Chlamydia clinical presentation and diagnosis - Sexually Transmitted Diseases

Infections caused by C. trachomatis are believed to be the most common STD in the United States that has more than doubled in the past 10 years.

Clinical presentation

In comparison with gonorrhea, chlamydial genital infections are more frequently asymptomatic, and when present, symptoms tend to be less noticeable. Table Presentation of Chlamydia Infections summarizes the usual clinical presentation of chlamydial infections.
Similar to gonorrhea, chlamydia may be transmitted to an infant during contact with infected cervicovaginal secretions. Nearly two thirds of infants acquire chlamydial infection after endocervical exposure, with the primary morbidity associated with seeding of the infant’s eyes, nasopharynx, rectum, or vagina.

Diagnosis

Culture of endocervical or urethral epithelial cell scrapings is the most specific method for detection of chlamydia, but sensitivity is as low as 70%. Between 3 and 7 days are required for results.
Tests that allow rapid identification of chlamydial antigens in genital secretions are the direct fluorescent antibody test, the enzyme immunoassay (requires just 30 minutes for results), and the DNA hybridization probe.

TABLE. Drug Therapy and Follow-up of Syphilis

Stage/Type of Syphilis	Recommended Regimens^a	Follow-up Serology
Primary, secondary, or latent syphilis of less than 1-yr duration (early latent syphilis)	Benzathine penicillin G 2.4 million units intramuscularly in a single dose^b	Quantitative nontreponemal tests at 6 and 12 months for primary and secondary syphilis; at 6, 12, and 24 months for early latent syphilis^c
Latent syphilis of more than 1-yr duration (late latent syphilis) or syphilis of unknown duration	Benzathine penicillin G 2.4 million units intramuscularly once a week for 3 successive weeks (7.2 million units total)	Quantitative nontreponemal tests at 6, 12, and 24 months^d
Neurosyphilis	Aqueous crystalline penicillin G 18-24 million units intravenous (3-4 million units every 4 h or by continuous infusion) for 10-14 days^e or	CSF^f examination every 6 months until the cell count is normal; if it has not decreased at 6 months or is not normal by 2 yr, retreatment should be considered
	Aqueous procaine penicillin G 2.4 million units intramuscularly daily plus probenecid 500 mg orally four times daily, both for 10-14 days^e
Congenital syphilis	Aqueous crystalline penicillin G 50,000 units/kg intravenous every 12 h during the first 7 days of life and every 8 h thereafter for a total of 10 days or	Quantitative nontreponemal tests every 2-3 months until nonreactive or titers have decreased 4-fold
	Procaine penicillin G 50,000 units/kg intramuscularly daily for 10 days
Penicillin-allergic patients^g
Primary, secondary, or early latent syphilis	Doxycycline 100 mg orally 2 times daily for 2 wk^h^,i or	Same as for non-penicillin-allergic patients
	Tetracycline 500 mg orally 4 times daily for 2 wk^h^,i
Latent syphilis of more than 1 year’s duration (late latent syphilis) or syphilis of unknown duration	Doxycycline 100 mg orally 2 times a day for 4 wkⁱ or	Same as for non-penicillin-allergic patients
	Tatracycline 500 mg orally 4 times daily for 4 wkⁱ
^aRecommendations are those of the Centers for Disease Control. ^bSome experts recommend multiple doses of benzathine penicillin G or other supplemental antibiotics in addition to benzathine penicillin G in HIV-infected patients with primary or secondary syphilis; HIV-infected patients with early latent syphilis should be treated with the recommended regimen for latent syphilis of more than 1-yr duration. ^cMore frequent follow-up (i.e., 3, 6, 9, 12, and 24 months) recommended for HIV-infected patients. ^dMore frequent follow-up (i.e., 6, 12, 18, and 24 months) recommended for HIV-infected patients. ^eSome experts administer benzathine penicillin G 2.4 million units intramuscularly once per week for up to 3 weeks after completion of the neurosyphilis regimens to provide a total duration of therapy comparable to that used for late syphilis in the absence of neurosyphilis. ^fCSF, cerebrospinal fluid. ^gFor nonpregnant patients; pregnant patients should be treated with penicillin after desensitization. ^hAlthough less effective than either the doxycycline or tetracycline regimen, erythromycin 500 mg orally 4 times daily can be considered as an alternative regimen for nonpregnant patients. ⁱPregnant patients allergic to penicillin should be desensitized and treated with penicillin.

TABLE. Presentation of Chlamydia Infections

	Males	Females
General	Incubation period – 35 days	Incubation period – 7-35 days
General	Symptom onset – 7-21 days	Usual symptom onset – 7-21 days
Site of infection	Most common – urethra	Most common – endocervical canal
Site of infection	Others – rectum (receptive anal intercourse), oropharynx, eye	Others – urethra, rectum (usually due to perineal contamination), oropharynx, eye
Symptoms	Over 50% of urethral and rectal infections are asymptomatic	Over 66% of cervical infections are 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
Signs	Scant to profuse, mucoid to purulent urethral or rectal discharge	Abnormal vaginal discharge or uterine bleeding, purulent urethral, or rectal discharge can be scant to profuse
Signs	Rectal infection – pain, discharge, bleeding
Complications	Epididymitis, Reiter’s syndrome (rare)	Pelvic inflammatory disease and associated complications (i.e., ectopic pregnancy, infertility)
Complications	Epididymitis, Reiter’s syndrome (rare)	Reiter’s syndrome (rare)

Treatment

Single-dose azithromycin and 7-day doxycycline are the agents of choice.
For prophylaxis of ophthalmia neonatorum, various groups have proposed the use of erythromycin (0.5%) or tetracycline (1%) ophthalmic ointment in lieu of silver nitrate. Although silver nitrate and antibiotic ointments are effective against gonococcal ophthalmia neonatorum, silver nitrate is not effective for chlamydial disease and may cause a chemical conjunctivitis.

TABLE. Treatment of Chlamydial Infections

Infection	Recommended Regimens^a	Alternative Regimen
Uncomplicated urethral, endocervical, or rectal infection in adults	Azithromycin 1 g orally once, or doxycycline 100 mg orally 2 times daily for 7 days	Ofloxacin 300 mg orally 2 times daily for 7 days, or levofloxacin 500 mg orally once daily for 7 days, or erythromycin base 500 mg orally 4 times daily for 7 days, or erythromycin ethyl succinate 800 mg orally 4 times daily for 7 days
Urogenital infections during pregnancy	Erythromycin base 500 mg orally 4 times daily for 7 days, or amoxicillin 500 mg orally 3 times daily for 7 days	Erythromycin base 250 mg orally 4 times daily for 14 days, or erythromycin ethyl succinate 800 mg orally 4 times daily for 7 days (or 400 mg orally 4 times daily for 14 days), or azithromycin 1 g orally as a single dose^b
Conjunctivitis of the newborn or pneumonia in infants	Erythromycin base 50 mg/kg/day orally in 4 divided doses for 14 days^c
^aRecommendations are those of the Centers for Disease Control. ^bData are insufficient to recommend routine use of azithromycin in pregnant women at this time. ^cTopical therapy alone is inadequate and is unnecessary when systemic therapy is administered.

The only acceptable treatment for chlamydial ophthalmia neonatorum is systemic therapy with oral erythromycin, 50 mg/kg/day in four divided doses, for 10 to 14 days.

Evaluation of therapeutic outcomes

Treatment of chlamydial infections with the recommended regimens is highly effective; therefore, posttreatment cultures are not routinely recommended.
Infants with pneumonitis should receive follow-up testing, because erythromycin is only 80% effective.