Sexually transmitted diseases (STDs) have always been widespread, but the incidence today is rapidly increasing, especially among teenagers.

We live in a society where sex is used to sell anything from cars to perfume. Television, music and the personal lives of famous people tell us it's okay to have sex, but we are offered information about abstinence, protection against pregnancy and the hazards of STDs.

Many parents feel uncomfortable discussing such subjects with their children or lack the sexual knowledge to teach them. Even parents who have a wonderful relationship with their children may find it difficult to communicate effectively on the topic of sexuality.

Sex education in American schools is inadequate. The program "Sex Respect," used in public schools, asserts that abstinence is the only answer. It fails to address issues such as puberty, human development, conception, prenatal care, pregnancy or homosexuality.

It dismisses contraception as something that doesn't work. Sweden and the Netherlands, on the other hand, teach sex education and responsibilities to children beginning in the fifth grade. These countries have half the pregnancy and abortion rates of the United States.

The value of abstinence and responsibility should be taught to children of all ages, as well as adults. Knowledge of STDs and how they can be prevented is vital information for everyone today.

STDs are carried by certain viruses and bacteria, and are spread when a person comes in contact with the semen, vaginal discharge or blood of an infected person. (Viruses and bacteria are microorganisms that can cause infection diseases.

Infections caused by viruses do not respond to antibiotics, whereas those caused by bacteria generally do.) Kissing or touching an infected area also spreads the disease.

A pregnant woman can transmit an STD to her unborn child. In addition to the pain and discomfort of many of their symptoms, STDs can result in mental and physical illness, as well as sterility and cancer. Some may even cause death.

Many women, even though they know they should protect themselves and insist on condoms during intercourse, do not do so. Many men refuse to use condoms because they alter sensation and satisfaction. And the woman in a relationship of control or abuse may agree to have unprotected sex for fear that she will lose her man.

The most common STDs in the United States are chlamydia, herpes, gonorrhea, syphilis, genital warts, trichomoniasis, hepatitis B, and HIV or AIDS. HIV (human immunodeficiency virus) is the virus responsible for AIDS (Acquired Immunodeficiency Syndrome).

Several other diseases are less common. Granuloma inguinale and chancroid are characterized by painful genital ulcers and the formation of pus in the lymph nodes of the groin. Lymphogranuloma venereum, caused by a member of the chlamydia group of organisms, creates a sore, inflammation and pus in the lymph system.

Two insect-caused skin diseases can also be transmitted sexually -- scabies (caused by mites) and pediculosis pubis (caused by lice).

Most of these diseases can be prevented by changing lifestyles, principally through abstinence or a monogamous relationship, and avoiding sexual contact with people who have genital sores or high-risk lifestyles.

Chlamydia
This disease is caused by a bacteria transmitted by an infected person during sexual intercourse. Men experience a painful discharge from the penis, burning upon urination, and sometimes burning and itching at the tip of the penis. Unfortunately, up to 20% of males with the disease show no symptoms. Chlamydia can be treated with oral antibiotics. Without treatment, men may develop a secondary infection in the testes, leading to sterility.

A woman may have a whitish or yellowish vaginal discharge that may be heavy. But up to 75% of women with chlamydia have no symptoms.

Without treatment, chlamydia can result in pelvic inflammatory disease and infertility. Children born to infected women can have eye infections and pneumonia.

Genital Herpes
Herpes is an inflammatory viral disease that causes eruptions and ulcers of the skin. Symptoms usually appear two to 20 days after contact with the virus. In some cases, the first eruption doesn't appear until months or years after contact. Or the symptoms may be so mild, like a slight discomfort at the site, that a person doesn't realize an eruption is occurring and may unknowingly contaminate a sexual partner.

Generally the symptoms consist first of itching and pain in the genital area or the mouth, then painful blisters and ulcerations.

Even when the infected woman has no symptoms, she can sometimes pass the herpes virus.

A pregnant woman can pass the infection to her newborn if there is contact with the infected area. If the woman goes into labor while the disease is active, she will need to have a cesarean section.

The herpes virus can remain inactive in the nerve roots and can recur at any time. Keeping the area dry and avoiding sexual contact during an eruption will prevent transmission of the virus.

There is no cure for genital herpes, but an antiviral medication can hasten the healing process after an eruption or prevent recurrence.

Syphilis
This disease, caused by a spiral bacteria called treponema pallidum, is transmitted by direct contact and is characterized by a painless sore on the penis and in the vagina, and sometimes in the mouth, throat and anus. Syphilis can be cured with antibiotics.

Symptoms usually appear three to four weeks after the initial contact. The lesion disappears within five weeks, even without treatment, but the disease itself does not go away. If left untreated, the disease later can cause weakness, fever, painful joints, an eruption on the palms of the hands and plantar warts on the feet.

