Gonorrhea is a common sexually transmitted disease. The responsible organism, Neisseria gonorrhoeae, can survive only in a moist environment approximating body temperature and is transmitted only by sexual contact (genital, genital-oral, or genital-rectal) with an infected person. Purulent burning urethritis in males and asymptomatic endocervicitis in females are the most common forms of the disease, but gonorrhea is also found at other sites. All forms of the disease have the potential for evolving into a bacteremic phase, producing the arthritis-dermatitis syndrome. From an epidemiologic point of view the disease is becoming more difficult to control because of the increasing number of asymptomatic male carriers. All forms of the disease previously responded to penicillin, but resistant strains have emerged.
N. gonorrhoeae is a gram-negative coccus that is found in pairs (diplococci) within polymorphonuclear leukocytes in purulent material. The bacterium is an obligate aerobe that grows best at 35° to 37° C, in an atmosphere of 3% to 5% CO2. A modified Thayer-Martin medium (chocolate agar) incubated in a candle jar to elevate CO2 levels provides optimum conditions for isolation.
The organism can survive only in blood and on mucosal surfaces including the urethra, endocervix, rectum, pharynx, conjunctiva, and prepubertal vaginal tract. It does not survive on the stratified epithelium of the skin and postpubertal vaginal tract.
A slightly alkaline medium is required, such as that found in the endocervix and in the vagina during the immediate premenstrual and menstrual phases. The antibodies produced during the disease offer little protection from future attacks. A fluorescent antibody test identifies the organism in tissue specimens such as in the skin in disseminated gonococcal infection (bacteremia-arthritis syndrome).
GENITAL INFECTION IN MALES
The risk of infection for a man after a single exposure to an infected woman is estimated to be 20% to 35%. After a 3- to 5-day incubation period, most infected men have a sudden onset of burning, frequent urination, and a yellow, thick, purulent urethral discharge. In some men symptoms do not develop for 5 to 14 days. They then complain only of mild dysuria with a mucoid urethral discharge as observed in nongonococcal urethritis. Five to fifty percent of men who are infected never have symptoms and become chronic carriers for months, acting, as do women without symptoms, as major contributors to the ongoing gonorrhea epidemic. Infection may spread to the prostate, seminal vesicles, and epididymis, but presently these complications are uncommon because most men with symptoms are treated.
The diagnosis can be confirmed without culture in men with a typical history of acute urethritis by finding in urethral exudate gram-negative intracellular diplococci within polymorphonuclear leukocytes. Urethral culture is indicated when the result of Gram stain is negative, in tests of cure, or as a test for asymptomatic urethral infection. Material for culture is obtained by inserting a bacteriologic wire loop or a sterile narrow synthetic swab approximately 2 cm into the anterior urethra. No attempt should be made to insert the larger cotton-tipped swabs contained in standard culture kits.
GENITAL INFECTION IN FEMALES
The risk of infection for a woman after a single exposure to an infected man is estimated to be 60% to 90%. Female genital gonorrhea has traditionally been described as an asymptomatic disease, but symptoms of urethritis and endocervicitis may be elicited from 40% to 60% of the women. Urethritis begins with frequency and dysuria after a 3- to 5-day incubation period. These symptoms are of variable intensity. Pus may be seen exuding from the red external urinary meatus or after the urethra is "milked" with a finger in the vagina.
Endocervical infection may appear as a nonspecific, pale-yellow vaginal discharge, but in many cases this is not detected or is accepted as being a normal variation. The cervix may appear normal, or it may show marked inflammatory changes with cervical erosions and pus exuding from the os. Skenes glands, which lie on either side of the urinary meatus, exude pus if infected.
The Bartholin ducts, which open on the inner surfaces of the labia minora at the junction of their middle and posterior thirds near the vaginal opening, may, if infected, show a drop of pus at the gland orifice. After occlusion of the infected duct, the patient complains of swelling and discomfort while walking or sitting. A swollen, painful Bartholin gland may be palpated as a swollen mass deep in the posterior half of the labia majora.
The diagnosis of acute urethritis can be made with a high degree of certainty if gram-negative intracellular diplococci are found in the purulent exudate from the urethra. Fifty percent of the cases of endocervical gonorrhea can be diagnosed by a carefully interpreted gram-stained smear of the endocervical canal. Neisseria species (e.g., N. catarrhalis and N. sicca) inhabit the female genital tract; thus the diagnosis is considered only if gram-negative diplococci are present inside polymorphonuclear leukocytes.
Culture is the most reliable technique for establishing the presence of endocervical infection. However, the diagnosis will be missed in 10% of cases if reliance is exclusively on culture. An endocervical culture is taken by initially localizing the cervix with a water-moistened, nonlubricated speculum. Excess cervical mucus is most easily removed with a cotton ball held in a ring forceps. A sterile cotton-tipped swab is inserted into the endocervical canal, moved from side to side, and allowed to remain in place for 10 to 30 seconds before it is inoculated onto appropriate media. A culture of the anal canal need be performed only if there are anal symptoms, a history of rectal sexual exposure, or follow-up of treated gonorrhea in women.
