II. Epidemiology

  1. Most common Sexually Transmitted Infection in the United States
  2. Incidence: 2.8 million cases/year in U.S. as of 2010
  3. Asymptomatic teenage female test positive: 5-10%
  4. Sexually active persons: 10%
  5. Chlamydia infection is 6 to 10 times more common than Gonorrhea

III. Cause

  1. Chlamydia trachomatis (obligate intracellular organism)

IV. Symptoms: Women

  1. General
    1. Untreated infections may persist for months
    2. Usually asymptomatic
  2. Urethritis: Dysuria sterile-pyuria syndrome
    1. Persistent Dysuria and pyuria
    2. No frequency or urgency
    3. Negative Urine Culture
  3. Other symptoms
    1. Cervicitis
      1. Presents as post-coital bleeding (Friable Cervix)
      2. Mucopurulent discharge from Cervix
    2. Vaginitis
      1. Vaginal Discharge (no odor, mucus)
    3. Pelvic Pain
      1. Consider Pelvic Inflammatory Disease

V. Symptoms: Men

  1. Asymptomatic in up to 98% of men
  2. Epididymitis
  3. Urethritis
    1. Mild to moderate, clear or white Urethral discharge

VI. Labs: Screening Indications

  1. Women
    1. Screen all women with Mucopurulent Cervicitis
    2. Screen all sexually active women age 25 and younger
    3. Screen all pregnant women
  2. Men
    1. Urethritis in men (especially age <35 years)

VII. Labs: Differential Diagnosis

  1. Vaginitis evaluation
    1. Wet Prep
    2. Potassium Hydroxide exam
  2. Sexually Transmitted Disease testing
    1. Gonorrhea (CDC recommends)
    2. STD Blood Testing (strongly consider)
      1. HIV Test (recommended in all patients with Chlamydia)
      2. Hepatitis B (HepBsAg)
      3. Syphilis (RPR)

VIII. Labs: Diagnosis

  1. Chlamydia Polymerase Chain Reaction DNA Probe (preferred)
    1. Same swab can be sent for Gonorrhea DNA testing
      1. Swab source can be endocervical, Urethral, vaginal, pharyngeal or rectal
      2. Dirty urine (no cleansing prior) can be tested as well (first morning void is preferred)
    2. Test Sensitivity
      1. Cervix: >90%
      2. Male Urethra: >95%
      3. Urine male and female: >90%
    3. Test Specificity: 94 to 99.5%
    4. Avoid Chlamydia Rapid Point-Of-Care Test (Test Sensitivity <58%)
  2. Chlamydia Culture
    1. Indication: required for medicolegal cases only
    2. Test Sensitivity: 60-80%
    3. Test Specificity: 100%
  3. Urinalysis Leukocyte Esterase test (men)
    1. High Test Sensitivity for Chlamydia
      1. Sensitivity for Chlamydia Infection: 46-100%
    2. Positive test: perform urine Chlamydia Antigen
  4. Gram Stain findings suggestive of Chlamydia
    1. Urethral discharge: WBCs >5/hpf (no Gonorrhea seen)
    2. First void urine: WBCs >10/hpf
  5. Everted inner lid swab for Chlamydia PCR (neonates)

X. Management: General

  1. Refer all sexual contacts within prior 60 days for treatment
  2. No intercourse until both partners have been fully treated and for 7 days after
  3. Strongly consider concurrent empiric treatment for Gonorrhea (especially in Emergency Department)
    1. Ceftriaxone 500 mg IM/IV for 1 dose (1 gram IM/IV if weight > 150 kg, dose increased in 2020) AND
    2. Azithromycin or Doxycyline (see below)
    3. At minimum, test for Gonorrhea
  4. Rescreen for new Chlamydia infection in 3-4 months (re-infection is common)
    1. Test of cure is recommended only in pregnancy and if symptoms persist
      1. Re-test all pregnant women 3-4 weeks after treatment
  5. Consider other causes of STI in refractory symptoms despite treatment
    1. See differential diagnosis as above
    2. Mycoplasma Genitalium is responsible for 30% of Non-Gonococcal Urethritis

