Figure 1.
Aerial view of Sams Point neighborhood on Ladys Island, Beaufort County, SC depicting the location of the mosquito collection trap and various underground stormwater catch basins.
Figure 2.
Aerial view of Battery Point neighborhood on Port Royal Island, Beaufort County, SC depicting the location of the mosquito collection trap and various underground stormwater catch basins.
Table 1.
Public health insecticides applied from spray trucks to control adult mosquitoes throughout Beaufort County, SC (including the two study sites) during 2006–2012.
Figure 3.
Schematic representation of the model.
Model equations, variables, and parameters are given in the Appendix S1 in File S1, Tables 2 and 3, respectively.
Table 2.
Definitions of variables used in the model.
Table 3.
Parameter definitions, values, and references.
Figure 4.
Model comparison with mosquito surveillance data.
Model predictions of adult mosquito populations (blue lines) based on the best-fit to Culex pipiens complex surveillance data collected during the summer months at the Sams Point and Batter Pont trap locations (blue dots) during 2006–2012. The best-fit parameters estimates are listed in Table 4.
Table 4.
Best fit parameter values to the Culex pipiens complex surveillance data.
Table 5.
Summary of adult female mosquitoes (with mean females per trap night) collected in an EVS trap located at Sams Point neighborhood in Beaufort County, SC from 2006–2012.
Table 6.
Summary of adult mosquitoes (with mean females per trap night) collected in an EVS trap located at Battery Point neighborhood in Beaufort County, SC from 2006–2012.
Figure 5.
Effectiveness of various treatment scenarios predicted by the model in the absence of the WNV infection.
Demonstration of how various insecticide applications impact the adult mosquito (A and C) and larval populations (B and D). Dates of the insecticide treatments (A and B) and treatment effectiveness were varied (C and D) as indicated in the legends in each figure. The remaining parameter estimates were taken from the Tables 3 and 4 (best-fit parameter values are taken for the year 2006 from Sams Point trap location).
Figure 6.
Sensitivity test of the predicted adult mosquito population to the model parameter representing treatment effectiveness in the absence of the WNV infection in the model.
Contour plot of the adult mosquito populations as a function of the treatment effectiveness (s) versus time. The remaining parameters were fixed and chosen from the Tables 3 and 4 (best-fit parameter values are taken for the year 2006 from Sams Point trap location).
Figure 7.
Model predictions of the mosquito, bird, and human populations in the presence of the WNV infection.
The changes of mosquito (A–C), bird (D–F), and human (G–I) populations predicted by model (equations are listed in the Appendix S1 in File S1). The insecticide treatments scenarios, non-treatment (A, D, and G), biweekly (B, E, and H), and weekly (C, F, and I) are represented in each column. Model variables and parameter values are given in Tables 2–4 (best-fit parameter values are taken for the year 2006 from Sams Point trap location).
Figure 8.
Sensitivity test of the predicted basic reproductive ratio to the selected model parameters.
The basic reproductive ratio (ℜ0) as the function of the mosquito biting rate per day (β) and adult mosquito death rate per day (δM). The remaining parameters in the formula are taken from the Tables 3 and 4 (best-fit parameter values are taken for the year 2006 from Sams Point trap location). The ratio formula and its derivation are provided in the Appendix S2 in File S1.
Table 7.
Sensitivity test of the predicted basic reproductive ratio to the mosquito biting rate and the death rate of the susceptible adult mosquitoes.