Transcript for CDC Telebriefing: Study on Clostridium difficile infection

OPERATOR: Welcome and thank you for standing by. At this time, all participants are in listen only mode.  During the question and answer please press star and one on your phone. Today's conference is being recorded.  If you have objections, you may disconnect.  I'd like to turn over today's meeting to Benjamin Haynes.  You may begin. 

BENJAMIN HAYNES:  Thank you Rebecca, Good afternoon and thank you for joining us for today's briefing on the new burden estimates of Clostridium difficile infections in the United States. We are joined by Dr. Michael Bell, the deputy director of CDC’s Division of Healthcare Quality Promotion and Mr. Christian Lillis, the founder and executive director of the Peggy Lillis memorial foundation.  Dr. Bell and Mr. Lillis will provide opening remarks before taking your questions. But before turning it over to Dr. Bell I want to remind you that all materials are embargoed until 5:00 p.m. eastern time. I will now turn it over to Dr.  Bell. 

MICHAEL BELL:  Welcome to everybody on the phone today. We're here to discuss new data regarding clostridium difficile or C-difficile as it's also known C-difficile causes severe diarrhea and damage to the colon and ask often triggered by exposure to antibiotics.  Infections have become increasingly common over the last few decades and are in seen in patients in health care facilities as well as people in communities. A New England Journal of Medicine article reports that in a single year it caused nearly half a million infections and thousands of deaths.  In the past, patients infected with C-difficile have had diarrhea that was often perceived as a nuisance but not a major problem. Unfortunately the type of c-diff circulating in the U.S. today produces such a powerful toxin that it can cause a truly deadly diarrhea. Patients receiving antibiotics are now at risk for not just a mild diarrhea, but intense illness that can include damage to the bowels so painful and severe that part of the colon needs to be surgically removed a condition called toxic megacolon. Many patients who recover can still suffer relapses at least one out of five patients has one relapse that requires further treatment. This is a very severe illness that causes tremendous suffering and death. C-difficile infection is caused by the combination of taking antibiotics and being exposed to the bacteria.  Antibiotics damage the normal bacteria in a person's intestines and create the opportunity for C-difficile to take over.  Once infected with C-difficile it can be very difficult to restore the normal balance of intestinal bacteria needed for health. Unfortunately, it's very easy to spread. The bacteria form a durable spore that can contaminate hands or the environment so that any breach in correct glove use, hand hygiene or cleaning protocols can allow the spores to spread. Because hand sanitizers don't kill spores, it's essential that you thoroughly wash your hands with soap and water to remove them. This is one reason why we recommend glove use when caring for patients with C-difficile to make it easier to maintain good hand hygiene. There's no room for error. Today's article gives us a better picture of where C-difficile infections are happening. In both nursing homes and hospitals we're seeing similar numbers of infections about 100,000 infections each.  Although people receiving care in hospitals made up two-thirds of all infections, two-thirds of those actually occurred after the patient went home. It's essential that patients and their clinicians be aware that they need to take any diarrhea following antibiotic use very seriously.  People of all ages get C-difficile but about 65% of health care associated C-difficile infections and 80% of the deaths that occur because of it happen in people 65 years of age or older. In fact, one out of nine patients over 65 years old with health care associated C-difficile infections dies within 30 days of diagnosis. That's a frightening statistic. This study also shows that more than 150,000 infections reported were community associated. Meaning, they had no documented inpatient hospital exposure. Nonetheless, as we showed in another recent CDC study, 80% of patients with community associated C-difficile infections did, in fact, have contact with health care setting like a doctor's office or a dental clinic and that was generally during the three months right before their diagnosis. Most of those patients were also given antibiotics. Overall, there are two main things that need to be improved. Number one is how antibiotics are being used. Making sure that we use them when they're truly necessary and only for as long as necessary. Of course, we always want patients to receive the lifesaving antibiotics they need without delay. We don't want anyone to be at risk for sepsis or other complications but we also want to be sure that the essential medications are used correctly. The second element is to ensure rigorous infection control in all health care settings. C-difficile infections must be diagnosed quickly and correctly so that the infected patient can be cared for using the right infection control techniques, this includes cleaning the environment near the patient with the right spore-killing disinfectants, ensuring perfect hand hygiene all the time and also letting facilities know when a patient with C-difficile is about to be transferred to them so they can use the right infection control practices. CDC has taken a number of steps to stop the rise of C-difficile infections. First, we're working to ensure that health care personnel follow current evidence-based strategies that prevent the spread of C-difficile from one patient to another.  Thanks to the Centers for Medicare-Medicaid Services or CMS, hospital inpatient quality reporting program hospitals have been required to C-difficile infections to CDC's national health care safety network since 2013.  This now lets us track and report the nation's progress in controlling this disease.  So far we've seen at least a 10% reduction in infections since 2011.  However, more needs to be done. Beginning in 2017, C-difficile prevention will also be included in CMS's value-based purchasing program also known as pay for performance.  In preparation for that CDC is using a targeting strategy that identifies which hospitals are having infection issues so we and our partners in state and local health departments and agencies like CMS can deliver assistance where it's needed most. To reduce the majority of infections we'll need to improve how antibiotics are being prescribed in hospitals and throughout health care. If we can improve antibiotic prescribing we expect to see rates of C-difficile infections improve dramatically. We believe this because, for example, in England over a three-year period they were able to push C-difficile infection rates down by over 60% just by doing a better job of managing how antibiotics are used.  In the United States, we have the national strategy to combat antibiotic resistant bacteria, a strategy includes a focus on improving antibiotic prescribing and use or antibiotic stewardship as it's also known.  In addition the strategy addresses more surveillance for outbreak detection and robust prevention activities in all 50 states and major cities. These efforts have a potential to cut d difficile infections in half and the proposed funding in the president's FY-16 budget would allow us to ramp up C-difficile prevention efforts by supporting specific antibiotic resistance preventive programs in health care facilities across the nation. The programs are intended to improve both antibiotic prescribing as well as infection control practices. Finally, there will likely be some C-difficile infections that continue to happen even with implementation of antibiotic stewardship and great infection control and there's a need for ongoing innovation and discovery of new technologies and strategies that will help us address those remaining infections. Examples of this kind of innovation includes research on the human microbiome and understanding the relationship of bacteria that make up a healthy human colon and also improving the role of patients who may carry C-difficile without having symptoms. How many there are, and how much they contribute to the transfer of infection within communities and hospitals. In addition, there is a need to better understand approaches to cleaning health care environments whether it's through new technologies or new targeted strategies so that we can ensure that the environment doesn't create an opportunity for transmission and then finally understanding how C-difficile moves in community settings outside of health care and making sure that we're able to diagnose C-difficile as quickly and accurately as possible.  Finally, when we look in to the future there's also the possibility of new vaccines that can prevent C-difficile infection altogether. So, as we look forward there are many potential opportunities for innovation that we continue to pursue.  At the end of the day, we have enough information now on these devastating infections to realize that the time to act is well upon us and failing to act would be disastrous. I'll conclude my remarks and we'll be happy to take questions at the end of the teleconference.  I hope I’ve conveyed how dangerous and concerning this infection is and the primary actions we have to take to keep them from harming more patients and taking more lives. I'd like to introduce now Mr. Christian Lillis, founder of the Peggy Lillis memorial foundation.  I wish it was under more positive circumstances that we had him with us today, but I’m very honored that he's here to share his very personal experience and the work he's doing to turn a family tragedy into action and race awareness to help prevent C-difficile from hurting others. 

