Chlamydia infection 7037 224563163 2008-07-09T12:48:48Z Manco Capac 5812100 tr iw correction {{DiseaseDisorder infobox | Name = Chlamydia | Image = Pap smear showing clamydia in the vacuoles 500x H&E.jpg| Caption = Pap smear showing ''C. trachomatis'' (H&E stain) | ICD10 = {{ICD10|A|55||a|50}}-{{ICD10|A|56|8|a|50}}, {{ICD10|A|70||a|70}}-{{ICD10|A|74|9|a|70}} | ICD9 = {{ICD9|099.41}}, {{ICD9|483.1}} | ICDO = | OMIM = | DiseasesDB = 2384 | MedlinePlus = | eMedicineSubj = med | eMedicineTopic = 340 | MeshID = D002690 | }} '''Chlamydia''' (from the [[Ancient Greek|Greek]], χλαμύδος meaning "cloak") is a common [[sexually transmitted infection]] (STI) caused by the bacterium ''[[Chlamydia trachomatis]]''. 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> Chlamydia is a major infectious cause of human [[genital]] and [[eye disease]]. Chlamydia infection is one of the most common sexually transmitted infections in people worldwide &mdash; 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> It is the most common bacterial STI in humans.<ref name="STI-epidemiology">{{cite journal |author=Gerbase AC, Rowley JT, Mertens TE |title=Global epidemiology of sexually transmitted diseases |journal=Lancet |volume=351 Suppl 3 |issue= |pages=2–4 |year=1998 |pmid=9652711 |doi=}}</ref> ''C. trachomatis'' is naturally found living only inside human cells. 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. Chlamydia [[conjunctivitis]] or '''[[trachoma]]''' is a common cause of [[blindness]] worldwide. The World Health Organization estimates that it accounted for 15% of blindness cases in 1995, but only 3.6% in 2002.<ref name="WHO1995">{{cite journal |author=Thylefors B, Négrel AD, Pararajasegaram R, Dadzie KY |title=Global data on blindness |journal=Bull World Health Organ |volume=73 |issue=1 |pages=115–21 |year=1995 |pmid=7704921 |doi= |url=http://whqlibdoc.who.int/bulletin/1995/Vol73-No1/bulletin_1995_73(1)_115-121.pdf}}</ref><ref name="WHO2002">{{cite journal |author=Resnikoff S, Pascolini D, Etya'ale D ''et al'' |title=Global data on visual impairment in the year 2002 |journal=Bull World Health Organ |volume=82 |issue=11 |pages=844–851 |year=2004 |pmid=15640920 |doi= |url=http://www.who.int/bulletin/volumes/82/11/en/844.pdf}}</ref><ref name="NatRevMicrobiol">{{cite journal |author=Belland R, Ojcius D, Byrne G |title=Chlamydia |journal=Nat Rev Microbiol |volume=2 |issue=7 |pages=530–1 |year=2004 |pmid=15248311 |doi=10.1038/nrmicro931}}</ref> == Related conditions == ===Genital disease=== <!-- Wikipedia is NOT censored and contains many different images, some of which are considered objectionable or offensive by some readers. The images shown here are relevant to the content, please do not remove them.--> [[Image:SOA-Chlamydia-trachomatis-female.jpg|thumb|Chlamydial [[cervicitis]] in a female patient characterized by [[mucopurulent]] [[cervix|cervical]] discharge, [[erythema]], and [[inflammation]].]] Chlamydial infection of the neck of the womb ([[cervicitis]]) is an [[asymptomatic]] sexually transmitted illness for about 50-70% of the female population. Of those who have an asymptomatic infection that is not detected by their doctor, approximately half will develop [[pelvic inflammatory disease]] (PID), a generic term for infection of the [[uterus]], [[fallopian tubes]], and/or [[ovaries]]. PID can cause scarring inside the [[reproductive organ]]s, which can later cause serious complications, including chronic [[pelvis|pelvic]] pain, difficulty becoming [[pregnancy|pregnant]], [[ectopic pregnancy|ectopic (tubal) pregnancy]], and other dangerous complications of pregnancy. Chlamydia causes 250,000 to 500,000 cases of PID every year in the United States. Women infected with chlamydia are up to five times more likely to become infected with HIV, if exposed.<ref>{{cite web |url=http://www.cdc.gov/std/chlamydia/STDFact-Chlamydia.htm#complications |title=STD Facts - Chlamydia |accessdate=2007-10-26 |format= |work=}}</ref> Chlamydia is known as the "Silent Epidemic" because in women, it may not cause any [[symptom]]s and will linger for months or years before being discovered. Symptoms that may occur include: unusual [[vagina]]l bleeding or discharge, pain in the abdomen, painful [[sexual intercourse]] ([[dyspareunia]]), [[fever]], [[Dysuria|painful urination]] or the urge to urinate more frequently than usual ([[urinary urgency]]). <!