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Author(s): Nancy Moreno, PhD, Barbara Tharp, MS, Deanne Erdmann, MS, Sonia Rahmati Clayton, PhD, and James Denk, MA.

Disease Information: HIV/AIDS

Everyone has heard of HIV and AIDS. You might even know someone infected with HIV. But what, exactly, is HIV? What’s the difference between AIDS and HIV? And why is it important for you to know about it?

The Difference Between HIV & AIDS 
HIV (human immunodeficiency virus) is the very serious—and always deadly—virus that causes the disease called AIDS (acquired immunodeficiency syndrome). Scientists and doctors aren’t sure exactly when or where the HIV virus developed, but they know it has been present in the U.S. since the late 1970s. They also know that the HIV virus kills specialized blood cells needed by the body’s immune system to fight disease. 

Over time, as the virus kills more and more of these blood cells, people who carry the virus (referred to as HIV-positive) lose the ability to battle infections and diseases. People infected with HIV often develop specific illnesses or types of infections associated with this virus. At that point, they are considered to have AIDS. Microbes that might not make another person sick can be life threatening for people with AIDS, because their immune systems are weakened.

A simple blood test can show if a person has the HIV virus. On the other hand, doctors have to look for specific symptoms, such as a decrease in the number of certain blood cells, to determine if a patient’s illness has progressed to AIDS. It may take years for these symptoms to appear or for a person to begin feeling ill, so HIV is considered to have a long incubation period (length of time between when the disease-causing microbe enters the body and when symptoms develop). Thus, it is possible for someone to have the virus in his or her body and not know it. All the while, this person could be spreading HIV to others. 

Facts, Myths & Hope
You can become infected with HIV if you come in close contact with body fluids, such as blood, of someone who has the virus. Most often, HIV is spread through unprotected sex or by sharing needles for drug use. HIV-positive mothers can infect their babies during pregnancy or birth, or by breast-feeding. It also is possible to become infected if dirty needles are used when getting tattoos or piercings.

You cannot get HIV or AIDS through saliva, sweat or tears; from mosquitoes; or from an animal bite, such as from a dog or cat. Some animals can carry viruses that are similar to HIV, but these viruses do not affect humans. 

Twenty years ago, about half of all people with HIV developed AIDS within ten years. But in the last decade, powerful new drugs have been created to slow the progress of HIV. Other medicines also are being developed to prevent or treat life-threatening AIDS-related illnesses. The side effects of treatment are very serious, but many people infected with HIV now are able live longer than they would have in the past. 

A Universal Problem
Unfortunately, not everyone is able to get the new medicines, and millions of people continue to die from AIDS every year. By the end of 2003, more than 500,000 people in the U.S. had died from AIDS—about as many people as live in Las Vegas or Oklahoma City. In 2006, about 2.9 million people around the world died from AIDS; 39.5 million people were living with HIV; and 4.3 million people became newly infected with HIV. Today, about one of every 300 Americans over the age of 13 is HIV-positive.

HIV doesn’t care who you know, how old you are, how wealthy or poor you may be, the color of your skin, your gender, or your sexual orientation. If you do risky things, you may become infected. And once you’re infected, you have HIV forever. While new drug treatments are helping some people with HIV live longer, more normal lives, there is no cure for this disease.

Funded by the following grant(s)

Science Education Partnership Award, NIH

Grant Number: 5R25RR018605