104 research outputs found
MOESM1 of Modelling the implications of stopping vector control for malaria control and elimination
Additional file 1. Baseline parameterization of the African scenario
MOESM2 of Modelling the implications of stopping vector control for malaria control and elimination
Additional file 2. Baseline parameterization of the Western Pacific scenario
Overview of the population structure and compartments of the model.
<p>A): Human populations are divided in a stationary (N<sub>h1</sub>) population that remains in low exposure habitats (e.g., a village), and a smaller population (N<sub>h2</sub>) which commute and spend a proportion ξ of their time in a potentially high exposure setting (e.g., a plantation). Each of these habitats harbours tsetse (N<sub>v1</sub> and N<sub>v2</sub>) and non-human vertebrate animal populations (N<sub>a1</sub> and N<sub>a2</sub>) of varying sizes and characteristics. B): Compartmental diagram highlighting the transmissions between states of infection of the animal, tsetse, and human populations in the high exposure area 2. A similar diagram explains transmission in area 1, although there both human populations are exposed to tsetse bites. Solid lines depict transitions between compartments, while dashed lines represent transmission rates.</p
Zero-growth isoclines (<i>R</i><sub>0</sub> = 1) of <i>T</i>.<i>b</i>. <i>gambiense</i> under perturbation of specific parameters.
<p>The parameter values used were the median values obtained for the high transmission setting, except for those varied in the analysis. In the left plot, isoclines at different levels of vector mortality are shown, depending on the daily removal rate of infected humans (<i>r</i>) and the proportion of time commuters spend in the high exposure area (ξ). The areas above the isoclines represent values of <i>R</i><sub>0</sub> greater than 1, and below and to the right of the isoclines values smaller than 1. In the middle plot the impact of screening humans in the low risk setting (<i>r</i><sub><i>a</i></sub>) in combination with screening commuting humans (<i>r</i><sub><i>b</i></sub>) is shown for different levels of animal to human ratios (A/H<sub>1</sub>). In the right plot isoclines are depicted along removal rates (<i>r</i>) and tsetse density (V/H) in both areas when animals either do not contribute to transmission (<i>c</i><sub><i>a</i></sub> = 0) or they can infect tsetse (<i>c</i><sub><i>a</i></sub> = 0.003).</p
Median (lines) and 95<sup>th</sup> percentiles (shaded areas) of simulations on the impact of interventions on prevalence over time in high transmission settings without (left) and with (right) animal-tsetse transmission, assuming a range of efficacies for screen & treat (solid line) and screen & treat with vector control (dashed line).
<p>Median (lines) and 95<sup>th</sup> percentiles (shaded areas) of simulations on the impact of interventions on prevalence over time in high transmission settings without (left) and with (right) animal-tsetse transmission, assuming a range of efficacies for screen & treat (solid line) and screen & treat with vector control (dashed line).</p
The proportion of simulations where HAT was eliminated (i.e., prevalence < 1 x 10<sup>−6</sup>) and the mean time to elimination, depending on the percentage of the human population screened per year, with varying levels of vector control (expressed as additional vector mortality, indicated by the symbols in the legend), for a moderate transmission setting without an animal reservoir (A) and with an animal reservoir (B).
<p>The proportion of simulations where HAT was eliminated (i.e., prevalence < 1 x 10<sup>−6</sup>) and the mean time to elimination, depending on the percentage of the human population screened per year, with varying levels of vector control (expressed as additional vector mortality, indicated by the symbols in the legend), for a moderate transmission setting without an animal reservoir (A) and with an animal reservoir (B).</p
The proportion of simulations where HAT was eliminated (i.e., prevalence < 1 x 10<sup>−6</sup>) and the mean time to elimination, depending on the percentage of the human population screened per year, with varying levels of vector control (expressed as additional vector mortality, indicated by the symbols in the legend), for a low transmission setting without an animal reservoir (A) and with an animal reservoir (B).
<p>The proportion of simulations where HAT was eliminated (i.e., prevalence < 1 x 10<sup>−6</sup>) and the mean time to elimination, depending on the percentage of the human population screened per year, with varying levels of vector control (expressed as additional vector mortality, indicated by the symbols in the legend), for a low transmission setting without an animal reservoir (A) and with an animal reservoir (B).</p
Rate parameter descriptions, values used and ranges for model versions based on heterogeneity, but no animal reservoir.
<p><sup>†</sup>Values were zero (and not fit to prevalence levels) unless the interventions of screening and treatment of humans was simulated.</p><p>Rate parameter descriptions, values used and ranges for model versions based on heterogeneity, but no animal reservoir.</p
Relationship of parasite prevalence (a), uncomplicated episodes (b), severe episodes (c), and mortality (d) to annual average EIR by seasonality index (<i>φ</i>).
<p>Triangles represent simulated results. The lines show the estimated relationship between indicators from the simulation runs, fitted using fractional polynomial regression, for each pattern of seasonality as described by (the seasonality index , number of peaks) (<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003812#pcbi-1003812-g001" target="_blank"><b>Figure 1</b></a>). Unbroken red line represents (0, 0). Brown dashed line represents (1,1). Orange dotted-dashed line represents (1,2). Green dotted line represents (2,1). Black dotted-dashed line represents (2,2). Blue dashed line represents (0.5, 2).</p
Annual pattern of transmission, defined as the simulated daily EIR, for each seasonality profile as described by (the seasonality index <i>φ</i>, number of peaks).
<p>Unbroken red line represents (0, 0). Brown dashed line represents (1,1). Orange dotted-dashed line represents (1,2). Green dotted line represents (2,1). Black dotted-dashed line represents (2,2). Blue dashed line represents (0.5, 2).</p
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