Cost-Effectiveness of PBO versus Conventional Long-Lasting Insecticidal Bed Nets in Preventing Symptomatic Malaria in Nigeria: Results of a Pragmatic Randomized Trial.

Insecticide treated nets (ITNs) have been the major tool in halving malaria's burden since 2000, but pyrethroid insecticide resistance threatens their ongoing effectiveness. In 2017, the WHO concluded that long-lasting ITNs (LLINs) with a synergist, piperonyl butoxide (PBO), provided additional public health benefit over conventional (pyrethroid-only) LLINs alone in areas of moderate insecticide resistance and endorsed them as a new class of vector control products. We performed an economic appraisal of PBO nets compared with conventional LLINs in 2019 US$ from prevention and health systems perspectives (including treatment cost offsets). We used data from a pragmatic randomized 2012-2014 trial in Nigeria with epidemiological outcomes in an area with confirmed pyrethroid resistance. Each village had 50 months of epidemiologic data, analyzed by village by month, using negative binomial regression. Compared with LLINs, although adding $0.90 per net delivered, PBO nets reduced symptomatic malaria cases by 33.4% (95% CI 10.2-50.6%). From a prevention perspective, the incremental cost-effectiveness ratio was $11 (95% CI $8-$37) per disability-adjusted life year averted. From the health systems perspective, PBO nets were significantly cost-saving relative to conventional LLINs. The benefit-cost analysis found that the added economic benefits of PBO nets over LLINs were $201 (95% CI $61-$304) for every $1 in incremental costs. Growing pyrethroid resistance is likely to strengthen the economic value of PBO nets over LLINs. Beyond their contribution to reducing malaria, PBO nets deliver outstanding economic returns for a small additional cost above conventional LLINs in locations with insecticide resistance.

Field trial efficacy of Anvil 10+10 and Biomist 31:66 against Ochlerotatus sollicitans in Delaware.

Anvil 10+10 (hereafter Anvil) and Biomist 31:66 (hereafter Biomist) were applied by ground ultra-low volume (ULV) methods to determine the effectiveness of each formulation against Ochlerotatus sollicitans. Each formulation was tested at 50, 67, and 100% of respective maximum label dosage rates. Mosquitoes were exposed in cages on a 3 x 3 grid at distances of 30.5, 60.9, and 91.4 m. Mortality data were collected at intervals of 1, 4, and 12 h after treatment. No significant differences (P > or = 0.05) were found among formulations at applications of 100% of the label rate and no significant differences (P > or = 0.05) were found between Anvil applied at 100% of the label rate and Biomist applied at 50 and 67% of label rates. Ground ULV applications of Anvil at 100% label rate and Biomist at all tested rates were effective (> or = 95% mortality) adulticides. Applications of Anvil at 50 and 67% label rates were significantly less effective (P < or = 0.05) than applications of Biomist at equal percentages of the maximum label rate. Applications of Anvil at rates of 50 and 67% were not effective.