Age-stratified incidence of different arboviral diseases by time since emergence.

Expected changes in age-specific incidence for a viral disease that emerged 20 years ago with an annual FoI of 50/1000, assuming the first infection causes disease (like chikungunya or Zika) vs. when there are four circulating viruses that emerged 20 years ago each with an annual FoI of 50/1000 and the second infection causes disease (like dengue).