Serological diagnosis of HIV infection using oral fluid samples

The serological identification of antibodies to human immunodeficiency virus (HIV) in blood is the most widely used method to diagnose HIV infection. Recently, however, the use of oral fluid samples for the detection of antibodies to HIV has been suggested as an alternative. This review describes some basic information about oral fluids, the application of these samples for HIV testing, and summarizes results from many of the studies performed using HIV tests with oral fluids. The fluids obtained from the oral cavity include saliva and crevicular fluid, and can be collected directly (by dribbling) or by using commercially available devices. The immunoglobulin content of oral fluids is similar to that of blood, but their levels are less. However, the use of an HIV IgG antibody capture assay (GAC ELISA) designed specifically for testing oral fluids, and certain routine HIV blood tests that have been optimized for use with oral fluids, has produced encouraging results. A number of studies, including several in developing countries, report that the sensitivities and specificities of these optimized tests lie in the range 95-100% and 98-100%, respectively. Also, the performance of the GAC ELISA was consistent and in general, excellent. The article identifies several issues that need to be addressed before a recommendation on the routine use of oral fluid samples for HIV antibody detection can be made.