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