hiv

HIV stands for human immunodeficiency virus. It attacks the body's immune system, in particular CD4-positive T cells, which can lead to progressive immune deficiency. Without treatment, HIV infection can progress to AIDS, the advanced stage defined by a very low CD4 count or the occurrence of certain opportunistic infections or cancers.

HIV is transmitted through specific body fluids: blood, semen, vaginal and rectal fluids, and breast milk. It is primarily spread via sexual contact, sharing needles, or from an HIV-infected parent to child during pregnancy, birth, or breastfeeding. It is not spread by casual contact, such as hugging, sharing utensils, or coughing.

Clinical course: After infection, many people develop flu-like symptoms during acute HIV infection. Thereafter, the virus persists at low levels in a latent reservoir. If untreated, immune deterioration continues, leading to AIDS.

Diagnosis and treatment: HIV is diagnosed with tests that detect antibodies and/or HIV antigens or RNA. Monitoring includes CD4 count and viral load. Antiretroviral therapy (ART) is the standard treatment. ART reduces viral load to undetectable levels in most people, preserves immune function, and prevents transmission by sex (undetectable = untransmittable). People on ART require lifelong adherence. There is no cure yet.

Prevention: Safe sex practices, condom use, harm reduction for people who use drugs, regular testing, PrEP for HIV-negative individuals at high risk, and PEP after potential exposure. Vaccines are not yet available.