What Is HIV (and How Is It Different from AIDS)?

Studies around HIV, or human immunodeficiency virus, have greatly improved our understanding of the disease since its initial appearance in the early 1980s. At that time, our lack of knowledge about HIV meant almost no treatment was available, leading to a global pandemic and, unfortunately, an early death for those infected with HIV.

Thankfully, this is no longer the case. Now that more information is available, various treatments for HIV have allowed those infected to live longer, healthier lives, and prevention efforts have successfully reduced HIV rates in the United States and around the world.

Here’s what we know about HIV. This virus attacks the immune system, or the part of our bodies that protect us against infections. Specifically, HIV attacks the CD4 T-cells. As these cells are destroyed, the body becomes less able to fight off infections, and HIV patients become more vulnerable to cancers, viral hepatitis, tuberculosis, and other infections.

Doctors can track the progression of a patient’s HIV using the T-cell count. Once a person infected with HIV has a T-cell count under 200, this condition is now considered AIDS, or Acquired Immune Deficiency Syndrome. AIDS is the last stage of HIV infection, so those with AIDS are more vulnerable to infections than those with HIV. (Here are more details about the symptoms of HIV stages.)

There are two types of HIV, known simply as HIV-1 and HIV-2. In the United States, most cases are HIV-1 (the second type is more prevalent in West Africa).

Transmission of HIV-1 occurs when bodily fluids—semen, blood, breast milk—from an infected person enter another person’s bloodstream. Contrary to popular belief, HIV is not transmitted through air, water, hugging, saliva, sweat, tears, mosquitos, or sharing food or drinks.

Usually, HIV is passed in one of three ways: sexual contact, sharing needles, or between mother and child through pregnancy, labor and delivery, or breastfeeding.

Abstinence is the only guaranteed way to prevent sexual transmission of HIV, but condoms can reduce the risk. It is important to remember that not all people with HIV show symptoms, so consistently using a condom with sexual partners is highly recommended. In fact, if someone has HIV and another sexually transmitted disease, the infected person is more likely to transmit the HIV virus.

Shared needles can transmit HIV, which is why 9 percent of HIV diagnoses are caused by injection drug use. Another instance in which HIV could be transmitted through needles is at the tattoo parlor. Make sure you visit trusted businesses and that all needles and devices are sterilized before receiving any tattoos or piercings. It is possible for a healthcare worker to become infected with HIV if they are stuck with a contaminated needle, but this is rare. 

Mothers can transmit the HIV virus to their children in multiple ways. Pregnant women should be tested for HIV before or during pregnancy to receive the proper medical care, and anti-retroviral medicines can reduce the chances of the virus being transmitted to the unborn child. Additionally, doctors do not recommend breastfeeding to HIV-infected mothers.

The CDC recommends that everyone between the ages of 13 and 64 should be tested for HIV at least once. Some populations should be tested at least once a year, such as gay or bisexual men, those who share needles, those with other sexually tra

Dr. Keri Peterson

This video features Dr. Keri Peterson. Dr. Keri Peterson specializes in Internal Medicine at Mount Sinai Medical Center in New York City and is board certified in Internal Medicine. She holds appointments at Lenox Hill Hospital and Mount Sinai Medical Center.

Duration: 05:41. Last Updated On: 2016-10-12
Reviewed by: Dr. Preeti Parikh, Dr. Holly Atkinson, Dr. Mera Goodman . Review date: January 08, 2017
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