Multiple blood feeding in mosquitoes shortens the Plasmodium falciparum incubation period and increases malaria transmission potential
Fig 3
Mosquitoes are infectious sooner following a second blood meal.
(A–B) Salivary glands of females fed twice (two red circles) show (A) a significantly higher prevalence (P, pie charts) of sporozoites at 8 and 10 d pIBM (χ2 test: 8 d, χ2 = 15, d.f. = 3, p = 0.0018; 10 d, χ2 = 43, d.f. = 3, p<0.0001; FDR-corrected post-hoc χ2 tests shown) and (B) significantly more sporozoites at 10 d pIBM (Linear mixed model; #BF: p = 0.0001; FDR-corrected post-hoc Student’s t tests shown) than females fed once (one red circle). Horizontal bars indicate median values. There is no difference in sporozoite prevalence at a later time point (χ2 test: 14 d, χ2 = 2.4, d.f. = 3, n.s.). (C) The EIP50 (time to 50% infectious–dotted line; values also shown ± 95% C.I.) of control (Cntrl) females fed a second time (blue solid line) is reduced by 2.3 d (21%) compared with controls fed once (orange solid line), as determined from the sporozoite prevalence data shown in (A) (z test, Z = 5.7, p<0.0001). Similarly, EIP50 is reduced by 2.4 d (20%) in Lp-depleted females fed a second time (purple dashed line) compared to those fed once (red dashed line) (z test, Z = 5.3, p<0.0001). Fitted logistic curves (lines), EIP50 ± 95% C.I. (shaded). n = numbers of mosquitoes analyzed from 4 different experiments. n.s. = not statistically significant. See S1–S4 Tables for details of statistical models.