The period between infection with HIV

The period between infection with HIV and the development of positive test results on ELISA and Western blot is called the window period. This term refers to the window of time between getting the HIV infection and the ability to detect the body's response to infection with one of these two tests. If the test results are positive, another test, called the HIV RNA blood test, can measure the amount of HIV virus in the blood (viral load). To confirm the diagnosis of AIDS, your doctor will order a blood test for CD4 cell count. A count less than 200 cells per cubic milliliter of blood indicates AIDS. You also may have tests to diagnose AIDS-related conditions, including opportunistic infections, brain illness, a tumor, body wasting or lung illness, depending on your symptoms.

Expected Duration

HIV infection is a lifelong illness.

Prevention

HIV infection can be passed from person to person in any of the following ways:

• Unprotected sexual intercourse (heterosexual or homosexual)
• Oral sex with an infected person
• A contaminated blood transfusion (very rare in the United States since 1985, when blood supplies started being tested for HIV)
• Needle sharing (if one intravenous drug user is infected)
• Occupational exposure (needle stick with infected blood)
• Artificial insemination with infected semen
• Organ transplant taken from an HIV-infected donor

Newborns can catch HIV infection from their mothers before birth or through breastfeeding.

There is no evidence that HIV can be spread through the following: kissing; sharing food utensils, towels or bedding; swimming in pools; using toilet seats; using telephones; or having mosquito or other insect bites.

Although several HIV vaccines are being tested, none has been approved. You can decrease your chances of being infected with HIV by avoiding high-risk behaviors. To decrease the risk of HIV infection:

• Don't have sex, have sex with only one partner who is also committed to having sex with only you or use barrier methods of contraception such as condoms.
• If you use intravenous drugs, never share needles.
• If you are a health care worker, strictly follow universal precautions (the established infection-control procedures to avoid contact with bodily fluids).
• If you are a woman thinking about becoming pregnant, have a test for HIV beforehand, especially if you have a history of behaviors that put you at risk of HIV infection. Pregnant women who are HIV-positive need special prenatal care and medications to decrease the risk that HIV will pass to their newborn babies.