4.1. Basic Model
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new infection is dependent on the total size of the stock of INFECTED, not
on a single cohort within that stock. However, it may be the case that
newly infected individuals are more prone to come into contact with susceptible individuals than with those carrying the disease for more than a
week, since the latter may be weakened, less mobile and thus have reduced
interaction with others . If this is the case, then you would need to specify a
separate contact rate for the individual cohorts among the INFECTED and
use that contact rate and cohort size to specify INFECTION.
EPIDEMIC
IMMUNE(t) = IMMUNE(t-dt) + (RECOVERY-LOSS_OF_IMMUNITY)
* dt
INIT IMMUNE = °
TRANSIT TIME = 30
INFLOW LIMIT =
CAPACITY =
INFLOWS:
RECOVERY = CONVEYOR OUTFLOW
OUTFLOWS :
LOSS_OF_IMMUNITY = CONVEYOR OUTFLOW
INFECTED(t) = INFECTED (t-dt) + (INFECTION-RECOVERYDEATH) * dt
INIT INFECTED = 10,0,0
TRANSIT TIME = 3
INFLOW LIMIT =
CAPACITY
INFLOWS:
INFECTION = CONTACT_RATE*SUSCEPTIBLE*INFECTED
OUTFLOWS:
RECOVERY = CONVEYOR OUTFLOW
DEATH = LEAKAGE OUTFLOW
LEAKAGE FRACTION = MORTALITY_RATE
NO-LEAK ZONE = 2.4
SUSCEPTIBLE(t) = SUSCEPTIBLE(t-dt) + (LOSS_OF_IMMUNITYINFECTION) * dt
INIT SUSCEPTIBLE = 1990
INFLOWS:
LOSS_OF_IMMUNITY