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Here’s a draft model that could apply to potentially foodborne diseases such as hepatitis. This flexible model allows for two routes of infection, person-to-person and from infected food, and two restaurants with two suppliers
By setting the slider for person-to-person transmission probability to a lower-level, and infection from food to a higher level, we can model diseases such as hepatitis A (which can be transmitted person to person or from contaminated food or water).
We have people go from home to school and work and then to restaurants before returning home*
We include food suppliers that deliver food to two restaurants every morning. We can “infect” that food by hitting a button. We can also infect persons, by hitting the infect person button.
One reason for having two restaurants is that health departments would have to figure out which one is the source. In fact, they would also have to rule out person-to-person. Right now we assume the health department has a perfect surveillance system. If the alert threshold is reached, the health department signals an alert, and then the restaurant may or may not close—It will if we set the restaurant_closes_if _alert button on. If the restaurant closes, people will not go to the restaurant. Instead they go to the other restaurant. We could add delays with a slider.
We can “disinfect” the food. Otherwise it will stay infected.
Eventually (after the infection duration is over) people will recover. The alert will be ended once the number of infected people falls below the threshold again. Then if we set the “reopen_when_alert_over” people will go back to the restaurant. Again, we could add delays with a slider.
Hit Setup. Hit Go. Hit “infectfood” when you are ready. Try changing the other settings.
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* Notes: 1. For simplicity, we don’t have them go home in between work and going to the restaurant. Also, we could have a slider for proportion of people going to restaurant, but I’ll add that later.
2. Remember that these models were inspired by Epstein's model showing the spread of small pox as people going from homes to public places and back. What's unique here is the addition of a) government authority, b) foodborne transmission mechanism. Also, I attempt to follow Epstein's general approach including starting simple, and adding incrementally, under his guidance.
3. One can change the transmission rates: a) foodborne transmission or b) person-to-person transmission rates, and duration of disease to be more appropriate for Hep A, or for that matter whatever disease they want. The food transmission route could also be set to approximate transmission of anthrax. etc. You can set foodborne transmission rate to zero, or set person-to-person to zero.