FoodNet Studies and Surveys
More than 650 clinical laboratories in the FoodNet surveillance area test specimens from ill persons. These laboratories differ in their routine testing practices for foodborne pathogens and in methods they use. Such differences may contribute to variation in the incidence rate of reported infections between FoodNet sites. To understand current practices and to monitor changes in practices over time, FoodNet conducts periodic surveys of all clinical laboratories within the surveillance area.
Identification of a case of infection with a pathogen transmitted commonly through food depends upon accurate diagnosis by a healthcare provider and on appropriate laboratory testing. To understand current knowledge, attitudes, and practices of physicians, FoodNet conducts periodic surveys of physicians practicing within the surveillance area.
FoodNet determines the incidence of laboratory-confirmed infections for bacterial pathogens transmitted commonly through food. However, these reports represent only a subset of the true number of cases of diarrheal illness that occur in the community; most diarrheal illnesses are undiagnosed and, therefore, not reported. To more precisely estimate the burden of acute diarrheal illness and to describe the frequency of important exposures, FoodNet has conducted population-based telephone surveys of persons residing in the surveillance area.
Case-Control, Cohort, and other Studies
Although foodborne outbreaks are common, approximately 95% of foodborne infections occur as sporadic (non-outbreak) cases. It is difficult to determine what specific exposure caused a person with a sporadic infection to become ill, however, risk factors can be explored through population-based studies. Studies are conducted to examine the importance of various possible risky exposures (such as specific foods) and practices ( such as food preparation and handling practices) as contributors to illness caused by specific pathogens.