May 25, 2007
Three updates on Wednesday's post about food safety.
Thanks to commenter Spencer E. for pointing out that the sharp rise in outbreaks and cases between 1997 and 1998 is at least partly an artifact of data collection. The CDC writes, "The annual number of FBDOs [foodborne-disease outbreaks] reported to CDC increased during this period [1998-2002] compared with previous years, following implementation of measures to enhance outbreak surveillance (3--5). Certain observations suggest that the increase in outbreak reports probably represents the effect of enhanced surveillance rather than a true increase in the occurrence of FBDOs."
The number of outbreaks in 2004 should be 1319, not 1310.
Finally, from information readily available at the CDC website, the time series on outbreaks and cases can be pushed back to 1983:
| Year | Outbreaks | Cases |
| 1983 | 505 | 14898 |
| 1984 | 543 | 16420 |
| 1985 | 495 | 31079 |
| 1986 | 467 | 12781 |
| 1987 | 387 | 16500 |
| 1988 | 451 | 15732 |
| 1989 | 505 | 15867 |
The message of the combined data is that from 1983 through 1997 there is no trend in cases and almost no trend in outbreaks; after the change in methodology, from 1998 through 2005, there is again essentially no trend in either outbreaks or cases. If we are currently experiencing a "crisis", it's a crisis that we seem to have had for a while.