Chapter 21 - Section 21.6 - Immune System Disorders - Before You Go On - Page 841: 27

HIV (Human Immunodeficiency Virus) infection and AIDS (Acquired Immunodeficiency Syndrome) are related but distinct terms that describe different stages of the same disease progression. Here's the distinction between the two: 1. **HIV Infection:** - HIV is a virus that attacks the immune system, specifically the CD4+ T cells, which play a crucial role in the body's defense against infections. - When a person becomes infected with HIV, the virus enters their bloodstream and begins to replicate within CD4+ T cells. This can lead to a decrease in the number of these cells, weakening the immune response. - During the initial stages of HIV infection, a person may experience flu-like symptoms, but often, there are no noticeable symptoms. - HIV infection is typically categorized into three stages: acute infection, clinical latency, and AIDS. 2. **AIDS (Acquired Immunodeficiency Syndrome):** - AIDS is the advanced stage of HIV infection, characterized by severe immune system damage and a significant decline in CD4+ T cell count. - In order to be diagnosed with AIDS, certain criteria must be met, usually involving a CD4+ T cell count below a specific threshold or the occurrence of opportunistic infections or AIDS-related cancers. - Opportunistic infections are infections that take advantage of a weakened immune system. These infections are typically rare or uncommon in individuals with a healthy immune system. - AIDS-related cancers, such as Kaposi's sarcoma and non-Hodgkin lymphoma, can also develop in individuals with severely compromised immune systems. - People with AIDS are at a higher risk of developing life-threatening infections and illnesses due to their compromised immune system. In summary, the key distinction between a person with an HIV infection and a person with AIDS lies in the stage of disease progression and the level of immune system impairment. HIV infection is the initial stage when a person becomes infected with the virus, while AIDS is the advanced stage characterized by a severely weakened immune system, opportunistic infections, and often the presence of certain AIDS-related cancers. Effective antiretroviral therapy (ART) can help slow down the progression of HIV infection and delay the development of AIDS.

HIV (Human Immunodeficiency Virus) infection and AIDS (Acquired Immunodeficiency Syndrome) are related but distinct terms that describe different stages of the same disease progression. Here's the distinction between the two: 1. **HIV Infection:** - HIV is a virus that attacks the immune system, specifically the CD4+ T cells, which play a crucial role in the body's defense against infections. - When a person becomes infected with HIV, the virus enters their bloodstream and begins to replicate within CD4+ T cells. This can lead to a decrease in the number of these cells, weakening the immune response. - During the initial stages of HIV infection, a person may experience flu-like symptoms, but often, there are no noticeable symptoms. - HIV infection is typically categorized into three stages: acute infection, clinical latency, and AIDS. 2. **AIDS (Acquired Immunodeficiency Syndrome):** - AIDS is the advanced stage of HIV infection, characterized by severe immune system damage and a significant decline in CD4+ T cell count. - In order to be diagnosed with AIDS, certain criteria must be met, usually involving a CD4+ T cell count below a specific threshold or the occurrence of opportunistic infections or AIDS-related cancers. - Opportunistic infections are infections that take advantage of a weakened immune system. These infections are typically rare or uncommon in individuals with a healthy immune system. - AIDS-related cancers, such as Kaposi's sarcoma and non-Hodgkin lymphoma, can also develop in individuals with severely compromised immune systems. - People with AIDS are at a higher risk of developing life-threatening infections and illnesses due to their compromised immune system. In summary, the key distinction between a person with an HIV infection and a person with AIDS lies in the stage of disease progression and the level of immune system impairment. HIV infection is the initial stage when a person becomes infected with the virus, while AIDS is the advanced stage characterized by a severely weakened immune system, opportunistic infections, and often the presence of certain AIDS-related cancers. Effective antiretroviral therapy (ART) can help slow down the progression of HIV infection and delay the development of AIDS.