Only one of the APDIC calls was a potential match to a confirmed PCHD case.
Only one potential match was identified as a PCHD laboratory-confirmed illness, indicating that the APDIC data collection system is not duplicative of cases reported to and evaluated by PCHD during the same period.
Comparing the incubation period noted for the majority of APDIC callers (<24 hours) with that for persons whose cases were identified by PCHD suggests that the two data sets are identifying persons from different populations.
Demographic and clinical data are missing from both the APDIC and PCHD databases.
food handlers, child-care providers or attendees, and callers with an increase in severity of symptoms) will, upon informed consent, be referred to PCHD for evaluation of their symptoms.
Studies are needed to determine whether a temporal relationship exists between APDIC calls and PCHD cases; if such a relation is demonstrated, prospective monitoring of increases in APDIC calls might be predictive of increases in the number of foodborne illness cases.