1-1. What is HIV?

 

HIV stands for 'human immunodeficiency virus'. HIV is a retrovirus that infects cells of the human immune system (mainly CD4 positive T cells and macrophages?key components of the cellular immune system), and destroys or impairs their function. Infection with this virus results in the progressive depletion of the immune system, leading to 'immune deficiency'. 

 

The immune system is considered deficient when it can no longer fulfil its role of fighting off infection and diseases. Immunodeficient people are much more vulnerable to a wide range of infections, most of which are very rare among people without immune deficiency. Diseases associated with severe immunodeficiency are known as 'opportunistic infections', because they take advantage of a weakened immune system.

 

1-2. What is AIDS?

 

AIDS stands for 'acquired immunodeficiency syndrome' and describes the collection of symptoms and infections associated with acquired deficiency of the immune system. Infection with HIV has been established as the underlying cause of AIDS. The level of HIV in the body and the appearance of certain infections are used as indicators that HIV infection has progressed to AIDS