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HIV incidence in South African blood donors from 2012 to 2016: a comparison of estimation methods
Author(s) -
Vermeulen Marion,
Chowdhury Dhuly,
Swanevelder Ronel,
Grebe Eduard,
Brambilla Donald,
Jentsch Ute,
Busch Michael,
Van Zyl Gert,
Murphy Edward L
Publication year - 2021
Publication title -
vox sanguinis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.68
H-Index - 83
eISSN - 1423-0410
pISSN - 0042-9007
DOI - 10.1111/vox.12987
Subject(s) - incidence (geometry) , avidity , medicine , window period , human immunodeficiency virus (hiv) , nat , immunology , antibody , statistics , mathematics , serology , geometry
Background Measuring incidence is important for monitoring and maintaining the safety of the blood supply. Blood collected from repeat‐donors has provided the opportunity to follow blood donors over time and has been used to estimate the incidence of viral infections. These incidence estimates have been extrapolated to first‐time donors using the ratio of NAT yield cases in first‐time versus repeat‐donors. We describe a model to estimate incidence in first‐time donors using the limiting antigen (LAg) avidity assay and compare its results with those from established models. Methods HIV‐positive first‐time donations were tested for recency using the LAg assay. Three models were compared; incidence estimated for (1) first‐time donors using LAg avidity, (2) first‐time and repeat‐donors separately using the NAT yield window period (WP) model and (3) repeat‐donors using the incidence/WP model. Results HIV incidence in first‐time donors was estimated at 3·32 (CI 3·11, 3·55) and 3·81 (CI 3·07, 4·73) per 1000 PY using the LAg assay and NAT yield WP models, respectively. Incidence in repeat‐donors was between 2·0‐ and 2·5‐fold lower than in first‐time donors estimated at 1·56 (CI 1·37, 1·77) and 1·94 (CI 1·86–2·01) per 1000 PY using the NAT yield/WP and incidence/WP models, respectively. Conclusion Testing HIV‐positive donations using the LAg assay provides a reliable method to estimate incidence in first‐time donors for countries that collect the majority of blood from first‐time donors and do not screen with NAT.