Table 1.
Parameter values used in the model, based on literature sources or specified assumptions.
Fig 1.
A compartmental diagram of the disease dynamics of a mixed-species flock. The top and bottom parts represent the chicken and duck populations, respectively. We assumed that all infected chickens became symptomatic, while ducks might not exhibit clinical signs with probability (1−pd).
Fig 2.
Histogram final deaths pd = 0.2.
Histogram of distribution of final death numbers with varied number of chickens in flocks of size 40. Duck symptomatic probability set to 0.2.
Fig 3.
Histogram final deaths pd = 0.8.
Histogram of distribution of final death numbers with varied number of chickens in flocks of size 40. Duck symptomatic probability set to 0.8.
Fig 4.
Heat map showing the average number of deaths in all simulation results given the parameter combinations of chicken populations and duck asymptomatic probability.
Fig 5.
Detection time for different death thresholds for detection and chicken population out of 40 total birds. Top plot: the duck’s symptomatic probability pd = 0.2; Bottom plot: the duck’s symptomatic probability pd = 0.8. The boxes indicate the interquartile range (25th and 75th percentiles), and the whiskers indicate the 2.5th and 97.5th percentiles. The white dot in the box indicates the average detection time, which also corresponds to the fourth and first row of Fig 6 (for detection after 2 deaths).
Fig 6.
Heat map showing the average detection time (with detection occurring when two deaths have occurred) in all simulation results given the parameter combinations of chicken populations and duck symptomatic probability. Note that no detection would occur for duck flocks with duck symptomatic probability equal to zero (Black grid).
Fig 7.
Undetected burden of infection (total time birds spent infectious up to the point of detection) for different death thresholds for detection and chicken population out of 40 total birds. Top plot: the duck’s symptomatic probability pd = 0.2; Bottom plot: the duck’s symptomatic probability pd = 0.8. The boxes indicate the interquartile range (25th and 75th percentiles), and the whiskers indicate the 2.5th and 97.5th percentiles. The white dot in the box indicates the average detection time, which also corresponds to the fourth and first row of Fig 8 (for detection after 2 deaths).
Fig 8.
Heat map showing the average undetected burden of infections (with detection occurring when two deaths have occurred) in all simulation results given the parameter combinations of chicken populations and duck asymptomatic probability. Note that no detection would occur for duck flocks with duck symptomatic probability equal to zero (Black grid).
Fig 9.
The Spearman correlation between the sampled parameters and final deaths (left), detection time (middle), and burden of infection (right), respectively, with fixed pd = 0.2, and all 40 birds are chickens.
Fig 10.
The Spearman correlation between the sampled parameters and final deaths (left), detection time (middle), and burden of infection (right), respectively, with fixed pd = 0.2, and all 40 birds are ducks.