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Table 2 User-modifiable disease-specific parameters

From: FRED (A Framework for Reconstructing Epidemic Dynamics): an open-source software system for modeling infectious diseases and control strategies using census-based populations

Parameter type

Parameter

Definition

Natural history parameters

Days latent

Discrete cdf for number of days between becoming exposed and becoming infectious

Symptomatic rate

The probability of an infected person becoming symptomatic

Days asymptomatic

Discrete cdf for number of days the agent is infectious but asymptomatic

Days symptomatic

Discrete cdf for number of days the agent is infectious and symptomatic

Immunity loss rate

Rate at which a person loses immunity after recovering from infection

Mortality rate

The probability of an infected person dying

Contact parameters

Probability of staying home

The baseline probability that an agent stays home if the agent experiences a symptomatic infection.

Household contact rates

The expected number of potentially infective daily contacts between an infectious agent and a susceptible agent in a household. All contact rates are positive real numbers.

Neighborhood contact rates

The expected number of potentially infective daily contacts between an infectious agent and a susceptible agent in a neighborhood

School contact rates

The expected number of potentially infective daily contacts between an infectious agent and a susceptible agent in a school

Workplace contact rates

The expected number of potentially infective daily contacts between an infectious agent and a susceptible agent in a workplace.

Transmission parameters

Transmissibility

The transmissibility of disease relative to an arbitrary baseline set by calibration

Asymptomatic infectivity

Multiplier for how infective an asymptomatic infected agent is, relative to an symptomatic agent

Household transmission probability

A table of probabilities that a potentially infective contact between an infectious agent and a symptomatic agent in the same household actually results in an infection, given the age of the potential infector/infectee pair

Neighborhood transmission probability

A table of probabilities that a potentially infective contact between an infectious agent and a symptomatic agent occurring in a neighborhood actually results in an infection, given the age of the potential infector/infectee pair

School transmission probability

A table of probabilities that a potentially infective contact between an infectious agent and a symptomatic agent occurring in a school actually results in an infection, given the age of the potential infector/infectee pair

Workplace transmission probability

A table of probabilities that a potentially infective contact between an infectious agent and a symptomatic agent occurring in a workplace actually results in an infection, given the age of the potential infector/infectee pair

  1. FRED includes natural history and transmission parameters for pandemic influenza as used in previous models [512]. Contact parameters were calibrated for the FRED synthetic population using the methods described in [12]. For more details about these and other user-settable parameters, please see the FRED User Guide.