Testing for the HIV Virus

The new test on oral fluid can detect HIV-1 and HIV-2 antibodies approximately 6 weeks after infection, the same as other HIV tests. HIV-1 is the retrovirus that typically causes AIDS and is the one most prevalent in most of the world, including the United States. If a person has antibodies to HIV-1, it may mean that he or she is infected with the HIV-1 virus that causes AIDS.  

HIV-2 is a variant found primarily in western, sub-Saharan Africa. HIV-2 is rare in other parts of the world, but it has been reported sporadically in many locations. It is believed to be spread by the same methods of transmission as HIV-1. If a person has antibodies to HIV-2, it may indicate that he or she is infected with the HIV-2 virus.
 
Testing for both HIV-1 and HIV-2 is important, particularly in people who may have acquired their infection in western Africa or from someone who may have links to that area. Most of the HIV testing currently done in the United States detects both HIV-1 and HIV-2 (for example, the test used by the American Red Cross to screen blood donations). 
 
The new oral test has not yet been approved for home testing or to screen blood donors.