Squared boxes and circles correspond respectively to human and vector compartments. Plain arrows represent transitions from one state to the next. Dashed arrows indicate interactions between humans …
Posterior median number of observed Zika cases (solid line), 95% credible intervals (shaded blue area) and data points (black dots). First column: particle filter fit. Second column: Simulations …
Posterior median number of observed Zika cases (solid line), 95% credible intervals (shaded blue area) and data points (black dots). First column: particle filter fit. Second column: Simulations …
Simulations from the posterior density: posterior median (solid line), 95% and 50% credible intervals (shaded blue areas) and observed seroprevalence (black dots). First column: Infected humans ().…
Simulations from the posterior density: posterior median (solid line), 95% and 50% credible intervals (shaded blue areas) and observed seroprevalence (black dots). First column: Infected humans ().…
Pandey model, Yap island.
Pandey model, Moorea island.
Pandey model, Tahiti island.
Pandey model, New Caledonia.
Laneri model, Yap island.
Laneri model, Moorea island.
Laneri model, Tahiti island.
Laneri model, New Caledonia.
Pandey model, Yap island.
Pandey model, Moorea island.
Pandey model, Tahiti island.
Pandey model, New Caledonia.
Laneri model, Yap island.
Laneri model, Moorea island.
Laneri model, Tahiti island.
Laneri model, New Caledonia.
Parameter estimations for the Pandey model. Posterior median (95% credible intervals). All the posterior parameter distributions are presented in Figures 6–9 .
Pandey model | Yap | Moorea | Tahiti | New Caledonia | |
---|---|---|---|---|---|
Population size | H | 6892 | 16,200 | 178,100 | 268,767 |
Basic reproduction number | 3.2 (2.4–4.1) | 2.6 (2.2–3.3) | 2.4 (2.0–3.2) | 2.0 (1.8–2.2) | |
Observation rate | 0.024 (0.019-0.032) | 0.058 (0.048-0.073) | 0.060 (0.050-0.073) | 0.024 (0.010-0.111) | |
Fraction of population involved | 74% (69–81) | 50% (48–54) | 50% (46–54) | 40% (9–96) | |
Initial number of infected individuals | 2 (1–8) | 5 (0–21) | 329 (16–1047) | 37 (1–386) | |
Infectious period in human (days) | 5.2 (4.1–6.7) | 5.2 (4.1–6.8) | 5.2 (4.1–6.7) | 5.5 (4.2–6.8) | |
Extrinsic incubation period in mosquito (days) | 10.6 (8.7–12.5) | 10.5 (8.6–12.4) | 10.5 (8.6–12.6) | 10.7 (8.9–12.5) | |
Mosquito lifespan (days) | 15.6 (11.7–19.3) | 15.3 (11.4–19.1) | 15.1 (11.2–19.0) | 15.4 (11.6–19.4) |
Parameter estimations for the Laneri model. Posterior median (95% credible intervals). All the posterior parameter distributions are presented in Figures 10–13.
Laneri model | Yap | Moorea | Tahiti | New Caledonia | |
---|---|---|---|---|---|
Population size | H | 6892 | 16,200 | 178,100 | 268,767 |
Basic reproduction number | 2.2 (1.9–2.6) | 1.8 (1.6–2.0) | 1.6 (1.5–1.7) | 1.6 (1.5–1.7) | |
Observation rate | 0.024 (0.019–0.033) | 0.057 (0.047–0.07) | 0.057 (0.049–0.069) | 0.014 (0.010–0.037) | |
Fraction of population involved | 73% (69–78) | 51% (47–55) | 54% (49–59) | 71% (27–98) | |
Initial number of infected individuals | 2 (1–10) | 9 (1–28) | 667 (22–1570) | 82 (2–336) | |
Infectious period in human (days) | 5.3 (4.1–6.6) | 5.3 (4.1–6.7) | 5.2 (4.1–6.7) | 5.4 (4.1–6.8) | |
Extrinsic incubation period in mosquito (days) | 10.7 (8.8–12.7) | 10.6 (8.6–12.6) | 10.5 (8.5–12.5) | 10.8 (8.9–12.8) |
Details of the observation models for seroprevalence
Island | Date | Standard deviation | Observed seroprevalence |
---|---|---|---|
Yap | 2007-07-29 | 150 | 5005 (Duffy et al., 2009) |
Moorea | 2014-03-28 | 325 | 0.49 × 16200 = 7938 (Aubry et al., 2015b) |
Tahiti | 2014-03-28 | 3562 | 0.49 × 178100 = 87269 (Aubry et al., 2015b) |
Prior distributions of parameters. 'Uniform[0,20]' indicates a uniform distribution in the range [0,20]. 'Normal(5,1) in [4,7]' indicates a normal distribution with mean five and standard deviation …
Parameters | Pandey model | Laneri model | References | |||
---|---|---|---|---|---|---|
squared basic reproduction number | Uniform[0, 20] | Uniform[0, 20] | assumed | |||
transmission from human to mosquito | Uniform[0,10] | . | assumed | |||
infectious period (days) | Normal(5,1) in [4,7] | Normal(5,1) in [4,7] | (Mallet et al., 2015) | |||
intrinsic incubation period (days) | Normal(4,1) in [2,7] | Normal(4,1) in [2,7] | (Nishiura et al., 2016b; Bearcroft, 1956; Lessler et al., 2016) | |||
extrinsic incubation period (days) | Normal(10.5,1) in [4,20] | Normal(10.5,1) in [4,20] | (Hayes, 2009; Chouin-Carneiro et al., 2016) | |||
mosquito lifespan (days) | Normal(15,2) in [4,30] | . | (Brady et al., 2013; Liu-Helmersson et al., 2014) | |||
fraction of population involved | Uniform[0,1] | Uniform[0,1] |
Initial conditions (t=0) | Pandey model | Laneri model | ||||
---|---|---|---|---|---|---|
HI(0) | infected humans | Uniform[10-6,1]N | Uniform[10-6,1]N | |||
HE(0) | exposed humans | HI(0) | HI(0) | |||
HR(0) | recovered humans | 0 | 0 | |||
infected vectors | VI(0)=Uniform[10-6,1]H | L(0)=Uniform[10-6,1]N | ||||
exposed vectors | VE(0) = VI(0) | K(0)=L(0) |
Local conditions | Yap | Moorea | Tahiti | New Caledonia | References | |
---|---|---|---|---|---|---|
r | observation rate | Uniform[0,1] | Uniform[0,1] | Uniform[0,0.3] | Uniform[0,0.23] | (Mallet et al., 2015; DASS, 2014) |
H | population size | 6,892 | 16,200 | 178,100 | 268,767 | (Duffy et al., 2009; Insee, 2012, 2014) |
Square root of the number of secondary cases after the introduction of a single infected individual in a naive population. Median and 95% credible intervals of 1000 deterministic simulations using …
Pandey model | Laneri model | |
---|---|---|
Yap | 3.1 (2.5–4.3) | 2.2 (1.9–2.6) |
Moorea | 2.6 (2.2–3.3) | 1.8 (1.6–2.0) |
Tahiti | 2.4 (2.0–3.2) | 1.6 (1.5–1.7) |
New Caledonia | 2.0 (1.8–2.2) | 1.6 (1.5–1.7) |
Sensitivity analysis in Pandey model. Tahiti island. 1000 parameter sets were sampled with latin hypercube sampling (LHS), using 'lhs' R package (Carnell, 2016). On each parameter set, the model was …
Parameters | Distribution | Seroprevalence | Peak intensity | Peak date |
---|---|---|---|---|
Model parameters | ||||
Uniform[0,20] | 0.87 | 0.90 | −0.55 | |
Uniform[0,10] | −0.66 | −0.73 | 0.35 | |
Uniform[4,7] | −0.25 | 0.10 | 0.20 | |
Uniform[2,7] | −0.03 | −0.10 | 0.15 | |
Uniform[4,20] | −0.05 | −0.07 | 0.06 | |
Uniform[4,30] | −0.56 | −0.70 | 0.49 | |
Initial conditions | ||||
HI(0) | Uniform[2.10-5,0.011] | 0.05 | −0.02 | 0.02 |
VI(0) | Uniform[10-4,0.034] | 0.11 | −0.00 | −0.26 |
Fraction involved and observation model | ||||
Uniform[0.46,0.54] | 0.47 | 0.15 | −0.03 | |
Uniform[0.048,0.072] | −0.04 | 0.03 | 0.05 |
Sensitivity analysis in Laneri model. Tahiti island. 1000 parameter sets were sampled with latin hypercube sampling (LHS), using 'lhs' R package (Carnell, 2016). On each parameter set, the model was …
Parameters | Distribution | Seroprevalence | Peak intensity | Peak date |
---|---|---|---|---|
Model parameters | ||||
Uniform[0,20] | 0.62 | 0.93 | −0.50 | |
Uniform[4,7] | 0.01 | 0.62 | 0.15 | |
Uniform[2,7] | −0.03 | −0.54 | 0.21 | |
Uniform[4,20] | −0.03 | −0.70 | 0.47 | |
Initial conditions | ||||
HI(0) | Uniform[10-5,0.015] | 0.05 | 0.02 | −0.32 |
L(0) | Uniform[2.10-5,0.004] | 0.05 | 0.00 | −0.16 |
Fraction involved and observation model | ||||
Uniform[0.49,0.59] | 0.80 | 0.34 | 0.02 | |
Uniform[0.048,0.068] | −0.01 | 0.01 | −0.02 |
Codes for the implementation of each model.
Data file, Yap island.
Number of cases per week and number of immune individuals at the end of the epidemic (Duffy et al., 2009).
Data file, Moorea island.
Number of cases per week and number of immune individuals at the end of the epidemic (Mallet et al., 2015; Aubry et al., 2015b).
Data file, Tahiti island.
Number of cases per week and number of immune individuals at the end of the epidemic (Mallet et al., 2015; Aubry et al., 2015b).
Data file, New Caledonia.
Number of cases per week (DASS, 2014).