Reducing Malaria Mortality at the Lowest Budget: An Optimization Toolfor Selecting Malaria Preventative Interventions Applied toGhana

摘要

Background. Preventative malaria interventions include long-lasting insecticidal nets (LLINs), indoor residual spraying (IRS), and seasonal malaria chemoprevention (SMC). The RTS,S vaccine candidate is now also approved for pilot introduction. This analysis estimates the optimal approach when combining current interventions with the vaccine to reduce under-five malaria mortality in Ghana at the lowest cost. Methods. A vector model was combined with a static human cohort model, using country-specific unit costs. Current coverage of each intervention was used as baseline. The base-case vaccine price was US$5/dose, with US$2 or US$10 tested in sensitivity analysis. Model simulations used a goal for extra mortality reduction in children aged <5 years, and identified the optimal combination of interventions to reach that goal at the lowest cost. The time horizon was 5 years. Results. The optimal sequence of investments would be the following: (1) introduce RTS,S; (2) introduce SMC; (3) increase LLINs and IRS concurrently. RTS,S introduction was associated with mortality reduction of 16% for a budget increase of US$15.6 million. Adding SMC with a partial coverage of 4% further reduced mortality by 1% at an additional budget of US$1.4 million.Subsequently scaling-up IRS, LLINs, and SMC at their maximum achievable coveragefurther reduced mortality by 82% (total reduction 98%) at an additional budgetof US$474 million. At an RTS,S price of US$10/dose, SMC was first in the optimalsequence. A lower RTS,S price maintained the sequence but reduced the budgetneed. Conclusions. In Ghana, RTS,S introduction in addition tothe existing measures would be the optimal first step for reducing under-fivemalaria mortality at the lowest cost, followed by SMC in relevant areas, andthen further scaling-up of IRS and LLINs.