Chlamydia is caused by Chlamydia trachomatis, an obligate intracellular parasite with 15 different serotypes.
- The chlamydial organism has two forms.
Elementary body (infectious): serotypes
LI, L2, L3: lymphogranuloma venereum
A, B, Ba, C: endemic blinding trachoma
D, E, F, G, H, I, J, K: oculogenital and STD strains
Reticulate body (multiplies to form inclusions) Epidemiology (Box 10-1).
Emerging as most common STD
Four million cases per year
Prevalence three to four times more than GC
Overall prevalence 3% to 5% (low risk), but greater than 20% of cases in STD clinics
Transmission exclusively by sexual contact or perinatal contact
Incubation period 6 to 14 days Risk factors for acquiring C. trachomatis.
Unmarried and sexually active
Multiple sexual partners
Use of oral contraceptives
Use of intrauterine device (IUD)
History of previous sexually transmitted disease
Known exposure with partner having an STD
Presence of concomitant STD especially N. gonorrhoeae
- Spotting after intercourse
- Intermenstrual spotting
- Vague complaints of lower abdominal pain
|CDC Screening Criteria for Chlamydia|
| Mucopurulent cervicitis
Sexually active fewer than 20 years
20 to 24 years age (one criterion)
Greater than 24 years age (both criteria)
Inconsistent barrier contraception
New partner or more than 1 partner in last 3 months
CDC, Centers for Disease Control and Prevention.