Human immunodeficiency virus, or HIV. HIV causes AIDS ( acquired immunodeficiency syndrome). HIV is a lentivirus of the retrovirus family, and has a long incubation period, with a slow disease evolution. HIV is transmitted most commonly via sexual intercourse, as well as any other contact between a mucous membrane and an infected bodily fluid. It provokes an often mortal collapse of the immune system. Viral diameter approximately: 145nm. Viral magnification 690,000 X at 10cm and image colorization with HDRI treatments on a Transmission Electron Micrograph view (TEM).