AIDS is an acronym that stands for Acquired Immune Deficiency Syndrome. The AIDS virus is known as the Human Immuno-Deficiency Virus (HIV). The virus can destroy a body's immune system so that it cannot fight off infections. Eventually a person with the HIV virus succumbs to life-threatening infections and opportunistic diseases (including unusual forms of pneumonia and cancer).
The origin of AIDS is unknown, although many trace its origins to Central Africa. The green monkey of Africa carries a virus similar to AIDS, and many researchers believe that the virus was transmitted by monkeys to people. Apparently those infected with the virus either moved to other countries or infected American tourists, who brought the disease to this country.
Although AIDS seems to have arrived in the United States much earlier than the 1970s, it was only formally identified in 1982 when doctors were confronted with a previously unknown disease. Within five years after its formal identification, AIDS had spread rapidly. By that time over 40,000 Americans had been diagnosed with the disease, and fewer than half of those who had been diagnosed were still alive.
While getting accurate estimates of the number of people diagnosed with the disease is difficult, getting accurate estimates for the number infected with the HIV virus is even more difficult. In 1987 the Centers for Disease Control (CDC) estimated that 900,000 to 1.4 million Americans were infected with the HIV virus. Some experts believe that the CDC estimate is low and should be 10 to 50 percent higher.
Physicians have identified three stages in the progression of AIDS. Stage one is the asymptomatic carrier stage. People in this stage are infected with the HIV virus but show no discernable signs or symptoms of AIDS. Unless they have had a blood test, these people may be unaware they have the disease. Nevertheless, these carriers can infect others with the virus even though they themselves do not manifest any visible sign of infection. Some people remain in this stage for a number of years.
The second stage is AIDS-Related Complex (ARC). Individuals begin to show some of the symptoms of HIV infection when they enter this stage of infection. Such symptoms include sudden unexplained weight loss, night sweating, diarrhea, swelling of the lymph nodes, neurologic disorders (memory loss, partial paralysis, or loss of coordination), and chronic fatigue.
The third stage is full-blown AIDS. This stage is characterized by opportunistic infections, which occur due to a deficiency of the person's immune system. A healthy immune system would normally protect against the damaging effects of these diseases, but the HIV impairs the normal immune protection system and allows these infections to weaken and eventually kill the infected person.
The HIV virus is transmitted through the exchange of infected bodily fluids. Some 89 percent of persons known to have AIDS are homosexuals or intravenous drug users. Another 3 percent became infected through blood transfusions (most before blood banks began testing for the AIDS antibody), 1 percent are infants and children, and 3 percent are undetermined.
These figures leave 4 percent of known AIDS patients who became infected with the disease through heterosexual contact. Some health officials estimate that in the 1990s the number of AIDS cases resulting from heterosexual contact will increase to 6 percent, though this is still a matter of some debate in the medical community.
A more alarming statistic is that, based upon the 1986 Surgeon General's Report, we have at least 1.5 million carriers of the HIV virus in the United States. Most of these people do not know they are carriers and thus may unknowingly transmit the virus through sexual activity or intravenous drug use.
Although there is some disagreement about the number of modes by which the AIDS virus can be transmitted, there is near universal agreement that it can be transmitted in at least four major ways: sexual activity, intravenous drug use, blood transfusions, and perinatal infection, which occurs when an AIDS-infected mother passes the virus to her child during pregnancy, labor, or delivery.
The primary modes by which the HIV virus is spread are blood, semen, and vaginal secretions. The virus has also been found
in other body fluids such as saliva, tears, breast milk, and urine. Yet there is scant evidence that AIDS is passed through casual contact. The Public Health Service has stated that no evidence exists to suggest that there is a risk of contracting the HIV virus from day-to-day social or family contact with someone who has AIDS.
The symptoms of acquired immune deficiency syndrome (AIDS) and the symptoms of human immunodefiency virus (HIV) overlap, because these two conditions are caused by the same virus. In the case of HIV, the virus infects the body and can cause an array of symptoms as it undermines the function of the immune system. When the symptoms progress to a certain state, the patient is said to have AIDS.
In a patient with HIV, flu-like symptoms such as tiredness, , easy bruising, swollen lymph nodes, and headaches can emerge. As the infection progresses, the patient may experience diarrhea, lesions on the skin or mouth, repeated yeast infections, severe headaches, and extreme fatigue. A blood test may reveal that the patient has HIV, which has the potential to progress to AIDS. All of these symptoms are also symptoms of AIDS.
Anti-HIV (also called antiretroviral) medications are used to control the reproduction of the virus and to slow or halt the progression of HIV-related disease. When used in combinations, these medications are termed Highly Active Antiretroviral Therapy (HAART). HAART combines three or more anti-HIV medications in a daily regimen, sometimes referred to as a "cocktail". Anti-HIV medications do not cure HIV infection and individuals taking these medications can still transmit HIV to others. Anti-HIV medications approved by the U.S. Food and Drug Administration (FDA) fall into four classes:
1. Nonnucleoside Reverse Transcriptase Inhibitors (NNRTIs), such as nevirappine (Viramune) and efavirenz (Sustiva), bind to and block the action of reverse transcriptase, a protein that HIV needs to reproduce.