Even without treatment, these symptoms also disappear within four to 12 weeks, but again the disease remains in the body.

For two to 10 years after the initial contact, though no outward symptoms appear, the disease is attacks the heart, blood vessels and central nervous system. The result can be blindness, mental disorders and stroke.

Infected women can pass the disease to their unborn children, in whom it is called congenital syphilis. They also have a high incidence of spontaneous abortion and stillbirth.

An estimated 50 million people have syphilis worldwide.

Gonorrhea
This is an acute disease of the lining (epithelium) of the urethra, cervix and rectum transmitted by direct contact. It can be cured with antibiotics.

Symptoms usually appear from two to 14 days in men and seven to 21 days in women after initial contact. Men have painful urination and a whitish discharge from the penis, rectum and eyes. Sometimes the throat is also infected. Some infected men have no symptoms.

Women may have a whitish, yellowish or greenish vaginal or anal discharge, but 80% of infected women have no symptoms. Without treatment, gonorrhea can cause pelvic inflammatory disease, sterility, blindness, arthritis and heart disease. Gonorrhea is also passed to newborn babies during childbirth.

Venereal Warts
These skin growths are caused by a virus and are transmitted by sexual contact. Different-sized warts can show up on or in the genital organs and in the rectum within six months of initial contact. Sometimes itching and a burning sensation around the genital organs also occur.

Venereal warts can be treated with painful localized treatments for up to six months until they no longer recur. The person must be patient and continue treatment because the virus can lie dormant under the skin.

Trichomoniasis
This disease is caused by a microorganism known as a protozoa that infects the urinary system and the vagina. It is transmitted not only during sex, but sometimes by way of contaminated clothing, towels or toilet seats.

Symptoms in women are a yellowish or greenish vaginal discharge, sometimes bloody and with an offensive odor. Yet some women, as well as the majority of men, have no symptoms at all.

Treatment for trichomoniasis is with oral antibiotics.

Hepatitis B
The hepatitis B virus lives in the blood, so infection is passed by contact with tainted blood. This is especially true of drug addicts who share needles. Symptoms appear between six weeks and six months of initial contact, and include nausea and vomiting, abdominal pain, loss of appetite, and yellowing of the skin and the white of the eye.

There is no cure, but the majority of infected people feel better when the symptoms, which are similar to those of the flu, are treated. The infection itself may disappear spontaneously. Some people become chronic carriers and are always contagious.

Hepatitis B can be prevented by a vaccine that builds immunity against the disease.

HIV and AIDS
HIV (human immunodeficiency virus) is the virus that causes AIDS. It is acquired during intercourse or by coming in contact with blood, semen or vaginal secretions of an infected person.

So far, AIDS is 100% fatal.

High-risk people include those with multiple partners, drug addicts who share needles, the unborn child of an infected mother, and an infant breast-fed by an infected mother. HIV is also transmitted during transfusion of infected blood.

HIV is not transmitted through shaking hands, food, sneezing, mosquito bites, toilet seats or clothing.

The virus attacks certain white blood cells called T lymphocytes. These cells are an intrinsic part of the body's defense mechanism.

When the body has too few T cells, the body cannot fight off infection, and is in an immunosuppressed state. Immunosuppression caused by HIV eventually develops into AIDS (acquired immunodeficiency syndrome), and the afflicted person succumbs to pneumonia, tuberculosis, chronic diarrhea, and/or lymphoma and Kaposi's sarcoma (two types of cancer) -- infections that a healthy body routinely staves off.

A person with HIV does not necessarily have AIDS. The latency period for AIDS -- during which the person is infected by HIV and remains without symptoms, but can pass the infection on to others -- has lasted, to date, for 15 years.

There is no existing cure for HIV or AIDS.

When AIDS was first recognized in the early 1980s, it was considered a disease of homosexual males. Now, throughout the world, it is largely a disease of heterosexual individuals -- men, women and children.

According to the World Health Organization, in 1993 the AIDS-caused mortality rate was higher in women age 20-29 than in previous years, meaning these women contacted HIV as teenagers.

Since HIV cannot be detected for the first six months after initial contact, the proper precaution to take when entering a new relationship is for both partners to wait six months before becoming sexually intimate, and then have blood tests for HIV. If the test results are negative for both people, it is then safe for them to become sexually involved.

Some Final Words About STDs
STDs are more widespread than ever these days. The most effective protection against them is abstinence from sex, a practice which -- if life must go on -- is bound to be broken. Married couples should avoid extramarital affairs, because both partners are at risk. Adolescents often have promiscuous sexual lives, and only 42% use condoms or other contraceptives. Parents should educate themselves as well as their children.