An Introduction to HIV and AIDS
AIDS (acquired immune deficiency syndrome) was first reported in the United States in 1981 and has since become a major worldwide epidemic. AIDS is caused by the human immunodeficiency virus (HIV). By killing or damaging cells of the body's immune system, HIV progressively destroys the body's ability to fight infections and certain cancers.
The term AIDS applies to the most advanced stages of HIV infection. More than 700,000 cases have been reported in the United States since 1981, and as many as 900,000 Americans may be infected with HIV. The epidemic is growing most rapidly among women and minority populations.
HIV is spread most commonly by having sex with an infected partner. HIV also is spread through contact with infected blood, which frequently occurs among injection drug users who share needles or syringes contaminated with blood from someone infected with the virus. Women with HIV can transmit the virus to their babies during pregnancy, birth, or breastfeeding; however, if the mother takes the drug AZT during pregnancy, she can significantly reduce the chances that her baby will be infected with HIV.
Many people do not develop any symptoms when they first become infected with HIV. Some people, however, have a flu-like illness within a month or two after exposure to the virus. More persistent or severe symptoms may not surface for a decade or more after HIV first enters the body in adults, or within two years in children born with HIV infection. This period of "asymptomatic" (without symptoms) infection varies from person to person. During the asymptomatic period, however, the virus is actively multiplying, infecting, and killing cells of the immune system, and people are highly infectious -- meaning they can transmit the virus to others.
(Click HIV Symptoms for a more detailed list of possible symptoms.)
As the immune system deteriorates, a variety of complications start to take over. For many people, the first sign of infection is large lymph nodes or "swollen glands" that may be enlarged for more than three months. Other symptoms often experienced months to years before the onset of
AIDS include:
- Lack of energy
- Weight loss
- Frequent fevers and sweats
- Persistent or frequent yeast infections (oral or vaginal)
- Persistent skin rashes or flaky skin
- Pelvic inflammatory disease, in women, that does not respond to treatment
- Short-term memory loss.
Many people are so debilitated by the symptoms of AIDS that they cannot hold steady employment or do household chores. Other people with AIDS may experience phases of intense, life-threatening illness followed by phases in which they function normally.
Because early HIV infection often causes no symptoms, a doctor or other healthcare worker usually can diagnose it by testing a person's blood for the presence of antibodies (disease-fighting proteins) for HIV. HIV antibodies generally do not reach levels in the blood that the doctor can see until one to three months after infection, and it may take the antibodies as long as six months to be produced in quantities large enough to show up in standard blood tests. Therefore, people exposed to the virus should get an HIV test within this time period.
Over the past 10 years, researchers have developed antiretroviral drugs to fight both HIV infection and its associated infections and cancers. However, the drugs that are currently available do not cure people of the HIV infection or
AIDS. In addition, these drugs all have potential side effects that can be severe. Because no vaccine for HIV is available, the only way to prevent infection with the virus is to avoid behaviors that put a person at risk of infection, such as sharing needles and having unprotected sex.