2. Nucleoside Reverse Transcriptase Inhibitors (NRTIs), such as zidovudine (Retrovir), tenofovir DF (Viread), and stavudine (Zerit), are faulty versions of building blocks that HIV needs to make more copies of itself. When HIV uses an NRTI instead of a normal building block, reproduction of the virus is stalled.
3. Protease Inhibitors (PIs), such as lopinavir/ritonavir (Kaletra), disable protease, a protein that HIV needs reproduce itself.
4. Fusion Inhibitors, such as enfuvirtide (Fuzeon), are newer treatments that work by blocking HIV entry into cells.
Causes and Risk factors
AIDS is transmitted via three main routes:
The most common mode of transmission is the transfer of body secretions through sexual contact. This is accomplished through exposure of mucous membranes of the rectum, vagina or mouth to blood, semen or vaginal secretions containing the HIV virus.
Blood or blood products can transmit the virus, most often through the sharing of contaminated syringes and needles.
HIV can be spread during pregnancy from mother to fetus.
You cannot get AIDS/HIV from touching someone or sharing items, such as cups or pencils, or through coughing and sneezing. Additionally, HIV is not spread through routine contact in restaurants, the workplace or school. However, sharing a razor does pose a small risk in that blood from a minor nick can be transmitted from one person to another.
Screening for HIV infection is most commonly done by testing blood for HIV antibodies. A newer test, the Orasure test, involves collecting secretions between the cheek and gum and evaluating them for HIV antibodies. Orasure is essentially as accurate as a blood test, and, because it doesn't involve a needle stick, it is favored by many individuals. Orasure is available through physicians' offices and many public health clinics. Finally, a new urine test available for screening, although if the test is positive, blood tests need to be performed for confirmation of the presence of HIV.
In 1996, a home HIV blood test (called Home Access) became available to the public. These home kits are available in pharmacies and by mail. The kit contains a few sharp tools called lancets, a piece of blotting paper marked with a unique identification number and a prepaid return envelope with a protective pouch. After pricking the finger with the lancet, a few drops of blood are blotted onto the paper, sealed into the envelope and sent to the address on the envelope. In about a week, the person calls a toll-free number to get the results of the test.
Medicine and medications
The treatment of HIV infection and AIDS is in a highly dynamic state. Individuals with this condition are advised to seek out experts in their local community who are current with the latest modes of therapy and ongoing clinical trials for evaluating newer therapies.
The following is a partial list of drugs approved for the treatment of HIV infection.
Nonnucleoside Reverse Transcriptase Inhibitors (NNRTIs)
Delavirdine (Rescriptor, DLV) Pfizer
Efavirenz (Sustiva, EFV) Bristol-Myers Squibb.
Nevirapine (Viramune, NVP) Boehringer Ingelheim.
Nucleoside Reverse Transcriptase Inhibitors (NRTIs).
Abacavir (Ziagen, ABC) GlaxoSmithKline.
Abacavir, Lamivudine, Zidovudine (Trizivir) GlaxoSmithKline.
Didanosine (Videx, ddI, Videx EC) Bristol-Myers Squibb.
Emtricitabine (Emtriva, FTC, Coviracil) Gilead Sciences.
Lamivudine (Epivir, 3TC) GlaxoSmithKline.
Lamivudine, Zidovudine (Combivir) GlaxoSmithKline.
Stavudine (Zerit, d4T) Bristol-Myers Squibb.
Tenofovir DF (Viread, TDF) Gilead Sciences.
Zalcitabine (Hivid, ddC) Hoffmann-La Roche.
Atripla (tenofovir, emtricitabine, efavirenz) Gilead Sciences
Zidovudine (Retrovir, AZT, ZDV) GlaxoSmithKline
Protease Inhibitors (PIs)
Amprenavir (Agenerase, APV) GlaxoSmithKline, Vertex Pharmaceuticals.
Atazanavir (Reyataz, ATV) Bristol-Myers Squibb.
Fosamprenavir (Lexiva, FPV) GlaxoSmithKline, Vertex Pharmaceuticals.
Indinavir (Crixivan, IDV) Merck.
Lopinavir, Ritonavir (Kaletra, LPV/r) Abbott Laboratories.
Nelfinavir (Viracept, NFV) Agouron Pharmaceuticals.
Ritonavir (Norvir, RTV) Abbott Laboratories.
Saquinavir (Fortovase, SQV) Invirase Hoffmann-La Roche.
Tipranavir (Aptivus) Boehringer-Ingelheim.
Darunavir (Prezista) Tibotec Therapeutics.
Enfuvirtide (Fuzeon, T-20) Hoffmann-La Roche, Trimeris.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.
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