Press Briefing Transcript

CDC Telebriefing on Listeria

June 6, 2013, Noon

• Audio recording [MP3, 4.01MB]

OPERATOR: Good morning or good afternoon.  This is the conference coordinator.  All lines will be placed on listen only until we're ready for the question and answer question.  I would like to remind all parties that the call is being recorded.  If you do have any objections, you may disconnect at this time.  I had would now like to introduce your speaker, Mr. Tom Skinner.  You may begin, sir. 

TOM SKINNER: Thank you all for joining us today for the release of another CDC Vital Signs.  This Vital Signs “Listeria illnesses, deaths and outbreaks, United States, 2009 to 2011.”  We're joined today by the director of the CDC, Dr. Tom Frieden, the Undersecretary for Food Safety at the USDA,  Dr.  Elisabeth Hagen and the Deputy Commissioner for Foods and Veterinary Medicine at the FDA, Mr. Michael Taylor.  Each will provide some opening remarks and then we will get to your questions.  Dr. Frieden. 

TOM FRIEDEN: Thanks very much for joining us for this month's Vital Signs report.  At CDC we work 24/7 protecting people from threats, including food-borne outbreaks.  This month's Vital Signs focuses on one of the most deadly germs we face, listeria, and the people who are most susceptible to serious illness from it.  I’m delighted to be here not only with those listening in on the call but also with colleagues from the Food and Drug Administration and the Department of Agriculture's Food Safety and Inspection Service.  We've been working together for many years to stop food-borne illness and in fact I would say that our collaboration among these three agencies today is closer than it ever has been.  Every year about 48 million Americans, one in six people, get sick from eating contaminated food.  Listeria is relatively rare, but it is especially deadly for people with cancer and other immunosuppressing conditions that may make them more susceptible to severe infection.  I'd like to tell you about a patient I took care of some years ago.  He was a middle-aged man with a loving family.  He had a form of cancer called multiple myeloma and he developed meningitis.  We never found out where it came from and it was very hard to figure out what was causing it, because listeria can be quite difficult to diagnose, but we did identify it as listeria meningitis.  Because of his cancer and the treatment of his cancer, it was extremely difficult to get him cured.  It took months and months in the hospital with difficult treatment, relapses, till finally he was able to get out of the hospital and go home.  So when I tell you that it's a terrible infection, I think back to the patients I have cared for and how difficult it is to both detect and cure. 

Listeria strikes particularly hard at people who can't fight it off.  It causes things like blood infection, meningitis and miscarriage in pregnant women.  It can cause serious infections with very high rates of hospitalization and death, and it is the third leading cause of death from food poisoning.  Most people who have listeria infection require hospital care, and about one in five with the infection die from it.  Today's Vital Signs report is a national snapshot of the years 2009 to 2011, looking at the rates of disease as well as the foods associated with listeria infections and the outbreaks that we at CDC and our state and local partners investigated.  The key findings include, first, that people age 65 and older are four times more likely to get listeria.  Second, that pregnant women are ten times more likely to get listeria and pregnant Hispanic women 24 times more likely.  We looked at 12 outbreaks that made more than 200 people in 38 states sick.  Of the ten outbreaks that we could find a food source for, six were linked to cheese and two to raw produce.  In the six outbreaks linked to cheese, five were linked to soft cheeses, which had been made from pasteurized milk that was likely contaminated during the process of making cheese.  Four of these were Mexican-style cheese, queso fresco.  The two raw products outbreaks were the whole cantaloupe infections, which many of you wrote about, and the pre-cut celery, not usually linked with listeria. 

Listeria is a really challenging infection to fight because it can be unnoticed in factories, it can contaminate food not only in the production but in the processing and preparation.  In your refrigerator, it can continue to grow, as happened, for example, in the cantaloupe outbreak.  And when someone eats it, sickness or miscarriage may not occur for weeks later, when it can be quite hard to trace back and figure out what the contaminated food was.  In the 1980s we began tracking just how much listeria was occurring.  In the 1990s, we developed genetic fingerprinting of listeria, which helped us identify many outbreaks.  This led to an excellent collaboration with the food industry, with regulatory changes, and that made foods such as hot dogs and deli meats safer.  There was a lot of progress in the '90s and rates of sickness fell by about 25percentby the early 2000s.  However, although we continue to refine our tools for finding and stopping listeria, the bottom line is that progress reducing rates of listeria infection has stalled.  Rates have not budged in more than a decade.  In 2011, we had a large outbreak of listeria related to cantaloupes.  That was one of the deadliest food-borne outbreaks in U.S.  history.  Rapid response saved lives and prevented sickness.  In fact the state of Colorado sounded the alarm.  They were monitoring trends and they noticed in just days that there was an increasing number of listeria cases.  They worked over a holiday weekend.  They interviewed patients, they identified cantaloupe as the likely vehicle, they got it off the shelves and they saved lives because they did that.  Because they have full-time experts tracking food-borne disease, they were able to find and stop the outbreak quicker.  Without that, it would have been much deadlier and yet they're one of only ten states to whom we provide additional support for that kind of outbreak detection response.