CHRISTIAN LILLIS:  Thank you, Dr. Bell.  Like most Americans, I was unaware of C-diff's existence until it killed my mother Peggy Lillis on April 21st, 2010.  My mother was an extraordinary person, from the age of 25 she was a single mother of two sons. We were on welfare for a while as my mom attended college to become a teacher. Nothing made her happier than educating children. Unlike the majority of C-diff victims my mother was 56 years old and in good health. She had not been hospitalized until she gave birth to my brother in 1976. Her case like tens of thousands recognized in the study was community acquired. We can't be sure exactly where or when she was colonized by C-diff but her dentist precipitated her illness and death, her dentist didn't warn her that c-diff was a possible side effect. So when mom came down with diarrhea early one Friday morning she thought it was stomach flu.  She called her doctor that weekend because it was so severe. He prescribed a strong anti-diarrhea medication without examining her. When her symptoms persisted on Monday she called him again and was referred to a GI doctor. That Tuesday fearing she was badly dehydrated we took her to the emergency room.  It was there that I first heard the words Clostridium difficile. Less than 36 hours later, despite the hospital's best efforts including extensive antibiotics, IV fluids my mother was dead. Our grief was epic. Mom was one of nine siblings from an Irish Catholic family in Brooklyn.  It felt like our entire community was in mourning as more than 500 people attended her funeral.  We struggled for weeks to understand how our mother could die from a disease we'd never heard of.  We studied c-diff and learned it causes thousands and thousands of deaths every year. Fuelled by our outrage and the outpouring of love her we started the Peggy Lillis Foundation in July 2010.  Since then we've worked diligently to raise awareness and educate the public and increasingly to shape policy. I'm grateful to CDC for increasing your understanding of the true burden of this disease. That's critical to reducing the death and harm it causes. It is my sincere hope that this new, more comprehensive assessment will spark much greater attention from the press and the health care industry and lawmakers. Greater public awareness of the risk factors and prevention and treatment is absolutely crucial so Americans can make informed decisions and seek help early. It's also incumbent on all of us to translate this awareness into tangible policy changes that we know will save lives.  That's why Peggy Lillis foundation advocates for robust antibiotic stewardship and sanitation and hygiene programs at every health care facility, mandatory public reporting in every state and increased public and private investment in both prevention and treatment for all antibiotic resistant infections including C-diff.  Lastly, the numbers in this new study of 450,000 infections and 29,000 deaths are big, often abstract numbers. It's important to keep in mind the actual people behind them.  Every day we hear from citizens whose lives have been changed by C-diff.  People like Farrah who infection left her unable to conceive a child. People like Jeff who has had 13 occurrences. People like the patients of 5-month-old Molly and families like the Dexters, the Adams, the Mulligans and tens of thousands more who have lost a loved one to this disease. As you write and speak about C-diff please keep them in mind and help us to amplify their voices. Thank you. 

