Figure 2.

The dose at which 50% of mosquitoes become infected (ID₅₀) with either chikungunya virus (CHIKV) 91077 or dengue virus (DENV) 306. Aedes aegypti were blood fed using three doses of virus, including ∼10⁵, 10⁶, and 10⁷ pfu/mL, and virus-positive mosquito were identified by plaque assay at 14 days post-feeding. Linear regression analyses were used to determine the relationship between dose and infectivity and ID₅₀ values were extrapolated from these linear relationships.