 I'd like to tell you the story of Michael Howser.  Michael was recovering from cancer treatment.  He was making vacation plans when he got listeria infection after eating cantaloupe in September, 2011.  He was hospitalized, found to have listeria meningitis.  He was in a coma.  Despite surgery and a brief return home, he died in the hospital on February 24st, 2012.  This reminds us that listeria is a formidable enemy and it motivates us to seek solutions.  There's a lot more that needs to be done to make progress.  We know which foods and places are problems for contamination.  FDA and Health Canada estimate that risk of illness from soft cheeses is around 100 times higher than from pasteurized cheese -- when those soft cheeses are made from unpasteurized milk.  And even if soft cheese is made from pasteurized milk, it can be contaminated, as has happened particularly with queso fresco, Mexican cheese.  We're also seeing new forms, new food vehicles for listeria, such as the cantaloupe outbreak.  We're working together to develop innovations.  One of the things that we're doing is finding cutting edge technologies so that we can sequence the genome of bacteria in real-time and identify outbreaks faster.  We're working with our partners to prevent listeria and other food-borne infections.  FDA and USDA are working together so that we can be vigilant and identify and stop problems as quickly as possible.  I’ll now turn it over to Dr.  Elisabeth Hagen, the Undersecretary for Food Safety in the U.S. Department of Agriculture.  And then to Mike Taylor, Deputy Commissioner for Foods and Veterinary Medicine at the Food and Drug Administration.  Dr. Hagen. 

ELISABETH HAGEN: Thank you so much, Dr. Frieden.  It's great to be here alongside with Dr. Frieden and Mr. Taylor.  Good afternoon to everyone on the call.  I want to thank Tom and his team at CDC for putting this together.  Listeriosis is such a public health concern and everybody should be grateful for the work CDC is doing to bring attention to it.  Listeria monocytogenes, or LM, as we call it, as long been a pathogen of concern and the agency has taken strong steps to address it.  Our zero tolerance policy for LM in ready-to-eat products dates back to 1989.  Boy 1993 the rate of illness declined 44 percent.  Outbreaks associated with deli meats in the late 1990s and 2000 led us to take a closer look at LM.  The agency found not all establishments producing ready-to-eat foods such as deli meats or hot dogs were adequately controlling the threat of LM in their establishments.  Specifically in the areas of the plant where cooked products were processed and packaged, some steps were not taken to prevent LM.  This is really important because these are products that consumers are not going to be cooking. In a raw product the risk of illness can be reduced with safe cooking.  That's not the case with a ready to eat product like sliced chicken breast or deli meat.  Because of the nature of LM, its ability to cross contaminate and spread rapidly at low temperatures, it's all the more important the product be absolutely free of  contamination.  To address this problem, in 2001 the agency issued a proposed rule that outlined steps that plants could take to control LM.  Based on input received in the proposed rule, the agency issued an interim and final rule on LM.  This rule requires establishments producing fully cooked ready-to-eat products to take meaningful steps to prevent contamination in the problem area we identified.  The area where fully cooked products are further processed and packaged.  This policy has done what it was designed to do, reduce listeria in FSIS regulated products.  Following the implementation of this rule, the agency observed a 75 percent drop in the percentage of ready-to-eat meat and poultry products testing positive for LM.  From about 1.2 percent in 2001 to 0.3 percent in 2011.  The policy was particularly effective at lowering contamination rates of two products of concern, deli meats and hot dogs.  More recently FSIS has expanded our reach to clinicians and caregivers for at risk populations.  Having practiced medicine, I’m very aware of the unique role clinicians and caregivers can play in preventing food-borne illness, especially with those at most risk.  The agency has also worked with our partners at FDA to increase outreach directly to consumers so they are aware of steps they can take to protect themselves from food-borne illness. Today cases of listeriosis are rare relative to other pathogens.  So the incidence is low, as Dr.  Frieden just pointed out, the consequences are often very high.  Listeria tends to strike vulnerable populations.  It has a very high hospital rate and the highest mortality rate among food-borne illnesses.  All these illnesses and deaths are preventable.  Developing preventive based policies first requires an understanding of the problem at hand.  The inter-agency risk assessment on LM at retail delis that was just released last month not only gives us a better understanding of this public health threat, it also describes a clear path forward.  We can prevent illnesses and save lives by taking some simple steps.  Controlling temperatures in the deli case and putting in measures to prevent cross contamination can have a really powerful impact to public health.  We look forward to working with our federal, state and local partners to share what we've learned from this risk assessment and what steps can be taken to prevent it.  We've had a lot of success reducing listeria in the past and we're going to have more success in the future thanks to the collaboration we have going on today.  Thank you and I’ll turn it over to Mr. Taylor. 

