Optimizing the World Health Organization algorithm for HIV vertical transmission risk assessment by adding maternal self-reported antiretroviral therapy adherence
Authors: Fernández-Luis Sheila , Lain Maria Grazia , Serna-Pascual Miquel , Domínguez-Rodríguez Sara , Kuhn Louise , Liberty Afaaf , Barnabas Shaun , Lopez-Varela Elisa , Otwombe Kennedy , Danaviah Siva , Nastouli Eleni , Palma Paolo , Cotugno Nicola , Spyer Moira , Giannuzzi Viviana , Giaquinto Carlo , Violari Avy , Cotton Mark F. , Nhampossa Tacilta , Klein Nigel , Ramsagar Nastassja , van Rensburg Anita Janse , Behuhuma Osee , Vaz Paula , Maiga Almoustapha Issiaka , Oletto Andrea , Naniche Denise , Rossi Paolo , Rojo Pablo , Tagarro Alfredo ,   EPIICAL Consortium, Rossi Paolo , Giaquinto Carlo , Faggion Silvia , Pena Daniel Gomez , Rossi Inger Lindfors , James William , Nardone Alessandra , Palma Paolo , Zangari Paola , Paganin Carla , Nastouli Eleni , Spyer Moira J , Marcelin Anne-Genevieve , Calvez Vincent , Rojo Pablo , Tagarro Alfredo , Dominguez Sara , Munoz Maria Angeles , Foster Caroline , Pahwa Savita , De Rossi Anita , Cotton Mark , Klein Nigel , Persaud Deborah , De Boer Rob J. , Schroeter Juliane , Ceci Adriana , Giannuzzi Viviana , Luzuriaga Kathrine , Chomont Nicolas , Cotugno Nicola , Kuhn Louise , Yates Andrew , Violari Avy , Otwombe Kennedy , Vaz Paula , Lain Maria Grazia , López-Varela Elisa , Nhamposssa Tacilta , Naniche Denise , Levy Ofer , Goulder Philip , Lichterfeld Mathias , Peay Holly , Sylla Pr Mariam , Maiga Almoustapha 
Published: July 2022

Abstract
Background
The World Health Organization (WHO) risk assessment algorithm for vertical transmission of HIV (VT) assumes the availability of maternal viral load (VL) result at delivery and early viral control 4 weeks after initiating antiretroviral treatment (ART). However, in many low-and-middle-income countries, VL is often unavailable and mothers’ ART adherence may be suboptimal. We evaluate the inclusion of the mothers’ self-reported adherence into the established WHO-algorithm to identify infants eligible for enhanced post-natal prophylaxis when mothers’ VL result is not available at delivery.

Methods
We used data from infants with perinatal HIV infection and their mothers enrolled from May-2018 to May-2020 in Mozambique, South Africa, and Mali. We retrospectively compared the performance of the WHO-algorithm with a modified algorithm which included mothers’ adherence as an additional factor. Infants were considered at high risk if born from mothers without a VL result in the 4 weeks before delivery and with adherence <90%.

Results
At delivery, 143/184(78%) women with HIV knew their status and were on ART. Only 17(12%) obtained a VL result within 4 weeks before delivery, and 13/17(76%) of them had VL ≥1000 copies/ml. From 126 women on ART without a recent VL result, 99(79%) had been on ART for over 4 weeks. 45/99(45%) women reported suboptimal (< 90%) adherence. A total of 81/184(44%) infants were classified as high risk of VT as per the WHO-algorithm. The modified algorithm including self-adherence disclosure identified 126/184(68%) high risk infants.

Conclusions
In the absence of a VL result, mothers’ self-reported adherence at delivery increases the number of identified infants eligible to receive enhanced post-natal prophylaxis.