(chlamydial disease) Diseases associated with bacteria from the family Chlamydiaceae.

(chlamydial infection) An infection that is caused by Chlamydia trachomatis.

Infections with bacteria of the genus CHLAMYDIA.

Chlamydia is a common sexually transmitted disease. It is caused by bacteria called Chlamydia trachomatis. It can infect both men and women. Women can get chlamydia in the cervix, rectum, or throat. Men can get chlamydia in the urethra (inside the penis), rectum, or throat. You can get chlamydia during oral, vaginal, or anal sex with someone who has the infection. A woman can also pass chlamydia to her baby during childbirth. If you've had chlamydia and were treated in the past, you can get re-infected if you have unprotected sex with someone who has it. Chlamydia is more common in young people, especially young women. You are more likely to get it if you don't consistently use a condom, or if you have multiple partners. Chlamydia doesn't usually cause any symptoms. So you may not realize that you have it. People with chlamydia who have no symptoms can still pass the disease to others. If you do have symptoms, they may not appear until several weeks after you have sex with an infected partner.

Three species of Chlamydia cause human disease, including sexually transmitted infections and respiratory infections. All are susceptible to macrolides (eg, azithromycin), tetracyclines (eg, doxycycline), and fluoroquinolones.