According to the Center of Disease Control, the United States experiences as many as 37,041 news cases of AIDS each year. Those numbers join the estimated 1,051,875 AIDS cases in the United States (as of 2007). According to the International AIDS charity AVERT, there are an estimated 33 million people living throughout the world with HIV/AIDS. Of those, as many as 2 million will die each year from the disease after it has progressed to full blown AIDS.
Full-blown AIDS does not occur until the human immunodeficiency virus (HIV) has run its full course. After primary infection of HIV, the body's immune system becomes under attack by the virus as it disables the body's ability to protect itself from disease. The length of this stage of infection varies depending on the individual and the form of treatment being given. HIV is not considered AIDS until certain Center for Disease Control criteria are met. To be diagnosed with full blown AIDS, the patient must either have a low enough lymphocyte count, or must be afflicted with a common AIDS related opportunistic infection.
According to the Center for Disease Control, the final stage of full-blown AIDS is marked by a dramatic drop in lymphocytes. Lymphocytes are important immune system cells that help fight off disease. The HIV/AIDS virus uses these cells to replicate and increase in number, destroying the lymphocyte's abilities to protect the body in the process. To reach full-blow AIDS status, the lymphocyte cell count must be less than 200. A normal lymphocyte cell count ranges from 800 to 1,200.
The second criteria for moving into the final stages of full-blown AIDS is the presence of an opportunistic infection. Opportunistic infections are diseases that are often fought by the body when healthy, but take advantage of the body once the immune system becomes compromised. Common opportunistic infections include generalized lymphadenopathy, pneumocystis pneumonia, herpes zoster, lymphoma, or tuberculosis. Since the immune system is compromised during this disorder, many of those that die from AIDS, will die from an opportunistic infection and not the disease itself.