Figure 1.
Overview of model components.
Table 1.
State variables.
Table 2.
Parameters.
Figure 2.
Vector and epidemiological dynamics, with release ratio 10∶1.
Release ratio C: 10. Over time (A) total number of vectors, (B) total number of infectious hosts (primary or secondary infections), by serotype (1: solid line, 2: dashed), (C) total number of hosts recovered from secondary infection (solid) or susceptible to either or both serotypes (dashed). Default parameter values (Table 2), with initial conditions host population N0: 2 million and primary infections I1: 1, I2: 2. The release ratio is sufficiently high (), that the vector and virus are eliminated. Over subsequent years, immunity is lost from the host population.
Figure 3.
Vector and epidemiological dynamics, with release ratio 1∶1.
Release ratio C: 1. Over time (A) total number of vectors, (B & C) total number of infectious hosts (primary or secondary infections), by serotype (1: solid line, 2: dashed); Default parameter values (Table 2), with initial conditions host population N0: 2 million and primary infections I1: 1, I2: 2. With this low release ratio (), the vector population is reduced but remains above the transmission threshold vector abundance (
); panel (C) is on different scales (note the much longer time period) and shows that the disease returns after initial suppression and persists in the longer term.
Table 3.
Simulation results.
Table 4.
Estimated cost of simulated releases.
Figure 4.
Importance of different parameter values to cost per dengue case averted.
Relative change in cost per dengue case averted as a result of increasing each parameter value, one at a time, by 5%, for 5 year (black) or 10 year (white) release program. This is shown as “standard elasticity”, i.e. the relative change in the cost per case averted divided by the 5% relative change in each parameter value. Default parameter values (Table 2), initial host population N0: 2 million, and release ratio C: 10. 1C was increased by 5% only in the calculations of cost, with the effective release ratio kept at 10 in the epidemiological model, to represent losses during delivery of engineered males. 2We also tested a 5% increase in the mosquito mortality rate for males only, which affects the numbers to be released and hence the program costs.