BENJAMIN HAYNES:  Thank you, gentlemen. We’re ready to take questions. 

OPERATOR:  Thank you. We'll begin the question & answer session.  If you'd like to ask a question, please press star one.  Please remember to unmute your phone and I’ll introduce you by name.  To withdraw a request press star two.  Our first question comes from Liz Szabo from “USA Today" you may ask your question. 

LIZ SZABO:  Hi. I was just wondering if you can talk about how resistant these infections are.  Are antibiotics still usually effective or are you seeing growing rates of antibiotic resistance? 

MICHAEL BELL:  So, antibiotics can be effective.  But I think it's important to realize that there's more to it than just treating this infection with an antibiotic. The problem with the infection is that especially if it goes unrecognized, the toxins can create so much damage that it's not just about the organism being there, but also about the damage to the colon leading to leakage into the bloodstream and sepsis and in other terrible outcomes. So, there's the treatment issue. There's also the fact that once somebody gets clostridium difficile, and I’ll ask Dr. Cliff McDonald to also say a few words about this, once you have C-difficile it means your normal bacteria in your bowels are so damaged that returning to normal can be very difficult.  So, even if you have an antibiotic that kills the C-difficile it can come back very easily. Hence the relapse that Mr. Lillis also described. Cliff, you want to say a word? 

CLIFF MCDONALD:  I will say something.  Many people have this question of why do we talk about C-difficile as an antibiotic resistant organism when the main antibiotics used to treat it, there's not clear resistance to those.  I won't even go in to what those are right now, but Dr. Bell is saying is exactly right.  That although there is not resistance against the drugs used to treat it, the actions of antibiotics are principal in this infection, it's the disruption of the biology of the intestine that leads vulnerability. The epidemic strain emerged over ten years ago that is responsible for a lot of this increase in severity is resistant to a commonly used class of antibiotics and that's one way that strain may have become more successful over other strains.  So, there are many elements of antibiotic resistance except for this important part that we always think about first is that the infection will be less treatable. That's not clearly the center of this.  But antibiotics clearly are driving this whole epidemic. 

BENJAMIN HAYNES:  Next question, please, Rebecca. 

OPERATOR:  The next question is from Mike Stobbe with the Associated Press.  You may ask your question. 

MIKE STOBBE:  Hi, thank you for taking my question.  Dr. McDonald just referred to the strain that emerged over ten years ago, the more severe strain. I was just wondering, is that -- that's continuing to be the most severe strain, or is there -- are there different strains out there?  Is the balance of which ones predominating changing at all?  And also is there any changes in the severe strain itself that bode either good or bad news for us? 

MICHAEL BELL:  Thanks, Mike.  I think Dr. McDonald will be the expert on the ecology of the organism.  I will say that the fact that the very severe strain producing toxins has spread across the country, means that we have to take all potential infections with C-difficile with the same seriousness. Cliff, do you want to say a word? 

