Chlamydia trachomatis: Difference between revisions

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Chlamydia trachomatis
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== Microbiology ==
==Background==
* Small, obligate intracellular [[Has Gram stain::Gram-negative]] [[Has shape::coccobacillus]]
** Very difficult to Gram stain due to lack of peptidoglycan in cell wall
* Two forms exist:
** '''Elementary body (EB):''' spore-like form than can survive short times outside the body
** '''Reticulate body (RB):''' replicative form
* Virulence factors include lipopolysaccharide (LPS)


===Microbiology===
== Clinical Presentations ==

* Presentation varies by serovar
*Small, obligate intracellular [[Stain::Gram-negative]] [[Shape::coccobacillus]]
**Very difficult to Gram stain due to lack of peptidoglycan in cell wall
*Two forms exist:
**'''Elementary body (EB):''' spore-like form than can survive short times outside the body
**'''Reticulate body (RB):''' replicative form
*Virulence factors include lipopolysaccharide (LPS)

===Risk Factors===

*Sexual contact with chlamydia-infected person
*New sexual partner, or more than two sexual partners in the past year
*Previous STI
*Specific populations: people who inject drugs, incarcerated people, sex trade workers, street-living youth

==Clinical Manifestations==

*Incubation period is [[Usual incubation period::2 to 3 weeks]] ([[Incubation period range::up to 6 weeks|Incubation period range::1 to 6 weeks]])
*Many are asymptomatic
*Presentation varies by serovar


{| class="wikitable"
{| class="wikitable"
!Serovars
! Syndrome !! Serovars
!Syndromes
|-
|-
|A to C
| Urethritis, PID, neonatal infection || D to K
|[[Trachoma]] (chronic conjunctivitis)
|-
|-
|D to K
| Trachoma (chronic conjunctivitis) || A to C
|[[Urethritis]], [[PID]], neonatal infection
|-
|-
|L1 to L3
| Lymphogranuloma venereum (LGV) || L1 to L3
|[[Lymphogranuloma venereum]] (LGV)
|}
|}


===Sexually-Transmitted Infection===
=== Urethritis ===

* In men, most are symptomatic
*In men, most are symptomatic
** Incubation or 7 to 21 days in men
**Incubation period is 7 to 21 days in men
** Purulent urethritis
**Purulent urethritis, urethral itch, dysuria, testicular pain
* In women, often asymptomatic
**Conjunctivitis
**Proctitis (often asymptomatic)
**Sequelae include [[epididymo-orchitis]] and [[reactive arthritis]]
*In women, often asymptomatic
**Cervicitis, vaginal discharge, dysuria, lower abdominal pain, abnormal vaginal bleeding, dyspareunia
**Conjunctivitis
**Proctitis (often asymptomatic)
**Sequelae include [[pelvic inflammatory disease]], [[ectopic pregnancy]], [[infertility]], [[chronic pelvic pain]], and [[reactive arthritis]]

===Lymphogranuloma Venereum===

*See [[Lymphogranuloma venereum#Clinical Presentation|lymphogranuloma venereum]]

===Fitz-Hugh-Curtis syndrome===

*Liver capsular inflammation, possibly autoimmune

===Pediatric Infections===

*Serovars associated with STIs can also cause:
**[[Conjunctivitis]] in neonates
**Pneumonia in children under 6 months of age

===Trachoma===

*Chronic [[keratoconjunctivitis]] caused by recurrent infection
*Leading infectious cause of blindness worldwide
*Spread via direct contact of ocular or nasal secretions and via fomites, and possibly via eye-seeking flies including [[Musca sorbens]]
*Presents with two phases:
**Active trachoma, with acute, mild, self-limited [[conjunctivitis]]
***May be asymptomatic
***Usually detected with screening
**Cicatricial disease causing conjunctival scarring
***Scar tissue distorts the eyelid margin, causing entropion (the eyelid turned inwards)
***Entropion causes trichiasis, where the eyelashes rub against the eye and cause scarring
***Eventually leads to blindness

==Diagnosis==

*Molecular testing
**Urine NAAT is ~80% sensitive, and is preferred when there is no other indication for a pelvic examination
**Self-collected vaginal swab likely has better sensitivity, though
**MD-collected cervical swab best sensitivity (90+%)
*Culture
**For throat specimens
**Done in cell culture
*Serology
**IgM antibodies can be helpful for diagnosting pneumonia in infants under 3 months of age
**Not helpful for diagnosing genital infections

==Management==

=== Adults ===

* Non-pregnant, non-lactating adults with urethral, endocervical, rectal, or conjunctival infection