XI. Management: Antibiotics

  1. See Chlamydia Conjunctivitis (includes Trachoma, Inclusion Conjunctivitis)
  2. See Lymphogranuloma venereum
  3. First-line agents for uncomplicated genitourinary infections in non-pregnant patients
    1. Azithromycin 1 gram orally for 1 dose OR
    2. Doxycycline 100 mg orally twice daily for 7 days (preferred)
  4. Alternative agents for uncomplicated genitourinary infections in non-pregnant patients
    1. Ofloxacin 300 mg orally twice daily (or 600 mg once daily) for 7 days or
    2. Levofloxacin (Levaquin) 500 mg orally daily for 7 days or
    3. Erythromycin 500 mg orally four times daily for 7 days or
    4. Erythromycin Ethylsuccinate (EES) 800 mg orally four times daily for 7 days or
  5. Pregnancy
    1. Azithromycin 1 gram orally once as single dose or
    2. Erythromycin OR EES as above for 7 days or
    3. Amoxicillin 500 mg orally three times daily for 7 days (Only 50% effective)
  6. Neonates (Neonatal Conjunctivitis or Chlamydia Pneumonia)
    1. Erythromycin base or EES 50 mg/kg orally divided four times daily for 14 days
    2. Second course needed in 20% of cases
  7. Persistant or recurrent Urethritis despite treatment
    1. Metronidazole 2 grams orally for 1 dose and
    2. Erythromycin base 500 mg orally twice daily x7 days
  8. Chronic Reactive Arthritis (Reiter Syndrome)
    1. Rifampin 300 mg once daily for 6 months AND
    2. One of the following:
      1. Doxycycline 100 mg orally twice daily for 6 months or
      2. Azithromycin 500 mg orally daily for 5 days and then 500 mg twice weekly for 6 months

XII. Complications

  1. Pelvic Inflammatory Disease
  2. Infertility
  3. Preterm Labor
  4. Perinatal transmission to newborn
    1. Chlamydia Conjunctivitis
    2. Neonatal Chlamydia Pneumonia
  5. Epididymitis (men)
  6. Reiter's Syndrome (more common in men)
    1. Arthritis
    2. Conjunctivitis
    3. Urethritis
  7. Fitz-Hugh-Curtis Syndrome (rare)
    1. Perihepatitis Syndrome presents with right upper quadrant pain
  8. Extra-genital infections
    1. Chlamydia Conjunctivitis
    2. Pharyngitis (oral sex)
      1. Gonorrhea is more common orally
    3. Anal infection (Receptive anal intercourse)
      1. Rectal Chlamydia may be resistant to Azithromycin (Doxycycline is preferred)

XIII. Prevention: Annual screening guidelines

  1. All sexually active women under age 25 years
  2. All sexually active women with STD risks
  3. Consider in sexually active men under age 25 years or with STD risks

Images: Related links to external sites (from Bing)

Related Studies

Ontology: Chlamydia (C0008148)

Definition (NCI_CDISC) Any bacteria that is not assigned to the species level but can be assigned to the Chlamydia genus level.
Definition (NCI) A genus of bacteria within the Chlamydiae phylum that contains only the three species Chlamydia trachomatis, Chlamydia suis, and Chlamydia muridarum.
Definition (MSH) A genus of the family CHLAMYDIACEAE whose species cause a variety of diseases in vertebrates including humans, mice, and swine. Chlamydia species are gram-negative and produce glycogen. The type species is CHLAMYDIA TRACHOMATIS.
Concepts Bacterium (T007)
MSH D002689
SnomedCT 16241000
LNC LP20682-8, LA16984-9
English Miyagawanella, Chlamydia, Chlamydia (organism), Genus Chlamydia (organism), bedsonia, Chlamydia Jones et al. 1945 (Approved Lists 1980) emend. Everett et al. 1999, chlamydiae, chlamydias, chlamydia, chlamydia bacteria, Bedsonia, Rakeia, Rickettsiaformis, CHLAMYDIA, Chlamydia, NOS, Genus Chlamydia
Swedish Chlamydia
Czech Chlamydia, Bedsonia
Spanish Chlamydia (organismo), género Chlamydia, clamidia, género Chlamydia (organismo), Chlamydia
Finnish Klamydiabakteeri
Croatian Not Translated[Chlamydia]
Polish Chlamydia
Norwegian Chlamydia
French Chlamydia
German Chlamydia, Miyagawanella
Italian Chlamydia
Dutch Chlamydia
Portuguese Chlamydia

