Abstract
Long lasting insecticidal nets (LLINs), being safe and inexpensive, have been the major tool towards halving malaria’s burden since 2000. By 2016, 81% of malaria endemic countries with monitoring data reported resistance to pyrethroids. Growing insecticide resistance threatens their ongoing value. In 2017, the World Health Organization concluded that LLINs with a synergist, piperonyl butoxide (PBO), provided additional public health benefit over conventional LLINs alone in areas of moderate insecticide resistance and endorsed them as a new class of vector control products. However, as PBO nets cost 95% more than conventional LLINs ($4.08 vs. $2.09 per net), critics fear that their use could reverse progress towards universal net coverage. This study assesses the cost-
effectiveness of a PBO-LLINt compared to pyrethroid-only LLINs in an area with confirmed pyrethroid resistance. Data come from a randomized two-village trial in Nigeria with epidemiological outcomes. After 18 months of observation with no nets, beginning in 2014 residents in the control village received LLINs and those in the intervention village received PBO nets. Both were followed an additional 32 months. The health center recorded and tested all suspect malaria cases from both villages. Impacts on disability adjusted were modeled. The negative binomial regression analyses found that the PBO LLIN reduced symptomatic malaria cases by 33.4% (p<0.01). The incremental cost per net was US $1.99. The incremental cost-effectiveness ratio was US $16 per DALY averted. Even excluding the offsets in treatment costs and health gains, the added economic benefits of PBO nets over conventional LLINS yielded an extraordinary benefit-cost ratio of 85 to 1. Beyond its public health value, PBO LLINs appear to deliver excellent value for a small additional cost in areas of insecticide resistance