Friday, October 31, 2014

AIDS and HIV Infection

Definition

AIDS stands for Acquired Immune Deficiency Syndrome. AIDS is a serious condition that weakens the body's immune system, leaving it unable to fight off illness.

AIDS is the last stage in a progression of diseases resulting from a viral infection known as the Human Immunodeficiency Virus (HIV or AIDS virus). The diseases include a number of unusual and severe infections, cancers and debilitating illnesses, resulting in severe weight loss or wasting away, and diseases affecting the brain and central nervous system.

There is no cure for HIV infection or AIDS nor is there a vaccine to prevent HIV infection. However, new medications not only can slow the progression of the infection, but can also markedly suppress the virus, thereby restoring the body’s immune function and permitting many HIV-infected individuals to lead a normal, disease-free life.

Description

The immune system is a network of cells, organs and proteins that work together to defend and protect the body from potentially harmful, infectious microorganisms (microscopic life-forms), such as bacteria, viruses, parasites and fungi. The immune system also plays a critical role in preventing the development and spread of many types of cancer.

When the immune system is missing one or more of its components, the result is an immunodeficiency disorder. AIDS is an immunodeficiency disorder.

Lymphocytes (white blood cells) are one of the main types of immune cells that make up the immune system. There are two types of lymphocytes: B cells and T cells. (T cells are also called CD4 cells, CD4 T cells, or CD4 cell lymphocytes). B cells secrete antibodies (proteins) into the body's fluids to ambush and attack antigens (foreign proteins such as bacteria, viruses or fungi). T cells directly attack and destroy infected or malignant cells in the body.

There are two types of T cells: helper T cells and killer T cells. Helper T cells recognize the antigen and activate the killer T cells. Killer T cells then destroy the antigen.

When HIV is introduced into the body, this virus is too strong for the helper T cells and killer T cells. The virus then invades these cells and starts to reproduce itself, thereby not only killing the CD4 T cells, but also spreading to infect otherwise healthy cells.

The HIV virus cannot be destroyed and lives in the body undetected for months or years before any sign of illness appears. Gradually, over many years or even decades, as the T cells become progressively destroyed or inactivated, other viruses, parasites or cancer cells (called "opportunistic diseases") which would not have been able to get past a healthy body's defense, can multiply within the body without fear of destruction. Commonly seen opportunistic diseases in persons with HIV infection include: pneumocystis carinii pneumonia, tuberculosis, candida (yeast) infection of the mouth, throat or vagina, shingles, cytomegalovirus retinitis and Kaposi's sarcoma.

Causes

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.

Symptoms

Immediately following infection with HIV, most individuals develop a brief, nonspecific “viral illness” consisting of low grade fever, rash, muscle aches, headache and/or fatigue. Like any other viral illness, these symptoms resolve over a period of five to 10 days. Then for a period of several years (sometimes as long as several decades), people infected with HIV are asymptomatic (no symptoms). However, their immune system is gradually being destroyed by the virus. When this destruction has progressed to a critical point, symptoms of AIDS appear. These symptoms are as follows:

  • extreme fatigue
  • rapid weight loss from an unknown cause (more than 10 lbs. in two months for no reason)
  • appearance of swollen or tender glands in the neck, armpits or groin, for no apparent reason, lasting for more than four weeks
  • unexplained shortness of breath, frequently accompanied by a dry cough, not due to allergies or smoking
  • persistent diarrhea
  • intermittent high fever or soaking night sweats of unknown origin
  • a marked change in an illness pattern, either in frequency, severity, or length of sickness
  • appearance of one or more purple spots on the surface of the skin, inside the mouth, anus or nasal passages
  • whitish coating on the tongue, throat or vagina
  • forgetfulness, confusion and other signs of mental deterioration

It can take as short as a year to as long as 10 to 15 years to go from being infected with HIV to "full-blown" AIDS.

According to the Center for Disease Control and Prevention, a person is considered to have AIDS when they have a T cell count (also called CD4 cell count) of 200 or less (healthy T cell levels range from 500 to 1500) or they have an AIDS-defining condition. The AIDS-defining conditions are:

· Candidiasis

· Cervical cancer (invasive)

· Coccidioidomycosis, Cryptococcosis, Cryptosporidiosis

· Cytomegalovirus disease

· Encephalopathy (HIV-related)

· Herpes simplex (severe infection)

· Histoplasmosis

· Isosporiasis

· Kaposi's sarcoma

· Lymphoma (certain types)

· Mycobacterium avium complex

· Pneumocystis carinii pneumonia

· Pneumonia (recurrent)

· Progressive multifocal leukoencephalopathy

· Salmonella septicemia (recurrent)

· Toxoplasmosis of the brain

· Tuberculosis

· Wasting syndrome

People who are not infected with HIV may also develop these diseases; the presence of any one of these conditions does not mean the person has AIDS. To be diagnosed with AIDS, a person must be infected with HIV.

