R: An exemple on Escherichia coli in ground beef

ec {mc2d} | R Documentation

## An exemple on Escherichia coli in ground beef

### Description

The fictive example is as following:

A batch of ground beef is contaminated with E. coli, with a mean concentration conc.

Consumers may eat the beef "rare", "medium rare" or "well cooked". If "rare", no bacteria is killed. If "medium rare", 1/5 of bacteria survive. If "well cooked", 1/50 of bacteria survive.

The serving size is variable.

The risk of infection follows an exponential model.

For the one-dimensional model, it is assumed that:

`conc <- 10`

`cook <- sample(n, x=c(1,1/5,1/50),replace=TRUE,prob=c(0.027,0.373,0.600))`

`serving <- rgamma(n, shape=3.93,rate=0.0806)`

`expo <- conc * cook * serving`

`dose <- rpois(n, lambda=expo)`

`risk <- 1-(1-0.001)^dose`

For the two-dimensional model, it is assumed moreover that the concentration and the r parameter of the dose response are uncertain.

`conc <- rnorm(n,mean=10,sd=2)`

`r <- runif(n ,min=0.0005,max=0.0015)`

### Usage

    ec

### Format

A list of two expression to be passed in `mcmodel`

### Source

Fictive example

### References

None

[Package mc2d version 0.1-18 Index]