When is a person said to have AIDS?

AIDS (Acquired Immunodeficiency Syndrome) is the most advanced stage of HIV (Human Immunodeficiency Virus) infection. It is characterized by the depletion of the body's immune system, making the person vulnerable to life-threatening infections and certain types of cancer.

A person is said to have AIDS when their HIV infection meets any of the following criteria:

1. CD4 Count: If the person's CD4 count (a type of white blood cell that plays a crucial role in the immune system) drops below 200 cells/mm³. A healthy person usually has a CD4 count of 500-1200 cells/mm³.

2. Opportunistic Infections (OIs): A person is diagnosed with AIDS if they develop certain OIs that are associated with advanced HIV infection. These OIs include conditions such as Pneumocystis jirovecii pneumonia (PCP), toxoplasmosis of the brain, cryptococcal meningitis, Kaposi's sarcoma (a type of cancer), and others.

3. Severe HIV-Related Symptoms: In some cases, a person may be diagnosed with AIDS even if their CD4 count is above 200 cells/mm³, but they experience severe HIV-related symptoms or illnesses. These symptoms may include persistent fever, weight loss, diarrhea, neurological disorders, and others.

It's important to note that the diagnostic criteria for AIDS may vary in different countries and settings, and updates can occur over time. In general, a healthcare professional will conduct a thorough evaluation, including blood tests, CD4 count, review of symptoms, and medical history, to determine if a person meets the criteria for an AIDS diagnosis.