Detecting and responding to emerging pathogens in the food supply quickly and effectively is essential to preventing widespread illness. PulseNet—a collaborative project between CDC, FDA, USDA and state health departments—uses dedicated, high-speed Internet connections for the rapid comparison of DNA fingerprints of foodborne bacteria with those in an ever-growing database at CDC. When the system detects a match between fingerprints of bacteria isolated from different areas, an automated E-mail message is sent to all the participants alerting them of a possible multi-state outbreak.

Farukh M. Khambaty, Ph.D., is the microbiologist in charge of PulseNet at CFSAN. "Using the method of Pulsed-Field Gel Electrophoresis (PFGE) to generate DNA fingerprints of bacteria has proved to be the most reproducible and discriminatory solution for linking sporadic cases of foodborne illness with larger foodborne outbreaks," he said.

"With advances in the speed of computers and the development of the Internet, we can rapidly analyze and transfer huge files of information," he said. "Prior to 1997, a few gel tracks could be visually reviewed by a microbiologist. Now, we have a database with thousands of samples that will generate a report of strains that are identical or related."

In FY 99 an important case stands out as illustrative of the benefits of PulseNet. PulseNet proved useful in linking cases of Shigella infections in Minnesota, Massachusetts, California and Canada to fresh parsley from a single operation in Mexico. "A swift regulatory response from FDA staved off numerous more cases than would have otherwise resulted," said Khambaty.

A PFGE gel of multi-drug resistant Salmonella strains; each vertical barcode-like pattern depicts the "DNA fingerprint" of a distinct isolate.

In FY 99 PulseNet capability was expanded to FDA labs in Los Angeles; Brooklyn, N.Y.; Atlanta; Denver; Seattle; and Jefferson, Ark. They will fingerprint samples and transfer the information electronically to FDA in Washington for analysis. "This will significantly speed the process," said Khambaty.

Also in FY 99, two televised courses, which included information on PulseNet and the companion program FoodNet, were shown at more than 200 locations. FDA and state and local health department officials had an opportunity to learn how the programs operate.

Khambaty summed up the benefits of PulseNet by saying it allows us to do the detective work much faster, and thereby reduce significantly the number of illnesses and deaths from outbreaks.

FDA is leading an effort to improve coordination and communication among public health and food regulatory officials, particularly around foodborne illness outbreaks. This effort, known as the National Food Safety System (NFSS) project, contributes significantly to more effective implementation of existing food safety programs. Work began in September 1998 with an FDA-hosted meeting of food safety and agriculture officials from all 50 states, Puerto Rico, and the District of Columbia; epidemiologists and laboratory staff from state and local health departments; and colleagues from CDC, USDA and EPA.

Discussions from that meeting led to the creation, in FY 99, of a nationwide Coordinating Committee and workgroups to generate ideas for activities that would promote an integrated national food safety system. Workgroups were established in six areas: Roles and Responsibilities; Outbreak Coordination and Investigations; Laboratory Operations and Coordination; National Uniform Criteria; Information Sharing and Data Collection; and Communication.

In FY 99 the Laboratory Operations and Coordination Workgroup developed a vision for a fully integrated national laboratory system. Marion Allen, FSI inspections coordinator, said "this system will assure competency, credibility and equivalency of test results among federal, state and local government laboratories that perform food safety testing. The Workgroup concluded that the best and most cost-effective approach to achieving this is to establish a network of accredited laboratories generating equivalent test results."

In FY 99, two laboratory accreditation training programs were held. The first, in March, was for Workgroup members. The second, in June, was held in conjunction with the Association of Food and Drug Officials (AFDO) and preceded AFDO's annual meeting. Over 70 federal, state, university and private laboratory personnel attended the workshop.

The Outbreak Coordination and Investigations Workgroup also made progress in FY 99. Their goal is to develop a protocol on how to conduct multi-state outbreak investigations. Jack Guzewich, FDA's outbreak coordinator, said there needs to be greater clarity about the roles of various players in an outbreak situation and this initiative will address that.

A draft outline of a Guidelines Manual for Coordinating Foodborne Outbreak and Traceback Investigations was completed. Guzewich said the manual will take about a year to complete. FDA hired two new epidemiologists to work on writing the manual.

Also discussed at the Kansas City meeting was the need for on-going training of state and local officials. Responding to that need FDA produced two satellite video courses viewed by more than 6,000 people nationwide.

