Information for Public Health Professionals
Clinical laboratories report the isolation of Shigella bacteria to state health departments, which then report them to CDC. Shigellosis is a nationally notifiable infectious disease and is tracked using the following surveillance tools.
Reports trends in foodborne infections and tracks the impact of food safety policies nationally.
Foodborne Diseases Active Surveillance Network (FoodNet), conducts surveillance for Campylobacter, Cryptosporidium, Cyclospora, Listeria, Salmonella, Shiga toxin-producing Escherichia coli (STEC) O157 and non-O157, Shigella, Vibrio, and Yersinia infections diagnosed by laboratory testing of samples from patients.
The network, established in July 1995, is a collaborative program among CDC, 10 state health departments, the U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA-FSIS)External, and the Food and Drug Administration (FDA)External. FoodNet personnel in state health departments get timely reports of infections diagnosed in residents of ConnecticutExternal, GeorgiaExternal, MarylandExternal, MinnesotaExternal, New MexicoExternal, OregonExternal, TennesseeExternal and selected counties in CaliforniaExternal, ColoradoExternal, and New YorkExternal and are in regular contact with the clinical laboratories serving these areas. The surveillance area includes 15% of the United States population (about 49 million persons). FoodNet is the principal foodborne disease component of CDC’s Emerging Infections Program.
Collects laboratory data, such as serotype, on Shigella
National Shigella surveillance data are collected through passive surveillance of laboratory-confirmed human Shigella infections. Clinical diagnostic laboratories submit Shigella isolates to state and territorial public health laboratories, where they are confirmed, speciated, and subtyped. Unusual or untypable serotypes are forwarded to the Centers for Disease Control and Prevention’s (CDC) National Shigella Reference Laboratory at the Enteric Diseases Laboratory Branch (EDLB) for further characterization or confirmation; results are reported back to state and territorial public health laboratories.
State and territorial public health laboratories report Shigella infections electronically to CDC through a variety of mechanisms. Data are collected into the Laboratory-based Enteric Disease Surveillance (LEDS) system. The Division of Foodborne, Waterborne, and Environmental Diseases (DFWED) in the National Center for Emerging and Zoonotic Infectious Diseases maintains the national Shigella surveillance data in LEDS. The annual summaries of these data are the only regularly published national source of serotype information for Shigella.
For more information, see Foodborne Illness Surveillance, Response, and Data Systems.
Tracking trends in resistance
The National Antimicrobial Resistance Monitoring System for Enteric Bacteria (NARMS) is an interagency public health surveillance system that tracks antimicrobial resistance in foodborne and other enteric (intestinal) bacteria from humans, retail meats, and food animals in the United States. The NARMS program at CDC helps protect public health by providing information about resistance in bacteria isolated from ill people, the ways in which resistance is spread, and how resistant infections differ from susceptible infections.
- CDC. NARMS Human Isolates Reports
- FDA. NARMS Retail Meat Isolates Reports and NARMS Interagency Executive Reports (FDA website)External
- USDA. NARMS Animal Isolates ReportsExternal
For more information, see National Antimicrobial Resistance Monitoring System (NARMS).
The National Notifiable Disease Surveillance System, or NNDSS, tracks contagious diseases that laboratory professionals and doctors are required to report to the state or territorial public health agency. These agencies voluntarily submit the information to NNDSS, which CDC oversees. Notifiable disease surveillance is “passive” (i.e., the investigator at CDC waits for disease reports from those requested to report) and is susceptible to underreporting. Foodborne diseases that are nationally notifiable include botulism, hemolytic uremic syndrome (HUS), listeriosis (Listeria), shigellosis (Shigella), salmonellosis (Salmonella), Shiga Toxin-producing Escherichia coli (STEC) infections, cryptosporidiosis and vibriosis (cholera and its relatives).
For more information, see National Notifiable Diseases Surveillance System (NNDSS).
The National Outbreak Reporting System, or NORS, is a web-based platform designed to support reporting to CDC by local, state, and territorial health departments in the United States of all waterborne disease outbreaks and enteric disease outbreaks transmitted by food, contact with environmental sources, infected persons or animals, or unknown modes of transmission.
For more information, see The National Outbreak Reporting System (NORS).
To find outbreaks, see the Foodborne Outbreak Online Database (FOOD).
Connects cases of illness nationwide to quickly identify outbreaks, including many that would otherwise go undetected
The National Molecular Subtyping Network for Foodborne Disease Surveillance, or PulseNet, connects cases to potential outbreaks, especially across states. PulseNet has revolutionized the detection and investigation of foodborne disease outbreaks, especially those occurring in multiple sites across the country which, before PulseNet, often went undetected or were detected only after they grew very large. The PulseNet USA network of 83 local, state, territorial, agricultural, and federal laboratories in all 50 states is coordinated by CDC along with the Association of Public Health Laboratories (APHL). PulseNet International has 7 regions in 88 countries. Each laboratory tests enteric bacteria that cause illness, like E. coli and Shigella, through a standardized subtyping process using multiple analytical tools, including pulsed-field gel electrophoresis (PFGE)*, multiple locus variable number tandem repeat analysis (MLVA), and whole genome sequencing (WGS). All of these techniques are used to determine the DNA fingerprint of the bacteria.
*Public health scientists upload these different fingerprints (such as PFGE patterns, MLVA profiles, and DNA sequences) to their respective electronic databases to compare them to fingerprints isolated from other people, animals, and foods to identify matches that may indicate an outbreak is happening.