Ontology: Chlamydia trachomatis (C0008151)

Definition (NCI_CDISC) Any bacterial organism that can be assigned to the species Chlamydia trachomatis.
Definition (NCI) A Gram-negative bacterium in the genus Chlamydia. It is an obligate intracellular pathogen and is the causative agent of vaginal Chlamydial infections in humans and lymphogranuloma venereum.
Definition (NCI) A species of facultatively aerobic, Gram-negative, coccobacilli assigned to the phylum Chlamydiae. This species cannot be grown on an artificial medium, lacks peptidoglycan within the cell wall, forms elementary and reticulate bodies and can be identified using monoclonal antibodies (mAbs) to epitopes in the VS 4 region of MOMP along with DNA sequencing. C. trachomatis is an obligate intracellular parasite that can be transmitted through sexual contact causing infections of the genital tract and rectum and infertility in women, as well as cause eye infections.
Definition (CSP) bacteria belonging to genus Chlamydia; causes a variety of ocular and urogenital diseases.
Definition (MSH) Type species of CHLAMYDIA causing a variety of ocular and urogenital diseases.
Concepts Bacterium (T007)
MSH D002692
SnomedCT 63938009
LNC LP14298-1, MTHU004885
Swedish Chlamydia trachomatis
Czech Chlamydia trachomatis
English Rickettsia trachomae, C. trachomatis, Chlamydia trachomatis (Busacca 1935) Rake 1957 (Approved Lists 1980) emend. Everett et al. 1999, chlamydias trachomatis, chlamydia trachomatis, c trachomatis, c. trachomatis, CHLAMYDIA TRACHOMATIS, Chlamydozoon trachomatis, Rickettsia trachomatis, Lymphogranuloma venereum virus, CT - Chlamydia trachomatis, Chlamydia trachomatis (organism), Chlamydia trachomatis
Finnish Chlamydia trachomatis
Polish Chlamydia trachomatis, Zarazki jaglicy
Norwegian Chlamydia trachomatis
Spanish Chlamydia trachomatis (organismo), virus del linfogranuloma venéreo, Chlamydia trachomatis
French Chlamydia trachomatis
German Chlamydia trachomatis
Italian Chlamydia trachomatis
Dutch Chlamydia trachomatis
Portuguese Chlamydia trachomatis

Ontology: Proctitis chlamydial (C0149856)

Concepts Disease or Syndrome (T047)
English Chlamydial Proctitis, Chlamydial proctitis, Proctitis chlamydial, proctitis; chlamydial, Chlamydia; proctitis
Italian Proctite da Chlamydia, Proctite da Clamidia
Japanese クラミジア性直腸炎, クラミジアセイチョクチョウエン
Czech Chlamydiová proktitida
Hungarian Chlamydia okozta proctitis, chlamydiás proctitis
Dutch Chlamydia; proctitis, proctitis; Chlamydia, Chlamydia-proctitis
Portuguese Proctite a clamídia
Spanish Proctitis por clamidia
French Proctite à Chlamydia
German Proktitis durch Chlamydien

Ontology: Chlamydial cervicitis (C0341834)

Concepts Disease or Syndrome (T047)
ICD10 A56.09
SnomedCT 155984003, 198208000, 237084006
Dutch Chlamydia-cervicitis, Chlamydia; cervicitis, cervicitis; Chlamydia
French Cervicite à Chlamydia
German Zervizitis durch Chlamydien
Italian Cervicite clamidiale
Portuguese Cervicite a clamídia
Spanish Cervicitis por clamidia, cervicitis por clamidia (trastorno), cervicitis por clamidia
Japanese クラミジアセイシキュウケイカンエン, クラミジア性子宮頚管炎
English Chlamydia trachomatis cervicitis, Chlamydia trachomatis cervicitis (diagnosis), sexually transmitted disease of cervix due to Chlamydia trachomatis (diagnosis), sexually transmitted disease of cervix due to Chlamydia trachomatis, Chlamydial cervicitis, Chlamydial cervicitis (disorder), cervicitis; chlamydial, Chlamydia; cervicitis
Czech Chlamydální cervicitida
Hungarian Chlamydia okozta cervicitis

