HIV/AIDS: Risk Factors and Prevention of Transmission

What is AIDS?

AIDS (acquired immunodeficiency syndrome) is a preventable, life-threatening illness caused by infection with the human immunodeficiency virus (HIV). With time, infection with HIV causes you to lose your ability to fight off serious infections. When this happens, HIV infection becomes AIDS.

Who is at risk?

If you are infected with HIV, you can pass the virus to other people even when you may have no signs of illness. The virus can be spread by contact with your blood or semen. It can also be spread to babies by breast milk if a mother is infected. People close to you are not at increased risk if they do not have sexual contact with you or contact with your blood.


IV drug users and people receiving blood transfusions can be exposed to the virus through infected blood. In North America the risk of getting HIV from blood transfusions has become much lower since testing of donated blood for the virus began in the mid-1980s.


Men and women can transmit the virus sexually. The virus has been found in semen and vaginal secretions. Vaginal and oral intercourse can spread the virus. Anal intercourse and intercourse with numerous partners especially increase the risk of getting AIDS.


The following groups are at high risk for contracting HIV infection and possible development of AIDS:

  • sexually active homosexual men
  • bisexual men and their partners
  • IV drug users and their sexual partners
  • people who share needles (for IV drug use, tattooing, or piercing)
  • heterosexual men and women with more than one sexual partner
  • people given transfusions of blood or blood products in countries where the blood is not rigorously tested
  • immigrants from areas with many cases of AIDS (such as Haiti and east central Africa)
  • people who have sex with an HIV-infected partner or with anyone in the above groups if they do not always use a latex or polyurethane condom
  • babies born to HIV-infected mothers.

Who should be tested for HIV?

You should be tested for HIV if:

  • You are or were in a high-risk group (listed above).
  • You have ever had unprotected sex and have not been tested.
  • You are or plan to become pregnant (in this case testing is especially important to prevent HIV in the baby).

Where can I get the test?

Ask your health care provider where you can get the test. Many community health centers, family planning clinics, hospitals, STD clinics, and county health departments offer testing. Call the Centers for Disease Control National AIDS Hotline at 1-800-342-AIDS to find a testing center near you. Do not use donating blood as a way of being tested.

What do the test results mean?

If your test is negative, it means you have not been infected with the AIDS virus before 2 to 6 months ago. As long as you do not engage in any high-risk activity and always practice safe sex, you have almost no risk of becoming HIV-infected and developing AIDS. If you are or were at high risk, however, you should discuss with your health care provider how often you should be retested.


If your first test is positive, a second test will be done to confirm that you are infected with the virus.


If there are questions about your test results, your health care provider will tell you how soon you should be retested and what precautions you should take in the meantime.

How can I prevent giving HIV to others?

If you are infected with HIV, you should take these precautions to avoid spreading the virus to others:

  • Avoiding sexual and other high-risk activities, such as sharing needles, is the best way to prevent spread of the virus. People with HIV can give the virus to others before they know they are infected. Safe sex should always be practiced to help prevent the spread of infection.
  • If you are sexually active, you should engage only in safe sex. Avoid exposure to blood and sexual secretions during sex. This means:
    • Avoid vaginal and anal intercourse unless condoms are used.
    • Do not use a spermicide containing nonoxynol 9 as a spermicide and do not use condoms coated with this spermicide.
    • Avoid oral-genital sex without condoms.
    • Avoid oral-anal sex.
    • Avoid getting semen or blood in cuts or in the eyes.
  • Do not donate blood, plasma, or semen.
  • Do not plan to donate organs, such as corneas. (If you were previously planning to donate organs, have that statement removed from your driver's license.)
  • Do not share or reuse IV needles and syringes. Do not self-inject drugs unless directed to do so by your health care provider. Do not share needles for tattooing or body piercing. Boiling does not guarantee sterility of needles or syringes.
  • Do not use nitrate inhalants (poppers).
  • Do not share razors, toothbrushes, or anything that could be contaminated with body fluids or blood.
  • Tell your health care providers that you are HIV positive.
  • If you work in a dental, medical, or other health care profession and perform invasive procedures or have skin sores, use latex gloves to protect patients from risk of infection.
  • Get medical checkups at least once a year, or more often if your health care provider recommends it or if you have symptoms that suggest AIDS.
  • If you are a woman, discuss pregnancy with your health care provider. HIV may be spread to a baby during pregnancy, delivery, or breast-feeding. (Taking the medicine zidovudine (AZT) during pregnancy makes it less likely that the baby will be infected.)

How can I practice safe sex by using condoms?

  • Use a latex or polyurethane condom every time you have intercourse or any other intimate genital activity.
  • Put the condom on after the penis is erect but before before it touches your partner.
  • Put the condom on the head of the penis and unroll or pull it all the way to the base of the penis.
  • Leave an empty space at the end of the condom to collect semen. Remove any air remaining in the tip of the condom by gently pressing the air out toward the base of the penis.
  • If you use a lubricant, use one that is water based. Do not use oil-based lubricants made with petroleum jelly, mineral oil, vegetable oil, or cold cream. They can damage the condom.
  • After ejaculation, carefully withdraw the penis while it is still erect. Hold onto the rim of the condom as you withdraw so the condom doesn't slip off.
  • Store condoms in a cool, dark, dry place.
  • If a condom appears sticky, brittle, discolored, or obviously damaged, don't use it.
  • Use each condom only once.

For more information about HIV and AIDS, contact your health care provider or the National AIDS Hotline at 1-800-342-AIDS (1-800-342-2437) (24 hours, 7 days a week). Hotline numbers are also available for Spanish speakers at 1-800-344-7432 (8 a.m. to 2 a.m., EST, 7 days a week). The TDD number for the hearing impaired is 1-800-243-7889 (10 a.m. to 10 p.m., EST, Monday through Friday). These hotlines are provided by the US Centers for Disease Control and Prevention.


Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.


HIA File INF4500F.HTM Release 9.0/2006

Copyright © 2006 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.

Copyright © 2006 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.