Some people infected with HIV may develop a disease that is less serious than AIDS, referred to as AIDS Related Complex (ARC). ARC is a condition caused by the AIDS virus in which the patient tests positive for AIDS infection and has a specific set of clinical symptoms. However, ARC patients' symptoms are often less severe than those with classic AIDS because the degree of destruction of the immune system has not progressed as far as it has in patients with classic AIDS.

Symptoms of ARC may include loss of appetite, weight loss, fever, night sweats, skin rashes, diarrhea, tiredness, lack of resistance to infection or swollen lymph nodes.

Note:Not everyone who has been infected with HIV develops AIDS. Very rarely, some individuals can be infected with HIV yet maintain normal immune function and general good health even after 20 years of infection.

Diagnosis

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.

Treatment

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.

(View more complete list of HIV drugs).

How many pills you will need to take and how often you will take them depends on what medications you and your doctor choose.

There is no one "best" regimen. You and your doctor will decide which medications are right for you. For people taking HAART for the first time, the recommended regimens are:

  • Sustiva + Truvada, Sustiva + Epzicom, or Atripla
  • Kaletra + Truvada, Kaletra + Epzicom, or Kaletra + Combivir

In general, taking only one or two drugs is not recommended because any decrease in viral load is almost always temporary without three or more drugs. The exception is the recommendation for pregnant women, who may take Combivir plus nevirapine to reduce the risk of passing HIV to their infants. If you are pregnant or considering becoming pregnant, there are additional treatment considerations. Recently, a number of drugs have been developed that combine two or even three separate medications in a single pill. Some of these, such as Truvada (emtricitabine + tenofovir) and Epzicom (abacavir + lamivudine) need be taken only once daily. Atripla (emtricitabine + tenofovir + efavirenz) combines three drugs in one pill and needs to be taken only once daily, thereby providing a complete HAART regimen with one pill once daily.

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

Fusion Inhibitors

Enfuvirtide (Fuzeon, T-20) Hoffmann-La Roche, Trimeris

Questions

What tests need to be done to diagnose this condition? How accurate is the test?

Does a positive test mean AIDS?

What type of treatment will you be recommending? How successful is it?

Will you be prescribing any medications to prevent the development of some AIDS related infections?

Are there any alternative treatments available?

Are there experimental protocols in which I might participate?

What are the chances of remaining well? For how long?

Are there any support groups in the area?

Prevention

The only way to protect from contracting AIDS sexually is to abstain from sex outside of a mutually faithful relationship with a partner whom the person knows is not infected with the AIDS virus. Otherwise, risks can be minimized if they:

  • Don't have sexual contact with anyone who has symptoms of AIDS or who is a member of a high risk group for AIDS.
  • Avoid sexual contact with anyone who has had sex with people at risk of getting AIDS.
  • Don't have sex with prostitutes.
  • Avoid having sex with anyone who has multiple and/or anonymous sexual partners.
  • Avoid oral, genital and anal contact with partner's blood, semen, vaginal secretions, feces or urine. Unless they know with absolute certainty that their partner is not infected, a latex condom should be used during each sexual act, from start to finish. The use of a spermicidal agent may provide additional protection.
  • Avoid anal intercourse altogether.
  • Don't share toothbrushes, razors or other implements that could become contaminated with the blood of anyone who is or might be infected with the AIDS virus.
  • Exercise caution regarding procedures, such as acupuncture, tattooing, ear piercing, etc., in which needles or other nonsterile instruments may be used repeatedly to pierce the skin and/or mucous membranes.

    Such procedures are safe if proper sterilization methods are employed or disposable needles are used. Ask what precautions are taken before undergoing such procedures.

  • If an individual is scheduling surgery in the near future, and is able, they could consider donating blood for their own use. This will eliminate completely the already very small risk of contracting AIDS through a blood transfusion. It will also eliminate the risk of contracting other bloodborne diseases (such as hepatitis) from a transfusion.

If a person is an IV drug user, adhere to the prevention tips mentioned earlier, as well as:

  • Get professional help for terminating the drug habit.
  • Do not share needles or syringes. Be aware that some street sellers are resealing previously used needles and selling them as new.
  • Clean the needle before using.

Some people apparently remain well after infection of the AIDS virus. They may have no physically apparent symptoms of illness. However, if proper precautions are not used with sexual contacts and/or intravenous drug use, these infected individuals can spread the virus to others.

Anyone who thinks he or she is infected, or who is involved in high-risk behaviors, should not donate his/her blood, organs, tissues, or sperm as they may now contain the AIDS virus.