Ontology: Chlamydial vulvovaginitis (C0341841)

Concepts Disease or Syndrome (T047)
ICD10 A56.02
SnomedCT 237097008
English Vulvovaginitis chlamydial, Chlamydial vulvovaginitis (diagnosis), vulvovaginitis chlamydial, Chlamydial vulvovaginitis, Chlamydial vulvovaginitis (disorder), Chlamydia; vulvovaginitis, vulvovaginitis; chlamydial
Dutch vulvovaginitis door Chlamydia, Chlamydia; vulvovaginitis, vulvovaginitis; Chlamydia
French Vulvovaginite chlamydiale
German Vulvovaginitis durch Chlamydien
Italian Vulvovaginite da Chlamydia
Portuguese Vulvovaginite por clamídia
Spanish Vulvovaginitis por clamidia, vulvovaginitis por clamidia (trastorno), vulvovaginitis por clamidia
Japanese クラミジア性外陰部腟炎, クラミジアセイガイインブチツエン
Czech Vulvovaginitida chlamydiální
Hungarian chlamydiás vulvovaginitis

Ontology: Chlamydial pelvic inflammatory disease (C0520777)

Concepts Disease or Syndrome (T047)
SnomedCT 188463006, 73107008
Italian Malattia infiammatoria pelvica da Clamidia
French Inflammation pelvienne à Chlamydiae, Syndrome inflammatoire pelvien à Chlamydia
German Beckenentzuendung verursacht durch Chlamydien, Beckenentzuendung durch Clamydien
Portuguese Doença inflamatória pélvica a clamídia, Doença inflamatatória da pélvis por clamídia
Spanish Enfermedad inflamatoria pélvica por clamidia, enfermedad inflamatoria pelviana clamidial, EPI por clamidia, enfermedad inflamatoria pélvica por clamidia, enfermedad pelviana inflamatoria por clamidia, enfermedad pélvica inflamatoria por clamidia (trastorno), enfermedad pélvica inflamatoria por clamidia, Enfermedad inflamatoria pélvica por clamidias
Japanese クラミジア性骨盤内炎症性疾患, クラミジアセイコツバンナイエンショウセイシッカン
English pelvic inflammatory disease due to Chlamydia trachomatis, pelvic inflammatory disease due to Chlamydia trachomatis (diagnosis), Pelvic inflammatory disease chlamydial, Chlamydial pelvic inflammatory disease, Chlamydial pelvic inflammatory disease (disorder)
Czech Chlamydiové zánětlivé onemocnění pánve
Hungarian Chlamydia okozta kismedencei gyulladásos betegség, kismedencei gyulladásos betegség, chlamydiás
Dutch inflammatoire aandoening in het bekken door Chlamydia

Ontology: Genitourinary chlamydia infection (C0589616)

Concepts Disease or Syndrome (T047)
SnomedCT 312099009
Italian Infezione genito-urinaria da clamidia
Japanese 泌尿生殖器クラミジア感染, ヒニョウセイショクキクラミジアカンセン
English Genitourin chlamydia infection, sexually transmitted disease due to Chlamydia trachomatis, venereal disease due to Chlamydia trachomatis, sexually transmitted disease due to Chlamydia trachomatis (diagnosis), genitourinary venereal disease due to Chlamydia trachomatis, sexually transmitted disease of genitourinary tract due to Chlamydia trachomatis (diagnosis), sexually transmitted disease of genitourinary tract due to Chlamydia trachomatis, Genitourinary chlamydia infection, Genitourinary chlamydia infection (disorder)
Czech Urogenitální chlamydiová infekce
Hungarian urogenitalis chlamydia fertőzés
Spanish infección genitourinaria por Chlamydia (trastorno), infección genitourinaria por Chlamydia, Infección genitourinaria por clamidia
Portuguese Infecção geniturinária a clamídia
Dutch genito-urinaire Chlamydia-infectie
French Infection génito-urinaire à Chlamydiae
German Chlamydieninfektion der Geschlechtsorgane und der Harnwege

Ontology: Chlamydial urethritis (C1278807)