-- Wikipedia is NOT censored! The images shown here are relevant to the content, please do not remove them.-->[[Image:SOA-Chlamydia-trachomatis-male.jpg|thumb|right|Male patients may develop a white, cloudy or watery discharge (shown) from the tip of the [[penis]].]] In men, Chlamydia shows symptoms of infectious [[urethritis]] ([[inflammation]] of the [[urethra]]) in about 50% of cases. Symptoms that may occur include: a painful or burning sensation when urinating, an unusual discharge from the [[penis]], swollen or tender [[testicle]]s, or fever. Discharge, or the purulent exudate, is generally less viscous and lighter in color than for [[gonorrhea]]. If left untreated, it is possible for Chlamydia in men to spread to the testicles causing [[epididymitis]], which in rare cases can cause [[infertility|sterility]] if not treated within 6 to 8 weeks. Chlamydia causes more than 250,000 cases of epididymitis in the U.S. each year. Chlamydia is also a potential cause of [[prostatitis]] in men, although the exact relevance in prostatitis is difficult to ascertain due to possible contamination from urethritis.<ref name="urology">{{cite journal |author=Wagenlehner FM, Naber KG, Weidner W |title=Chlamydial infections and prostatitis in men |journal=BJU Int. |volume=97 |issue=4 |pages=687–90 |year=2006 |pmid=16536754 |doi=10.1111/j.1464-410X.2006.06007.x |url=http://www.blackwell-synergy.com/openurl?genre=article&sid=nlm:pubmed&issn=1464-4096&date=2006&volume=97&issue=4&spage=687}}</ref> ===Eye disease=== [[Image:SOA-conjunctivitis.jpg|thumb|Conjunctivitis due to chlamydia.]] Chlamydia conjunctivitis or trachoma was once the second most important cause of blindness worldwide, but its role diminished from 15% of blindness cases by trachoma in 1995 to 3.6% in 2002, according to WHO estimates.<ref name="NatRevMicrobiol"/><ref name="WHO1995"/><ref name="WHO2002"/> The infection can be spread from eye to eye by fingers, shared towels or cloths, coughing and sneezing and eye-seeking flies.<ref name="LancetTrachoma">{{cite journal |author=Mabey DC, Solomon AW, Foster A |title=Trachoma |journal=Lancet |volume=362 |issue=9379 |pages=223–9 |year=2003 |pmid=12885486 |doi=10.1016/S0140-6736(03)13914-1 |url=http://linkinghub.elsevier.com/retrieve/pii/S0140-6736(03)13914-1}}</ref> Newborns can also develop chlamydia eye infection through [[childbirth]] (see below). Using the SAFE strategy ([[acronym]] for surgery for [[trichiasis|in-growing]] or [[entropion|in-turned]] lashes, [[antibiotics]], facial cleanliness, and environmental improvements), the [[World Health Organisation]] aims for the global elimination of trachoma by 2020 (GET 2020 initiative).<ref name="GET2020">[[World Health Organisation]]. [http://www.who.int/blindness/causes/trachoma/en/index.html Trachoma]. Accessed March 17, 2008.</ref><ref name="LancetSAFE">{{cite journal |author=Ngondi J, Onsarigo A, Matthews F, ''et al'' |title=Effect of 3 years of SAFE (surgery, antibiotics, facial cleanliness, and environmental change) strategy for trachoma control in southern Sudan: a cross-sectional study |journal=Lancet |volume=368 |issue=9535 |pages=589–95 |year=2006 |pmid=16905023 |doi=10.1016/S0140-6736(06)69202-7 |url=http://linkinghub.elsevier.com/retrieve/pii/S0140-6736(06)69202-7}}</ref> ===Rheumatological conditions=== Chlamydia may also cause [[reactive arthritis]] - the triad of arthritis, conjunctivitis and urethritis (inflammation of the urethra) - especially in young men. About 15,000 men develop reactive arthritis due to chlamydia infection each year in the U.S., and about 5,000 are permanently affected by it. It can occur in both sexes, though is more common in men. ===Perinatal infections=== As many as half of all [[infant]]s born to mothers with chlamydia will be born with the disease. Chlamydia can affect infants by causing spontaneous abortion; [[premature birth]]; [[conjunctivitis]], which may lead to [[blindness]]; and [[pneumonia]]. Conjunctivitis due to chlamydia typically occurs one week after birth (compare with chemical causes (within hours) or gonorrhea (2-5 days)). ===Other conditions=== Chlamydia trachomatis is also the cause of [[lymphogranuloma venereum]], an infection of the [[lymph nodes]] and [[lymphatics]]. It usually presents with [[genital ulcer]]ation and [[Lymphadenopathy|swollen lymph nodes]] in the [[groin]], but it may also manifest as [[proctitis]] (inflammation of the [[rectum]]), [[fever]] or swollen lymph nodes in other regions of the body.