Epidemiologic surveillance of enteric diseases in Alaska--value of case investigation

Patients infected by Salmonella, Shigella, Giardia, Campylobacter, Yersinia, and Hepatitis A virus were interviewed during a 15-month period to evaluate the benefit of intensive follow-up, to assess the proportion of cases who had contact with children less than four years of age, and to determine risk factors. Of 746 reported infections, we interviewed 345 patients (46%) and identified 199 other ill people. Follow-up of sporadic, passively reported cases required considerable resources, but no large outbreaks were uncovered. Investigation of patients [N = 103 (43%)] who had contact with children less than four years of age, or children who attended daycare centers often resulted in identification of additional illness, especially for cases of giardiasis. Primary health care providers can play a key role in reducing enteric disease by increasing efforts to identify illness among daycare and family contacts of their patients.