HIV/AIDS Basic
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HIV is an infection caused by the Human Immunodeficiency Virus, a virus that weakens the body's immune defenses by destroying CD4 lymphocytes. CD4 (T cell) lymphocytes are a group of white blood cells that normally help to guard against attacks by bacteria, viruses, and other germs. When HIV destroys CD4 lymphocytes, the body becomes vulnerable to many different types of opportunistic infections (infections that have an "opportunity" to invade the body because its immune defenses are weak.) HIV infection also increases the risk for certain malignancies (cancers), neurologic illnesses (illnesses of the brain and nerves), a syndrome of body wasting, and death. The entire spectrum of symptoms and illnesses that can happen when HIV infection significantly depletes immune defenses is called the Acquired ImmunoDeficiency Syndrome (AIDS).
Since 1981, when HIV/AIDS was first recognized as a new illness, scientists have learned much about the HIV infection process. HIV is spread through contact with an infected person's body fluids, especially through blood, semen, and vaginal fluids. Once inside the body, HIV viral particles attach to CD4 lymphocytes and use a series of chemicals including viral RNA (Ribonucleic Acid) and viral proteins to turn the CD4 lymphocytes into viral factories. When this happens, infected CD4 cells devote their energy to manufacturing new HIV particles rather than to protecting the body. As newly manufactured HIV particles enter the bloodstream, they infect more CD4 cells, which produce even more HIV particles. In this way, the cycle of HIV infection continues, and the number of infected CD4 lymphocytes increases. Eventually, HIV destroys the infected CD4 lymphocytes and, as CD4 numbers drop, the body's immune defenses weaken. In addition, HIV may also remain "silent" as a latent (dormant) infection in some CD4 cells, only to awaken and spread after long periods of inactivity.
Within the past two decades, over 400 million people worldwide have become infected with HIV, and approximately 12 million have died. As of mid-1997, there had been over 612,000 cases of AIDS reported in the United States, with almost 380,000 deaths, including 4,600 children.
In its early stages, HIV infection either has no symptoms, or causes only a flu-like illness with the following symptoms: fever, nausea and vomiting, diarrhea, fatigue, swollen lymph nodes, muscle aches, headaches, and joint pain. In a small number of cases, this early stage of infection may progress to encephalitis (inflammation of the brain) or meningitis (in inflammation of membranes covering the brain).
Next, as CD4 cell levels drop below normal (normal is 800 -1,200), the patient may begin to have: night sweats; fever; weight loss; diarrhea; weakness; swollen lymph nodes; or easy bruising.
Finally, as CD4 cell levels continue to drop, the patient develops AIDS. In an HIV-infected person, some signs that AIDS has developed are:
· CD4 count has decreased to 200 or below
· An opportunistic infection has developed, such as pneumonia, diarrhea, or meningitis. Some of the germs that can cause these opportunistic infections include: Candida fungus; coccidioidomycosis; cryptococcosis; cytomegalovirus (CMV); herpes simplex virus; histoplasmosis; tuberculosis; Pneumocystis carinii; and others.
· A tumor has developed, including: cervical cancer; Kaposi's sarcoma (an aggressive cancer that is most common in men who practice homosexual sex); Non-Hodgkin's lymphoma (certain types); or brain lymphoma.
· An AIDS-related brain illness has developed, including HIV encephalopathy ("AIDS dementia") or Progressive Multifocal Leukoencephalopathy (PML)
· There is severe body wasting (HIV wasting syndrome)
· There is an AIDS-related lung illness - pulmonary lymphoid hyperplasia or lymphoid interstitial pneumonia
After asking about your history of exposure to HIV-infected body fluids, your doctor will check for signs and symptoms of HIV/AIDS and perform a physical examination. Your doctor will look for fever, weight loss, a thick white coating on your tongue that may represent thrush (a sign of opportunistic infection with Candida fungus), Kaposi's sarcoma, or other symptoms of AIDS (see above: Symptoms). Your doctor will confirm the diagnosis of HIV infection through blood tests. The initial screening test is an EHSA (enzyme-linked immunosorbent assay) which detects antibodies specific for HIV. If this test is positive, the HIV RNA blood test can then measure "viral load" (amount of HIV virus in the blood). To confirm the diagnosis of AIDS in someone who has an HIV infection, your doctor will order a blood test for CD4 cell count (a count below 200 indicates AIDS) and also perform tests to diagnose AIDS-related conditions, including opportunistic infections, brain illness, tumor, body wasting, or lung illness.
