Animal & Veterinary
Antimicrobial Resistance Activities at CDC by Robert Tauxe, M.D., M.P.H., Deputy Director
DR. TAUXE: Thank you very much, Pat. Good morning. Good morning to all. Welcome to the meeting, welcome to Atlanta.
We have been undergoing a certain amount of reorganization and name change and hope soon to be able to drop the proposed from our various organizational structural titles.
Actually, you’re here in Atlanta for a very specific reason. At least CDC is here in Atlanta for a very specific reason. And that is that it was established in Atlanta as the only Federal agency with headquarters outside of Washington, D.C. in order to control malaria. And the result was actually that malaria was quickly eradicated.
Shortly, thereafter, in 1948, the Salmonella Reference Laboratory was established. And that’s proved to be much more durable.
Our emergency response mission, the Epidemic Intelligence Service was created in the 1950's and the “Epi-AID” emergency investigation model that we’ve used ever since. We are team of epidemiologist, microbiologists, statisticians, and other public health professions who form around problems as they arise. And we are non-regulatory. We provide independent scientific assessment to the regulatory agencies and other partners.
The main purpose is, the main roles, the main functions of the Centers for Disease Control and Prevention are first of all to conduct national surveillance of a whole array of public health issues and problems. And just a word on surveillance, we consider it to be the ongoing systematic collection, analysis and interpretation of disease-specific data in a population, in order to inform public health decision making.
We are also responding to outbreaks and other emergencies. And an outbreak is a whole collection of the same disease in a place or time concentrated.
Public health research we conduct to define better methods for diagnosing, understanding and controlling the important public health issues. We provide support for state and local public health departments. And there are many collaborations with many partners in the United States and abroad that are a fundamental part of what we do.
We are at this point under new titles. In the National Center for Emerging and Zoonotic Infectious Diseases are a merger of two previous centers. That has a total of seven divisions. I’m not going to go through them with you. Two of them of note, perhaps, of interest, the Division of Healthcare Quality and Prevention, which is the Locus of the Office of Antimicrobial Resistance, which is a hub for many of the antimicrobial resistance activities at CDC. And the Division of High Consequence Pathogens and Pathology, which is where our high security laboratory work goes on.
We are another division in the same center, the Division of Foodborne, Waterborne, and Environmental Diseases which is most of the previous group that had the enteric disease functions plus the waterborne disease group and the mycotic disease branch.
Two of our branches, the Enteric Diseases Epidemiology Branch and the Enteric Diseases Laboratory Branch are the Locus for NARMS. NARMS has an epidemiology component, a laboratory component at CDC and they are in those two adjacent branches.
Antimicrobial resistance is an important issue across the entire agency. There are many infectious disease pathogens and resistance emerges virtually anywhere that antimicrobials are used as a natural consequence of evolution and selection.
The pathogens with major human reservoirs are concerned, including Mycobacterium tuberculosis, gonococcus, pneumococcus, and methacholine resistant Staphylococcus aureus, and S. typhi. And there is ongoing surveillance and guidelines for appropriate treatment. There are functions dealing with the antimicrobial resistance in many of these pathogens. And interventions that involve antimicrobial use policies, hygiene and barrier approaches to reduce transmission, and education about prudent use such as the Get Smart program to reduce the unnecessary use of antimicrobial in mild respiratory infections.
There are also those pathogens with major reservoirs in our domesticated animals, including Salmonella, Campylobacter, E. coli 0157, that are most often transmitted to humans through the food supply. And we are concerned with those. And that of course is the central focus of NARMS.
Now, the resistance, poses important public health challenges, whatever pathogen it occurs in. And a antimicrobial resistance poses a problem to both clinical and public health medicine. It makes the treatment of that infection less effective, requiring more expensive and multi-drug courses at best, or becoming entirely untreatable at worst.
The result of that is longer duration and more severe illnesses of a whole variety of infections. Because antimicrobial treatment of an asymptomatic Salmonella colonization can easily convert it to an overt infection, resistant Salmonella has a couple of extra challenges. It can complicate the treatment for other infections because suddenly a resistant Salmonellosis emerges from, during treatment for the other infection.
And also because of this effect we’ve seen larger outbreaks and more sporadic illnesses due to the resistance itself.
Now, the Interagency Task Force on Antimicrobial Resistance that was just mentioned by Dave White, was created in 1999, Co-Chaired by CDC, FDA and NIH and it’s the public health action plan to combat antimicrobial resistance. First posted as the completed plan in 2001. There is an updated version. As was just mentioned we’re anticipating will be posted in 2010.
