Improved HIV-1 incidence estimates using the BED capture enzyme immunoassay

Area of Science:

• Epidemiology
• Immunology
• Public Health

Background:

• Accurate estimation of HIV-1 incidence is crucial for effective public health interventions.
• Cross-sectional surveys are valuable for HIV surveillance, but require reliable incidence estimation tools.
• The BED capture enzyme immunoassay has been proposed for estimating recent HIV-1 infections.

Purpose of the Study:

• To validate the BED capture enzyme immunoassay for Human Immunodeficiency Virus type 1 (HIV-1) subtype C.
• To derive adjustments for the BED assay to improve HIV-1 incidence estimation from cross-sectional surveys.

Main Methods:

• Archived plasma samples from Zimbabwe were analyzed using the BED assay.
• Serial samples from 85 women who seroconverted during the postpartum year were used to estimate the BED assay's window period.
• HIV-1 incidence was calculated using BED assay results from baseline and 12-month follow-up samples.

Main Results:

• The mean window period for the BED assay (absorbance cut-off 0.8) was 187 days.
• A proportion of 5.2% of individuals with confirmed HIV-1 at 12 months were falsely identified as recent seroconverters by the unadjusted BED assay.
• Adjusted BED incidence estimates more closely reflected prospective incidence estimates and showed a decline with maternal age, unlike unadjusted estimates.

Conclusions:

• The BED assay is applicable in an African setting for HIV-1 incidence estimation.
• Further validation with larger sample sizes and diverse populations is necessary to refine epsilon estimates and the window period.
• Adjustments are essential for accurate HIV-1 incidence estimation using the BED assay in cross-sectional surveys.