Microbiology

The reproductive systems of males and females open to the external environment, and therefore, the organs can be easily reached by infectious organisms. The diseases may then spread to deeper organs of the human body.

Gonorrhea. At this writing, gonorrhea is the most‐reported infectious disease in the United States. The etiologic agent is the Gram‐negative diplococcus Neisseria gonorrhoeae. The organism attaches to the epithelial cells of the male and female urethra causing urethritis. Transmission occurs during sexual contact, and males exhibit more extensive symptoms than do females, with pain on urination and a whitish discharge from the urethra. Treatment with tetracycline, penicillin, and other antibiotics is usually successful.

Complications of gonorrhea may involve many organs. For example, in females, the Fallopian tubes may be blocked with scar tissue, thereby preventing passage of the egg cells and resulting in sterility. A similar complication may occur when the epididymis and vas deferens are blocked in males. Many females suffer pelvic inflammatory disease (PID), an inflammation of organs of the pelvic cavity such as the uterus, cervix, and ovaries. Infection may also occur in the rectum, pharynx, meninges, and joints. Newborns subjected to N. gonorrhoeae during passage through the birth canal may suffer eye infection called gonococcal ophthalmia. Treatment with silver nitrate and/or erythromycin shortly after birth prevents infection.

Chlamydia. A gonorrhealike infection called chlamydia is caused by Chlamydia trachomatis, a member of the chlamydia group of bacteria. The disease is often referred to as nongonococcal urethritis to distinguish it from gonorrhea. It is accompanied by pain during urination, a frequent desire to urinate, and a watery discharge. Several million people are believed to suffer from it annually. Tetracycline is used in therapy. Pelvic inflammatory disease may complicate the condition. Sterility is also a long‐term complication. Chlamydial ophthalmia may occur in the eyes of newborns.

Mycoplasmal and ureaplasmal urethritis. Mycoplasmal urethritis is caused by a mycoplasma known as Mycoplasma hominis, while ureaplasmal urethritis is due to a mycoplasma known as Ureaplasma urealyticum. Both organisms cause infection of the urethra, with symptoms similar to those of gonorrhea and chlamydia. Tetracycline is used to treat both conditions, and PID may complicate the condition.

Syphilis. Syphilis has been known to exist for many centuries and was once known as the Great Pox. It is caused by the spirochete Treponema pallidum. Transmitted by sexual contact, the etiologic agent causes a disease occurring in three stages. The primary stage is accompanied by the chancre, a raised, hard, dry, crusty sore occurring at the site of infection. Spirochetes observed from the chancre constitute diagnosis. Penicillin therapy at this stage is successful.

The secondary stage of syphilis occurs several weeks after the chancre disappears. This stage is accompanied by an influenza‐like syndrome of the respiratory system, a skin rash over the body surface with spirochete‐laden lesions (pox), loss of hair, and mild fever. Treatment continues to be successful at this stage. A latent period follows, and in a small percentage of cases, the disease recurs in the tertiary stage. This stage is probably an immunological reaction. It is characterized by gummy, rubbery masses of damaged tissues called gummas occurring in the nervous and cardiovascular systems. In the most severe cases, aneurysms and paralysis may develop and mental deficiencies may become severe. Treatment at this stage is not always successful.

Congenital syphilis may occur if spirochetes pass between a pregnant woman and her fetus. Numerous diagnostic tests exist for the detection of both spirochetes and antibodies produced against the spirochetes.

Chancroid. Infection of the reproductive tract may be due to Haemophilus ducreyi. This small, Gram‐negative rod causes an STD called chancroid. The disease is characterized by a swollen, painful ulcer on the genital organs, with infection of the lymph nodes called buboes. It is referred to as soft chancre and is treated with tetracycline. Sexual contact is the mode of transmission.

Vaginitis. Another disease of bacterial origin is vaginitis due to Gardnerella vaginalis. The bacterium is a Gram‐negative rod commonly found in the vagina as an opportunistic organism. Often the infection is associated with the destruction of lactobacilli normally found in the vaginal tract (such as by excessive antibiotic use). The drug metronidazole is used in therapy.

Lymphogranuloma venereum. Lymphogranuloma venereum is caused by a strain of Chlamydia trachomatis the organism that also causes chlamydia. The disease is characterized by lesions at the infection site followed by swollen lymph nodes. Transmission occurs during sexual contact. Tetracycline is used for therapy.