Tools for the biological diagnosis of HIV infection: 25 years of progress.

The biological tools for an efficient diagnosis of HIV infection have made major progresses during the three last decades. The dynamics of the viral markers during natural infection is well known and provides a strong rationale for the diagnostic strategy. The 4th generation enzyme immunoassays that allow the simultaneous detection of the p24 capsid antigen and HIV antibodies must be used as first-line diagnostic in priority. Nucleic acid testing are complementary tools, particularly useful for the early diagnosis of primary infection and for diagnosis of HIV infection in infants born to infected mothers. The rapid tests constitute major tools for the HIV diagnosis in developing countries, but are also helpful in at-risk populations than cannot be reached easily with classical assays in industrialized countries. However, one must be aware of their lower sensitivity, especially in the first weeks following infection. The growing diversity and the ongoing evolution of HIV constitute a permanent challenge for the optimal efficacy of any diagnostic tool.