LC. Sexually Transmitted Diseases. In: DiPiro, JT, Talbert RL, Yee
GC, Matzke GR, Wells BG, Posey LM. Pharmacotherapy: A Pathophysiologic
Approach. 8th edition. http://www.accesspharmacy.com/content.aspx?aid=8004605.
Accessed July 16, 2012.
- Sexually transmitted infection (STI)
- C. trachomatis is an obligate
intracellular parasite with some similarities to viruses and bacteria.
- Requires cellular material from host cells for replication.
- Maintains cellular identity throughout development.
- Frequent coinfection with gonorrhea.
- Most common STI in the United States
- Mutually monogamous sexual relationship between uninfected
- Barrier contraceptive methods
- Patients who seek STI testing should be screened
for syphilis and HIV.
- Annual screening recommended by CDC for sexually active females:
- 25 years of age or younger
- With new sex partners or multiple sex partners
- Unprotected sex
- Number of sexual partners
- Sexual preference
- Age: Two-thirds of STIs occur in persons in their teens and
- Chlamydial genital infections more frequently asymptomatic,
and when present, symptoms tend to be less noticeable (Table 1).
- Nearly two-thirds of infants acquire chlamydial infection
after endocervical exposure, with primary morbidity associated with
seeding of infant’s eyes, nasopharynx, rectum, or vagina.
Table 1. Presentation
of Chlamydia Infections |Favorite Table|Download (.pdf)
Table 1. Presentation
of Chlamydia Infections
Incubation period—35 days
Incubation period—7–35 days
Symptom onset—7–21 days
Usual symptom onset—7–21 days
Site of infection
Most common—endocervical canal
Others—rectum (receptive anal intercourse), oropharynx,
Others—urethra, rectum (usually due to perineal
contamination), oropharynx, eye
>50% of urethral and rectal infections asymptomatic
>66% of cervical infections asymptomatic
Urethral infection—mild dysuria, discharge
Urethral infection—usually subclinical; dysuria
and frequency uncommon
Pharyngeal infection—asymptomatic to mild pharyngitis
Rectal and pharyngeal infection—symptoms same
as for men
Scant to profuse, mucoid to purulent urethral or rectal
Abnormal vaginal discharge or uterine bleeding;
purulent urethral or rectal discharge can be scant to profuse
Rectal infection—pain, discharge, bleeding
Epididymitis, Reiter’s syndrome (rare)
Pelvic inflammatory disease and associated complications (i.e.,
ectopic pregnancy, infertility)
Reiter’s syndrome (rare)
Means of Confirmation
- Cell culture is reference standard but 3- to 7-day delay
in results has led to use of tests that rapidly detect chlamydial
antigens and nucleic acid.
- Culture of endocervical or urethral epithelial cell scrapings
- Most specific method (close to 100%)
- Sensitivity is as low as 70%.
- Results available in 3–7 days.
- Non-culture tests:
- Enzyme immunosorbent assay
(EIA), DNA hybridization, nucleic acid amplification tests (NAATs)
- Allow rapid identification of chlamydial antigens and
- Technically less demanding
- Less costly, and in some situations have greater sensitivity ...