HIV stands for human immunodeficiency virus. This is the virus that causes AIDS. HIV is different from most other viruses because it attacks the immune system. The immune system gives our bodies the ability to fight infections. HIV finds and destroys a type of white blood cell (T cells or CD4 cells) that the immune system must have to fight disease.
How HIV Is and Is Not Transmitted
HIV is a fragile virus. It cannot live for very long outside the body. As a result, the virus is not transmitted through day-to-day activities such as shaking hands, hugging, or a casual kiss. You cannot become infected from a toilet seat, drinking fountain, doorknob, dishes, drinking glasses, food, or pets. You also cannot get HIV from mosquitoes.
HIV is primarily found in the blood, semen, or vaginal fluid of an infected person. HIV is transmitted in 3 main ways:
- Having sex (anal, vaginal, or oral) with someone infected with HIV
- Sharing needles and syringes with someone infected with HIV
- Being exposed (fetus or infant) to HIV before or during birth or through breast feeding
HIV also can be transmitted through blood infected with HIV. However, since 1985, all donated blood in the United States has been tested for HIV. Therefore, the risk for HIV infection through the transfusion of blood or blood products is extremely low. The U.S. blood supply is considered among the safest in the world.
Risk Factors for HIV Transmission
You may be at increased risk for infection if you have
- injected drugs or steroids, during which equipment (such as needles, syringes, cotton, water) and blood were shared with others
- had unprotected vaginal, anal, or oral sex (that is, sex without using condoms) with men who have sex with men, multiple partners, or anonymous partners
- exchanged sex for drugs or money
- been given a diagnosis of, or been treated for, hepatitis, tuberculosis (TB), or a sexually transmitted disease (STD) such as syphilis
- received a blood transfusion or clotting factor during 1978–1985
- had unprotected sex with someone who has any of the risk factors listed above
Your risk of getting HIV or passing it to someone else depends on several things. Do you know what they are? You might want to talk to someone who knows about HIV. You can also do the following:
- Abstain from sex (do not have oral, anal, or vaginal sex) until you are in a relationship with only one person, are having sex with only each other, and each of you knows the other’s HIV status.
- If both you and your partner have HIV, use condoms to prevent other sexually transmitted diseases (STDs) and possible infection with a different strain of HIV.
- If only one of you has HIV, use a latex condom and lubricant every time you have sex.
- If you have, or plan to have, more than one sex partner, consider the following:
- Get tested for HIV
- If you are a man who has had sex with other men, get tested at least once a year.
- If you are a woman who is planning to get pregnant or who is pregnant, get tested as soon as possible, before you have your baby.
- Talk about HIV and other STDs with each partner before you have sex.
- Learn as much as you can about each partner’s past behavior (sex and drug use), and consider the risks to your health before you have sex.
- Ask your partners if they have recently been tested for HIV; encourage those who have not been tested to do so.
- Use a latex condom and lubricant every time you have sex.
- If you think you may have been exposed to another STD such as gonorrhea, syphilis, or Chlamydia trachomatis infection, get treatment. These diseases can increase your risk of getting HIV.
- Get vaccinated against hepatitis B virus.
- Even if you think you have low risk for HIV infection, get tested whenever you have a regular medical check-up.
- Do not inject illicit drugs (drugs not prescribed by your doctor). You can get HIV through needles, syringes, and other works if they are contaminated with the blood of someone who has HIV. Drugs also cloud your mind, which may result in riskier sex.
- If you do inject drugs, do the following:
- Do not have sex when you are taking drugs or drinking alcohol because being high can make you more likely to take risks.