Chapter 20, Problem 3CTQ

Summary Introduction

To explain:

The reasons that over the years the incidence of HIV infection has declined in the U.S while the prevalence of AIDS has increased.

Concept introduction:

HIV belongs to the retroviruses family, all of which contains the RNA genome. The virus attaches and penetrates T cells of the human that play an essential role in the immunity of a person. Infected cells express the viral genes and produce new viruses which in turn infect other T cells leading to a decrease in the population of T cells. Eventually, loss of T cells results in a decline in the immune system of the body for other diseases as well.