Fig 1.
Flow diagram for the mosquito ecological model, mosquito SEI model, and human SI model.
E, Early Instar; L, Late Instar; P, Pupae; Sv, Susceptible Vectors; Ev, Exposed Vectors, Iv, Infected Vectors; SH, Susceptible Humans; and IH, Infected Humans.
Fig 2.
Targeting the mosquito on multiple fronts.
The schematic highlights opportunities for existing and novel vector control tools that can be used to target mosquitoes both indoors and outdoors and at all stages of the mosquito life and feeding cycles. Synergy and layering between interventions follows from this schematic diagram (Fig 2) and how all the interventions are encoded from it.
Fig 3.
Sensitivity analysis for vector control optimization model.
Sensitivity analysis is performed using Latin Hypercube Sampling/Partial Rank Correlation Coefficient (LHS/PRCC) sensitivity analysis approach based on the impact of selected vector control tools at 50% coverage in reducing entomological inoculation rate for An. gambiae s.s. (A) and An. arabiensis (B). The names for parameters are given in the second column titled “Key” of Table C in S2 Appendix.
Fig 4.
Evaluating the impact of combining ITNs at 50% and 80% coverage with additional tools against An. gambiae s.s.
The tools selected in this example are attractive toxic sugar baits (ATSB), topical (ECT) endectocide-treated cattle, mosquito-proofed housing (HOU), larviciding (LAR) and personal protection measure (e.g. insecticide-treated clothing) (PPM). Adding one or two tools to ITNs at 50% coverage might be sufficient to interrupt transmission in low transmission settings (A); but in most cases not sufficient in moderate (C) and high transmission (E) settings. Scaling up ITNs to 80% coverage and adding another tool with 50% coverage might be sufficient to interrupt transmission in low (B) transmission but not necessarily in moderate (D) and high (F) transmission settings unless the tool added is mosquito proofed housing.
Fig 5.
Evaluating the impact of combining ITNs at 80% coverage with additional tools against An. arabiensis.
Similar tools presented in Fig 4 are presented here showing EIR values at equilibrium but with ITN coverage set to 80% and coverage with additional vector control tools set to 50% in panels A, C and E and 80% panels B, D and F. Adding a tool or two is insufficient to interrupt transmission in most cases for An. arabiensis in moderate and high transmission settings, except when larviciding or endocticide-treated cattle is added (either alone or in combination).
Fig 6.
Evaluating the impact of combining ITNs at 80% coverage with other interventions.
This figure shows equilibrium values of EIR simulated based on selected tools added to high transmission areas against An. arabiensis (A), An. gambiae (B), and An. funestus (C). The box plot shows the median, the interquartile ranges and the 95% confidence ranges of the EIR for different parameter values shown on Fig 3 corresponding to either specific mosquito parameters and/or vector control tools used to interrupt transmission. Adding larviciding at 80% to ITNs at 50% might not be sufficient to interrupt transmission (A, B, and C); but adding another intervention (e.g. ATSB at 50%) reduces transmission dramatically and adding the fourth intervention (e.g. endectocide-treated cattle at 80%) is sufficient to interrupt transmission with baseline EIR of 100.