Chlamydia

For other uses, see Chlamydia (disambiguation).

Chlamydia
Other namesChlamydia infection
Pap smear showing C. trachomatis (H&E stain)
Pronunciation
SpecialtyInfectious disease, gynecology, urology
SymptomsNone, vaginal discharge, discharge from the penis, burning with urination[1]
ComplicationsPain in the testicles, pelvic inflammatory disease, infertility, ectopic pregnancy[1][2]
Usual onsetFew weeks following exposure[1]
CausesChlamydia trachomatis spread by sexual intercourse or childbirth[3]
Diagnostic methodUrine or swab of the cervix, vagina, or urethra[2]
PreventionNot having sex, condoms, sex with only one non–infected person[1]
TreatmentAntibiotics (azithromycin or doxycycline)[2]
Frequency4.2% (women), 2.7% (men)[4][5]
Deaths~200 (2015)[6]

Chlamydia, or more specifically a chlamydia infection, is a sexually transmitted infection caused by the bacterium Chlamydia trachomatis.[3] Most people who are infected have no symptoms.[1] When symptoms do appear they may occur only several weeks after infection;[1] the incubation period between exposure and being able to infect others is thought to be on the order of two to six weeks.[7] Symptoms in women may include vaginal discharge or burning with urination.[1] Symptoms in men may include discharge from the penis, burning with urination, or pain and swelling of one or both testicles.[1] The infection can spread to the upper genital tract in women, causing pelvic inflammatory disease, which may result in future infertility or ectopic pregnancy.[2]

Chlamydia infections can occur in other areas besides the genitals, including the anus, eyes, throat, and lymph nodes. Repeated chlamydia infections of the eyes that go without treatment can result in trachoma, a common cause of blindness in the developing world.[8]

Chlamydia can be spread during vaginal, anal, oral, or manual sex and can be passed from an infected mother to her baby during childbirth.[1][9] The eye infections may also be spread by personal contact, flies, and contaminated towels in areas with poor sanitation.[8] Infection by the bacterium Chlamydia trachomatis only occurs in humans.[10] Diagnosis is often by screening which is recommended yearly in sexually active women under the age of twenty-five, others at higher risk, and at the first prenatal visit.[1][2] Testing can be done on the urine or a swab of the cervix, vagina, or urethra.[2] Rectal or mouth swabs are required to diagnose infections in those areas.[2]

Prevention is by not having sex, the use of condoms, or having sex with only one other person, who is not infected.[1] Chlamydia can be cured by antibiotics with typically either azithromycin or doxycycline being used.[2] Erythromycin or azithromycin is recommended in babies and during pregnancy.[2] Sexual partners should also be treated, and infected people should be advised not to have sex for seven days and until symptom free.[2] Gonorrhea, syphilis, and HIV should be tested for in those who have been infected.[2] Following treatment people should be tested again after three months.[2]

Chlamydia is one of the most common sexually transmitted infections, affecting about 4.2% of women and 2.7% of men worldwide.[4][5] In 2015, about 61 million new cases occurred globally.[11] In the United States about 1.4 million cases were reported in 2014.[3] Infections are most common among those between the ages of 15 and 25 and are more common in women than men.[2][3] In 2015 infections resulted in about 200 deaths.[6] The word chlamydia is from the Greek χλαμύδα, meaning 'cloak'.[12][13]

  1. ^ a b c d e f g h i j k "Chlamydia – CDC Fact Sheet". CDC. May 19, 2016. Archived from the original on 11 June 2016. Retrieved 10 June 2016.
  2. ^ a b c d e f g h i j k l m "2015 Sexually Transmitted Diseases Treatment Guidelines". CDC. June 4, 2015. Archived from the original on 11 June 2016. Retrieved 10 June 2016.
  3. ^ a b c d "2014 Sexually Transmitted Diseases Surveillance Chlamydia". November 17, 2015. Archived from the original on 10 June 2016. Retrieved 10 June 2016.
  4. ^ a b Newman L, Rowley J, Vander Hoorn S, Wijesooriya NS, Unemo M, Low N, et al. (8 December 2015). "Global Estimates of the Prevalence and Incidence of Four Curable Sexually Transmitted Infections in 2012 Based on Systematic Review and Global Reporting". PLOS ONE. 10 (12): e0143304. Bibcode:2015PLoSO..1043304N. doi:10.1371/journal.pone.0143304. PMC 4672879. PMID 26646541.
  5. ^ a b "Sexually transmitted infections (STIs) Fact sheet N°110". who.int. December 2015. Archived from the original on 25 November 2014. Retrieved 10 June 2016.
  6. ^ a b Wang H, Naghavi M, Allen C, Barber RM, Bhutta ZA, Carter A, et al. (October 2016). "Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980-2015: a systematic analysis for the Global Burden of Disease Study 2015". Lancet. 388 (10053): 1459–1544. doi:10.1016/s0140-6736(16)31012-1. PMC 5388903. PMID 27733281.
  7. ^ Shors T (2018). Krasner's Microbial Challenge. p. 366.
  8. ^ a b "CDC – Trachoma, Hygiene-related Diseases, Healthy Water". Centers for Disease Control and Prevention. December 28, 2009. Archived from the original on September 5, 2015. Retrieved 2015-07-24.
  9. ^ Hoyle A, McGeeney E (2019). Great Relationships and Sex Education. Taylor and Francis. ISBN 978-1-35118-825-8. Retrieved July 11, 2023.
  10. ^ Graeter L (2014). Elsevier's Medical Laboratory Science Examination Review. Elsevier Health Sciences. p. 30. ISBN 9780323292412. Archived from the original on 2017-09-10.
  11. ^ Vos T, Allen C, Arora M, Barber RM, Bhutta ZA, Brown A, et al. (October 2016). "Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015". Lancet. 388 (10053): 1545–1602. doi:10.1016/S0140-6736(16)31678-6. PMC 5055577. PMID 27733282.
  12. ^ Stevenson A (2010). Oxford dictionary of English (3rd ed.). New York, NY: Oxford University Press. p. 306. ISBN 9780199571123. Archived from the original on 10 September 2017. Retrieved 10 June 2016.
  13. ^ Byrne GI (July 2003). "Chlamydia uncloaked". Proceedings of the National Academy of Sciences of the United States of America. 100 (14): 8040–8042. Bibcode:2003PNAS..100.8040B. doi:10.1073/pnas.1533181100. PMC 166176. PMID 12835422. The term was coined based on the incorrect conclusion that Chlamydia are intracellular protozoan pathogens that appear to cloak the nucleus of infected cells.