For World AIDS day
WHAT IS HIV?
To understand what HIV is, let’s break it down:
H – Human – This particular virus can only infect human beings.
I – Immunodeficiency – HIV weakens your immune system by destroying important cells that fight disease and infection. A “deficient” immune system can’t protect you.
V – Virus – A virus can only reproduce itself by taking over a cell in the body of its host.
Human Immunodeficiency Virus is a lot like other viruses, including those that cause the “flu" or the common cold. But there is an important difference – over time, your immune system can clear most viruses out of your body. That isn’t the case with HIV – the human immune system can’t seem to get rid of it. Scientists are still trying to figure out why.
We know that HIV can hide for long periods of time in the cells of your body and that it attacks a key part of your immune system – your T-cells or CD4 cells. Your body has to have these cells to fight infections and disease, but HIV invades them, uses them to make more copies of itself, and then destroys them.
Over time, HIV can destroy so many of your CD4 cells that your body can’t fight infections and diseases anymore. When that happens, HIV infection can lead to AIDS.
WHAT IS AIDS?
To understand what AIDS is, let’s break it down:
A – Acquired – AIDS is not something you inherit from your parents. You acquire AIDS after birth.
I – Immuno – Your body’s immune system includes all the organs and cells that work to fight off infection or disease.
D – Deficiency – You get AIDS when your immune system is “deficient,” or isn’t working the way it should.
S – Syndrome – A syndrome is a collection of symptoms and signs of disease. AIDS is a syndrome, rather than a single disease, because it is a complex illness with a wide range of complications and symptoms.
Acquired Immunodeficiency Syndrome is the final stage of HIV infection. People at this stage of HIV disease have badly damaged immune systems, which put them at risk for opportunistic infections (OIs).
You will be diagnosed with AIDS if you have one or more specific OIs, certain cancers, or a very low number of CD4 cells. If you have AIDS, you will need medical intervention and treatment to prevent death.
For more information, see CDC’s Basic Information About HIV And AIDS.
WHERE DID HIV COME FROM?
Scientists believe HIV came from a particular kind of chimpanzee in Western Africa. Humans probably came in contact with HIV when they hunted and ate infected animals. Recent studies indicate that HIV may have jumped from monkeys to humans as far back as the late 1800s.
For more information, see CDC’s Where Did HIV Come From?
WHICH BODY FLUIDS CAN TRANSMIT HIV?
HIV transmission can occur when fluids containing HIV from an infected person enter the body of an uninfected person. These fluids include:
- Semen (cum)
- Pre-seminal fluid (pre-cum)
- Vaginal fluid
- Breast milk
HIV can enter the body through:
- Lining of the anus or rectum
- Lining of the vagina and/or cervix
- Opening to the penis
- Mouth that has sores or bleeding gums
- Cuts and sores
- Needles (syringes)
Healthy skin is an excellent barrier against HIV and other viruses and bacteria. HIV cannot enter the body through unbroken skin.
These are the most common ways that HIV is transmitted from one person to another:
- Having sex (anal, vaginal, or oral) with someone who is HIV-positive
- Sharing needles or injection equipment (“works”) with a user who is HIV-positive
- From HIV-positive women to their babies—before or during birth, or through breastfeeding after birth
Some healthcare workers have been infected after being stuck with needles contaminated with HIV-infected blood—or, less frequently, by having infected blood splashed into their eyes, nose, mouth, or into an open cut or sore.
For more information, see CDC’s HIV Transmission and Exposure to Blood: What Healthcare Personnel Need to Know(PDF).
HIV also can be transmitted through transfusion of infected blood or blood clotting factors. However, since 1985, all donated blood in the United States has been tested for HIV. The risk of infection through transfusion of blood or blood products is extremely low—but if you have risk factors for HIV, you should avoid donating blood. It is important to remember that you should not donate blood for the purpose of getting tested for HIV.
For more information, see CDC’s How safe is the blood supply in the United States?
learn more about AIDS, including help for people who are newly infected and who may be infected here