Rethink HIV: Prevention of the Non-Sexual Transmission of HIV Perspective, Johri
This perspective paper focuses on a single mode of non-sexual HIV transmission, mother-to child transmission of HIV (MTCT), currently responsible for about 20% of new HIV infections annually in sub-Saharan Africa. Specifically, it examines the Assessment Paper (AP) proposal to evaluate the costs and benefits of a single strategy to prevent MTCT, consisting of WHO Option A delivered to over 90% of pregnant women by 2015 via a pattern of linear scale up from current levels (Bollinger 2011). The paper is structured in four parts.
(1) The first section presents some general comments on the methods and findings of the AP. The critical assessment of HIV MTCT is then developed in three steps.
(2) The second section reviews the reasoning surrounding the choice of WHO Option A as the sole MTCT strategy. It assesses representation of Option A in the analysis and finds that it is unlikely fully to capture costs. It also demonstrates that methodological and modelling choices lead to a truncated assessment of benefits, such that potentially relevant differences among therapeutic options A, B and B+ are not considered. The section concludes that analysis of a more comprehensive range of MTCT intervention options is required, including family planning, reproductive counselling, cotrimoxazole prophylaxis, early infant diagnosis, maternal ART for women requiring therapy for their own health, and WHO Options A, B and B+.
(3) The third section examines the assumption of linear programme scaleup. The production function for an intervention is rarely described in economic evaluations and results are usually given without regard to programme scale. The costs and cost-effectiveness of Preventing Mother-to-Child-Transmission (pMTCT) programmes are substantially affected by variations in HIV prevalence and health system infrastructure. Within countries, existing MTCT programmes are generally located in settings of higher HIV prevalence and better health infrastructure, with the result that the costs of scale-up are likely to be importantly non-linear. The term pMTCT “cascade” has been used to describe the sequence of steps required to deliver antiretroviral-based MTCT interventions to HIV+ mothers and their infants. It is argued that, at the population level, health system performance at each step of the cascade is likely to be the single most important factor for determining the number of infections in children.
(4) The final section sketches four additional MTCT intervention strategies that are likely to offer good value for money in some contexts and have received less attention to date. These include interventions to improve health system performance, HIV screening in the labour ward, and interventions to interrupt MTCT for HIV+ women not delivering in a health facility. Most importantly, this section highlights the potential of an emerging “leapfrog” technology, multiplex point-of- care diagnostics, to overcome the problems outlined in section 3. This technology could play a decisive role in increasing access to the pMTCT cascade while providing good value for money and thus, in synergy with health system improvements, in elimination of new infant HIV infections. Prevention of HIV transmission from mother-to-child is a high leverage intervention with implications for health and development. It is an opportunity too important to miss.
By Mira Johri, Associate Professor, International Health Unit and Department of Health Administration, University of Montreal.