AIDS 

is short for: 

Acquired Immune Deficiency Syndrome

Nearly 30 million people have died of AIDS, or complications related to the disease since the beginning of the epidemic. In 2010, 1.8 million people died of AIDS worldwide, a 25 percent decrease since 2005, thanks to effective medications and access to treatment. Yet HIV/AIDS still is the single leading cause of death globally.

At the end of 2010, an estimated 34 million people [31.6 million–35.2 million] were living with HIV worldwide, up 17% from 2001. This reflects the continued large number of new HIV infections and a significant expansion of access to antiretroviral therapy, which has helped reduce AIDS-related deaths, especially in more recent years.

Genetic research indicates that HIV originated in west-central Africa during the late nineteenth or early twentieth century. AIDS was first recognized by the U. S. Centers for Disease Control and Prevention in 1981 and its cause, HIV, identified in the early 1980s.

Although treatments for HIV/AIDS can slow the course of the disease, there is no known cure or HIV vaccine. Antiretroviral treatment reduces both the deaths and new infections from HIV/AIDS, but these drugs are expensive and the medications are not available in all countries

There is clear evidence that AIDS is caused by a virus called HIV, which is short for:

Human Immunodeficiency Virus

HIV is a virus. Illnesses caused by a virus cannot be cured by antibiotics. (Although medicines may help to reduce the symptoms) People who have a virus - such as a cold- usually get better after a few days or weeks because the white blood cells of the immune system - which are responsible for fighting diseases - successfully overcomes them.

When a person is infected with HIV the immune system tries to fight off the virus and does make some antibodies, but these antibodies are not able to defeat HIV.
The person is said to be HIV Positive. Many people do not feel ill at all when they are first infected. They may have no symptoms for a long time. They have not yet got AIDS.

HIV acts by gradually destroying the immune system of the infected person. After about 5 to 10 years (although much earlier in a minority of cases) the immune system becomes so weak - or 'deficient'- that it cannot fight off infections as it used to.

Eventually the infected person may lose weight and become ill with diseases like persistent severe diarrhea, fever, or pneumonia, or skin cancer. He or she has now developed AIDS.
At the moment, in spite of much research, there is no cure for HIV or for AIDS and so, sadly, it is almost certain that people diagnosed with AIDS will die.

These are the most common ways that HIV is transmitted from one person to another:

• by having sexual contact with an HIV-infected person

• by sharing needles or injection equipment with an injection drug user who is infected with HIV

• from HIV-infected women to babies before or during birth, or through breast-feeding after birth

HIV also can be transmitted through transfusions of infected blood or blood clotting factors.

HIV is not transmitted by day-to-day contact in the workplace, schools, or social settings. HIV is not transmitted through shaking hands, hugging, or a casual kiss. You cannot become infected from a toilet seat, a drinking fountain, a door knob, dishes, drinking glasses, food, or pets.

The Red Ribbon is an international symbol of AIDS awareness that is worn by people all year round and particularly around world AIDS day to demonstrate care and concern about HIV and AIDS, and to remind others of the need for their support and commitment. The red ribbon started as a "grass roots" effort, and as a result there is no official red ribbon, and many people make their own. To make your own ribbons, get some ordinary red ribbon, about 1.5 cms wide and cut it into strips about 15 cms long. Then fold at the top into an inverted "V" shape and put a safety pin through the center which you use to attach the ribbon to your clothing.

A submicroscopic organism that infects another organism's cells and can cause harm.  Viruses can be composed of DNA or RNA genetic material.

What are some examples of viruses?

Common cold, measles, chicken pox, flu, hepatitis, herpes, polio, …

What is a retrovirus?

A virus that stores its genetic information as RNA, but translates back to DNA before replicating.  This process is the reverse of the usual process and requires a special viral enzyme called Reverse Transcriptase.  HIV is one example of a retrovirus.
 

What is the structure of HIV?

The structure of HIV is like most other viruses.  It consists of:

An envelope, which provides structure to the virus and houses the nucleic acid core.
Outer surface glycoproteins, which act as "keys" that can latch onto the outside of T cells, and help inject the nucleic acid into the cell.
An RNA genome, which contains the information and directions on infecting the cell, replicating, and performing the actions that eventually destroy the cell.
 

What is the immune system?

The body's defense against foreign invaders and cancerous cells.  It involves B cells that produce antibodies, T cells that directly attack foreign cells, and phagocytes that eat up foreign material.

How does HIV affect the immune system?

HIV infects helper T cells that display a certain protein, called the CD4 receptor.  Once inside the cell, HIV takes over the cell and the virus replicates.  In a couple of days, the cell dies and the new virus particles go on to infect more helper T cells.

What are the stages of the disease?

Stage 1 - Primary HIV infection - lasts a few weeks, flu-like symptoms
Stage 2 - Latent period - may last years, patient has no symptoms
Stage 3 - Symptomatic HIV infection - as more and more T cells are destroyed, the body        becomes overly susceptible to opportunistic infections and cancers
Stage 4 - AIDS - helper T cell count is <200, patient develops 1 or more opportunistic infections

What is an opportunistic infection?

An illness that normal people with healthy immune systems can fight off.  People with AIDS cannot fight these infections and will eventually die.  Even the common flu can kill a person with AIDS.

