Part one of term paper
AIDS is the final, life-threatening stage of infection with human immunodeficiency virus (HIV). AIDS stands for acquired immunodeficiency syndrome. The name refers to the fact that HIV severely damages the patient's disease-fighting immune system. Cases of AIDS were first identified in 1981 in the United States, but researchers have traced ...

Part two of term paper
... France identified another closely related virus that also produces AIDS. This virus, named HIV-2, occurs mainly in Africa. HIV-1 occurs throughout the world. HIV infects certain white blood cells, including T-helper cells and macrophages, that play key roles in the functioning of the immune system. The virus attaches to specific molecules found only on the surface of the cells. These molecules are called CD4 receptor molecules, and the cells themselves are often referred to as CD4 cells. When a ...