Chlamydia is a sexually transmitted disease caused by parasitic microorganisms. These microorganisms cause a wide range of infections in humans, including infections of the male and female genital tract, eye infections, and pneumonia.

Recently, infections with certain types of chlamydia have been associated with coronary heart disease.

Different strains of chlamydia cause genital, eye, lymph node, and respiratory infections. Chlamydia causes trachoma, which is the most common cause of blindness in the world.

In the developed world, infections due to chlamydia are a common sexually transmitted disease; in the U.S., approximately 50 women per 100,000 are infected annually, with women aged 15-24 at greatest risk. Risk factors include multiple sexual partners. Chlamydia is the most common reportable disease in the United States.

Sexually transmitted chlamydia infections can infect the the urethra, the rectum, and the throat. In women, the infection may lead to inflammation of the cervix. If untreated, infection may spread to the uterus or the fallopian tubes and cause pelvic inflammatory disease. This can cause infertility and can increase the risk of ectopic pregnancy.

• burning on urination
• vaginal discharge or bleeding
• abdominal pain
• painful intercourse

• culture from cervix in women
• non-culture tests including:
  • DNA probes
  • immunofluorescence assays
  • enzyme immunoassays
  • nucleic acid amplification tests

• Pelvic inflammatory disease, including salpingitis (infected fallopian tube) and pelvic peritonitis
• Infertility in women caused by fallopian tube scarring
• Ectopic pregnancy
• Chronic pelvic pain syndrome