Since there is currently no cure for HIV infection, it is a lifelong illness.
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; contaminated blood transfusion; needle stick with contaminated injection equipment; artificial insemination with infected semen; organ transplant taken from an HIV-infected donor. Newborns can also catch HIV infection from their mothers before birth or through breast-feeding.
Although several HIV vaccines are being tested, none has been approved. For now, AIDS prevention depends on decreasing your chances for HIV infection by avoiding high-risk behaviors. To decrease the risk of HIV infection you can:
· practice abstinence; have a monogamous (one partner only) sexual relationship; or use barrier methods of contraception such as condoms.
· pre-donate your own blood before anticipated surgery (this is an autologous blood transfusion)
· avoid sharing injection equipment
· if you are a healthcare worker who cares for HIV patients, strictly follow established infection-control procedures for exposure to body fluids
· if you are a woman who is thinking about becoming pregnant, have a test for HIV beforehand, especially if you have a history of behaviors that put you at risk for HIV infection. Pregnant women who are HIV positive need special pre-natal care and medications to decrease the risk that HIV will pass to their newborn babies.
After measuring plasma HIV RNA ( to check the level of active HIV infection) and CD4 cell counts (to determine the amount of immune system damage) your doctor may choose a combination of antiretroviral drugs to fight HIV infection. By using several different drugs simultaneously, your doctor hopes to increase the effectiveness of AIDS treatment by attacking HIV at multiple points in its manufacturing cycle. Drug combinations also limit the risk that drug-resistant HIV will develop. The ultimate goal is to suppress HIV RNA to undetectable levels on follow-up blood tests. Currently-available antiretroviral drugs include:
· Nucleoside analogs : zidovudine (Retrovir or "AZT"); didanosine (Videx or "ddI"); zalcitabine (HIVID or "ddC"); stavudine (Zerit or "d4T"; or lamivudine (Epivir or "3TC"). There is also a combination pill called "Combivir," which contains both lamivudine and zidovudine.
· Protease inhibitors : saquinavir (Invirase and Fortovase); ritonavir (Norvir); indinavir (Crixivan); and nelfinavir (Viracept)
· Non-nucleoside reverse transcriptase inhibitors : nevirapine (Viramune); delavirdine (Rescriptor)
One common treatment approach is HAART (Highly Active Antiretroviral Therapy) - a combination of three drugs which includes 2 nucleoside analogues and one protease inhibitor.
The Food and Drug Administration (FDA) has also approved more than 22 drugs for treating AIDS-related conditions, including drugs that fight opportunistic infections and Kaposi's sarcoma. To treat AIDS-related body wasting, the following may be used: dronabinol (Marinol); megestrol acetate (Megace); and recombinant human growth hormone (Serostim).
Call your doctor if you believe that you have been exposed to the infected body fluids of someone who has an HIV/AIDS. If you have chosen to test for HIV at home using a store-bought test kit, call your doctor immediately if your result is "positive." Even if your result is "negative," you may wish to speak with your doctor about your concerns, questions, HIV prevention, or the need for follow-up testing.
Without anti-viral medication, or with only monotherapy (using just one anti-viral drug), the average time for HIV infection to progress to AIDS is 10-11 years. However, in about 20% of persons with HIV infection, AIDS develops sooner (5 years after infection), while in 2% of persons it develops later (more than 12 years after infection).
Once HIV infection has progressed to AIDS, there is an increased risk for death that varies dramatically from patient to patient. For example, some persons with AIDS have died shortly after they were diagnosed, while others have lived 12 years or more. A longer life expectancy is often seen in AIDS patients with the following characteristics: male sex; young adult age group; White ethnic background; first sign of illness was Kaposi's sarcoma rather than a serious opportunistic infection.
Since FDA approval of newer antiretroviral drugs in 1995, the number of deaths from AIDS has decreased dramatically in the United States. Between 1996 and 1997 alone, 44% fewer AIDS patients died, and the rate of AIDS hospitalizations and complications also declined. As more patients take advantage of the new combination therapies, there is hope that all patients with AIDS will have the chance to live longer and healthier lives.
AIDS
treatment scams rob trusting patients of $10 billion annually. To fight these
scams, the FDA formed the AIDS Health Fraud Task Force in 1989. Based on results
of FDA investigations, some important unapproved therapies to avoid are
"energized" water, "ozone therapy," and the hydrogen
peroxide "treatment."
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