One course focused on conducting a traceback investigation using the procedures outlined in the FDA Guide to Traceback of Fresh Fruits and Vegetables Implicated in Epidemiological Investigations. The training also covered the decision-making process for initiating tracebacks and the roles of producers, distributors, importers and investigators and how they fit into the overall traceback investigation. A foodborne illness course provided an opportunity to learn how to develop and maintain a surveillance system and how to apply epidemiological principles to an investigation. The role of the investigation team was also discussed.

In FY 99, FDA took several actions to help improve the safety of berries and other fresh produce exported from Guatemala to the United States. In 1996 and 1997, Cyclospora outbreaks during the spring and summer in the U.S. and Canada were traced to Guatemalan berry farms (primarily raspberry shipments, but also a few blackberry shipments).

FDA experts were sent to Guatemala to teach local inspectors to check implementation of that country's food safety program for fresh berries. "FDA also plans to evaluate how much progress the Guatemalan berry industry has made in adopting the Model Plan of Excellence (MPE) and train Guatemalan Ministry of Agriculture inspectors to check for correct implementation of safety measures designed to reduce the risk of Cyclospora contamination," said John Kvenberg, Ph.D., acting deputy director for the Office of Field Programs at FDA.

Growers are trying to implement the model program in an effort to obtain FDA permission for spring and summer export of their product. In FY 99, FDA allowed raspberry shipments from four Guatemalan farms for the spring and summer season because these farms complied with all the requirements of the MPE. Only three farms actually exported to the U.S. and no reported outbreaks of cyclosporiasis were associated with raspberries from these farms.

The United States now has in place a system that allows FDA to tell when foodborne bacteria that cause disease in humans begin to develop resistance to antimicrobials used in food animals. The system is called National Antimicrobial Resistance Monitoring SystemEnteric Bacteria (NARMSEB). It combines the resources of FDA, CDC and USDA to create a nationwide monitoring system. Linda Tollefson, DVM, MPH, director of Surveillance and Compliance at FDA's Center for Veterinary Medicine explained "under NARMS, isolates of E. coli, Salmonella, Enterococci and Campylobacter from humans and food animals are collected and tested to determine whether the bacteria are beginning to lose their susceptibility to antimicrobial drugs." The program alerts CDC and FDA to any change in bacterial response to antibiotics used in people.

Informed public health officials, responsible animal producers and drug manufacturers, and veterinarians can use this information to control and prevent harm from the use of antimicrobials in food animals through prudent antibiotic use practices. The system tests the three gram-negative bacteria for susceptibility to 17 different antibiotics and the susceptibility of gram -positive Enterococci to 27 antibiotics. The human isolates are tested by CDC, and the animal isolates by the Agricultural Research Services of USDA. FDA initiated the program in 1996 and significantly expanded it under the Food Safety Initiative in 1999 to collect more isolates from more locations and more types of bacteria from animals and humans.

In June 1999, FDA representatives of the National Antimicrobial Resistance Monitoring System Enteric Bacteria (NARMSEB) Linda Tollefson, DVM, MPH and Kathy Hollinger, DVM, MPH visited Mexico to help start a monitoring system for antimicrobial resistance in Salmonella and Campylobacter. The representatives described the NARMS-EB and presented current data on multiple drug resistance in Salmonella from poultry slaughter isolates and on antimicrobial resistance in Campylobacter from poultry.

Tollefson reported that "the project will begin with participation by sites in close proximity to the monitoring centers in five Mexican states with significant food animal agriculture." These sites are among fifteen collaborating laboratories situated throughout Mexico, Costa Rica, and Guatemala associated with the World Health Organization (WHO)Resistnet group. This group was organized in 1996 to monitor resistance among the human pathogens Salmonella, Shigella, Staphylococcus aureus, E. coli, and Pseudomonas aeruginosa.

Tollefson noted that "the new project will first collect isolates from children in daycare settings to characterize the carriage rates of Salmonella in children and identify the antimicrobial resistance patterns of the isolates."

This collaboration between the U.S. NARMS-EB and the Mexican antimicrobial surveillance group represents the initiation of the first international human and animal monitoring system for foodborne antimicrobial drug susceptibility surveillance in the Americas.

Working to improve coordination among state and local regulatory, industry, legislative and consumer organizations, FDA funded the establishment of 23 food safety task forces. "The goal is to create a better food safety system from the local level all the way up to the state level," said Richard Barnes, director of Federal-States Relations in FDA's Office of Regulatory Affairs.

During FY 99, organizational meetings were held to create the task forces. Participants included state departments of agriculture and health, local offices with responsibility for retail food protection programs, representatives of the retail food industry and consumer organizations. Topics for discussion included roles and responsibilities in retail food protection, adoption of the Food Code and its requirements and outbreak coordination.