Identifying the early post-HIV antibody seroconversion period.

BACKGROUND: Identifying persons with recent human immunodeficiency virus (HIV) antibody seroconversion is useful for treatment, research, and prevention, but the sensitivity and specificity of tests for this purpose are uncertain.

METHODS: We used longitudinal specimens panels from 155 persons identified prior to HIV seroconversion to assess antibody-based methods for classifying persons as within 30, 60, or 90 days of seroconversion, including 2 incidence assays, a less-sensitive (LS) enzyme immunoassay (EIA), and the BED assay.

RESULTS: Sensitivity and specificity, respectively, for identifying persons within 30 days of seroconversion were: 34%-57% and 98%-100% for 2 standard EIAs (employing a signal-to-cutoff ≤4.0; ≥1.0 defines HIV positive), 84% and 73% for the LS-EIA (≤0.2 cutoff), 88% and 72% for the BED (≤0.2 cutoff), and 43%-58% and 98% (≤3 bands) for 2 Western blot (WB) assays. By area under the receiver operator curves, the best test for identifying persons within 30 days of seroconversion was the number of bands on the Bio-Rad WB (0.90); within 60 days, the LS-EIA and BED (both 0.85); and for persons within 90 days the BED (0.86).

CONCLUSIONS: Standard EIAs, Western blots, and HIV incidence assays provide useful information for identifying persons 30 to 90 days after seroconversion.