title: Modification of rapid human immunodeficiency virus (HIV) antibody assay protocols for detecting recent HIV seroconversion.
abstract: Assay protocols of three rapid human immunodeficiency virus (HIV) assays, OraQuick-1/2, SeroStrip-1/2, and Determine-1/2, were modified to detect recent HIV seroconversion using a higher dilution of serum specimens. Optimal predilution of specimens resulted in negative test results during early periods of seroconversion (about 6 months), when antibody levels were low. A total of 269 seropositive specimens from routine HIV type 1 testing and from commercial sources (low-titer and seroconversion panels) were tested, and results were recorded as negative (score=0) or positive using intensity scores from 0.5 (weak positive) to 4 (strongly positive). The same specimens were previously tested by a less sensitive (LS) enzyme immunoassay (EIA), Abbott 3A 11-LS, and were classified as recent or long-term infections based on the standardized optical density (SOD) cutoff of 0.75. Overall concordance of >94% was observed between 3A 11-LS and modified rapid tests (RT-LSs) for detecting and distinguishing recent HIV seroconversion from long-term HIV infection (kappa statistics=0.894 to 0.901). Moreover, intensity scores on RT-LSs correlated well with median 3A 11-LS SOD values (R(2)>0.98). Our results indicate that rapid HIV tests can be modified to detect recent seroconversion with results comparable to those from less sensitive EIA.
authors.affiliation: Division of HIV/AIDS Prevention, National Center for HIV/AIDS, STD, and TB Prevention, Atlanta, GA 30333, USA.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Soroka
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Granade
authors.forename: Debra
authors.initials: D
authors.lastname: Candal
authors.forename: Bharat S
authors.initials: BS
authors.lastname: Parekh
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D015483:HIV Antibodies / Q000097:blood*; D015658:HIV Infections / Q000175:diagnosis* / Q000276:immunology*; D006679:HIV Seropositivity / Q000175:diagnosis* / Q000276:immunology; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods; D013997:Time Factors
chemical_list: D000914:Antibodies, Viral; D015483:HIV Antibodies; D011933:Reagent Kits, Diagnostic