Fig. 3
Projected impact of Wolbachia on dengue transmission in human populations. Colours indicate whether transmission is by Wolbachia-free (Wolb−, in blue) or Wolbachia-carrier (Wolb+, in green) mosquitoes. Left panels show dengue incidence versus transmission coefficient plotted from equilibrium solutions of a 4-serytope dengue model (Methods section) on human populations with heterogeneous risk (variance-to-mean ratio of 4): a, d mosquitoes parameterized from experiments in Brazil and released under different forces of selection by mosquito pathogens: a λM = 0; d λM = 0.3. g, j same as a, d, for Vietnam. Equilibrium curves adopted mean proportions of infected mosquitoes with detectable virus in the salivary glands3, and shaded areas represent lower and upper bounds encountered when mosquitoes were stratified by challenge dose. Dotted lines mark dengue incidence in Rio de Janeiro, and Ho Chi Minh City, averaged over a 4-year period and scaled by an expansion factor of 5. Right panels show model simulations of Wolbachia releases taking place in 2017, starting from the conditions on the respective left panels: b, e, h, k mosquito population sizes; c, f, i, l dengue epidemics in humans (shaded areas refer to notification data; lower bound showing the original data and upper bound the data multiplied by an expansion factor of 5). Parameter values: β = 0.59 (c), β = 0.74 (f), β = 0.13 (i), β = 0.17 (l); A = 0.25, Β = 0.25 (b, c, e, f); A = 0.05, Β = 0.1 (h, i, k, l)
