Direct methods for detection of HIV-1 infection

The detection of human immunodeficiency virus type 1 (HIV-1) antibodies has proved to be a highly sensitive and specific means for the diagnosis of HIV-1 infection. Serologic methods have limitations in several specific clinical situations, however. In response to these problems, a wide variety of alternative diagnostic tests has been developed that detect infectious virus or structural components of the virus. All of the macromolecular constituents of HIV-1, DNA, RNA, and protein, have served as markers for the presence of the virus. In this article, we review the use of such direct methods and attempt to determine the likely place for each class of direct test in the diagnostic armamentarium.