Remarks The conditionality of the recommendation to deploy spatial repellents is based on the GDG’s judgement that the balance of desirable and undesirable effects probably favours deployment alongside ITNs or IRS, but considers that the systematic review found considerable heterogeneity in protective effect, largely explained by different levels of coverage achieved with the spatial repellent in each trial. The GDG therefore noted that effective protection of the population with spatial repellents depends on continuous high coverage in the target area, with duration of efficacy of the product and distribution model being the key determinants of feasibility and cost-effectiveness. In deciding whether to deploy spatial emanators as a supplementary intervention, malaria programmes should:

• ensure that targeted coverage levels of interventions recommended for large-scale deployment (ITNs, IRS) are achieved and sustained;
• determine whether resources are adequate to cover the extra costs, especially given the residual efficacy of the specific spatial repellent product under consideration;
• generate additional information or conduct analyses with the aim of maximizing impact through targeted deployment (e.g. stratification of malaria risk, assessment of the characteristics of local vectors, such as local vector susceptibility to the active ingredient);
• note that only indoor use of spatial emanators has been assessed in the development of this recommendation, and therefore the recommendation only covers the indoor use of spatial emanators at this time; and
• note that WHO recommends selecting spatial emanators that are prequalified by WHO for deployment.

Practical info Several resource requirements have been identified that may be useful to consider before deploying spatial emanators as part of a coordinated deployment strategy. The distribution of spatial emanators involves several logistical and financial considerations. Transportation and storage costs, especially in remote or rural areas, can have a significant impact on overall expenses. Customs and import fees may further increase costs when importing spatial emanators into malaria-endemic regions. Effective distribution relies on community-based delivery systems, such as health workers, local vendors or clinics, to ensure broad access and uptake. These systems require investment in both infrastructure and personnel to maintain a steady supply of products. In addition, implementation costs may include initial programme set-up expenses, such as training and education, as well as recurring operational costs for product replacement and redistribution. Because spatial emanators often require regular replacement, their long-term affordability may depend on sustained financial and programmatic support. Integrating spatial emanators with existing vector control tools, such as ITNs and IRS, may also incur costs related to programme coordination and outreach efforts. Beyond distribution and implementation, monitoring and evaluation will be essential to assess the effectiveness of spatial emanators in further reducing malaria transmission. Appropriate metrics of coverage will need to be determined. Community feedback systems should track user acceptance and adherence. Regular programme oversight will ensure that existing interventions (e.g. ITNs and IRS) remain effective and appropriately distributed/applied. Overall, the feasibility of spatial emanators will depend not only on the direct costs but also on sustained investment in monitoring, education and integration with existing malaria control activities. Any deployment strategy will need to account for product-specific manufacturing instructions, in particular the intended duration of efficacy and number of units required per unit area. Disposal and waste management should be considered. In deciding whether to deploy spatial emanators, control programmes should consider the available resources and ensure that spatial emanators are not deployed at the expense of ITN distribution or continued IRS programmes. Additional evidence is needed before WHO would be able to support a recommendation for the replacement of interventions for wide scale deployment with spatial emanators.