vaginal discharge contaminates a towel and another person immediately uses it to dry her intimate parts, transmission may occur. This, however, is a very hypothetical situation, and what we see in practice is the sexual route as the only relevant form of transmission of this STD among adults.

Contamination of the eyes by chlamydia can occur if the hands are contaminated with vaginal secretions and the individual scratches the eyes without first washing them.


As already noted, most patients who become infected with chlamydia show no signs of disease. In women only 10% develop symptoms; in men, the number is slightly higher, around 30%. However, it is worth pointing out that even without symptoms, the infected patient is able to transmit the disease to their partners or partners.

In patients who develop symptoms, they usually appear between 1 and 3 weeks after the contamination.

In women, the main symptoms of Chlamydia trachomatis are:

In men, the most common symptoms of chlamydia include:
  • Burning or pain when urinating
  • Outflow of purulent discharge through the urethra
  • Pain in the testicles
  • Swelling of the scrotal sac
  • Proctite (inflammation of the anus occurring in passive homosexual men)

Pharyngitis due to Chlamydia trachomatis is uncommon, but may occur if the route of transmission is oral sex.


The complications of Chlamydia trachomatis infection usually occur in patients with few or no symptoms, who therefore do not seek medical treatment.

The main complication of chlamydia infection in women is progression of the bacterium towards the uterus, fallopian tubes and ovaries, causing a serious infection known as pelvic inflammatory disease (PID). About 10 to 15% of women infected with Chlamydia trachomatis develop PID.

Infertility is also a common complication of untreated chlamydia and occurs due to injury to the fallopian tubes and/or uterus due to prolonged infection.

Women with Chlamydia trachomatis infection (especially that caused by serotype G) present 6 times more risks for the development of cervical cancer.

In pregnant women, chlamydial infections can lead to premature labor. Babies born to infected mothers can become infected and develop early complications. Chlamydia is one of the major causes of pneumonia and conjunctivitis in newborns.

In men the most common complication is prostatitis, prostate infection. Infection of the epididymis, located above the testicles, may also occur.

Lymphogranuloma venereum

There are some serotypes of Chlamydia trachomatis , called L1, L2 and L3, which are capable of presenting a disease called lymphogranuloma venereum, a different picture of the classic chlamydia infection.

In venereal lymphogranuloma, the initial infection is characterized by a small lump, which ruptures and forms a genital ulcer. Two to six weeks later the infection extends to the regional lymph nodes, ie to the groin ganglia. The patient has one or more inflamed and enlarged ganglia, called buboes. These buboes can rupture, draining large amounts of pus.


The test to identify chlamydia is done through urine or a sample of material collected with a cotton swab in the vagina, cervix or urethra. Results are generally available within 24-48 hours.

Many physicians request serology for screening for IgM and IgG antibodies to chlamydia, but this test, though useful, is not the most reliable. If possible, Chlamydia trachomatis should be done by a technique called PCR, which looks for the presence of chlamydia DNA in the vaginal secretions. In men, this DNA research can be done in the urine.


The treatment of chlamydia is simple, being done with administration of antibiotics. Azithromycin in a single dose of 1 gram is the most prescribed antibiotic. The infected patient should stay for at least 7 days without sexual activity after starting treatment.

An alternative to azithromycin is Doxycycline for 7 days. In patients with lymphogranuloma venereum or anal chlamydia infection, the regimen with doxycycline is the most indicated.

Since the clinical picture of chlamydia can be very similar to that of gonorrhea, it is common for the doctor to prescribe a treatment that acts on both bacteria. Ceftriaxone is commonly associated with azithromycin.

All partners of the infected patient should be tested and, if necessary, treated for chlamydia, even if they do not present symptoms.

It is possible to contaminate with Chlamydia trachomatis more than once. Having previously had a chlamydial infection does not previously confer immunity.

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