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Table 1 Definition of variables and parameters used in the transmission model

From: Assessing the impact of intervention strategies against Taenia solium cysticercosis using the EPICYST transmission model

State variables Description  
S Susceptible humans  
I T Humans with taeniasis only  
I C Humans with cysticercosis only  
I TC Humans with taeniasis and cysticercosis  
S P Susceptible pigs  
I PL Pigs with cysticercosis (low cyst burden)  
I PH Pigs with cysticercosis (high cyst burden)  
R p Recovered (immune) pigs  
V p Vaccinated pigs  
E Taenia solium eggs (in the environment)  
Demographic rates Description Units
b H Human births (net rate, set to maintain stable population size) Month-1
d H Human death rate (per capita) Month-1
b P Pig births (net rate, set to maintain stable population size) Month-1
d P Pig death rate (per capita) Month-1
d E Egg removal/death rate (per capita) Month-1
Transmission parameters Description Units
α Human recovery rate from taeniasis (reciprocal of the average lifespan of the adult Taenia solium worm) Month-1
τ Egg to pig transmission coefficient (product of the contact rate and the probability of infection upon consumption of a Taenia solium egg) Month-1
ϕ Proportion of pigs with low cyst burden; (1-ϕ) is the proportion of pigs with high cyst burden
δ Egg production rate Month-1
ε Rate of loss of immunity in pigs Month-1
χ Rate of human pork meal procurement Month-1
π L Probability of human becoming infected having consumed infected pork with a low cyst burden
r consumption Risk multiplier of discarding high cyst-burden pork (relative to discarding low cyst-burden pork)
r infection Risk multiplier of infection on consuming high cyst-burden pork (relative to consuming low cyst-burden pork)
π H Probability of human becoming infected having consumed infected pork with a high cyst burden, π H = π L (1 + r consumption + r infection)
β L Pig (low cyst burden) to human transmission coefficient (a product of the contact rate and the probability of infection upon consumption of infected pork, β L  = χπ L Month-1
β H Pig (high cyst burden) to human transmission coefficient (a product of the contact rate and probability of infection upon consumption of infected pork, β H  = χπ H Month-1
θ Egg to human cysticercosis transmission coefficient (a product of the contact rate and probability of infection upon consumption of Taenia solium eggs) Month-1
r Cysticercosis Risk multiplier for cysticercosis (applied to theta if the individual has taeniasis)
η Human recovery rate from cysticercosis (reciprocal of the average duration of cysticercosis infection in humans) Month-1