| Penulis/Author |
Suzanne M. Dufault (1) ; dr. Citra Indriani, MPH. (2); Stephanie k. Tanamas (3); dr. Riris Andono Ahmad, MPH, Ph.D (4); Prof. dr. Adi Utarini, M.Sc., MPH.,Ph.D. (5); Nicholas P. Jewell (6); Cameron P. Simmons (7); Katherine L. Anders (8) |
| Abstrak/Abstract |
Dengue cases are known to exhibit focal clustering in space and time at the level of the household and neighborhood, driven by local mosquito population dynamics, human population immunity, and fine scale human and mosquito movement. We examined how the spatiotemporal clustering of dengue cases was disrupted by introduction of the arbovirus-blocking bacterium Wolbachia (wMel-strain) into the Aedes aegypti population
in a randomized controlled efficacy trial in Yogyakarta, Indonesia. We analysed 318 serotyped dengue cases and 5,921 test-negative controls with geolocated residence enrolled over 27 months following randomized wMel deployments. The odds that a pair of individuals within a given space-time window are homotypic dengue cases, versus heterotypic cases or test-negative controls, serves as a measure of local transmission. A lack of homotypic clustering is therefore supportive of limited or absent local transmission. We find evidence of significant spatial dependence up to 300m among the 265 dengue cases detected in the untreated arm of the trial. Spatial dependence is strongest within 50m, with a 4.68-fold increase (compared to 95% permutation null range: 0.13, 1.22) in the odds that
a pair of individuals enrolled within 30 days and 50m of each other are homotypic dengue cases – and therefore potentially transmission-related - compared to pairs occurring at any distance. In contrast, we find no evidence of spatial dependence among the 53 dengue cases detected in the wMel-treated arm. Strikingly, in 6 of the 12 wMel-treated areas not a single pair of homotypic dengue cases occurred in any 30-day window. This provides compelling evidence that introgression of wMel Wolbachia into Aedes aegypti mosquito populations interrupts local dengue virus transmission, leading to reduced case incidence. |