<ref name="proctitis">{{cite journal |author=Williams D, Churchill D |title=Ulcerative proctitis in men who have sex with men: an emerging outbreak |journal=BMJ |volume=332 |issue=7533 |pages=99–100 |year=2006 |pmid=16410585 |doi=10.1136/bmj.332.7533.99 |url=http://bmj.com/cgi/pmidlookup?view=long&pmid=16410585}}</ref> == Diagnosis == === Screening === For sexually active women who are not pregnant, screening is recommended in those under 25 and others at risk of infection.<ref name="AmFamPhys">Meyers D, Wolff T, Gregory K. ''et al''. [http://www.aafp.org/afp/20080315/819.html USPSTF Recommendations for STI Screening]. Am Fam Physician. 2008;77(6):819-824.</ref> Risk factors include a history of chlamydial or other sexually transmitted infection, new or multiple sexual partners, inconsistent [[condom]] use, and exchanging sex for money or drugs.<ref name="USPSTF">{{cite journal |author=U.S. Preventive Services Task Force |title=Screening for chlamydial infection: U.S. Preventive Services Task Force recommendation statement |journal=Ann Intern Med |volume=147 |issue=2 |pages=128–34 |year=2007 |pmid=17576996 |doi= |url=http://www.ahrq.gov/clinic/uspstf07/chlamydia/chlamydiars.htm}}</ref> For pregnant women, guidelines vary: screening women with age or other risk factors is recommended by the [[U.S. Preventive Services Task Force]] (USPSTF) (which recommends screening women under 25) and the [[American Academy of Family Physicians]] (which recommends screening women aged 25 or younger). The [[American College of Obstetricians and Gynecologists]] recommends screening all at risk, while the [[Centers for Disease Control and Prevention]] recommend universal screening of pregnant women.<ref name="AmFamPhys"/> The USPSTF acknowledges than in some communities there may be other risk factors for infection, such as ethnicity.<ref name="AmFamPhys"/> Evidence-based recommendations for screening initiation, intervals and termination are currently not possible.<ref name="AmFamPhys"/> There is no universal agreement on screening men for chlamydia. ===Laboratory detection=== 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. 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 they may give reliable results on rectal specimens. 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 (test)|gold standard]] for chlamydia diagnosis, and the non-amplified probe tests. 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. == Treatment == [[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: * [[Azithromycin]] 1 gram oral as a single dose, or * [[Doxycycline]] 100 milligrams twice daily for ten days. * [[Tetracycline]] * [[Erythromycin]] Untested Treatments * [[Ciprofloxacin]] 500 milligrams twice daily for 3 days. (Although this is not an approved method of treatment.) [[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.) === Areas of research === 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> 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. == Pathophysiology == {{dablink|For Chlamydia's life cycle, see [[Chlamydia (bacterium)]]}} ''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. 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. 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. ==Footnotes== {{reflist|2}} == External links == {{commonscat|Chlamydia}} * [http://www.youngandhealthy.ca/caah/Informations/STI/t428c431s442x413/Chlamydia.aspx STI: Chlamydia] a website information for adolescents * [http://www.netdoctor.co.uk/diseases/facts/chlamydia.htm NetDoctor Chlamydia fact sheet] * [http://www.lib.uiowa.edu/hardin/md/chlamydiapictures.html Links to chlamydia pictures] at [[University of Iowa]] * [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.'' {{STD/STI}} {{Bacterial diseases}} [[Category:Sexually transmitted diseases and infections]] [[Category:Bacterial diseases]] [[Category:Chlamydiae]] [[ar:كلاميديا]] [[da:Klamydia]] [[de:Chlamydien]] [[es:Chlamydia]] [[fr:Chlamydiose]] [[id:Infeksi Chlamydia]] [[it:Infezioni da clamidia]] [[he:כלמידיה]] [[mk:Хламидија]] [[ms:Penyakit kelamin Chlamydia]] [[nl:Chlamydia]] [[ja:クラミジア]] [[no:Klamydia-infeksjon]] [[pl:Chlamydia]] [[pt:Clamídia]] [[ru:Хламидиоз]] [[sl:Klamidioza]] [[fi:Klamydia]] [[sv:Klamydia]] [[ta:கிளமிடியா]] [[tr:Klamidya (hastalık)]] [[zh:衣原體屬]]