HIV does not survive well outside of the body.  There are many myths about how HIV is passed. Here are the facts:

• You cannot get HIV through casual contact such as shaking hands or hugging a person with HIV/AIDS.

• You cannot get HIV from using a public telephone, drinking fountain, restroom, swimming pool, Jacuzzi, or hot tub.

• You cannot get HIV from sharing a drink.

• You cannot get HIV from being coughed or sneezed on by a person with HIV/AIDS.

• You cannot get HIV from giving blood.

• You cannot get HIV from a mosquito bite.

HIV/AIDS Glossary

Acquired Immunodeficiency Syndrome (AIDS)
A disease of the body's immune system caused by the human immunodeficiency virus (HIV). AIDS is characterized by the death of CD4 cells (an important part of the body's immune system), which leaves the body vulnerable to life-threatening conditions such as infections and cancers.

Antibody
Also known as immunoglobulin. A protein produced by the body's immune system that recognizes and fights infectious organisms and other foreign substances that enter the body. Each antibody is specific to a particular piece of an infectious organism or other foreign substance.

Antiretroviral Therapy (ART)
Treatment with drugs that inhibit the ability of retroviruses (such as HIV) to multiply in the body. The antiretroviral therapy recommended for HIV infection is referred to as highly active antiretroviral therapy (HAART), which uses a combination of medications to attack HIV at different points in its life cycle.

CD4 Cell
Also known as helper T cell or CD4 lymphocyte. A type of infection-fighting white blood cell that carries the CD4 receptor on its surface. CD4 cells coordinate the immune response, signaling other cells in the immune system to perform their special functions. The number of CD4 cells in a sample of blood is an indicator of the health of the immune system. HIV infects and kills CD4 cells, leading to a weakened immune system

CD4 Cell Count
A measurement of the number of CD4 cells in a sample of blood. The CD4 count is one of the most useful indicators of the health of the immune system and the progression of HIV/AIDS. A CD4 cell count is used by health care providers to determine when to begin, interrupt, or halt anti-HIV therapy; when to give preventive treatment for opportunistic infections; and to measure response to treatment. A normal CD4 cell count is between 500 and 1,400 cells/mm3 of blood, but an individual's CD4 count can vary. In HIV-infected individuals, a CD4 count at or below 200 cells/mm3 is considered an AIDS-defining condition.

Clinical Trial
A research study that uses human volunteers to answer specific health questions. Carefully conducted clinical trials are regarded as the fastest and safest way to find effective treatments for diseases and conditions, as well as other ways to improve health. Interventional trials use controlled conditions to determine whether experimental treatments or new ways of using known treatments are safe and effective. Observational trials gather information about health issues from groups of people in their natural settings.

Co-Infection
Infection with more than one virus, bacterium, or other micro-organism at a given time. For example, an HIV-infected individual may be co-infected with hepatitis C virus (HCV) or tuberculosis (TB).

Human Immunodeficiency Virus (HIV)
The virus that causes Acquired Immunodeficiency Syndrome (AIDS). HIV is in the retrovirus family, and two types have been identified: HIV-1 and HIV-2. HIV-1 is responsible for most HIV infections throughout the world, while HIV-2 is found primarily in West Africa.

Immune System
The collection of cells and organs whose role is to protect the body from foreign invaders. Includes the thymus, spleen, lymph nodes, B and T cells, and antigen-presenting cells.

Investigational Drug
Also known as experimental drug. A drug that has not been approved by the FDA to treat a particular disease or condition. The safety and effectiveness of an investigational drug must be tested in clinical trials before the manufacturer can request FDA approval for a specific use of the drug.

Latency
The time period when an infectious organism is in the body but is not producing any noticeable symptoms. In HIV disease, latency usually occurs in the early years of infection. Also refers to the period when HIV has integrated its genome into a cell's DNA but has not yet begun to replicate.

Microbicide
A natural or man-made substance that kills microbes. Researchers are studying the use of microbicides to prevent the transmission of sexually transmitted diseases (STDs), including HIV infection.

Opportunistic Infections (OIs)
Illnesses caused by various organisms that occur in people with weakened immune systems, including people with HIV/AIDS. OIs common in people with AIDS include Pneumocystis carinii pneumonia; cryptosporidiosis; histoplasmosis; toxoplasmosis; other parasitic, viral, and fungal infections; and some types of cancers.

T Cell
A type of lymphocyte (disease-fighting white blood cell). The "T" stands for the thymus, where T cells mature. T cells include CD4 cells and CD8 cells, which are both critical components of the body's immune system.

Therapeutic HIV Vaccine
Any HIV vaccine used for the treatment of an HIV-infected person. Therapeutic HIV vaccines are designed to boost an individual's immune response to HIV infection in order to better control the virus. This therapeutic approach is currently being tested in clinical trials

Vaccine
A substance that stimulates the body’s immune response in order to prevent or control an infection. A vaccine is typically made up of some part of a bacteria or virus that cannot itself cause an infection. Researchers are testing vaccines both to prevent and treat HIV/AIDS; however, there is currently no vaccine approved for use outside of clinical trials.

Sources: New Scientist, WHO, UNAIDS, New York Times, The Henry J. Kaiser Family Foundation, AIDS Action