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Listeriosis (infection with Listeria monocytogenes) was added to the list of nationally notifiable diseases in 2001. To improve surveillance [PDF - 3 pages], the Council of State and Territorial Epidemiologists has recommended that all L. monocytogenes isolates be forwarded to state public health laboratories for subtyping through the National Molecular Subtyping Network for Foodborne Disease Surveillance (PulseNet).

All states have regulations requiring health care providers to report cases of listeriosis, and public health officials to interview all persons with listeriosis promptly using a standard questionnaire about high risk foods. The Listeria Initiative [PDF - 2 pages] is an enhanced surveillance system that aids in investigations of listeriosis outbreaks and clusters.  States participating in the Listeria Initiative conduct prompt interviews of patients using the Listeria Case Report [PDF - 13 pages], a standardized questionnaire developed to collect detailed information about food exposures.

When PulseNet, the National Molecular Subtyping Network for Foodborne Disease Surveillance, identifies a cluster of Listeria monocytogenes patient isolates with the same molecular pattern, epidemiologists can conduct a preliminary case-control analysis by comparing responses to food exposures reported on the Listeria Case Report from patients in the cluster to those from patients outside the cluster.

FoodNet and Listeria

FoodNet conducts active laboratory–and population–based surveillance for listeriosis.

National Case-Based Surveillance and Listeria

Surveillance for Listeria is part of national case-based surveillance, which is used to monitor the occurrence of botulism, cholera and other Vibrio illnesses including V. parahaemolyticus and V. vulnificus infections), Listeria infections, and Typhoid and Paratyphoid Salmonella infections by collecting information on individuals infected with these pathogens.  The CDC surveillance team analyzes these data to track and improve understanding of the human health impact of these infections in particular populations.  This information provides a national picture of the occurrence of these infections.

The case-based surveillance systems for enteric disease at CDC include the Listeria Initiative [PDF - 2 pages], the Cholera and Other Vibrio Illness Surveillance (COVIS) system, the National Typhoid and Paratyphoid Surveillance system, and the National Botulism Surveillance system.

Surveillance Summaries and Report Forms

Surveillance Summaries

Report Forms