Chlamydia is a common sexually transmitted disease (STD) caused by infection with Chlamydia trachomatis. It can cause cervicitis in women and urethritis and proctitis in both men and women. Chlamydial infections in women can lead to serious consequences including pelvic inflammatory disease (PID), tubal factor infertility, ectopic pregnancy, and chronic pelvic pain. Lymphogranuloma venereum (LGV), another type of STD caused by different serovars of the same bacterium, occurs commonly in the developing world, and has more recently emerged as a cause of outbreaks of proctitis among men who have sex with men (MSM) worldwide
Chlamydia is transmitted through sexual contact with the penis, vagina, mouth, or anus of an infected partner. Ejaculation does not have to occur for chlamydia to be transmitted or acquired. Chlamydia can also be spread perinatally from an untreated mother to her baby during childbirth, resulting in ophthalmia neonatorum (conjunctivitis) or pneumonia in some exposed infants. People who have had chlamydia and have been treated may get infected again if they have sexual contact with a person infected with chlamydia.
Chlamydia is known as a ‘silent’ infection because most infected people are asymptomatic and lack abnormal physical examination findings.
In women, the bacteria initially infect the cervix, where the infection may cause signs and symptoms of cervicitis (e.g., mucopurulent endocervical discharge, easily induced endocervical bleeding), and sometimes the urethra, which may result in signs and symptoms of urethritis (e.g., pyuria, dysuria, urinary frequency). Infection can spread from the cervix to the upper reproductive tract (i.e., uterus, fallopian tubes), causing pelvic inflammatory disease (PID), which may be asymptomatic (“subclinical PID”) or acute, with typical symptoms of abdominal and/or pelvic pain, along with signs of cervical motion tenderness, and uterine or adnexal tenderness on examination.
Men who are symptomatic typically have urethritis, with a mucoid or watery urethral discharge and dysuria. A minority of infected men develop epididymitis (with or without symptomatic urethritis), presenting with unilateral testicular pain, tenderness, and swelling.
Chlamydia can infect the rectum in men and women, either directly (through receptive anal sex), or possibly via spread from the cervix and vagina in a woman with cervical chlamydial infection. While these infections are often asymptomatic, they can cause symptoms of proctitis (e.g., rectal pain, discharge, and/or bleeding).
There are a number of diagnostic tests for chlamydia, including nucleic acid amplification tests (NAATs), cell culture, and others. NAATs are the most sensitive tests, and can be performed on easily obtainable specimens such as vaginal swabs (either clinician- or patient-collected) or urine. Vaginal swabs, either patient- or clinician-collected, are the optimal specimen to screen for genital chlamydia using NAATs in women; urine is the specimen of choice for men, and is an effective alternative specimen type for women.
Chlamydia can be easily cured with antibiotics. HIV-positive persons with chlamydia should receive the same treatment as those who are HIV-negative. Persons with chlamydia should abstain from sexual activity for 7 days after single dose antibiotics or until completion of a 7-day course of antibiotics, to prevent spreading the infection to partners. If a person’s symptoms continue for more than a few days after receiving treatment, he or she should return to a health care provider to be reevaluated.
Repeat infection with chlamydia is common. Women whose sex partners have not been appropriately treated are at high risk for re-infection. Having multiple chlamydial infections increases a woman’s risk of serious reproductive health complications, including pelvic inflammatory disease and ectopic pregnancy. Women and men with chlamydia should be retested about three months after treatment of an initial infection, regardless of whether they believe that their sex partners were successfully treated.
Latex male condoms, when used consistently and correctly, can reduce the risk of getting or giving chlamydia. The surest way to avoid chlamydia is to abstain from vaginal, anal, and oral sex, or to be in a long-term mutually monogamous relationship with a partner who has been tested and is known to be uninfected.