A 6-month, open-label, controlled trial examining whether spatial emanators could effectively reduce malaria transmission among internally displaced people in northern Nigeria during a humanitarian crisis.
Setting and design:
- 24 camps for internally displaced people in Maiduguri, Nigeria
- 12 camps received the intervention (spatial repellent emanators)
- 12 camps served as controls (no intervention)
- 1,655 children aged 6-10 years participated (842 intervention, 813 control)
N.B in this case Spatial Emanators were distributed on top of residual LLINs. Prior to distribution all study participants received an appropriate course of ACT to clear parasites. Children aged 6-10 were selected as those 0-5 years were targeted with annual Seasonal Malaria Prophylaxis.
Intervention:
- Guardian TM spatial emanators were installed in 50 eligible households per intervention camp
- These devices release transfluthrin that repel mosquitoes
- Designed to remain effective for 12 months and therefore the entire 6-month trial duration
Major findings:
- In the six months of follow up post distribution the estimated protective efficacy of spatial emanators against first time malaria infection was 22.5%.
- Pyrethroid resistant Anopheles density and blood feeding was significantly reduced.
- Spatial emanators were highly accepted by camp residents due to perceived entomological impact, this included a willingness to pay for spatial emanators in the future.
The significance:
Context of humanitarian crises:
- By 2030, two-thirds of the world’s poorest populations will live in areas affected by conflict and violence.
- 305 million people need humanitarian aid globally.
- Forcibly displaced populations face severe malaria risk, especially when moving into high-transmission areas.
Advantages of spatial emanators: These devices are particularly suited to humanitarian emergencies because they:
- Are lightweight, compact, and easily transported
- Work in diverse shelter types including tents
- Can be rapidly deployed
- Don’t require behaviour change from residents
- Can be stockpiled for emergency response
- Cannot be repurposed for other uses
Broader implications:
This study provides the first evidence that spatial emanators can effectively control malaria in African humanitarian crisis/ camp settings. The findings are particularly important because:
- Populations in vulnerable settings: The study demonstrates a practical tool to prevent malaria in humanitarian emergency contexts.
- Expanding the toolbox: These results support adding spatial repellents to the (limited) range of vector control tools suitable for humanitarian emergencies.
- Growing evidence base: This adds to previous trials from Kenya, Indonesia, Peru, and Syria showing protective effects of spatial repellents against various vector-borne diseases, specifically the first epidemiological efficacy data for spatial emanators in West Africa.
The researchers conclude that spatial emanators should be considered for deployment in humanitarian crisis settings to expand malaria control options beyond traditional interventions.
