Pongphol PongthaisongAnimal Immunology

6 Feb 2014

• HIV/AIDS Worldwide• General information of AIDS• AIDS and Immunity

HIV/AIDS Worldwide

• 38 million people live with HIV/AIDS worldwide.

• Sub-Saharan Africa is home to 70% of the people living with HIV.

• 2.1 million children are infected with HIV/AIDS in the world

Top HIV/AIDS-Infected Countries

1. South Africa

2. Nigeria

3. Zimbabwe

4. Tanzania

5. The Congo

6. Ethiopia

7. Kenya

8. Mozambique

Source: Steinbrook R. The AIDS epidemic in 2004. NEJM. 2004;351:115-117.

9. United States

10. Russian Federation

11. China

12. Brazil

13. Thailand

Sub-Saharan Africa

Acquired - because it's a condition one must acquire or get infected with, not something transmitted through the genes

Immune - because it affects the body's immune system, the part of the body which usually works to fight off germs such as bacteria and viruses

Deficiency - because it makes the immune system deficient

Syndrome - because someone with AIDS may experience a wide range of different diseases and opportunistic infections

AIDS is the final stage

Pathogenesis of

HIV infection

CD4 Count in HIV infection

• The CD4 cell , also known as "T4" or "helper T cell“ is responsible for signaling other parts of the immune system to respond to an infection.

• Initially in HIV infection there is a sharp drop in the CD4 count and then the count levels off to around 500-600 cells/mm (normal 500 -1500 )

• CD4 count is a marker of likely disease progression. CD4 percentage tends to decline as HIV disease progresses.

• CD4 counts can also be used to predict the risks for particular conditions such as Pneumocystis carinii pneumonia, CMV disease or MAI disease.

• Treatment decisions are often based on Viral Load and CD4 count.

Natural History of Untreated HIV Infection