Chlamydia Trachomatis

James W. Myers

Lamis Ibrahim

INTRODUCTION

Most frequently reported infectious disease.
Causes multiple complications, especially in females.
- PID
- Ectopic pregnancy and infertility, and infant pneumonia.
- Facilitates HIV transmission.

MICROBIOLOGY

They are similar in many ways to gram-negative bacteria (contain LPS) but they are obligate intracellular parasites.
Need tissue culture to grow in the laboratory.
Grow within a specialized vacuole in eukaryotic cells known as an “inclusion.”
Exist in two forms: an infectious form, elementary body [EB], and an intracellular noninfectious form, the reticulate body (RB) that multiplies by binary fission.
No long-lived immunity following infection.
Serovars D-K cause genital tract chlamydia.
Serovars L1-L3 cause lymphogranuloma venereum (LGV).

EPIDEMIOLOGY

CDC estimated approximately 4 million new C. trachomatis infections per year in the United States.
- Increased prevalence in women.
- Incidence of approximately 15% of sexually active young women.
Risk Factors:
- Adolescents and young adults
- Unmarried
- African Americans
- Those with multiple sex partners or a recent new sex partner
- Inconsistent use of barrier contraceptives
- Evidence of mucopurulent cervicitis or cervical ectopy
- History of previous STD
- Lower socioeconomic status or a lower level of education.
Up to 70% of females and 40% of men are asymptomatic.

CLINICAL MANIFESTATIONS

1. Genital infections in males:

Urethritis:
- C. trachomatis causes 30% to 50% of cases of symptomatic nongonococcal urethritis (NGU), and it is more common than gonococcal urethritis.
  - Risk factors: young age <20 years, African American, and heterosexual orientation.
  - Incubation period is usually 7 to 14 days. Often coinfected with gonorrhea, which has a shorter incubation period. Treatment for GC alone will miss the postgonococcal urethritis caused by chlamydia.
  - Dysuria
  - Mucoid or watery urethral discharge, worse in the am.
  - Gram stain of a urethral swab specimen shows five or more PMNs in case of urethritis.
  - Ten or more white blood cells per high-power field in a first-catch urine specimen or positive urine leukocyte esterase test are also suggestive of urethritis.
Epididymitis/Prostatitis
- C. trachomatis and Neisseria gonorrhoeae are the most common causes of epididymitis in men younger than 35 years, with gonorrhea being more common.
- Fever
- In young men, an associated urethritis is usually present, but they can be asymptomatic.
Usually unilateral swelling and pain.

2. Genital infection in females:

Cervicitis and Urethritis
- Seventy percent of women are asymptomatic.
- Symptoms include vaginal discharge, bleeding, postcoital bleeding, mild abdominal pain, or dysuria.
- Dysuria usually secondary to associated urethritis.
- Cervix may appear erythematous, friable, and swollen with a mucopurulent discharge but can be normal in appearance.
- Cervical ectopy
- Cofactor in cervical neoplasia?
Endometritis and Salpingitis/PID
- Twenty percent incidence of PID.
  - Asymptomatic to severe in symptoms.
  - Fever
  - Abdominal pain, cervical motion tenderness.
  - Uterine and adnexal tenderness.
Chlamydia and Pregnancy:
- Chlamydia is associated with increased risk of miscarriage, premature rupture of membranes, preterm labor, low birth weight, and infant mortality.
- Without treatment, up to 50% of infants will develop conjunctivitis and up to 20% may develop pneumonia.
- Long-term complications of PID include tubal infertility, ectopic pregnancy, and chronic pelvic pain syndrome. Treatment improves outcomes.
Perihepatitis (Fitzhugh-Curtis syndrome):
- Complicates approximately 15% of PID cases.
- Normal LFTs.
- Acute onset
- Right upper-quadrant pain and tenderness aggravated by breathing, coughing, or movement, and may be referred to the right shoulder as well.
- “Violin string” adhesions.
- Treatment: NSAIDS/Supportive

3. Infections in both males and females

Proctitis and Proctocolitis:
- Gay males predominate.
- Females can also acquire this by either anal intercourse or from the cervicovaginal route.
- Mucopurulent rectal discharge. Leukocytes on Gram stain.
- Pruritus, pain.
- Note that LGV strains may cause proctocolitis as well as proctitis. More severe in MSM who are HIV positive.
Sexually Reactive Arthritis
- One percent of NGU patients develop an acute aseptic arthritis syndrome referred to as sexually reactive arthritis, formerly known as Reiter syndrome.
- One-third of these patients have the complete manifestations (arthritis, uveitis, and urethritis) of this syndrome.
Conjunctivitis:
- Characteristically, this is a unilateral, acute inclusion conjunctivitis resulting from autoinoculation with infected genital secretions.
- No permanent scarring.