SURVEILLANCE FOR HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 GROUP-O INFECTIONS IN THE UNITED-STATES

Background: Reports that the human immunodeficiency virus type 1 (HIV- 1) group O variants are not reliably detected by some commercial diagn ostic tests have raised concerns about the sensitivity of existing scr eening tests, especially with regard to blood safety. Although it is u nlikely that these divergent strains are prevalent in North America, s ystematic, continuous surveillance is needed to monitor the potential spread of HIV variants into that region, Study Design and Methods: Sto red serum samples (n = 1072) from both high- and low-risk population g roups al several sites in the United Stales and Puerto Rico were teste d by peptide enzyme immunoassays specific for the prototypic HIV-1 gro up O strains, MVP5180 and ANT70. Results: None of the 1072 samples exa mined had peptide reactivity that was consistent with HIV-1 group O in fection. Conclusion: While no evidence of specific HIV-I group O (MVP5 180 or ANT70) infection was found in this study, the sensitivity of cu rrent tests has not been fully evaluated against the wide range of gen etic variation of HIV. Therefore, it is important to continue active s urveillance far HIV-1 and HIV type 2 strains, to characterize any dive rgent strains, and to judiciously modify tests to correct for any defi ciencies in sensitivity.