Concepts Disease or Syndrome (T047)
ICD9 099.41
SnomedCT 179101003, 246832008, 51131008, 236683007
Italian Uretrite da Chlamydia, Uretrite da Clamidia, Uretrite da Chlamydia trachomatis, Uretrite non specifica da Clamidia, Uretrite venerea da chlamydia trachomatis
Dutch Chlamydia niet-gespecificeerde urethritis, venerische urethritis door Chlamydia trachomatis, Chlamydia trachomatis urethritis, Chlamydia trachomatis urethritis reactie, Chlamydia-urethritis
French Urétrite à Chlamydiae, Urétrite à Chlamydia trachomatis, Urétrite vénérienne à chlamydia trachomatis, Urétrite à Chlamydia non précisée, Réaction d'urétrite à Chlamydia trachomatis, Urétrite à Chlamydia
German venerische Urethritis verursacht durch Chlamydia trachomatis, Chlamydien NSU, Chlamydia trachomatis-Urethritis, Chlamydia trachomatis-Urethritisreaktion, Urethritis durch Chlamydien
Portuguese UNE a clamídia, Uretrite venérea por Chlamydia trachomatis, Uretrite a Chlamydia trachomatis, Reacção de uretrite a Chlamydia trachomatis, Uretrite a clamídia
Spanish Uretritis moniliásica, Reacción a la uretritis por Chlamydia trachomatis, Uretritis venérea por chlamydia trachomatis, UNE por clamidia, Uretritis por Chlamydia trachomatis, uretritis debida a Chlamydia trachomatis (trastorno), uretritis debida a Chlamydia trachomatis, uretritis por Chlamydia trachomatis (trastorno), uretritis por Chlamydia trachomatis, UNG debida a Clamidia trachomatis, UNG por Chlamydia trachomatis, uretritis no gonocócica por Chlamydia trachomatis, uretritis no gonocócica por Chlamydia trachomatis (trastorno), uretritis debida a la Clamidia trachomatis (trastorno), uretritis debida a la Clamidia trachomatis, uretritis no gonocócica por Chlamydia trachomatis (concepto no activo), uretritis por Clamidia (trastorno), uretritis por Clamidia, Uretritis por clamidia
Japanese トラコーマクラミジア性尿道炎, トラコーマクラミジアによる性病尿道炎, トラコーマクラミジア性尿道炎の反応, クラミジア性尿道炎, クラミジア性非特異性尿道炎, クラミジアセイヒトクイセイニョウドウエン, クラミジアセイニョウドウエン, トラコーマクラミジアニヨルセイビョウニョウドウエン, トラコーマクラミジアセイニョウドウエン, トラコーマクラミジアセイニョウドウエンノハンノウ
English urethritis due to Chlamydia trachomatis, urethritis due to Chlamydia trachomatis (diagnosis), Venereal urethritis due to chlamydia trachomatis, Chlamydia trachomatis urethritis reaction, Chlamydia urethritis, Chlamydial NSU, Urethritis chlamydial, Chlmyd trachomatis ureth, Urethritis;chlamydial, chlamydia urethritis, Chlamydia trachomatis urethritis, Nongonococcal urethritis [NGU] due to Chlamydia trachomatis, Other nongonococcal urethritis, chlamydia trachomatis, Nongonococcal urethritis due to Chlamydia trachomatis (disorder), Urethritis due to Chlamydia trachomatis, Chlamydial urethritis, Chlamydial urethritis (disorder), Urethritis due to Chlamydia trachomatis (disorder), Nongonococcal urethritis due to Chlamydia trachomatis (disorder) [Ambiguous], NGU due to Chlamydia trachomatis, Nongonococcal urethritis due to Chlamydia trachomatis, chlamydial urethritis
Czech Uretrální reakce na infekci Clamydia trachomatis, Chlamydiová NSU, Venerická uretritida vyvolaná Chlamydia trachomatis, Uretritida vyvolaná Chlamydia trachomatis, Chlamydiová uretritida
Hungarian Chlamydia trachomatis okozta szexuális úton terjedő urethritis, Chlamydia trachomatis urethritis, Chlamydia trachomatis urethritis reakció, Chlamydia okozta NSU, Chlamydia urethritis, chlamydiás urethritis, Chlamydia okozta urethritis