*First-line: [[Is treated by::doxycycline]] 100 mg PO bid for 7 days
**Preferred, especially for rectal infection
*Alternative if adherence likely to be poor: [[azithromycin]] 1 g PO once
*Alternative: [[ofloxacin]] 300 mg PO bid for 7 days
*Alternative: [[erythromycin]] 2 g/day PO in divided doses for 7 days
*Alternative: [[erythromycin]] 1 g/day PO in divided doses for 14 days

=== Children ===
*Consider child abuse when chlamydia is diagnosed in a prepubertal child
**However, perinatal infection can persist for up to 3 years
*≤7 days old
**Infants ≤2 kg: [[erythromycin]] 20 mg/kg/day PO in divided doses for 14+ days
**Infants >2 kg: [[erythromycin]] 30 mg/kg/day PO in divided doses for 14+ days
*8 days to 1 month old: [[erythromycin]] 40 mg/kg/day PO in divided doses for 14+ days
*1 month to 9 years: [[azithromycin]] 12-15 mg/kg (max 1 g) PO once
**Alternative: [[erythromycin]] 40 mg/kg/day PO in divided doses (max 500 mg qid for 7 days or 250 mg qid for 14 days)
**Alternative: [[sulfamethoxazole]] 75 mg/kg/day PO in divided doses (max 1 g bid) for 10 days
*9-18 years: [[doxycycline]] 2.5 mg/kg (max 100 mg) PO bid for 7 days
**Alternative, if adherence likely to be poor: [[azithromycin]] 12-15 mg/kg (max 1 g) PO once
**Alternative: [[erythromycin]] 40 mg/kg/day PO in divided doses (max 500 mg qid for 7 days or 250 mg qid for 14 days)
**Alternative: [[sulfamethoxazole]] 75 mg/kg/day PO in divided doses (max 1 g bid) for 10 days

=== Pregnant or Nursing Women ===

* Pregnant and nursing women with urethral, endocervical, and rectal infections

*[[Azithromycin]] is generally considered safe for this purpose, while [[doxycycline]] and [[fluoroquinolones]] are contraindicated
*Options include any of:
**Alternative: [[amoxicillin]] 500 mg PO tid for 7 days
**Alternative: [[erythromycin]] 2 g/day PO in divided doses for 7 days
**Alternative: [[erythromycin]] 1 g/day PO in divided doses for 14 days
**Alternative if adherence is likely to be poor: [[azithromycin]] 1 g PO once
*Ensure that exposed neonates are tested shortly after birth and treated if positive, with monitoring for development of conjunctivitis or pneumonia

=== Lymphogranuloma Venereum ===

* [[doxycycline]] 100 mg PO bid for 21 days (see [[Lymphogranuloma venereum#Management|LGV-specific page]] for details)

=== Trachoma ===
*Usually addressed in mass drug administration projects using [[azithromycin]] or topical [[tetracycline]]
*Often needs surgery to correct trichiasis

=== Treatment Failure ===


* Reinfection (most common)
=== Fitz-Hugh-Curtis syndrome ===
* Non-adherence
* Inflammatory ?autoimmune liver capsular inflammation
* Vomiting
* True resistance, though it is rare and difficult to assess susceptibility


== Diagnosis ==
==Prevention==
* Urine NAAT ~80% sensitive
* Self-collected vaginal swab better
* MD-collected cervical swab best (90+%)
* No more serology!


== Management ==
===Trachoma===
* For serovars L1-L3 (LGV): treat for 21 days
* In pregnant women, [[Is treated by::azithromycin]] is best


*Mass drug administration using [[azithromycin]] for communities with high prevalence
*Facial cleanliness
*Improved sanitation and hygiene
{{DISPLAYTITLE:''Chlamydia trachomatis''}}
{{DISPLAYTITLE:''Chlamydia trachomatis''}}
[[Category:Bacteria]]
[[Category:Bacteria]]

Latest revision as of 01:00, 22 December 2021

Background

Microbiology

  • Small, obligate intracellular Gram-negative coccobacillus
    • Very difficult to Gram stain due to lack of peptidoglycan in cell wall
  • Two forms exist:
    • Elementary body (EB): spore-like form than can survive short times outside the body
    • Reticulate body (RB): replicative form
  • Virulence factors include lipopolysaccharide (LPS)

Risk Factors

  • Sexual contact with chlamydia-infected person
  • New sexual partner, or more than two sexual partners in the past year
  • Previous STI
  • Specific populations: people who inject drugs, incarcerated people, sex trade workers, street-living youth

