Endocervical Infections. Chlamydia. Gonorrhea

Gabbe: Obstetrics - Normal and Problem Pregnancies, 3rd ed., Copyright c 1996 Churchill Livingstone, Inc.

Endocervical Infections

Chlamydia

Epidemiology

Chlamydia trachomatis is the most common sexually transmitted pathogen in Western nations. The organism can cause localized infection of the urethra, endocervix, and rectum. It also is the most common cause of perihepatitis (Fitz-Hugh-Curtis syndrome) and an occasional cause of pneumonia. In addition, in the developing nations of the world, C. trachomatis is responsible for inclusion conjunctivitis, a leading cause of blindness. Infants delivered to infected women may develop conjunctivitis or pneumonia. The former complication occurs in up to 50 percent of infants delivered to infected mothers; the latter complication affects 3 to 18 percent of infants. [17] [18]

Diagnosis and Clinical Management

C. trachomatis may be grown in tissue culture. However, this methodology is relatively expensive and time-consuming. Fortunately, less expensive, rapid identification tests such as the monoclonal antibody test (Microtrak), enzyme-linked immunosorbent assay (ELISA, Chlamydiazyme), and DNA probe are sufficiently sensitive to justify their clinical use for identification of chlamydial infection. In high-risk populations, the sensitivity and specificity of these tests is approximately 90 and 95 percent, respectively. [17] [19]

Although tetracycline and doxycycline have the greatest activity against C. trachomatis, these drugs should not be used in pregnancy because of their harmful effects on fetal teeth. The agent of choice in pregnancy is erythromycin base 500 mg orally four times daily for 7 days. Erythromycin estolate should not be used in pregnancy because of possible hepatotoxicity. [20] For patients who cannot tolerate erythromycin, azithromycin, 1,000 mg orally in a single dose, [21] and amoxicillin, 500 mg orally three times a day for 7 days, are acceptable alternatives. [22]

In view of the fact that 5 to 10 percent of patients do not respond to the initial course of treatment, a culture for test of cure should be performed approximately 2 weeks after therapy is completed. In addition, infected patients should be screened for other sexually transmitted diseases like gonorrhea, syphilis, hepatitis B, and HIV infection. Neonates delivered to infected mothers should receive prophylaxis with tetracycline or erythromycin ophthalmic preparations and observed for evidence of an ensuing respiratory tract infection.

Gonorrhea

Epidemiology

Gonorrhea is caused by the gram-negative, intracellular diplococcus Neisseria gonorrhoeae. The infection is transmitted primarily by sexual contact. Gonorrhea also may be transmitted perinatally from mother to infant and cause serious ophthalmic injury.

In pregnant women, gonorrhea may be manifested as an asymptomatic to mildly symptomatic localized infection of the urethra, endocervix, or rectum. Local infection may increase the risk of preterm labor and preterm premature rupture of membranes and predispose to intrapartum and postpartum infection. Gonorrhea also may present as a disseminated infection. [17] The most common manifestation of disseminated gonococcal infection is arthritis, typically affecting several small- to medium-sized joints. The next most common manifestation is a diffuse violaceous, papular skin rash. Less common, but potentially more serious, sequelae of disseminated infection include meningitis, pericarditis, endocarditis, and perihepatitis (Fitz-Hugh-Curtis syndrome). [23]

Diagnosis and Management

The most reliable test for confirmation of gonococcal infection is culture of the organism on selective agar such as Thayer-Martin or VCN medium. Gram stain and nucleic acid probes are helpful when positive, but their sensitivity varies widely.

The drugs of choice for treating localized gonococcal infections in pregnancy are ceftriaxone (125 to 250 mg IM in a single dose) and cefixime (400 mg PO once). The former drug is the preferred agent for treatment of disseminated infection and should be administered in a dose of 1 g IV or IM every 24 hours until a clinical response has been achieved. [17] Tetracyclines and quinolones should not be used in pregnancy because of their injurious effects on fetal teeth and cartilage. Patients who are allergic to beta-lactam antibiotics may be treated with a single 2-g intramuscular dose of spectinomycin. [17] Treatment of the neonate with either silver nitrate or tetracycline ophthalmic preparations is effective in preventing most cases of ophthalmia neonatorum.

Patients who test positive for gonorrhea should be screened for other sexually transmitted diseases. Because of the uniformly excellent activity of ceftriaxone and cefixime against N. gonorrhoeae, tests of cure are not routinely indicated when patients are treated with these agents.