Fig. 6: Infection rates, stepwise dissemination rates, and stepwise transmission rates of six Aedes aegypti populations from the Caribbean-Americas region examined 21 days after exposure to an infectious blood meal containing one YFV strain (Bolivia, Ghana, Nigeria, Sudan or Uganda).

After exposure to an infectious blood meal provided at a titer of 10⁷ FFU/mL, engorged mosquitoes were kept for 21 days in controlled conditions until examination. Legs and wings of individual mosquitoes were removed, and the proboscis was inserted into a pipette tip to collect saliva. Then, mosquitoes were dissected to isolate the midgut from the carcass. The number of virus particles in midgut, carcass, and saliva were estimated by titration. A–E The infection rate was defined as the proportion of mosquitoes with an infected midgut among the total number of mosquitoes exposed to the blood meal (Table S4). F–J The stepwise dissemination rate was defined as the proportion of mosquitoes with an infected carcass among mosquitoes with an infected midgut (Table S4). K–O The stepwise transmission rate was defined as the proportion of mosquitoes with infectious saliva among mosquitoes with an infected carcass (Table S4). The error bars correspond to the confidence intervals (95%) for IR (A–E), SDR (F–J), and STR (K–O). *0.01 ≤ p < 0.05, **0.001 ≤ p < 0.01, ****p < 0.0001 by Fisher’s exact test (two-sided). In brackets are the numbers of mosquitoes tested. Source data are provided as a Source Data file.