aids

AIDS stands for acquired immunodeficiency syndrome and is the most advanced stage of infection with the human immunodeficiency virus (HIV). HIV attacks the body's immune system, especially the CD4 T cells, which can weaken the ability to fight infections and cancers. Without effective treatment, HIV progresses over time and AIDS is diagnosed when the immune system is severely damaged or when certain defining illnesses occur.

HIV is transmitted through unprotected sexual contact, sharing needles or other equipment to inject drugs, and from mother to child during pregnancy, birth, or breastfeeding. It can also be transmitted through contaminated blood products in settings with insufficient screening. HIV is not spread through casual contact such as kissing, sharing utensils, or using the same restroom.

AIDS-defining conditions and severe immune suppression characterize the syndrome. Typical AIDS-defining illnesses include certain opportunistic infections (for example Pneumocystis jirovecii pneumonia and toxoplasmosis of the brain) and specific cancers such as Kaposi’s sarcoma. Diagnosis of AIDS is usually based on a confirmed HIV infection plus a CD4 count below 200 cells per microliter or the presence of one or more defining illnesses.

Treatment and prognosis rely on antiretroviral therapy (ART), which suppresses HIV replication, preserves immune function, and prevents progression to AIDS. ART is life-long and aims for durable viral suppression. With current therapies, many people living with HIV achieve near-normal life expectancy and substantially reduced risk of transmission. Prevention strategies include pre-exposure prophylaxis (PrEP), post-exposure prophylaxis (PEP), safe sex practices, harm reduction for people who inject drugs, and treatment as prevention.