MICHAEL TAYLOR: Thanks, Dr. Hagen, Dr.  Frieden and again good afternoon to everybody.  I think my colleagues have set up well what an important public health issue this is.  I think you've also heard some examples of how critical the collaboration is among our agencies to address food safety issues like this, the epidemiological work that CDC does, the joint risk assessment work we do with USDA is an important area of collaboration.  I think that's how we can be successful.  I think from an FDA vantage point, as the regulatory agency that has jurisdiction over soft cheeses, over produce, over other food products that are vulnerable to listeria monocytogenes contamination, the real takeaway for us and our understanding is just what a dynamic problem this is.  It's not static.  We're seeing through the work of CDC and through our own experience investigating outbreaks new food commodities that we had not seen contaminated before being contaminated.  Of course the cantaloupe outbreak being most prominent among these.  And this for us really underscores the importance of a comprehensive prevention strategy.  The basic phenomenon here is that listeria monocytogenes is an environmental contaminant.  It's present in the environment anywhere food is being prepared, foods that are vulnerable and support growth of listeria monocytogenes are vulnerable to contamination that can make people sick.  That can happen at the growing stage for produce, it can happen in processing facilities for cheese and other products and it can happen at retail.  Conditions can contribute to contamination that can make people sick, so that's why collectively we're taking a comprehensive approach to understanding where the opportunities are, to take measures to reduce risk and then taking those measures in a comprehensive way. 

Dr. Hagen talked about some of the ways in which success has been achieved.  With respect to deli meats and hot dogs, we're very focused at FDA now on produce in light of the cantaloupe outbreak and what we learned from that.  FDA is targeting through inspection activities this growing season packinghouses where cantaloupe is being produced, collecting data on incidence of listeria, on product, in the environment in these facilities and on the finished product and taking action, of course, when we find troubling results to keep product out of commerce that could make people sick, but also gathering data so we can continue to be more science-based in how we drive prevention efforts in that particular sector.  Long term, though, we've really got to look across the food system so the Food Safety Modernization Act which the president signed into law in 2011 mandates that FDA establish standards for safe produce growing, operations on the farm, packing operations, and also modern prevention measures in food processing facilities all aimed at ensuring that in situations where listeria or other hazards are reasonably foreseeable, we're putting in place modern, preventive requirements that will ensure that firms are doing the right preventive things to reduce the risk of these illnesses.  We are in the midst of carrying forward with implementation of the Food Safety Modernization Act.  We published in January very important proposed regulations addressing produce safety standards and addressing preventive control standards in processing facilities.  The import situation is an important one and we're looking forward to, we hope publish soon, proposed rules to strengthen our oversight of imported product as well.  So it's critical that we take, again, just to sum up, a comprehensive approach to targeting opportunities to reduce the risk of contamination and growth of listeria monocytogenes and other pathogens that make food sick.  It's a system that make people sick.  It's a system problem, it's a system challenge, and we think the Food Safety Modernization Act will go a long way to establishing a system that can prevent these illnesses in the future. 

TOM FRIEDEN: Thanks very much, Dr. Hagen and Mr. Taylor.  And before we open up for questions, just briefly, the bottom line is that we need to target organisms like listeria for which we haven't seen recent progress, because infections are costly, both in terms of lives and in terms of money.  We need to continue to expand the molecular technology and the tracking technologies that we have to identify the causes and to figure out and then implement prevention strategies.  There are certain things that consumers can do to protect themselves.  Know which foods are problems.  To avoid for pregnant women, older adults and people with weakened immune symptoms in particular, to avoid these foods, to ensure that you heat deli meats and hot dogs until steaming hot before eating.  Be aware that Mexican-style cheeses made from pasteurized milk such as queso fresco can be contaminated and cause listeria infection.  So we have in our fact sheet, the four-pager that you should have received more details on this, this is a challenging problem and reminds us that more progress is needed.  And we look forward to working with you to move forward, remembering the many patients who have been ill, severely ill or died from this relatively rare but all-too-often deadly infection.  So thank you very much and we'll be taking questions now. 

TOM SKINNER: Lori, I believe we're ready for questions, please. 