CDC has the lead on the surveillance and prevention sections. NIH/NITID has the lead on the research section, and FDA has the lead on product development section.
We have at CDC a number of different surveillance networks that are -- deal with various aspects of antimicrobial resistance. And I’ll mentioned them. Under the egis of the Emerging Infection Program, at CDC, there is a surveillance network called the Active Bacterial Core Surveillance or the ABC surveillance network, which focuses particularly on antimicrobial resistance and the other issues involving primarily the respiratory bacteria of like pneumococcus.
There is the National Healthcare Safety Network a new and rapidly expanding surveillance system for hospital acquired infections and hospital associated infections. There is the Gonococcal Isolate Surveillance Project which is a way of doing surveillance for resistance in the organisms that cause gonorrhea and in providing advice and guidelines for treatment.
And then there is our National Antimicrobial Resistance Monitoring System, or NARMS, which we append enteric bacteria to clarify that we’re not doing all bacteria but just those.
To put this in the context of foodborne disease, foodborne disease in 2010 is a major and continuing public health concern in this country. It is common. There are approximately 1,300 outbreaks of foodborne disease reported each year. Those include many local outbreaks and also some large dispersed nationwide outbreaks. It’s important for us to remember that outbreaks are a small part of the problem. Most reported cases are sporadic individual cases, not necessarily attached to an identified outbreak.
And in previous estimates, about 1 in 4 of us have the chance of having a foodborne disease each year and there are approximately 5,000 deaths.
It’s a continuing problem that challenges and it has the highest priority. There has been some progress in prevention, but relatively little in recent years. A White House Food Safety Working Group since last summer has been coordinating actions across CDC, FDA and FSIS to enhance outbreak response and to improve long term prevention strategies by coordinated government action.
And making more progress in this, is a priority at CDC, our new Director has chosen food safety as one of the Director’s “Winnable Battles.” One of the things we really are going to try to make progress on in the next several years.
Now, there are many different pathogens and toxins that can cause foodborne illness and this is a challenge to us. More than 250 have been described. More pathogens continue to be identified. And many of them of course can spread in other ways besides food, through water, through direct animal or human contact.
And in terms of number of illnesses or number of deaths, the six most important pathogens listed here would be Listeria, E. coli 0157 and other shigotoxin producing E. coli, Toxoplasma, Salmonella, Campylobacter, and the virus, Norovirus.
Surveillance has been going on in one form or another for many years in the United States. Here are some information relating to two kinds of Salmonella, the Typhoid fever or S. typhi infections, going back to 1920 on the lefthand side and then since World War II the rise of the non-typhi Salmonella, which became reportable really in 1942. And you can see it rising and increasing and then really persisting as a standing problem actually with an incidence in the teens regularly since the 1980's.
This is evidence that maybe things are a little bit better then they were in the 1980's but we’re not making a great deal of progress with this organism.
The history of antimicrobial resistance in Salmonella and other enteric bacteria has been marked by dramatic outbreaks and by the emergence of new problems.
In the 1980's there were very large outbreaks of multi-drug-resistant S. Newport and Typhimurium that really highlight the clinical impact of the resistance, as well as for the first time provided strong evidence that traced -- linked it to the consumption of food from animal origin and linked the source of the resistance in those foods to what was happening on the farm.
In the 1990's we witnessed the emergence of multi-drug resistant S. typhimurim, DT 104, in both cattle and people and in other animals. And it further spread, multi-drug resistant S. Newport, the cmy2a version, in cattle and people again. And then with additional spread and amplification, the Quinolone resistant Campylobacter in chickens and people.
In the 2000's we’ve seen the emergence of the Quinolone resistant Salmonella, Ceftiofur resistance Salmonella, and most recently the multi-drug resistant Shigatoxin producing E. coli.
All of which are issues that I think we’re going to hear a great deal about in the next two days.
Since 1996, the public health surveillance for foodborne disease has been strengthened in the United States by a number of systems.
Our standard notifiable disease reporting in all 50 states, has been augmented and amplified. We have added Listeria, first -- well, 0157 was already reportable, non-0157 Shigatoxin producing E. coli were added, and the Vibrios. The serotying of Salmonella, and Shigella in the nation has been strengthened. This is done in the State Health Departments and -- local health department laboratories.
FoodNet is an active sentinel 10-site surveillance effort which was first launched in 1996 and it collects data about the diagnosed cases of the nine different pathogens for burden and trend monitoring and has a platform for research.
