Sexually transmitted infections (STIs), which used to be known as sexually transmitted diseases (STDs), are a group of infections similar to one another only in that they can be "caught" through sexual contact. STIs are caused by different organisms, usually bacteria or viruses, and have a wide variety of symptoms. Some can be cured with antibiotics. Others cannot be cured, only controlled. The following are the STIs usually seen in North America.
- Chlamydia is a very common sexually transmitted infection in North America, affecting both men and women. Chlamydia is caused by a bacterium called Chlamydia trachomatis. It's easily treated with antibiotics, but can sometimes lead to serious complications such as infertility, pelvic inflammatory disease (PID), and Reiter's syndrome (an arthritis-like condition) if it isn't caught early enough.
- Gonorrhea is another very common STI in North America, infecting over half a million people each year. As with chlamydia, gonnorrhea can lead to serious complications in women, such as infertility and pelvic inflammatory disease (PID). Gonorrhea is caused by bacteria, and can be treated with antibiotics. The disease can affect mucous linings in the vagina, cervix, penis, rectum, throat, and eyes. Gonorrhea is also known as "the clap."
- Syphilis used to be a leading cause of death and disability, but it's much less common today in our age of antibiotics. In the United States, the most affected age group is 35-39 in males, and 20-24 in females. It can be treated with antibiotics if caught early. If left untreated, it can come back later to cause damage to the heart, nerves, brain, bone, joints, liver, and blood vessels. Syphilis is also known as "syph" (and in some older literature is known as "the pox").
- HIV is the viral infection that can cause AIDS. The virus attacks cells of the immune system, leaving a person defenseless against many other infections and their complications. There is no cure, but anti-viral medications can be used to slow down the progression of the disease.
- Hepatitis B is caused by a virus that infects the liver. It can lead to chronic liver disease and liver cancer. Most people who are infected do not have any symptoms, but they can still pass the virus on. It cannot be cured, but a vaccine is available to help prevent it.
- Genital herpes, which produces cold-sore-type skin lesions in the genital area, is also caused by a virus. It can be treated, but not cured, with medications. The condition comes and goes, with skin lesions "flaring up" from time to time.
- Chancroid - a bacterial infection of the genitals that causes painful sores - was once rare in North America, but has cropped up more frequently in recent years. It can be treated with antibiotics.
- Crabs, also known as pubic lice, are lice (tiny, wingless insects) that live in the genital area. They can be treated with medication.
- HPV, or human papillomavirus, is a virus that affects the skin in the genital area, causing wart-like growths. It can also affect a woman's cervix and increases her risk of cancer of the cervix. It is important for women to have regular Pap tests (usually at their yearly physical exam) to catch any precancerous changes (changes in the cells of the cervix that may lead to cancer) so that they can be treated before they develop into cancer.
- Trichomoniasis is caused by a parasite. It usually causes no symptoms in men, although many women have symptoms. It can be cured with antibiotics.
Many STIs can lead to health problems later on if they are not found and treated. Being infected with HPV can increase a woman's risk of cervical cancer. Chlamydia can lead to infertility and long-term pain in women by damaging the Fallopian tubes, which are an important part of the reproductive system. HIV/AIDS eventually destroys the immune system, leading to an increased risk of infections, cancers, and death.