Lesson 3 HIV/AIDS

What is HIV/AIDS?  Human Immunodeficiency Virus (HIV)- virus that attacks the immune system  Once it enters the body, it finds a way to destroy the white blood cells that fight disease  Acquired Immunodeficiency Syndrome (AIDS)- a disease in which the immune system is weakened  AIDS has become one of the deadliest diseases in human history  25 million people around the world have died from AIDS  Considered a pandemic- global outbreak  Statistics of HIV/AIDS Approx. 12 million of the people who have HIV/AIDS are in the age group Half of all new HIV infections are among young people. 7,000 young people become infected everyday.

Understanding HIV/AIDS  The virus cannot live outside the human body  Exposure to air at room temperature kills the virus  HIV cannot spread through airborne transmission or casual contact  HIV is transmitted only when one person’s infected blood, semen, or vaginal secretions comes in contact w/ another person’s broken skin or mucous membranes (found in mouth, eyes, nose, vagina, rectum)

HIV can be spread:  1) During sexual intercourse  2) Sharing needles  3) From mother to baby

How HIV Affects the Immune System  HIV attacks the body’s immune system by destroying lymphocytes (specialized white blood cells that perform many immune functions)  2 types of lymphocytes: B Cells and T Cells. Helper T Cells stimulate B Cells to produce antibodies which destroy pathogens that enter the body.  When HIV enters certain cells, including lymphocytes, it reproduces itself and eventually destroys the cell. HIV can mutate causing the anitbodies not to recognize it.  As more cells are destroyed, the immune system becomes weaker  Body becomes more vulnerable to AIDS-opportunistic illnesses-infections the body could fight off if the immune system were healthy

3 Stages of HIV before progressing to AIDS  1) Asymptomatic stage  2) Middle Stage  3) Symptomatic Stage  4) AIDS Stage

Giving or Receiving Blood: Is It Safe?  Some people fear they might be infected w/ HIV when donating or receiving blood.  Health care professionals always use sterile needles to draw blood  All donated blood has been tested for HIV since 1985  U.S. blood supply is among the safest in the world

Answer the following questions and hand in  1) How does HIV affect the human immune system?  2) How can you protect yourself from contracting HIV/AIDS?  3) Why do the body’s antibodies fail to protect people from HIV?  4) Why has the CDC implemented mandatory testing for all donated blood?  5) How does the immune system respond to the presence of HIV in the body?