HIV/AIDS

Definition

Definition of AIDS/HIV
AIDS is caused by a virus called HIV, the Human Immunodeficiency Virus. If you get infected with HIV, your body will try to fight the infection. It will make “antibodies,” special molecules to fight HIV.

A blood test for HIV looks for these antibodies. If you have them in your blood, it means that you have HIV infection. People who have the HIV antibodies are called “HIV-Positive.” Fact Sheet 102 has more information on HIV testing.

Being HIV-positive, or having HIV disease, is not the same as having AIDS. Many people are HIV-positive but don’t get sick for many years. As HIV disease continues, it slowly wears down the immune system. Viruses, parasites, fungi and bacteria that usually don’t cause any problems can make you very sick if your immune system is damaged. These are called “opportunistic infections.” See Fact Sheet 500 for an overview of opportunistic infections.

Symptoms

Symptoms of AIDS/HIV
Many people with HIV do not know they are infected. In the United States, it is likely that 20% of HIV-positive individuals are unaware of their infection.

Many people do not develop symptoms after they first get infected with HIV. Others have a history of a flu-like illness within several days to weeks after exposure to the virus. Early HIV symptoms also include fever, headache, tiredness, and enlarged lymph nodes in the neck. These symptoms usually disappear on their own within a few weeks. After that, the person feels normal and has no symptoms. This asymptomatic phase often lasts for years.

The progression of disease varies widely among individuals. This state may last from a few months to more than 10 years.

Causes

Causes of AIDS/HIV
HIV is transmitted when the virus enters the body, usually by injecting infected cells or semen. There are several possible ways in which the virus can enter.

1. Most commonly, HIV infection is spread by having sex with an infected partner. The virus can enter the body through the lining of the vagina, vulva, penis, rectum, or mouth during sex. Although intercourse is the primary risk factor, oral sex transmission is also possible.
2. HIV frequently spreads among injection-drug users who share needles or syringes that are contaminated with blood from an infected person.
3. Women can transmit HIV to their babies during pregnancy or birth, when infected maternal cells enter the baby's circulation, or through breastfeeding.
4. HIV can be spread in health-care settings through accidental needle sticks or contact with contaminated fluids.
5. Very rarely, HIV spreads through transfusion of contaminated blood or blood components. All blood products are tested to minimize this risk. If tissues or organs from an infected person are transplanted, the recipient may acquire HIV. Donors are now tested for HIV to minimize this risk.
6. HIV has been spread when organs from an infected person are transplanted into an uninfected recipient. Because donors are tested for HIV routinely in the United States, this does not usually happen. However, a recent incident in Taiwan occurred when the HIV test results for the donor were mistakenly thought to have been negative.
7. People who already have a sexually transmitted infections, such as syphilis, genital herpes, chlamydial infection, human papillomavirus (HPV), gonorrhea, or bacterial vaginosis, are more likely to acquire HIV infection during sex with an infected partner.

Diagnosis

Diagnosis of AIDS/HIV
HIV infection is commonly diagnosed by blood tests. There are three main types of tests that are commonly used: (1) HIV antibody tests, (2) RNA tests, and (3) a combination test that detects both antibodies and a piece of the virus called the p24 protein. In addition, a blood test known as a Western blot is used to confirm the diagnosis.

No test is perfect. Tests may be falsely positive or falsely negative. For example, it can take some time for the immune system to produce enough antibodies for the antibody test to turn positive. This time period is commonly referred to as the "testing window period" and may last six weeks to three months following infection. Therefore, if the initial antibody test is negative, a repeat test should be performed three months later. Early testing is crucial, because early treatment for HIV helps people avoid or minimize complications. Furthermore, high-risk behaviors can be avoided, thus preventing the spread of the virus to others.

Prognosis

Prognosis of AIDS/HIV
There is no cure for HIV infection. Before we had any treatment for the virus, people with AIDS lived only for a couple of years. Fortunately, medications have substantially improved the outlook and survival rates. Prevention efforts have sharply reduced HIV infection in young children and have the potential to sharply limit new infections in other populations.

Treatment

Treatment of AIDS/HIV
There is no cure for AIDS. There are drugs that can slow down the HIV virus, and slow down the damage to your immune system. There is no way to “clear” the HIV out of your body.

Other drugs can prevent or treat opportunistic infections (OIs). In most cases, these drugs work very well. The newer, stronger ARVs have also helped reduce the rates of most OIs. A few OIs, however, are still very difficult to treat. See Fact Sheet 500 for more information on opportunistic infections.

Prevention

Prevention of AIDS/HIV
HIV can be transmitted in three main ways:

1. Sexual Transmission
2. Transmission Through Blood
3. Mother-to-child Transmission