Editing Chlamydia (section)

==Diagnosis==
[[File:ChlamydiaTrachomatisEinschlusskörperchen.jpg|thumb|''Chlamydia trachomatis'' inclusion bodies (brown) in a McCoy [[cell culture]]]]
The diagnosis of genital chlamydial infections evolved rapidly from the 1990s through 2006. [[Nucleic acid amplification test]]s (NAAT), such as [[polymerase chain reaction]] (PCR), transcription mediated amplification (TMA), and the DNA [[strand displacement amplification]] (SDA) now are the mainstays. NAAT for chlamydia may be performed on swab specimens [[sampling (medicine)|sampled]] from the cervix (women) or urethra (men), on self-collected vaginal swabs, or on voided urine.<ref>{{cite journal | vauthors = Gaydos CA, Theodore M, Dalesio N, Wood BJ, Quinn TC | title = Comparison of three nucleic acid amplification tests for detection of Chlamydia trachomatis in urine specimens | journal = Journal of Clinical Microbiology | volume = 42 | issue = 7 | pages = 3041–3045 | date = July 2004 | pmid = 15243057 | pmc = 446239 | doi = 10.1128/JCM.42.7.3041-3045.2004 | citeseerx = 10.1.1.335.7713 }}</ref> NAAT has been estimated to have a [[sensitivity and specificity|sensitivity]] of approximately 90% and a [[sensitivity and specificity|specificity]] of approximately 99%, regardless of sampling from a cervical swab or by urine specimen.<ref name="Haugland2010">{{cite journal | vauthors = Haugland S, Thune T, Fosse B, Wentzel-Larsen T, Hjelmevoll SO, Myrmel H | title = Comparing urine samples and cervical swabs for Chlamydia testing in a female population by means of Strand Displacement Assay (SDA) | journal = BMC Women's Health | volume = 10 | issue = 1 | pages = 9 | date = March 2010 | pmid = 20338058 | pmc = 2861009 | doi = 10.1186/1472-6874-10-9 | doi-access = free }}</ref> In women seeking treatment in a sexually transmitted infection clinic where a urine test is negative, a subsequent cervical swab has been estimated to be positive in approximately 2% of the time.<ref name=Haugland2010/>

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. Other methods also exist including: [[ligase chain reaction]] (LCR), direct fluorescent antibody resting, [[ELISA|enzyme immunoassay]], and cell culture.<ref>{{cite web|url=https://www.cdc.gov/mmwr/preview/mmwrhtml/rr6302a1.htm|title=Recommendations for the Laboratory-Based Detection of Chlamydia trachomatis and Neisseria gonorrhoeae — 2014|website=Centers for Disease Control and Prevention|access-date=2016-06-12|url-status=live|archive-url=https://web.archive.org/web/20160627175218/http://www.cdc.gov/mmwr/preview/mmwrhtml/rr6302a1.htm|archive-date=2016-06-27}}</ref>

The swab sample for chlamydial infections does not show difference whether the sample was collected in home or in clinic in terms of numbers of patient treated. The implications in cured patients, reinfection, partner management, and safety are unknown.<ref>{{cite journal | vauthors = Fajardo-Bernal L, Aponte-Gonzalez J, Vigil P, Angel-Müller E, Rincon C, Gaitán HG, Low N | title = Home-based versus clinic-based specimen collection in the management of Chlamydia trachomatis and Neisseria gonorrhoeae infections | journal = The Cochrane Database of Systematic Reviews | volume = 2015 | issue = 9 | pages = CD011317 | date = September 2015 | pmid = 26418128 | pmc = 8666088 | doi = 10.1002/14651858.CD011317.pub2 | collaboration = Cochrane STI Group }}</ref>

Rapid point-of-care tests are, as of 2020, not thought to be effective for diagnosing chlamydia in men of reproductive age and non-pregnant women because of high false-negative rates.<ref>{{cite journal | vauthors = Grillo-Ardila CF, Torres M, Gaitán HG | title = Rapid point of care test for detecting urogenital Chlamydia trachomatis infection in nonpregnant women and men at reproductive age | journal = The Cochrane Database of Systematic Reviews | volume = 1 | issue = 1 | pages = CD011708 | date = January 2020 | pmid = 31995238 | pmc = 6988850 | doi = 10.1002/14651858.CD011708.pub2 }}</ref>