AIDS is a possibly upcoming scenario in which the player must use HIV/AIDS to infect and wipe out the world. However, there is also speculation that it was cut during the development of the Scenarios DLC.
In real life Edit
AIDS is a spectrum of conditions caused by infection with HIV. It damages the immune system until it is gone, so you can die from a disease like tuberculosis. Without treatment, the average survival time after infection is 11 years. 4h was discovered in 1981, but named AIDS in late 1982. In 2016 about 36.7 million people were living with HIV and it resulted in 1 million deaths. There were 300,000 fewer new HIV cases in 2016 than in 2015. Most of those infected live in sub-Saharan Africa. Between its discovery and 2014 AIDS has caused an estimated 39 million deaths worldwide. HIV/AIDS is considered a pandemic—a disease outbreak which is present over a large area and is actively spreading. HIV is believed to have originated in west-central Africa during the late 19th or early 20th century.
Not much is known about this scenario, save that images related to it come up in folders in the game files of Plague Inc: Evolved.