Fig. 1

Comparison of CHIKV infection patterns and titers in midguts and carcasses of mosquitoes, which had received a bloodmeal (BM), protein meal (PM), or saline meal (SM) mixed with CHIKV containing cell culture medium at 1, 2, 4 days post-infection (dpi). a Immunofluorescence assay detection of CHIKV-antigen in midguts at different time points post-infectious SM/PM (1, 2, 4 dpi) and non-infectious SM/PM (negative control) at 4 days post-feeding (dpf). Images (c-d) and (g-h) are higher magnification views of (b) and (f), respectively as outlined by the white boxes. Bars: (a-b, e-f, i-l) 200 μm; (c-d, g-h) 50 μm. Virus titers of individual midguts (b) and carcasses (c) as analyzed by plaque assays in Vero cells. Each data point represents the CHIKV titer of a single midgut or carcass. Only infected mosquitoes were included in the statistical analysis based on the Mann–Whitney U-test to determine P values. Black bars indicate medians. The tables below b and c show the numbers of CHIKV infected midguts or carcasses in relation to the total numbers of midgut and carcass samples tested. d Prevalence of CHIKV infection in carcasses of mosquitoes. Fisher’s exact test was used to determine P values