DISSEMINATED GONOCOCCAL INFECTION (ARTHRITIS-DERMATITIS SYNDROME)
Disseminated gonococcal infection (DGI) develops in approximately 1% to 3% of patients with mucosal infections. It is the most common form of infectious arthritis. The rate of dissemination may be higher in patients with asymptomatic infection, presumably because of the long period in which the organism can enter the vasculature. Menses exposes the submucosal blood vessels and increases the risk of dissemination. The risk of systemic infection increases during the second and third trimesters of pregnancy. In one study, 71% of women with disseminated infection were diagnosed with the syndrome during pregnancy, during the postpartum period, or within 1 week of the onset of menses. Strains of Neisseria gonorrhoeae that disseminate and cause arthritis seem to belong to a subgroup with a unique membrane protein and to have a transparent appearance of the colonies on culture more frequently than strains that do not disseminate.
There is no evidence that dissemination is more likely from the pharynx. Dissemination was formerly much more common in women, but presently men and women in some areas are equally affected.
Initial presentation. Migratory polyarthralgias are the most common presenting symptoms, occurring in up to 80% of patients. Initial signs are tenosynovitis (67%), dermatitis (67%), and fever (63%). Less than 30% have symptoms or signs of localized gonorrhea, such as urethritis or pharyngitis; however, cervical cultures in women with DGI are positive in 80% to 90% of cases and mens urethral cultures are positive in 50% to 75% of cases.
Descriptions of the evolution of DGI vary. Some believe that there are two presentations: a bacteremic phase with positive blood cultures and dermatitis, followed by a joint-localization phase with monoarthritis and positive joint fluid but negative blood cultures. Others find that too much overlap occurs.
Two presentations. Patients usually exhibit one of two syndromes. The different presentations may result from a difference in gonococcal strains.
Polyarthralgias, tenosynovitis, dermatitis. Chills (25%) and fever (more than 50%) are accompanied by pain, redness, and swelling of three to six small joints without effusion. This polyarthritis and tenosynovitis occur in the hands and wrists, with pain in the tendons of the wrist and fingers. Toes and ankles may also be affected. These patients are more likely to have positive blood and negative joint cultures. Chills and fever terminate as the rash appears on the extensor surfaces of the hands and dorsal surfaces of the ankles and toes. The total number of lesions is usually less than 10. The skin lesions begin as tiny, red papules or petechiae that either disappear or evolve through vesicular and pustular stages, developing a grey necrotic and then hemorrhagic center (Figure 10-1, B). The central hemorrhagic area is the embolic focus of the gonococcus. These lesions heal in a few weeks.
Purulent arthritis. Usually one or two large joints are affected, most frequently the knee followed by the ankle, wrist, and elbow. The affected joint is hot, painful, and swollen, and movement is restricted.18 Permanent joint changes may occur. The mean leukocyte count in synovial fluid is often more than 50,000 cells/mm3. The joints are often sterile, possibly as a result of immunologic mechanisms. Dermatitis is usually absent.
Other less common complications of dissemination include endocarditis, myocarditis, and meningitis.
Gram stain of the skin lesions is performed on the pus obtained by unroofing the pustule. Blood culture results are usually positive only during the first few days and the rate of isolation is low. Mucosal surface cultures of the urethra, endocervix, pharynx, and anus should be done. Gram-stained smears on concentrated sediment of centrifuged synovial fluid show positive results in less than 25%. The diagnosis of septic arthritis is supported by finding an elevated leukocyte count, poor mucin clot, and elevated protein in the aspirated joint fluid. Fewer than 50% of joint culture results are positive for N. gonorrhoeae. Fluorescent antibody testing (not available in every laboratory) may be performed on joint exudate and on smears from skin lesions if the diagnosis is suspected, but identification has not been made by other means.
Differential diagnosis. Disseminated gonococcal infection is the most common cause of acute arthritis among sexually active young adults. Other infectious diseases mimic DGI. Hepatitis may present with tenosynovitis, polyarthralgia, and dermatitis. Bacterial endocarditis may be associated with sterile joint effusions and tenosynovitis; skin lesions are embolic. Systemic meningococcal infection is increasing in frequency in this group and can be accompanied by similar findings of joint and skin disease. Patients with meningococcal infection have more skin lesions, high peripheral white blood cell counts, and sterile genital cultures.19 Reiters syndrome (urethritis, arthritis, conjunctivitis, and keratoderma blennorrhagica, a psoriasis-like eruption) may be confused with DGI. The arthritis of Reiters syndrome, however, may be chronic and recurrent and does not respond to antibiotic therapy.