ICAR Logo
Disease Simulation Portal
Leptospirosis
NIVEDI Logo

Decoding of Infection And Transmission Dynamics

This section contains: Model architecture, Differential equations, and Equation parameterization for Leptospirosis.

Model Architecture

Architecture image not found at team\leptoimage.png. Upload it to that path to display it here.

Differential Equations

Humans

$$ \begin{aligned} \frac{dS_h}{dt} &= \Lambda_h + \omega_h R_h - \beta_{hb} S_h \frac{L_b}{k+L_b} - \beta_{hh} I_h S_h - \beta_{hr} I_r S_h - \beta_{ha} I_a S_h - \mu_h S_h \\ \frac{dE_h}{dt} &= \beta_{hb} S_h \frac{L_b}{k+L_b} + \beta_{hh} I_h S_h + \beta_{hr} I_r S_h + \beta_{ha} I_a S_h - \sigma_h E_h - \mu_h E_h \\ \frac{dI_h}{dt} &= \sigma_h E_h - r_h I_h - (\mu_h+\alpha)I_h \\ \frac{dR_h}{dt} &= r_h I_h - \omega_h R_h - \mu_h R_h \end{aligned} $$

Animals

$$ \begin{aligned} \frac{dS_a}{dt} &= \Lambda_a + \omega_a R_a - \beta_{ab} S_a \frac{L_b}{k+L_b} - \beta_{aa} I_a S_a - \mu_a S_a \\ \frac{dI_a}{dt} &= \beta_{ab} S_a \frac{L_b}{k+L_b} + \beta_{aa} I_a S_a - r_a I_a - \mu_a I_a \\ \frac{dR_a}{dt} &= r_a I_a - \omega_a R_a - \mu_a R_a \end{aligned} $$

Rodents

$$ \begin{aligned} \frac{dS_r}{dt} &= \Lambda_r - \beta_{rb} S_r \frac{L_b}{k+L_b} - \beta_{rr} I_r S_r - \mu_r S_r \\ \frac{dI_r}{dt} &= \beta_{rb} S_r \frac{L_b}{k+L_b} + \beta_{rr} I_r S_r - \mu_r I_r \end{aligned} $$

Environment

$$ \begin{aligned} \frac{dL_b}{dt} &= \eta_a I_a + \eta_r I_r - (\varepsilon+\tau)L_b \end{aligned} $$

Equation Parameterization

Sl. No Parameter Description
1 b₁ Human recruitment rate
2 b₂ Animal/Vector recruitment rate
3 Ω Human recruitment rate
4 Ωₑ Rodent recruitment rate
5 β₁ Human-to-human transmission/contact rate
6 β₂ Vector-to-human transmission/contact rate
7 β₃ Human-to-vector transmission/contact rate
8 β₁₁ Environmental-to-human transmission rate
9 β₁₂ Environmental-to-rodent transmission rate
10 β₂₁ Rodent-to-human transmission rate
11 β₂₂ Rodent-to-rodent transmission rate
12 α Human incubation/progression rate (E → I)
13 τ Rodent incubation/progression rate (Eₑ → Iₑ)
14 γ Human recovery rate
15 γₕ Human recovery transition (Iₕ → Rₕ)
16 λₕ Recovery rate of infected persons
17 σ Loss of immunity (waning immunity)
18 μ Human natural death rate
19 μₕ Human natural mortality rate
20 ε Rodent natural death rate
21 γᵥ Vector natural mortality rate
22 δ Human disease-induced mortality
23 δₕ Human disease fatality rate
24 δᵥ Vector disease-induced mortality
25 δᵣ Rodent disease-induced mortality
26 μₗ Environmental Leptospira removal rate
27 C Environmental Leptospira concentration
28 η₁ Contribution of infected humans/hosts to environmental Leptospira
29 η₂ Contribution of infected rodents to environmental Leptospira