What is HIV, what is AIDS?

HIV stands for Human Immunodeficiency Virus. Viruses have no metabolism and need host cells to replicate. HIV is a socalled retrovirus (which is also why HIV medications are called antiretroviral drugs). It carries its genetic material in the form of single-strand RNA, which is converted into double-strand DNA by the viral enzyme reverse transcriptase in infected cells and then incorporated into the human DNA. The infected cells then produce new viral components that “bud off” from the host cells and infect other cells as so-called virions.

HIV mainly attacks cells of the immune system. Without HIV therapy, the virus weakens the body’s ability to fight pathogens and defective body cells, causing damage to organs such as the intestines, kidneys, bones, and the brain as well as the nervous system.

AIDS (Acquired Immune Deficiency Syndrome) is present if certain, sometimes life-threatening conditions occur, including severe infections such as Pneumocystis pneumonia or tumours such as Kaposi’s sarcoma. One also speaks of AIDS if no symptoms are apparent, but the T helper cell count is below 200 per microlitre of blood serum. When started early and continued lifelong, antiretroviral therapy (ART) prevents AIDS and provides best chances of having a normal life expectancy while being largely free from symptoms. If AIDS is already present, ART can reverse the symptoms, allowing the immune system to recover.