Background:  Gastrointestinal (GI) illness causes substantial childhood morbidity.  CDC and public health department reports significantly underestimate total GI illness among this susceptible population.

Study Objectives:  1) To demonstrate the incidence and etiology of GI illness in children.  2) To determine risk factors for GI illness in children.

Design/Methods:  We are enrolling 200 families with healthy children and following them for a 2-year period.  Families are telephoned weekly to determine the presence of GI or other illness.  In the event of diarrhea, the family submits stool for analysis and completes a questionnaire regarding food- and water-borne exposures as well as exposures that could result in person-to-person transmission.  Rate of infection among the cohort is compared to insurance company reports and state surveillance data.

Results:  After following the under 5-year cohort for 41 person-years (out of 130 person-years expected by 11/2004), 34 diarrhea cases have been reported.  This results in a rate of 0.79 cases/person-year.  When analyzed by age, the diarrhea rate is inversely proportional to age.  Children under 5 years have diarrhea at a rate 72% higher than children 5-9 years.  Salmonella incidence in our cohort was approximately 70 times the state-reported rate.  We are currently analyzing data on risk factors for diarrhea such as swimming, inconsistent hand washing, and improper food handling.

Conclusions:  Our closely followed cohort reports significantly more episodes of GI illness than is reported at the state or national level.  Diarrhea rates are inversely proportional to age.  Food- and water-related risk factors appear important among young children.