Classification for the Investigation of a Waterborne Disease Outbreak

 

Parameters:

(1) adequacy of the epidemiologic data

(2) adequacy of the water quality data

Epidemiologic Data	Water Quality Data	Class
adequate	adequate	I
adequate	not provided or inadequate	II
limited	adequate	III
limited	not provided or inadequate	IV

 

where:

• In theory there could be additional classes if the epidemiologic data is not provided.

• Adequate epidemiologic data provides adequate data to assess risk in exposed and unexposed persons. The relative risk or odds ratio is >= 2.0 or the p value is <= 0.05.

• Limited epidemiologic data includes failure to include sufficient data to support claims (for example, that persons who were ill had no exposures in common).

• Adequate water quality data includes complete laboratory data and pertinent historical information.