PulseNet is the national sub-typing network for bacterial foodborne pathogens which was instituted in a few states, expanded rapidly to include all state laboratories and now includes all the public health laboratories in states and large cities, as well as the FDA and the USDA, to improve the detection of dispersed outbreaks and to focus the investigations on them.
I mention these because NARMS interacts with all of these. And these are part of our portfolio of systems that we use to collect information.
The National Outbreak Reporting System collects reports of foodborne outbreak investigations from state and local health departments. Again, about 1,300 year are reported.
And then there is our most recent network, the OutbreakNet, a team at CDC that coordinates the foodborne outbreak investigations which is developing a new network of state partners to really try to improve and accelerate these methods.
And then of course -- sorry, this is an example of the output from FoodNet, I’m sure familiar with most of you. Each year we publish an assessment of whether we’re making progress in the overall infection rates with the variety of infections that are under surveillance.
This shows from a baseline period established 1996 to 1998, whether there is a general up, which means more infections being diagnosed or a general downward trend, which means fewer infections are being diagnosed.
Below the midline across, which means there is no change at all. And actually there have been significant drops in E. coli 0157 of 41 percent since the baseline period. In Listeria of 26 percent, Campylobacter 30 percent, and even Salmonella of 10 percent.
There has been a significant increase of Vibrio of an 85 percent increase since that time period.
The progress in E. coli 0157 meant we actually achieved our goal of the healthy people 2010 incident subjective. We are very far from it for Salmonella.
And then of course there is NARMS, our part of the National Antimicrobial Resistance Monitoring System. The multi-agency collaboration between FDA, USDA and CDC that has already been outlined and that we’ll hear a great deal more about.
Our role in this is to provide surveillance information on resistance to a standard panel of enteric -- for a standard panel of enteric bacteria that are isolated from humans. To better understand the clinical and public health impart of that resistance. To better understand the mechanisms and prevalence of specific antimicrobial resistance genes. And to provide the scientific information needed to inform policy making.
There are, as I said, synergies important between NARMS and other resistance programs at CDC. With FoodNet, NARMS has collaborated to do special studies to determine the severity of illness, the travel history, and the association of specific exposures for resistant infections and whether they’re different or the same as susceptible infections.
For example, a great deal of work went into FQ-R Campylobacter, linking it to both foreign travel and to poultry served in restaurants and multi-drug resistance S. Newport has been studied in some detail linking it to exposures related to beef.
PulseNet is important. It allows NARMS and PulseNet when they are able to link their data to identify the PulseNet patterns that correlate with resistant strains.
OutbreakNet to assess resistance in an outbreak and determine a specific food associations that might be explained by that outbreak.
And with NORS the outbreak reporting system, to examine the associations between outbreaks due to resistant strains and to specific food vehicles.
NARMS also connects with other antimicrobial resistance programs at CDC through the Office of Antimicrobial Resistance. There is a constant sort of exchange of information and “Get Smart” inspired “Get Smart on the Farm.”
There is one other program not on this list, I would like to mention and that’s the WHO Global Foodborne Infection Network, GFM, with which we participate extensively in training and the beginnings of surveillance for both how to detect enteric infections in the first place, how to conduct surveillance, and also how to measure antimicrobial resistance, so the countries around the world can increase their capacity.
So, for the 21st Century, we know that foodborne disease will continue to be a major public heath problem, that antimicrobial resistance in a number of foodborne pathogens is a persistent challenge, a changing challenge with new aspects that need to be attended to. The prevention is farm-to-fork, so critical attention is needed to the circumstances and settings in which we produce our food. Better surveillance, both of the infections and of the resistance within the infections, means better understanding of the sources of the infection. Interagency and interdisciplinary collaboration has been critical to making progress and will continue to be vital to addressing these challenges.
Thank you very much.
DR. McDERMOTT: Thank you. Thanks very much Doctor Tauxe. And I was particularly gratified to see the ways in which NARMS supports other programs within CDC. And it’s always something in the front of my mind as is how we make NARMS more valuable and FDA as well to meet other public health goals. So that was gratifying to see.
Our next speaker representing USDA position, Doctor Mary Torrence. I think many of you also know Doctor Torrence. She’s National Program Leader for Food Safety at ARS. Before that, for ten years, she was at USDA’s Cooperative State Research Extension Services. And there was National Program Leader for Food Safety and Epidemiology.
And Mary is going to show us USDA’s perspective. Thanks, Mary, and welcome.