OPERATOR: Thank you, sir.  At this time if you would like to ask a question, please press star 1.  You will be prompted to record your name.  Press star 1 to ask a question.  Press star 2 to withdraw your request.  Our first question comes from Mike Stobbe with the Associated Press. 

MIKE STOBBE: Thanks.  Thanks for taking the question.  I may have misheard something and if I did, I hope you can just set me straight.  But Dr. Hagen, I heard you say that listeria was the -- had the highest mortality rate among food-borne illnesses, but I thought I heard Dr. Frieden say it was the third leading cause of death from food poisoning.  Could you reconcile those? 

TOM FRIEDEN: It’s a question of -- this is Dr.  Frieden.  It's a question of proportions versus numbers.  So it is the deadliest in terms of the proportion of people who get it who die, but because it is relatively rare, it is the third numerically, the third leading cause of death behind saLMonella and toxoplasma. 

MIKE STOBBE: Okay, thank you. 

OPERATOR:  Thank you.  Our next question comes from Lynne Terry with The Oregonian. 

LYNNE TERRY: Thanks for taking my call.  I’m just wondering if you've identified -- well, I have a couple questions.  But have you found any strains of listeria to become, you know, deadlier, more virulent than in the past?  Is the bacteria changing and mutating to a point of concern? 

TOM FRIEDEN: We don't see significant changes in the bacteria, which suggests that several other things may well be at work.  One is that we're getting better at finding it.  The second is that as food production processes change and food supply becomes more dispersed, it's possible to get more multi-state outbreaks.  Those are some of the key trends that we're seeing, but we're not seeing, as we did with, for example, C. diff, a new strain arising which is more virulent.  We're just seeing the persistence of very difficult to fight pathogens. 

ELISABETH HAGEN: I can jump in there too, this is Elisabeth Hagen.  Dr. Frieden is correct, it's not necessarily an evolution of strains, but one of the things all of the agencies have been involved with is to look at subtypes of listeria monocytogenes where you seem to have certain subtypes associated with more virulent infections or different types of infections and what's the best way that we can detect for particular subtypes and is there a way that we can incorporate that kind of advanced technology in the regulatory setting, so that's something that really all the agencies have been working on together for some time. 

TOM FRIEDEN:  The other thing I will mention is that even the term "serotype" is kind of quaint at this point.  We're in the era of whole genome sequencing and we don't yet know as much as we need to know about what the different genetic makeup of bacteria like listeria means in terms of how deadly, how readily it spreads, tying together different clusters or outbreaks.  The genetic-relatedness of different outbreaks.  And that's really what's behind the proposal of an advanced molecular detection initiative.  We're now able to sequence entire genomes in just a few hours.  And with advanced computing, put 10 thousands or tens of thousands of puzzle pieces together to sequence the entire genome.  That kind of spotlight has not yet been shone adequately on infections like listeria and there's more that we can learn by doing that.   

LYNNE TERRY: Thank you very much.  I had another quick question.  In your report of '98 to 2008 that report says that you need to identify gaps in industry and regulatory measures to fight listeria infection.  I’m just wondering if -- you know, if you have identified any, and if so, what are they?  Thank you very much. 

TOM FRIEDEN:  Well, there are important new regulations that are out for public comment now.  Mr. Taylor? 

MICHAEL TAYLOR:  I think what we've learned and what's reflected in our new food safety law is that we have to take steps comprehensively across the whole food system, wherever pathogens like listeria but listeria monocytogenes in particular can enter food and make sure practices are being taken at each stage to prevent that.  That's in our historic app.  Our program has been focused more on reacting and responding to problems after they occur.  We have to be systematically preventive, which again is the mandate that we have from congress and the Food Safety Modernization Act. 

OPERATOR: Thank you.  As a reminder, if you would like to ask a question, please press star 1.  You will be prompted to record your name.  One moment. 

TOM SKINNER: Okay, Lori, if you're showing no more questions, we'll conclude our call.  Is that the case? 

OPERATOR: One moment, sir.  Sir, at this time I am showing no further questions. 

TOM FRIEDEN: Okay.  This is Dr. Frieden.  I'd just like to very much thank our colleagues at the FDA and USDA.  It is really a very wonderful partnership where we share information regularly, we learn from each other and we work together to protect the public.  Thanks to all of you who participated in the call for shining attention to what is an important issue on which we need to make more progress.  Thank you for joining the call.  If you have follow-up question call the CDC press office at 404-639-3286 and thanks once again for joining us. 

OPERATOR: Thank you, sir.  That does conclude today's conference call.  Thank you all for joining, you may disconnect at this time.  

 
 

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U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES