|The Foodborne Diseases Active Surveillance Network
(FoodNet) is the principal foodborne disease component
of CDC's Emerging Infections Program (EIP). FoodNet
is a collaborative project of the CDC, ten EIP sites
(California, Colorado, Connecticut, Georgia, Maryland,
Minnesota, New Mexico, New York, Oregon, and Tennessee),
Department of Agriculture (USDA), and the Food
and Drug Administration (FDA). The project consists
of active surveillance for foodborne diseases and related
epidemiologic studies designed to help public health
officials better understand the epidemiology of foodborne
diseases in the United States.
Foodborne diseases include infections caused by bacteria
such as Campylobacter, Escherichia coli O157,
Listeria monocytogenes, Salmonella, Shigella, Vibrio,
and Yersinia enterocolitica, and parasites
such as Cryptosporidium and Cyclospora.
In 1995, FoodNet surveillance began in five locations:
California, Connecticut, Georgia, Minnesota and Oregon.
Each year the surveillance area, or catchment, has
expanded, with the inclusion of additional counties
or additional sites (New York and Maryland in 1998,
Tennessee in 2000, Colorado in 2001 and New Mexico
in 2004). The total population of the 2004 bacterial
catchment is 44.5 million persons, or 15.1% of the
United States population.
FoodNet provides a network
for responding to new and emerging foodborne diseases
of national importance, monitoring the burden of
foodborne diseases, and identifying the sources
of specific foodborne diseases.
Why is FoodNet important to public health?
Foodborne diseases are common; an estimated 76 million
cases occur each year in the United States. Although
most of these infections cause mild illness, severe
infections and serious complications do occur. The
public health challenges of foodborne diseases are
changing rapidly; in recent years, new and emerging
foodborne pathogens have been described and changes
in food production have led to new food safety concerns.
Foodborne diseases have been associated with many
different foods, including some previously thought
to be safe, such as eggs and fruit juice, both of
which have transmitted Salmonella during recent outbreaks.
Public health officials in the nine EIP sites are
monitoring foodborne diseases, conducting epidemiologic
and laboratory studies of these diseases, and responding
to new challenges from these diseases. Information
gained through this network will lead to new interventions
and prevention strategies for addressing the public
health problem of foodborne diseases.
How is FoodNet different from other foodborne disease
Current "passive" surveillance systems
rely upon reporting of foodborne diseases by clinical
laboratories to state health departments, which in
turn report to CDC. Although foodborne diseases are
extremely common, only a fraction of these illnesses
are routinely reported to CDC via these surveillance
systems. This is because a complex chain of events
must occur before such a case is reported, and a break
at any link along the chain will result in a case
not being reported. FoodNet is an "active"
surveillance system, meaning public health officials
frequently contact laboratory directors to find new
cases of foodborne diseases and report these cases
electronically to CDC. In addition, FoodNet is designed
to monitor each of the events that occur along the
foodborne diseases pyramid and thereby allow more
accurate and precise estimates and interpretation
of the burden of foodborne diseases over time. Because
most foodborne infections cause diarrheal illness,
FoodNet focuses these efforts on persons who have
a diarrheal illness.