Preface

Both HIV-1 and HIV-2 cause AIDS, but HIV-1 is found worldwide, whereas HIV-2 is found primarily in West Africa.

It is estimated that approximately 40 million people worldwide are infected with HIV, and two-thirds of them live in the sub-Saharan Africa. Three regions, Africa, Asia, and Latin America, have the highest rates of new infections, and AIDS is the fourth leading cause of death worldwide. Since 1981, more than 980,000 cases of AIDS have been reported in the US alone, and according to CDC, more than 1,000,000 Americans may be infected with HIV.

HIV preferentially infects and kills CD4+ T lymphocytes, and by killing or damaging CD4+ T cells of the body's immune system, HIV progressively destroys the body's ability to fight infections. People diagnosed with AIDS often suffer from lifethreatening diseases caused by opportunistic infections. HIV also infects other cells, such as macrophages, monocytes and dendritic cells.

This book provides a detailed overview on the HIV transmission, how HIV infection alters the host immune responses, and on the prevention and treatment of AIDS related diseases.

> **Vishwanath Venketaraman Ph.D.,**  Assistant Professor Microbiology/Immunology, Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences United States

**Part 1** 

**HIV and Altered Immune Responses** 
