Formerly known as venereal diseases, sexually
transmitted diseases (abbreviated as STDs) are highly specific
infections almost
always acquired during sexual contact. Bacteria, protozoans, or fungi that cause STDs generally attack only certain portions of the body, including the genital tract. They do not survive for long periods outside the human host, and transmission by such objects as clothing or toilet seats is extremely rare. The effects of STDs range from mild, annoying symptoms to life-threatening illnesses that spread from the reproductive tract to the entire body. The most serious diseases are AIDS, syphilis, and gonorrhea. Chlamydia, the most common STD in the United States today, is not life-threatening but can have serious effects and is a leading cause of sterility. Lesser
infections include herpes, chancroid, genital warts, cold sores (see canker), and vaginitis. None of these diseases is acquired exclusively through sexual contact, but the sexual partners of a person with an STD are likely to be infected as well and should be examined and tested for the disease.
Common Syndromes
People with a sexually
transmitted disease may have no symptoms or symptoms that are so mild that they do not prompt the person to seek medical attention. For example, almost half of the women with gonorrhea have no significant symptoms, and up to 3 percent of men will feel perfectly well. Some STDs have overlapping symptoms. Swelling of the lymph nodes in the groin may accompany many sexually transmitted infections and may be tender (herpes, chancroid) or painless (syphilis). Such swelling may be the only manifestation of a relatively rare STD called lymphogranuloma venereum. Unusual or increased discharge from the penis or vagina can be a symptom of a number of STDs, including gonorrhea, chlamydia, andÑin womenÑvaginitis, which encompasses three different infections: bacterial, yeast, and trichomoniasis, which is caused by a protozoan.
Some STDs can cause skin lesions in the genital area. One of the first symptoms of syphilis is the chancre, a relatively painless ulcer found at the site of infection, which is usually, but not always, the genital area. Herpes causes sores in the genital area that are very similar to cold sores. Genital warts, caused by the human papilloma virus, resemble warts on other parts of the body and can be found both internally and externally in the genital region. Women who have had genital warts are at greater risk for cervical cancer.
Large, painful genital ulcers are symptomatic of the bacterial infection chancroid, common in Southeast Asia but rare in the United States. Small bumps around the genitals may be molluscum contagiosum, a viral disease spread by contact; this infection is also acquired nonvenereally by young children. Itchy, crusted scabies lesions result from infestation with the mite Sarcoptes scabiei, which burrows into the superficial layers of the skin. Itching in the pubic-hair region may result from infestation with Phthirus pubis, the crab louse, which is spread by close contact.
There are some sexually transmitted diseases that do not necessarily cause symptoms in the genital area. For example, some forms of infectious hepatitis can be acquired by sexual contact, and gastrointestinal infections such as shigellosis and amebiasis have also been sexually transmitted. AIDS is considered an STD because it is transmitted by the exchange of bodily fluids, which occurs during sexual intercourse.
Prevention
Any sexually active person runs the risk of acquiring an STD, and the risk increases with the number of sexual partners. A person having sex with a single individual but whose partner has multiple contacts is at high risk for acquiring a sexually transmitted infection. Because STDs may be present without any symptoms, asking partners about symptoms does not assure good health.
Mutual fidelity between sexual partners will keep the pair free of sexually transmitted infections; noother method provides complete protection against sexually transmitted diseases. If a person has multiple sexual partners, safe sex, in which no bodily fluids are exchanged, can prevent the transmitting of AIDS as well as other STDs. The condom is partially effective if it is worn during all genital contact, but some of the genital area is still left uncovered. Washing the genitals or urinating immediately after intercourse also offers incomplete protection. Individuals with multiple sexual partners should probably be examined for STDs at regular intervals.
Diagnosis and Treatment
Accurate diagnosis of STDs can be made by a physician by taking a complete history of sexual practices and genital symptoms, carefully examining the entire genital area, and taking samples of discharge for microscopic examination and culture. There are blood tests or cultures for all STDs and cures or treatments for most STDs. If a person is diagnosed as having an STD, all sexual partners should be examined and treated if necessary.