Entomological outcomes of cluster-randomised, community-driven dengue vector-suppression interventions in Kampong Cham province, Cambodia

• Published in: PLoS neglected tropical diseases Vol. 16; no. 1; p. e0010028
• Main Authors: Jacob Bigio, Leo Braack, Thy Chea, Srun Set, Sokha Suon, Pierre Echaubard, John Hustedt, Mark Debackere, Bernadette Ramirez, Didot Budi Prasetyo, Sam Bunleng, Alexandra Wharton-Smith, Jeffrey Hii
• Format: Journal Article
• Language: English
• Published: Public Library of Science (PLoS) 01-01-2022
• ISSN: 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0010028

Cambodia has one of the highest dengue infection rates in Southeast Asia. Here we report quantitative entomological results of a large-scale cluster-randomised trial assessing the impact on vector populations of a package of vector control interventions including larvivorous guppy fish in household water containers, mosquito trapping with gravid-ovitraps, solid waste management, breeding-container coverage through community education and engagement for behavioural change, particularly through the participation of school children. These activities resulted in major reductions in Container Index, House Index, Breteau Index, Pupal Index and Adult Index (all p-values 0.002 or lower) in the Intervention Arm compared with the Control Arm in a series of household surveys conducted over a follow-up period of more than one year, although the project was not able to measure the longer-term sustainability of the interventions. Despite comparative reductions in Adult Index between the study arms, the Adult Index was higher in the Intervention Arm in the final household survey than in the first household survey. This package of biophysical and community engagement interventions was highly effective in reducing entomological indices for dengue compared with the control group, but caution is required in extrapolating the reduction in household Adult Index to a reduction in the overall population of adult Aedes mosquitoes, and in interpreting the relationship between a reduction in entomological indices and a reduction in the number of dengue cases. The package of interventions should be trialled in other locations.