API stands for Application Programming Interface, i.e. API is the way for an application to interact with certain system/application/library/etc. For example, there are API's for OS (WinAPI), API's for other applications (like databases) and for specific libraries (for example, image processing), etc.
Acute HIV infection: The first stage of HIV, known as the primary or acute infection, may cause symptoms of fever and skin rash. This is because the virus is multiplying rapidly in the body and infecting immune cells. This phase generally lasts several weeks.
The human immunodeficiency virus (HIV) is a virus transmitted by body fluids. Contact with blood, semen, vaginal fluid, rectal fluids, and breast milk from an infected person can cause infection. In the U.S., HIV infection is usually spread through sexual activity or by sharing needles or syringes.