A Non-Inferiority Evaluation of YAHE 4.0, an Alphacypermethrin-PBO Insecticide Treated Net Against Pyrethroid Resistant <em>Anopheles arabiensis</em> in Experimental Huts in Moshi, North-Eastern Tanzania

A new generation of insecticide treated nets (ITNs) that incorporate the synergist piperonyl butoxide (PBO) has been shown to restore susceptibility to pyrethroids where P450 enzymes are the primary mechanism conferring the resistance. The present study evaluated the efficacy of YAHE 4.0, a PBO ITN, against wild free flying Anopheles arabiensis in Experimental huts in Lower Moshi, north-eastern Tanzania. The bio efficacy evaluations were conducted using standard World Health Organization (WHO) guidelines. DuraNet Plus, a WHO recommended PBO ITN and Interceptor ITNs served as active and standard comparators respectively. Unwashed and 20×washed nets were subjected to experimental hut trials. The experimental hut data were analysed using multiple logistic regress with outcomes being mortality and blood- feeding inhibition. An analysis was also conducted to determine non-inferiority of YAHE 4.0 to DuraNet Plus ITN in terms of mortality and blood feeding according to the WHO guideline. The results for pooled unwashed and 20 times washed ITNs showed that YAHE 4.0 was superior to Interceptor ITN (adjusted odds ratio, AOR= 1.33; 95% CI = 1.04 – 1.69; non-inferiority margin, NIM= 0.68; p-value = 0.023) and non-inferior to DuraNet Plus (AOR=1.02; 95% CI=0.78 – 1.35; NIM=0.72; p-value = 0.867) in term of mortality. In terms of blood feeding inhibition for pooled unwashed and 20×washed ITNs, YAHE 4.0 was superior to both Interceptor ITN (AOR=0.80; 95% CI= 0.64 – 1.00; NIM=1.35; p-value=0.049) and DuraNet Plus (AOR=0.67; 95% CI=0.52 – 0.86; NIM=1.33; p-value= 0.002). Based on the study findings, YAHE 4.0 was no worse than the active comparator DuraNet Plus. Therefore, it should be an additional to the current list of PBO ITNs used for control of pyrethroid resistant vector populations with P450 enzymes as the main mechanism conferring resistance.