Discuss gonococcal urethritis, including clinical features, laboratory diagnosis, treatment, complications and prevention.

Outline:

·        Clinical features:

- men: urethritis, dysuria, purulent discharge.

- women: purulent vaginal discharge.

·        Complications: pelvic inflammatory disease in women

·        Diagnosis:

- Gram stain

- Culture on Thayer-Martin medium

- ELISA

- DNA probe assay

·        Treatment:

- ceftriaxone

- tetracycline for mixed infections with C. trachomatis.

Suggested Answer:

            Gonococci cause both localized infections, usually in the genital tract, and disseminated infections with seeding of various organs. Gonorrhea in men is characterized primarily by urethritis accompanied by dysuria and a purulent discharge. In women, infection is localized primarily in the endocervix, causing a purulent vaginal discharge and intermenstrual bleeding. The most frequent complication in women is an ascending infection of the uterine tubes, which can result in sterility or pustules. Disseminated infections commonly manifest as arthritis, tenosynovitis or pustules. It is the most common cause of septic arthritis in sexually active adults. In newborn infants, a purulent conjunctivitis is the result of gonococcal infection acquired from the mother during passage through the birth canal.

            The diagnosis of localized infections depends on Gram staining and culture of the discharge. In men, the finding of gram-negative diplococci within PMNs in a sample of urethral discharge is sufficient for diagnosis. In women, the use of the Gram stain alone can be difficult to interpret, so cultures should be done. Specimens are cultured on Thayer-Martin medium. The finding of an oxidase-positive colony composed of gram-negative diplococci is sufficient to diagnose Neisseria. Two rapid, sensitive, and specific tests are increasingly used for diagnosis, namely, the ELISA, which detects gonococcal antigens, and the DNA probe assay, which detects gonococcal ribosomal genes.

            Ceftriaxone is the treatment of choice in uncomplicated gonococcal infections. Spectinomycin or ciprofloxacin should be used if the patient is allergic to penicillin. Because mixed infections with C. trachomatis are common, tetracycline is recommended also.

            The prevention of gonorrhea involves the use of condoms and the prompt treatment of symptomatic patients and their contacts. Cases of gonorrhea must be reported to the public health department to ensure proper follow-up. Gonococcal conjunctivitis in newborns is prevented most often by the use of erythromycin ointment.

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