Clinical Manifestations

Serovars Syndromes
A to C Trachoma (chronic conjunctivitis)
D to K Urethritis, PID, neonatal infection
L1 to L3 Lymphogranuloma venereum (LGV)

Sexually-Transmitted Infection

Lymphogranuloma Venereum

Fitz-Hugh-Curtis syndrome

  • Liver capsular inflammation, possibly autoimmune

Pediatric Infections

  • Serovars associated with STIs can also cause:
    • Conjunctivitis in neonates
    • Pneumonia in children under 6 months of age

Trachoma

  • Chronic keratoconjunctivitis caused by recurrent infection
  • Leading infectious cause of blindness worldwide
  • Spread via direct contact of ocular or nasal secretions and via fomites, and possibly via eye-seeking flies including Musca sorbens
  • Presents with two phases:
    • Active trachoma, with acute, mild, self-limited conjunctivitis
      • May be asymptomatic
      • Usually detected with screening
    • Cicatricial disease causing conjunctival scarring
      • Scar tissue distorts the eyelid margin, causing entropion (the eyelid turned inwards)
      • Entropion causes trichiasis, where the eyelashes rub against the eye and cause scarring
      • Eventually leads to blindness

Diagnosis

  • Molecular testing
    • Urine NAAT is ~80% sensitive, and is preferred when there is no other indication for a pelvic examination
    • Self-collected vaginal swab likely has better sensitivity, though
    • MD-collected cervical swab best sensitivity (90+%)
  • Culture
    • For throat specimens
    • Done in cell culture
  • Serology
    • IgM antibodies can be helpful for diagnosting pneumonia in infants under 3 months of age
    • Not helpful for diagnosing genital infections

Management

Adults

  • Non-pregnant, non-lactating adults with urethral, endocervical, rectal, or conjunctival infection
  • First-line: doxycycline 100 mg PO bid for 7 days
    • Preferred, especially for rectal infection
  • Alternative if adherence likely to be poor: azithromycin 1 g PO once
  • Alternative: ofloxacin 300 mg PO bid for 7 days
  • Alternative: erythromycin 2 g/day PO in divided doses for 7 days
  • Alternative: erythromycin 1 g/day PO in divided doses for 14 days

Children

  • Consider child abuse when chlamydia is diagnosed in a prepubertal child
    • However, perinatal infection can persist for up to 3 years
  • ≤7 days old
    • Infants ≤2 kg: erythromycin 20 mg/kg/day PO in divided doses for 14+ days
    • Infants >2 kg: erythromycin 30 mg/kg/day PO in divided doses for 14+ days
  • 8 days to 1 month old: erythromycin 40 mg/kg/day PO in divided doses for 14+ days
  • 1 month to 9 years: azithromycin 12-15 mg/kg (max 1 g) PO once
    • Alternative: erythromycin 40 mg/kg/day PO in divided doses (max 500 mg qid for 7 days or 250 mg qid for 14 days)
    • Alternative: sulfamethoxazole 75 mg/kg/day PO in divided doses (max 1 g bid) for 10 days
  • 9-18 years: doxycycline 2.5 mg/kg (max 100 mg) PO bid for 7 days
    • Alternative, if adherence likely to be poor: azithromycin 12-15 mg/kg (max 1 g) PO once
    • Alternative: erythromycin 40 mg/kg/day PO in divided doses (max 500 mg qid for 7 days or 250 mg qid for 14 days)
    • Alternative: sulfamethoxazole 75 mg/kg/day PO in divided doses (max 1 g bid) for 10 days

Pregnant or Nursing Women

  • Pregnant and nursing women with urethral, endocervical, and rectal infections
  • Azithromycin is generally considered safe for this purpose, while doxycycline and fluoroquinolones are contraindicated
  • Options include any of:
    • Alternative: amoxicillin 500 mg PO tid for 7 days
    • Alternative: erythromycin 2 g/day PO in divided doses for 7 days
    • Alternative: erythromycin 1 g/day PO in divided doses for 14 days
    • Alternative if adherence is likely to be poor: azithromycin 1 g PO once
  • Ensure that exposed neonates are tested shortly after birth and treated if positive, with monitoring for development of conjunctivitis or pneumonia

Lymphogranuloma Venereum

Trachoma

  • Usually addressed in mass drug administration projects using azithromycin or topical tetracycline
  • Often needs surgery to correct trichiasis

Treatment Failure

  • Reinfection (most common)
  • Non-adherence
  • Vomiting
  • True resistance, though it is rare and difficult to assess susceptibility

Prevention

Trachoma

  • Mass drug administration using azithromycin for communities with high prevalence
  • Facial cleanliness
  • Improved sanitation and hygiene