The Food and Drug Administration today licensed the first test kit that detects antibody to human immunodeficiency virus type 2, or HIV-2 -- a second, but far less common, cause of AIDS than the human immunodeficiency virus type 1, or HIV-1.
Since the virus is rare in the United States, FDA will not require its use by blood banks at this time. However, the test may be used for epidemiologic studies, such as monitoring to determine if there is any spread of HIV-2 infection in the United States.
The first confirmed case of AIDS caused by HIV-2 infection in the United States was reported in 1987, and only 16 additional cases of HIV-2 infection have been reported in this country. Most known infections with HIV-2 have occurred in the general region of West Africa, although some nations in that area have not yet reported any cases.
The health consequences of HIV-2 infection are similar to those of HIV-1. Both are transmitted among adults primarily by sexual contact with infected partners, intravenous drug use and contaminated blood or blood products.
The test uses the enzyme-linked immunosorbent assay, or ELISA, format. A "reactive" reading with the screening test means that an individual may have been exposed to HIV-2 and that the body is producing antibodies to the virus. Since HIV-1 and HIV-2 are so closely related, tests for the antibody to one virus often crossreact with the other.
Because of the possibility of false positives, FDA recommends that reactive results to the HIV-1 or HIV-2 antibody ELISA tests be validated with Western blot tests. The manufacturer will provide in-house Western blot testing services specific to HIV-2 for validation.
The test will be manufactured by Genetics Systems Corporation of Seattle, Wash.