Solar Powered Spatial Emanators Do Not Lower Malaria Prevalence in Uganda

A novel solar-powered spatial emanator did not significantly reduce malaria infection prevalence among young children in Eastern Uganda, according to findings from a double-blinded, cluster-randomised, placebo-controlled trial. The Mossie-GO trial evaluated whether releasing volatile active ingredients from solar-assisted devices could lower community malaria transmission in rural and peri-urban settings. Following twelve months of continuous device deployment, the primary baseline-adjusted analysis demonstrated no statistically significant difference in malaria infection prevalence between children living in clusters assigned to the active emanators and those living in clusters receiving identical placebo devices.

The continued threat of malaria across endemic regions has motivated ongoing investigations into the efficacy of alternative vector control tools. Spatial emanators represent one such approach, designed to disperse active chemical ingredients into the local atmosphere to disrupt mosquito host-seeking vector behaviour and diminish contact between mosquitoes and humans. To evaluate this intervention in real-world community environments, researchers initiated the Mossie-GO trial to rigorously estimate the preventive effect of deploying solar-powered spatial emanator hardware in rural and peri-urban locations within the Jinja and Buikwe districts of Eastern Uganda.

The study protocol was established as a prospective, cluster-randomised, controlled field trial registered with the ClinicalTrials.gov registry under the identifier NCT06232954. Investigators enrolled fifty-six community clusters, randomising them in an equal one-to-one ratio to receive either the active intervention or a placebo control. Up to one hundred households were enrolled per cluster across the trial area. In the intervention arm, households received the solar-powered spatial emanator equipped with transfluthrin-treated coins. In the control arm, households received an identical emanator device containing no active ingredient. Throughout the evaluation, study participants, field staff, and investigators remained fully masked to cluster allocation.

The primary outcome of the Mossie-GO trial was malaria infection prevalence among children aged five years and younger at twelve months of follow-up, comparing intervention and control clusters with statistical adjustment for baseline cluster-level prevalence. In the unadjusted analysis, the odds ratio for malaria infection in the intervention arm relative to the control arm was 0.63, with a 95 percent confidence interval of 0.29 to 1.36 and a p-value of 0.239. After adjusting for baseline cluster-level infection prevalence, the odds ratio was 0.96, with a 95 percent confidence interval of 0.66 to 1.39 and a p-value of 0.813, showing no evidence of lower follow-up infection prevalence.

Entomological evaluations conducted during the trial mirrored the primary clinical findings, showing no statistically significant differences in mosquito density between the intervention clusters and the control clusters. Investigators did document an observed reduction in the human biting rate among households in the intervention clusters, but this decrease was not statistically significant. In addition, exploratory subgroup analyses revealed some indication of change across specific subsets, though researchers emphasized that these secondary patterns must be interpreted strictly as hypothesis-generating observations rather than confirmed evidence of intervention efficacy.

Safety monitoring throughout the twelve-month study period indicated that the solar-powered devices were well tolerated by residents. No serious adverse events were reported across either arm of the trial, and there was no difference in the overall rate of adverse events between the intervention and control groups. In discussing the absence of a statistically significant protective outcome, the study authors highlighted that large variation in baseline data and substantial variation between clusters may have limited the statistical power of the trial to detect significant differences between the two study arms.

Subject of Research: Solar-powered spatial emanators for malaria control

Article Title: Effect of a solar-powered spatial emanator on malaria prevalence in Uganda (Mossie-GO trial): A double-blinded, cluster-randomised, and placebo-controlled trial

Article References: Dennehy, J., Dyall, W., Jenkins, A., Sserwanga, A., Kigozi, R., Babirye, J., Bwanika, J. B., Arnett, M., Oduor, J., Nuwa, A., Ojangole, P., Mawejje, H. D., Turner, M. A., Wallace, R., Lyle, F. G. A., Hebden, J., Bradley, J., Hiscox, A., Logan, J. G., … Jones, R. T. (2026). Effect of a solar-powered spatial emanator on malaria prevalence in Uganda (Mossie-GO trial): A double-blinded, cluster-randomised, and placebo-controlled trial. PLOS Global Public Health, 6(11), e0007457. https://doi.org/10.1371/journal.pgph.0007457

Image Credits: AI Generated

DOI: 10.1371/journal.pgph.0007457

Keywords: malaria, Uganda, spatial emanator, transfluthrin, vector control, cluster-randomised trial, public health, mosquito prevention, Effect, solar-powered, spatial, emanator