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| | __NOTOC__ |
| {{DiseaseDisorder infobox | | | {{DiseaseDisorder infobox | |
| Name = Chlamydia | | | Name = Chlamydia | |
| Image = Pap smear showing clamydia in the vacuoles 500x H&E.jpg| | | Image = Pap smear showing clamydia in the vacuoles 500x H&E.jpg| |
| Caption = Pap smear showing ''C. trachomatis'' (H&E stain) | | | Caption = Pap smear showing ''C. trachomatis'' (H&E stain) - By http://visualsonline.cancer.gov/details.cfm?imageid=2331, Public Domain, https://commons.wikimedia.org/w/index.php?curid=859366 | |
| ICD10 = {{ICD10|A|55||a|50}}-{{ICD10|A|56|8|a|50}}, {{ICD10|A|70||a|70}}-{{ICD10|A|74|9|a|70}} |
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| ICD9 = {{ICD9|099.41}}, {{ICD9|483.1}} |
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| ICDO = |
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| OMIM = |
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| DiseasesDB = 2384 |
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| MedlinePlus = |
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| eMedicineSubj = |
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| eMedicineTopic = |
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| MeshID = D002690 |
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| }} | | }} |
| {{Chlamydia infection}} | | {{Chlamydia infection}} |
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| '''For patient information click [[{{PAGENAME}} (patient information)|here]]''' | | '''For patient information click [[{{PAGENAME}} (patient information)|here]]''' |
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| {{CMG}} | | {{CMG}}; {{AE}} {{Maliha}}, {{AAA}} |
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| | {{SK}} Chlamydial infection; Chlamydia; Sexually transmitted disease |
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| | ==[[Chlamydia infection overview|Overview]]== |
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| ==Overview== | | ==[[Chlamydia infection historical perspective|Historical Perspective]]== |
| Chlamydia is an infection of the bacterial genius, ''[[Chlamydia trachomatis]]''. It is one of the most common sexually transmitted infections in people worldwide — about 2.8 million cases of chlamydia infection occur in the [[United States]] each year.<ref>[http://www.cdc.gov/std/Chlamydia/STDFact-Chlamydia.htm Chlamydia fact sheet from the Centers for Disease Control and Prevention]</ref> If untreated, chlamydial infections can cause serious reproductive and other health problems with both short-term and long-term consequences. Chlamydia is easily treated with antibiotics.
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| ==Background== | | ==[[Chlamydia infection pathophysiology|Pathophysiology]]== |
| :''The term ''Chlamydia'' refers to an infection by any one of the species in the bacterial genus ''[[Chlamydia (bacterium)|Chlamydia]]''—''[[Chlamydia trachomatis]]'', ''[[Chlamydia suis]]'' or ''[[Chlamydia muridarum]]''—, but of these, only ''C. trachomatis'' is found in humans.<ref>{{cite web |url= http://www.chlamydiae.com/docs/Chlamydiales/diagram/taxondiag.htm|title= www.chlamydiae.com (professional) - Taxonomy diagram|accessdate=2007-10-27 |format= |work=}}</ref> For a list of [[species]] formerly included in the [[genus]] ''Chlamydia'', please see ''[[Chlamydophila]]''.<ref>Taxonomic Outline of the Procaryotes, Bergey's Manual of Systematic Bacteriology, Second Edition Release 1.0, April 2001. [http://www.cme.msu.edu/Bergeys/april2001-genus.pdf]</ref>''
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| '''Chlamydia''' (from the [[Ancient Greek|Greek]], χλαμύδος meaning "cloak") is a common [[sexually transmitted disease]] (STD) caused by the bacterium, ''[[Chlamydia trachomatis]]''. Chlamydia is a major infectious cause of human eye and [[genital]] disease.
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| ''C. trachomatis'' is naturally found living only inside human cells and is one of the most common sexually transmitted infections in people worldwide — about 2.8 million cases of chlamydia infection occur in the [[United States]] each year.<ref>[http://www.cdc.gov/std/Chlamydia/STDFact-Chlamydia.htm Chlamydia fact sheet from the Centers for Disease Control and Prevention]</ref> Chlamydia can be transmitted during [[vaginal intercourse|vaginal]], [[anal sex|anal]], or [[oral sex]], and can be passed from an infected mother to her baby during vaginal [[childbirth]]. Many people with Chlamydia exhibit no symptoms of infection. Between half and three-quarters of all women who have chlamydia have no symptoms and do not know that they are infected. If untreated, chlamydial infections can cause serious reproductive and other health problems with both short-term and long-term consequences. Chlamydia is easily treated with antibiotics.
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| Of equal importance, chlamydia infection of the eye is the most common cause of preventable [[blindness]] in the world. Blindness occurs as a complication of '''[[trachoma]]''' (chlamydia conjunctivitis).<ref>{{cite journal |author=Belland R, Ojcius D, Byrne G |title=Chlamydia |journal=Nat Rev Microbiol |volume=2 |issue=7 |pages=530 – 1 |year=2004 |id=PMID 15248311}}</ref>
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| == Detection == | | ==[[Chlamydia infection causes|Causes]]== |
| The diagnosis of genital chlamydial infections evolved rapidly from the 1990s through 2006. Nucleic acid amplification tests (NAAT), such as [[polymerase chain reaction]] (PCR), transcription mediated amplification (TMA), and the DNA strand displacement assay (SDA) now are the mainstays. As of January 2007, the most commonly used and widely studied chlamydia NAATs in the US and many other industrialized countries are Aptima (Gen-Probe), Probe-Tec (Becton-Dickinson), and Amplicor (Roche). The Aptima Combo II assay tests simltaneously for C. trachomatis and Neisseria gonorrhoeae, the cause of gonorrhea. NAAT for chlamydia may be performed on swab specimens collected from the cervix (women) or urethra (men), on self-collected vaginal swabs, or on voided urine. Urine and self-collected swab testing facilitates the performance of screening tests in settings where genital examination is impractical. At present, the NAATs have regulatory approval only for testing urogenital specimens, although rapidly evolving research indicates that the Aptima test may give reliable results on rectal specimens.
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| Because of improved test accuracy, ease of specimen management, convenience in specimen management, and ease of screening sexually active men and women, the NAATs have largely replaced culture, the historic gold standard for chlamydia diagnosis, and the non-amplified probe tests, such as Pace II (Gen-Probe). The latter test is relatively insensitive, successfully detecting only 60-80% of infections in asymptomatic women, and often giving falsely positive results. Culture remains useful in selected circumstances and is currently the only assay approved for testing non-genital specimens.
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| == Treatment == | | ==[[Chlamydia infection differential diagnosis|Differentiating Chlamydia Infection from other Diseases]]== |
| [[Image:ChlamydiaTrachomatisEinschlusskörperchen.jpg|thumb|right|''Chlamydia trachomatis'' inclusion bodies (brown) in a McCoy cell culture.]] | |
| ''C. trachomatis'' infection can be effectively cured with [[antibiotic]]s once it is detected. Current [[Centers for Disease Control]] guidelines provide for the following treatments:
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| * [[Azithromycin]] 1 gram oral as a single dose, or
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| * [[Doxycycline]] 100 milligrams twice daily for seven days.
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| * [[Tetracycline]]
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| * [[Erythromycin]]
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| Untested Treatments
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| * [[Ciprofloxacin]] 500 milligrams twice daily for 3 days. (Although this is not an approved method of treatment, as it is shown to be ineffective and may simply delay symptoms.)
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| [[β-lactams]] are not suitable drugs for the treatment of chlamydia. While they have the ability to halt growth of the organism (i.e. are microbistatic), these antibiotics do not eliminate the bacteria. Once treatment is stopped, the bacteria will begin to grow once more. (See below for Persistence.)
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| == Pathophysiology == | | ==[[Chlamydia infection epidemiology and demographics|Epidemiology and Demographics]]== |
| ===Chlamydial life cycle===
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| ''Chlamydiae'' are [[obligate]] intracellular bacterial pathogens, which means they are unable to replicate outside of a host cell. However, to disseminate effectively, these pathogens have evolved a unique biphasic life cycle wherein they alternate between two functionally and morphologically distinct forms. <ref>{{cite web |url=http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mmed.section.2173 |title=Structure |accessdate=2007-10-26 |format= |work=}}</ref>
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| * The ''elementary body (EB)'' is infectious, but metabolically inert (much like a spore), and can survive for limited amounts of time in the extracellular milieu. Once the EB attaches to a susceptible host cell, it mediates its own internalization through pathogen-specified mechanisms (via type III secretion system) that allows for the recruitment of [[actin]] with subsequent engulfment of the bacterium.
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| * The internalized EB, within a membrane-bound compartment, immediately begins differentiation into the ''reticulate body (RB)''. RBs are metabolically active but non-infectious, and in many regards, resemble normal replicating bacteria. The intracellular bacteria rapidly modifies its membrane-bound compartment into the so-called chlamydial inclusion so as to prevent phagosome-lysosome fusion. According to published data, the inclusion has no interactions with the endocytic pathway and apparently inserts itself into the exocytic pathway as it retains the ability to intercept sphingomyelin-containing vesicles.
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| To date, no one has been able to detect a host cell protein that is trafficked to the inclusion through the exocytic pathway. As the RBs replicate, the inclusion grows as well to accommodate the increasing numbers of organisms. Through unknown mechanisms, RBs begin a differentiation program back to the infectious EBs, which are released from the host cell to initiate a new round of infection. Because of their obligate intracellular nature, ''Chlamydiae'' have no tractable genetic system, unlike [[E. coli]], which makes ''Chlamydiae'' and related organisms difficult to investigate.
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| ===Persistence=== | | ==[[Chlamydia infection risk factors|Risk Factors]]== |
| ''Chlamydiae'' have the ability to establish long-term associations with host cells. When an infected host cell is starved for various nutrients such as [[amino acid]]s (e.g. [[tryptophan]]),<ref name="pmid17724071">{{cite journal |author=Leonhardt RM, Lee SJ, Kavathas PB, Cresswell P |title=Severe Tryptophan Starvation Blocks Onset of Conventional Persistence and Reduces Reactivation of Chlamydia trachomatis |journal=Infect. Immun. |volume=75 |issue=11 |pages=5105–17 |year=2007 |pmid=17724071 |doi=10.1128/IAI.00668-07}}</ref> [[iron]], or [[vitamin]]s, this has a negative consequence for ''Chlamydiae'' since the organism is dependent on the host cell for these nutrients.
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| The starved chlamydiae enter a persistent growth state wherein they stop cell division and become morphologically aberrant by increasing in size.<ref name="pmid16338585">{{cite journal |author=Mpiga P, Ravaoarinoro M |title=Chlamydia trachomatis persistence: an update |journal=Microbiol. Res. |volume=161 |issue=1 |pages=9–19 |year=2006 |pmid=16338585 |doi=10.1016/j.micres.2005.04.004}}</ref> Persistent organisms remain viable as they are capable of returning to a normal growth state once conditions in the host cell improve.
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| There is much debate as to whether persistence has in vivo relevance. Many believe that persistent chlamydiae are the cause of chronic chlamydial diseases. Some antibiotics such as β-lactams can also induce a persistent-like growth state, which can contribute to the chronicity of chlamydial diseases.
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| == Diseases caused by ''Chlamydia trachomatis'' == | | ==[[Chlamydia infection screening|Screening]]== |
| [[Image:SOA-conjunctivitis.jpg|thumb|Conjunctivitis due to chlamydia.]] | |
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| ''[[Chlamydia trachomatis]]'' can cause the following conditions:
| | ==[[Chlamydia infection natural history|Natural History, Complications and Prognosis]]== |
| <div style="-moz-column-count:2; column-count:2;">
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| * [[Cervicitis]]
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| * [[Conjunctivitis]]
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| * [[Fitz-Hugh-Curtis syndrome]]
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| * [[Lymphogranuloma venereum]]
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| * [[Pelvic inflammatory disease]]
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| * [[Pneumonia]] in infants
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| * [[Reactive arthritis]]
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| * [[Urethritis]]
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| * Rectal infection ([[proctitis]])
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| * [[Prostatitis]]
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| * [[Ectopic pregnancy]]
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| </div>
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| ==Recent genetic discoveries== | | ==Diagnosis== |
| Recent phylogenetic studies have revealed that chlamydia shares a common ancestor with modern plants, and retains unusual plant-like traits (both [[genetics|genetically]] and [[physiology|physiologically]]). In particular, the [[enzyme]] ''L,L-diaminopimelate aminotransferase'', which is related to [[lysine]] production in plants, is also linked with the construction of chlamydia's [[cell wall]]. The genetic encoding for the enzymes is remarkably similar in plants and chlamydia, demonstrating a close common ancestry.<ref name="pmid17093042">{{cite journal |author=McCoy AJ, Adams NE, Hudson AO, Gilvarg C, Leustek T, Maurelli AT |title=L,L-diaminopimelate aminotransferase, a trans-kingdom enzyme shared by Chlamydia and plants for synthesis of diaminopimelate/lysine |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=103 |issue=47 |pages=17909–14 |year=2006 |pmid=17093042 |doi=10.1073/pnas.0608643103}}</ref>
| | [[Chlamydia infection history and symptoms|History and Symptoms]] | [[Chlamydia infection physical examination|Physical Examination]] | [[Chlamydia infection laboratory tests|Laboratory Findings]] | [[Chlamydia infection ultrasound|Ultrasound]] | [[Chlamydia infection other imaging findings|Other Imaging Findings]] |
| This unexpected discovery may help scientists develop new treatment avenues: if scientists could find a safe and effective inhibitor of ''L,L-diaminopimelate aminotransferase'', they might have a highly effective and extremely specific new antibiotic against chlamydia.
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| ==References== | | ==Treatment== |
| {{reflist|2}}
| | [[Chlamydia infection medical therapy|Medical Therapy]] | [[Chlamydia infection surgery|Surgery]] | [[Chlamydia infection primary prevention|Primary Prevention]] | [[Chlamydia infection secondary prevention|Secondary Prevention]] | [[Chlamydia infection cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Chlamydia infection future or investigational therapies|Future or Investigational Therapies]] |
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| == External links == | | ==Case Studies== |
| {{commonscat|Chlamydia}}
| | [[Chlamydia infection case study one|Case #1]] |
| * [http://www.plannedparenthood.org/sexual-health/std/chlamydia.htm "Chlamydia: Questions and Answers"] from [[Planned Parenthood]]
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| * [http://www.netdoctor.co.uk/diseases/facts/chlamydia.htm NetDoctor Chlamydia fact sheet]
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| * [http://www.lib.uiowa.edu/hardin/md/chlamydiapictures.html Links to chlamydia pictures] at [[University of Iowa]]
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| * [http://www.chlamydiae.com/ Chlamydiae.com] - Information for [http://www.chlamydiae.com/docs/information/faq.asp patients,] as well as for [http://www.chlamydiae.com/restricted/ doctors and researchers] about Chlamydial infections. ''Note: Patient info is in multiple languages.''
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| {{STD/STI}} | | {{STD/STI}} |
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| [[zh:衣原體屬]] | | [[zh:衣原體屬]] |
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| [[Category:Sexually transmitted diseases]]
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| [[Category:Bacterial diseases]]
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| [[Category:Chlamydiae]]
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| [[Category:Infectious disease]]
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| [[Category:Gynecology]]
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| {{SIB}}
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| [[pl:Chlamydia]] | | [[pl:Chlamydia]] |
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