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FMD Simulation — Ramanagara District

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FMD Epidemic Calculator
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📅 Simulation Days
Range: 10 – 3650 days
Intervention day
50
Day cursor
0

R₀ Results

Intervention day: 50
Herd Immunity Threshold
The herd immunity threshold refers to the critical fraction of a population that must acquire immunity in order to interrupt disease transmission and protect susceptible individuals indirectly
Day
0

Preparedness

Day 0
Results
Susceptible Cattle (S_C)
1,092
Exposed Cattle (E_C)
179
Asymptomatic Infected Cattle (I_C1)
1,233
Symptomatic Infected Cattle (I_C2)
2,120
Recovered Cattle (R_C)
15,899
Infected Buffalo (I_B)
33
Infected Pig (I_P)
26
Infected Sheep (I_S)
4,584
R₀ summary + derived indicators + Equilibrium auto
R₀ (results)
from model equations (β, γ, μ, D, φ, F_env…)
Herd immunity threshold
HIT = 1 − 1/R₀ (if R₀>1)
Peak infected (I_total)
Day —
Time to peak
days from Day 0
Duration of infection
days with I_total > 1
Time endemic starts
first stable plateau window
Time epidemic starts
first day I_total > 1
Time epidemic ends
last day I_total > 1
I_total curve (scaled)
Markers: Peak (red), Endemic start (green), Epidemic start/end (blue/gray)
What-if: vary initial Symptomatic Infected Cattle (I_C20) and compare curves

Endemic equilibrium point (from equations)
S* (Susceptible cattle)
R* (Recovered cattle)
I_C2*
q_C*

📊 Year-wise Simulation Validation — District

How Hindcast Validation Works (RK4 Method):
For each historical year: (1) Year-specific cattle population is used as N. (2) Observed attacks seed I_C2 as the starting condition. (3) A year-specific β_C is back-calculated from observed incidence. (4) The full ODE system is solved using Runge-Kutta 4th order (RK4) for 365 days. (5) Predicted = Average Monthly I_C2 from the RK4 run. (6) Rule: Reported=Yes & model fires (pred > 0) → YES (TP) | Not Reported & model quiet → YES (TN) | Not Reported & model fires → NO (FP) | Reported & model silent → NO (FN).
📂 District Historical Data

Select a district to validate. Cattle population from 2019 Census; FMD attack data 2019–2024.

Required columns: Year, Observed_Attacks, Cattle_Population. Optional: District

Run validation to see hindcast validation against historical outbreaks.

📊 Scenario Comparison — Control Measures Summary

SCENARIO VACC RATE (%) ISOLATION (%) PEAK R₀ FINAL R₀ PEAK INFECTED PEAK DAY FINAL INFECTED ATTACK RATE EFFICACY VS NO CONTROL
Run simulation with different control measures to see scenario comparison
How to use: Run simulation with different vaccination rates (α_C) and isolation rates (φ) to compare scenarios. Each scenario is automatically categorized and tracked. The table shows effectiveness metrics and calculates efficacy compared to the "No Control" baseline.

🔬 With vs Without Control Measures — Comparison

Side-by-side Itotal curves showing impact of movement restriction, biosecurity, surveillance, culling & quarantine
No Control Peak
With Control Peak
Peak Reduction
% fewer infected
No Ctrl Final I
end-of-sim
With Ctrl Final I
end-of-sim
Duration Saved
fewer outbreak days
Metric Without Control measures With Control measures Change
Run simulation to see control measures comparison
📐 View Control Measure Equations
Force of Infection (Cattle):
λ_C = β_C · (1 - m_restrict) · (I_C1 + I_C2 + f_env·F·(1-b_biosec)·I_B2 + f_env·F·(1-b_biosec)·I_P + f_env·F·(1-b_biosec)·I_S) / N

dI_C2/dt = σ₁·I_C1 + K₂·Q_C − [γ₃ + μ_C + φ_base·(1+λ_surv)·(1+θ_outbreak) + D_C + cull_rate]·I_C2
dQ_C/dt = Δ_QC·(1−s_efficacy) − (K₁ + K₂ + μ_C + φ_quarantine)·Q_C
dS_C/dt = Δ_C + α_C3·ε_vac·V_C1 + χ₂·V_C2 + K₁·Q_C·(1−s_efficacy) + ∅·R_C − [α_C + μ_C]·S_C − λ_C·S_C

📊 3-Scenario Control Measure Comparison

Uniform distribution Monte Carlo · Baseline + Minimal / Moderate / Maximum · Exportable charts & tables
Baseline
No Control (all = 0)
Minimal
U(0.05, 0.20)
Moderate
U(0.30, 0.55)
Maximum
U(0.80, 0.95)
Metric Baseline Minimal (mean±SD) Moderate (mean±SD) Maximum (mean±SD)
Click ▶ Run to generate Monte Carlo results
📋 Uniform Distribution Parameter Ranges
Parameter ODE Effect Baseline Minimal Moderate Maximum
💉 VACCINATION IMPACT ANALYSIS
Vaccination Coverage
—%
R₀ After Vaccination
Current Re
Required Control %
—%
⚠️ Run simulation to see analysis
📊 How Much Vaccination Is Needed to Control FMD?

X-axis = Vaccination Coverage %, Y-axis = Effective Reproduction Re. Push the blue dot below the green dashed line to eliminate FMD.

Run the simulation to see the analysis here.
📌 How to read this graph:
🔵 Blue curve: Re for YOUR simulation R₀ as vaccination % rises
🔴 Red curve: Re if a high-risk outbreak strain (R₀=4.5) hits
🟢 Green dashed line: Control threshold — anything below this means FMD will die out
🔵 Filled dot: YOUR current vaccination coverage and Re
Dashed vertical lines show the minimum vaccination % needed to cross the threshold.
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