 Previous studies have identified strategies for the large-scale identification of acute HIV infections. One system using such strategies has already been implemented in North Carolina, and this system will be used in this study run by the Center of HIVAIDS Vaccine Immunology CHAVI. This study will collect data on the mechanism of HIV transmission and the genetic, biologic, antigenic, and structural characteristics of the virus. The study will enroll HIV infected people with acute HIV infection and their sexual partners, people with established HIV infection, and HIV uninfected people. 