*Article* **Developing Consensus Standard Operating Procedures (SOPs) to Evaluate New Types of Insecticide-Treated Nets**

**Natalie Lissenden 1,2,\*, Jennifer S. Armistead 3, Katherine Gleave 1, Seth R. Irish 4, Jackline L. Martin 5, Louisa A. Messenger 4, Sarah J. Moore 6,7,8,9, Corine Ngufor 10,11, Natacha Protopopoff 10, Richard Oxborough 12, Angus Spiers 2 and Rosemary S. Lees 1,2**


**Simple Summary:** Malaria control relies on insecticide-based tools which target the mosquito vector. Predominantly, a group of insecticides called pyrethroids are used in these tools. Globally, however, mosquitoes are increasingly developing resistance to pyrethroids. Subsequently, new products, such as insecticide-treated nets (ITNs), which contain combinations of insecticides from different classes, or chemicals that work synergistically with pyrethroids, are being developed. Several of these new net types are being rolled out for testing and use. However, standardized methods to measure how long these nets remain active against mosquitoes are lacking, which makes evaluating the long-term efficacy of these products challenging. In this publication, we propose a pipeline used to collate and interrogate several different methods to produce a singular 'consensus standard operating procedure (SOP)', for monitoring the residual efficacy of three new net types: pyrethroid + piperonyl butoxide (PBO), pyrethroid + pyriproxyfen (PPF), and pyrethroid + chlorfenapyr (CFP).

**Abstract:** In response to growing concerns over the sustained effectiveness of pyrethroid-only based control tools, new products are being developed and evaluated. Some examples of these are dualactive ingredient (AI) insecticide-treated nets (ITNs) which contain secondary insecticides, or synergist ITNs which contain insecticide synergist, both in combination with a pyrethroid. These net types are often termed 'next-generation' insecticide-treated nets. Several of these new types of ITNs are being evaluated in large-scale randomized control trials (RCTs) and pilot deployment schemes at a country level. However, no methods for measuring the biological durability of the AIs or synergists on these products are currently recommended. In this publication, we describe a pipeline used to collate and interrogate several different methods to produce a singular 'consensus standard operating procedure (SOP)', for monitoring the biological durability of three new types of ITNs: pyrethroid + piperonyl butoxide (PBO), pyrethroid + pyriproxyfen (PPF), and pyrethroid + chlorfenapyr (CFP).

**Citation:** Lissenden, N.; Armistead, J.S.; Gleave, K.; Irish, S.R.; Martin, J.L.; Messenger, L.A.; Moore, S.J.; Ngufor, C.; Protopopoff, N.; Oxborough, R.; et al. Developing Consensus Standard Operating Procedures (SOPs) to Evaluate New Types of Insecticide-Treated Nets. *Insects* **2022**, *13*, 7. https://doi.org/ 10.3390/insects13010007

Academic Editor: Geoffrey M. Attardo

Received: 6 December 2021 Accepted: 17 December 2021 Published: 21 December 2021

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This process, convened under the auspices of the Innovation to Impact programme, sought to align methodologies used for conducting durability monitoring activities of next-generation ITNs.

**Keywords:** insecticide-treated net (ITN); PBO ITN; synergist ITN; dual-AI ITN; insecticide resistance managemen<sup>t</sup> (IRM); method validation; durability monitoring
