Risk Factors for
Sexually Transmitted Diseases
It is with our passions, as it is with fire and water,
they are good servants but bad masters.
Aesop
Throughout the world, about 25 different diseases can be passed from person to person via sexual contact; 11 are common in North America. The World Health Organization estimates that each year 500-600 million people in the world acquire a sexually transmitted disease (STD), also referred to as a sexually transmitted infection (STI). In North America, the number of annual STD infections approximates 19 million, a rate second only to the common cold. About half of these infections occur in people under age 25.
A sexually transmitted disease (STD) is an infection that is transmitted by sexual contact, usually sexual intercourse. Human STDs are caused by viruses, bacteria, protozoa, worms, and insects.
STD-causing agents can enter the body 1) through breaks in the skin, 2) through the wet surface layers, or mucous membranes, of the body's orifices: nose and mouth, penis, vagina, urethra, and anus, and 3) the blood, either by injection or during sexual activity by means of tiny microscopic abrasions on the penis, in the vagina, or mouth. Once inside the body, STD-causing agents reproduce and their population grows in numbers.
In general, STDs are not transferred by animals, air, water, or contact with doorknobs, toilet seats, and other inanimate objects. In the case of insects, however, contact with any surface on which the organisms, their larvae, or eggs might be present may cause an infection.
A certain number of STD-causing agents must be transferred in order to cause an infection. This number varies according to how well the recipient's body can defend itself and a variety of specific host-parasite factors. For chlamydia and gonorrhea, the transfer of about 1000 organisms is sufficient to cause an infection. With syphilis, the requisite number of infecting organisms is about 100. With gonorrhea and chlamydia, the risk of becoming infected with one exposure is about 60 to 90 percent in men and 20-35 percent in women.
Risk Factors for STDs
- Multiple Sexual Partners: Many individuals have several lifetime sexual partners because they become sexually active in late adolescence and may not marry until their mid-to-late 20s or 30s. About 20% of unmarried adults have more than one sex partner in a year. Also, many people in a supposedly sexually exclusive relationship have sex with other partners, generally without the "exclusive" partnerÕs knowledge. Individuals who know that their partners have sexual relations with others have lower rates of STDs than individuals who do not know that their partners have sexual relations with other people.
- False Sense of Safety: Using hormonal contraceptives may reduce the use of condoms as people equate protection from pregnancy and prevention from STDs. Also, the availability of anti-STD medications such as antibiotics create the false assumption that all STDs are curable, which facilitates STD-risky behavior.
- Absence of Signs and Symptoms: Some STDs have mild or no symptoms, so an infection can worsen and unknowingly be passed to others. Among U.S. young adults aged 18-26, nearly 5% are infected with chalmydia and do not know it because of a lack of symptoms.
- Untreated Conditions: Some individuals do not know the signs and symptoms of STDs, may not have access to medical care, or may not comply with treatment regimens. Each of these factors contributes to an infected individual remaining contagious.
- Impaired Judgment: Drug- and alcohol-impaired individuals are less likely to use condoms and may have sex with people they do not know, this putting them at risk for contracting an STD. Higher alcohol taxes and increases in the legal drinking age are associated with decreased rates of gonorrhea This indicates that alcohol consumption contributes to acquiring this infection, probably through having unprotected sex with unfamiliar partners.
- Lack of Immunity: Some STD-causing organisms can escape the body's immune defenses, causing individuals to remain infected and transmit the infection, often for life. Human Immunodeficiency Virus, which causes AIDS, and herpes viruses are examples of such infections.
- Body Piercing: Wounds from piercing give infectious organisms direct access to the bloodstream. Nipple, tongue, and lip jewelry may increase the risk of infections from oral contact. People who have had their bodies pierced should follow aftercare instructions faithfully to prevent infection. They should refrain from sexual contact in the pierced region until the hole is completely healed, which may take 3-6 months.
- Value Judgments: Negative and moralistic attitudes about STDs prevent people from getting tested, contacting partners after a positive diagnosis, and talking to new partners about previous infections.
- Denial: "It can't happen to me," "He's too nice to have an STD," and "She's too pretty to have an STD" are fictions.
