Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
HIV (human immunodeficiency virus) infection has now spread to every country in the world. Statistics show that approximately 40 million people are currently living with HIV infection, and an estimated
35 million have died from this disease since the beginning of the epidemic. The scourge of HIV has been particularly devastating in sub-Saharan Africa and South Africa, but infection rates in other countries remain high. In the United States, approximately 1 million people are currently infected. Here are a few key
facts about the disease:
Globally, 85% of HIV transmission is through heterosexual intercourse.
In the United States, heterosexual transmission accounts for approximately
one-third of new diagnoses. Male-to-male sexual contact still accounts for
more than half of new diagnoses in the U.S. Intravenous drug use contributes to the remaining cases. Because the diagnosis may occur years after infection, it is likely that a higher proportion of recent infections are due to heterosexual transmission.
Infections in women are increasing. Worldwide, almost half of people with HIV are women. In the United States, approximately 20% of new diagnoses are in women, and the proportion is rising.
There is good news on one front. New HIV infections in U.S. children have fallen dramatically. This is largely a result of testing and treating infected mothers, as well as establishing uniform testing guidelines for blood products.
In order to understand HIV and acquired immunodeficiency syndrome (AIDS), it is important to understand the meanings behind these terms:
HIV stands for the human immunodeficiency virus. It is one of a group of viruses known as retroviruses. After getting into the body, the virus kills or damages cells of the body's immune system. The body tries to keep up by making new cells or trying to contain the virus, but eventually the HIV wins out and progressively destroys the body's ability to fight infections and certain cancers.
The virus structure has been studied extensively, and this ongoing research has helped scientists develop new treatments for HIV/AIDS. Although all HIV viruses are similar, small variations or mutations in the genetic material of the virus create drug-resistant viruses. Larger variations in the viral genes are found in different viral subtypes. Currently, HIV-1 is the predominant subtype that causes HIV/AIDS.
AIDS stands for the acquired immunodeficiency syndrome. HIV causes AIDS and occurs when the virus has destroyed so much of the body's defenses that immune-cell counts fall to critical levels or certain life-threatening infections or cancers develop.