Grocery Coupons

Grocery Coupons

Members can print free savings coupons

Brain Health Center

Brain Health Center

Learn how to live smart and stay sharp

Amazon Kindle

Amazon Kindle

Members save on e-
readers and tablets

Caring for loved ones?

Caring for loved ones?

Find the resources you need

Acquired Immune Deficiency Syndrome (AIDS) Learning Center

  • Enlarge
  • Print
  • Recommend

Acquired Immune Deficiency Syndrome (AIDS)


Human immunodeficiency virus (HIV) is contracted through sexual contact via anal, oral, or vaginal intercourse; blood exchange; shared intravenous syringes; or from mother to child during pregnancy, labor, delivery, or breast-feeding. It originated in primates but ultimately transmitted to humans. The first cases were discovered in Africa in 1950s and 1960s, and the disease spread rapidly throughout the globe, affecting more than 36 million people by 2001. 

HIV causes progressive failure of the immune system, making the body far more susceptible to infections and cancer.  Although some antiretroviral drugs reduce the mortality and morbidity of the infection, there is no cure for HIV, and it's high genetic variability makes treatment options limited. Most untreated HIV victims ultimately develop acquired immunodeficiency syndrome (AIDS).

As AIDS greatly compromises the immune system, patients die not from AIDS itself, but from opportunistic infections or malignancies, such as the common cold virus or pneumonia. The length of time for HIV to develop into AIDS varies but, if left untreated, HIV will transition to AIDS approximately 10 years after infection.


Most experts agree that HIV is a descendent of the simian immunodeficiency virus (SIV), which initially only affected primates but, after mutating, was able to be transmitted to humans, likely as a result of humans killing monkeys and eating their flesh.  After being acquired by humans, and once the disease was regularly transmitted from person to person, it became known as a human virus.  HIV was transmitted throughout the world when travel out of Africa to other parts of the world became accessible.  Roads and river transportation allowed for easier and quicker travel to industrialized parts of the world. The syndrome was finally regarded as a clinical virus in 1981 and named in 1986. 

Types of HIV

There are two types of HIV: Type 1, which can be broken down into several subgroups based on location, and type 2, which seems to be less easy to transmit.  Both are contracted through the exchange of bodily fluids, and both can cause clinically indistinguishable AIDS, the final, life-threatening stage of HIV.

  • HIV-1: HIV-1 is the more predominant form of the virus and is split into several subgroups. The dominant strain, group M, was found in chimpanzees and monkeys living in West Africa and is responsible for the AIDS pandemic.
  • HIV-2: HIV-2 is found primarily in West Africa and is not as transmittable or virulent as HIV-1, but it causes AIDS more frequently than type 1. The period between initial infection and illness is longer in HIV-2 cases.
Content licensed from:

Written by: The Healthline Editorial Team
Published on Aug 09, 2012
Medically reviewed on Aug 09, 2012 by Jennifer Monti, MD, MPH

This feature is for informational purposes only and should not be used to replace the care and information received from your health care provider. Please consult a health care professional with any health concerns you may have.
Condition & Treatment Search
Symptom Search
Drug Search



Discounts & Benefits

From companies that meet the high standards of service and quality set by AARP.

Tanger Outlets

Members can get a free Tanger Coupon Book with discount offers from top brand names.

Woman trying on glasses in optometrists shop

Members save 25% on orders of $200 or more and get 25% off lens upgrades at Glasses.com.

Outback Steak

Members save 15% on lunch every day & on dinner Mon-Thurs at Outback Steakhouse.

Member Benefits

Join or renew today! AARP members receive exclusive member benefits & affect social change.


African American, Asian Community Page

AARP In Your Corner

Visit Black Community, Español  and Asian Community pages.

AARP Drivers Safety logo

Driver Safety Program

Register at a location near you to keep your driving skills sharp. 

Create the Good

Create The Good 

Find opportunities to volunteer in your neighborhood. 

AARP Drive to End Hunger Logo

Drive to End Hunger

NASCAR champ Jeff Gordon teams up with AARP Foundation. 


Green Dot Prepaid Card

Prepaid MasterCard

AARP Foundation Prepaid MasterCard brought to you by Green Dot.

Most Popular


Nothing has been viewed