Infectious Disease Online
Pathology of Gonococcal Infections (Gonorrhea)
Gonorrhea is a sexually transmitted disease caused by various strains of the gram-negative diplococcus Neisseria gonorrhoeae.
The infection is usually localized to the urogenital tract, most commonly the urethra of men and the endocervix of women.
About one half of infected women have no symptoms.
In men, however, infection is usually symptomatic.
Gonorrhea is a serious public health problem in most parts of the world, and is epidemic in many countries. It is especially common in the tropics, where the prevalence is high in prostitutes, who transmit it to migrant male workers.
Gonococci are readily seen in smears (urethral, endocervical, or conjunctival exudates) and cultures, and appear as bean-shaped pairs, with the flat sides apposed.
The organisms are cultured from tampons, urethral swabs, urine, specimens from endocervix, vagina, anus, and pharynx.
Gonorrhea begins as a surface infection of the mucous membranes, that is, a catarrh.
The bacteria attach to and spread along the cells of the surface mucous membranes, after which they invade superficially and provoke acute inflammation.
The mucous membranes of the urethra, endocervix, and salpinx are characteristic sites.
The cell wall of Neisseria gonorrhoeae contains lipopolysaccharide, protein, and phospholipid.
It lacks a true polysaccharide capsule, but projecting from the cell wall are hairlike extensions called pili.
Within these pili is a protease that digest IgA on the surface of the mucus membrane, thus facilitating the attachment of gonococci to the columnar and transitional epithelium of the urogenital tract. "Smooth" strains with few pili are less virulent and less prone to cause urethritis or cervicitis.
After an incubation period of 3 to 5 days, men usually have purulent urethral discharge and dysuria.
With prompt antibiotic treatment the infection is arrested and gonococci are confined to the mucosa of the anterior urethra.
However, if treatment is not instituted promptly the organisms extend to the prostate, epididymis, accessory glands, where they cause urethral stricture, epididymitis, orchitis, and sometimes male infertility.
Urethral stricture may be associated with fistulas between the urethra and perineum (“watering can” perineum).
Male homosexuals develop pharyngitis and proctitis.
The first manifestation of infection in women is usually endocervicitis, with vaginal discharge or bleeding.
There may be urethritis, manifestated by dysuria rather than by urethral discharge.
In some women (usually during the first menses after exposure), the infection extends to the fallopian tubes, where it produces acute and chronic salpingitis and pelvic inflammatory disease.
The fallopian tubes swell with pus, causing acute abdominal pain.
Infertility occurs when inflammatory adhesions close the tubes at both ends, blocking the ascent of sperm and the descent of ova.
Infected fallopian tubes ('pus tubes') have the shape of a retort flask.
From the fallopian tubes the infection may spread to the peritoneum, healing as fine adhesions ("violin string" adhesions) between the capsule of the liver and the parietal peritoneum.
The vaginal discharge may infect the anal crypts, leading to mucopurulent anal discharge, rectal pruritus, and tenesmus.
Chronic endometritis is a persistent complication of gonococcal infection and is usually a consequence of chronic gonococcal salpingitis.
In such cases the endometrium contains many lymphocytes and plasma cells.
Women (and to a lesser extent men) may also develop bacteremia, producing disseminated gonococcal infection, which in turn leads to monoarthritis or polyarthritis.
Neonatal infections from infected amniotic fluid or an infected birth canal result in symptoms within a few days after birth.
These infections involve the conjunctiva and constitute a major cause of blindness in much of Africa and Asia.
Other sites of neonatal infection are the pharynx, respiratory tract, vagina, anus, leptomeninges, joints, and blood.
Uncomplicated gonococcal infections of the urethra and endocervix are treated with penicillin and other antibiotics. Neisseria gonorrhoea is displaying increasing resistance to penicillin.
Penicillinase-producing strains are especially common in Africa and Asia.
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