FIGURE 1.

Evolution of HIV diagnostic algorithms. (a) This cartoon depicts the abundance of HIV diagnostic substrates in the serum of a figurative patient during the first several weeks following infection. Although first-generation HIV tests that relied on detection of anti-HIV IgG antibodies in patient serum had a large ‘negative window’ between infection and detection, each successive generation of tests reduced this gap. Nucleic acid tests are primarily used for medical management of disease, but are used for diagnostic/screening purposes in some algorithms. (b) The current HIV testing algorithm based on guidelines from the Centers for Disease Control.