CLIFF MCDONALD:  Yeah, Dr. Bell, that's exactly right. We do have to take every infection with all seriousness. Look at each individual patient. That's the best foreteller of how someone will do.  The epidemic strain that emerged actually back in the year 2000 first in the Pittsburgh area and then Montreal, it has spread globally now. It is now accounting and it's approximately 30% in this study that we're talking about. 30% across the land.  It's a little higher in health care facilities than in the community. It is more easily transmitted than other strains it appears. It also does appear to cause more severe disease. We haven't noticed any specific changes to that strain.  But globally there are other strains like it that have emerged that appear to have increased virulence or severity and some of the other factors as well. So, it's not just unique to this strain, although this is the strain that is causing most of the more severe disease in the United States.  Dr. Lessa, did you have anything to add to that? 

FERNANDA LESSA: No, No, that's perfect, cliff.  Yeah, it was the most prevalent strain that we observed across CDC infections both in the community as well as in health care. 

BENJAMIN HAYNES:  Next question, please, Rebecca. 

OPERATOR:  Our next question comes from Yasmeen Abutaleb of Reuters. 

YASMEEN ABUTALEB: Hi, Thanks for taking my question, I was wondering what the current diagnosis methods are for C-difficile and whether there are shortcomings this? 

MICHAEL BELL: We’re in a transition point as a nation in terms of how we diagnose the disease. The good news is we have a more sensitive detection method and that is gradually taking over from the old methods in clinical settings across the country. Again, I’ll defer to Dr. McDonald in terms of the specific details about the deaths and the sensitivities therein. 

CLIFF MCDONALD: Yes. The guidelines of 2010, which CDC was -- some of us were co-authors on, did call for the use of more sensitive diagnostics and it’s something that we have been encouraging here at CDC in recommending. I think that the best way to sum it up is that we need to use better methods overall in diagnosing C-difficile and that includes the basics of determining who should be tested. There is no diagnostic test that makes the diagnosis for you. It's a combination of the clinical symptoms of the patient, their situation, and a laboratory test. The old tests that were commonly being used all the time were the enzyme amino assays and they were generally not sensitive enough. PCR tests are now being more and more used in this study and Dr. Lester can correct me again also, but I believe it was around 50 percent of all the labs or at least 50 percent of all the cases were diagnosed with the amplification test. They are much more sensitive. There is some controversy about sometimes if they're too sensitive. But it so much depends upon how you use them. If you use a very sensitive test, but are very selective in how you decide it should be used or who to test, it's a very good way to diagnose diseases in general. If you use highly sensitive tests indiscriminately, you'll end up over diagnosing the infections. We're very aware of this issue and we take measures to control for this factor when we look over time. And when we report data on hospital rates, we take into account the type of test they're using so that in the case of hospitals that are trying to perform better they're not unduly penalized for using a more sensitive test. But we're also cognizant that over time we may see some countermovement that cases might just go up because you're using more sensitive tests when you're really doing a better job in preventing the disease. And so we're taking that into account in looking at that. And we did in this study also. Dr. Lessa, do you want to say something about how if people were using more sensitive tests, 100 percent of the time you would see a different rate? 

FERNANDA LESSA: Yeah. So the national board presented the New England Journal of Medicine upcoming publications is taking into account the type of the diagnostic test. Also in the paper we present scenarios where you have hypothetical scenarios where no labs in the U.S. would be using that.  How that estimate may vary from zero use of the PCR up to 100 percent of laboratories using those more sensitive assays. So, that's in the upcoming publication that I think you all have received the copy of the paper. 

BENJAMIN HAYNES: Next question, please, Rebecca. 

OPERATOR: Next question, Eben Brown, Fox News Radio. 

EBEN BROWN: Hi, thank you for taking the question. I realize this may have been answered in one way before, but could you describe what kind of care someone with C-difficile has to go through and not necessarily the short term, but as you mentioned it's sort of a long-term thing, they can have a relapse. So, what does a person do if they have C-difficile? How do they live? Do they have to see their doctor regularly? Do they have to have regular checkups for this? What's the long-term care? 

MICHAEL BELL: Sure, that's a great question. So, first and foremost, what we want to have happen is for people who have had antibiotics, if they get diarrhea to immediately talk to their clinician and make sure they're tested appropriately to see if they have C-difficile. If they do, then they can be given treatment using oral antibiotics to control the infection. That's the standard approach that's been used for some time and is often successful, but not always. And what we've seen is that for many patients there can be multiple rounds of antibiotics required to finally suppress the infection and with luck give the body enough time to go back to normal in terms of the bacteria in the gut. The challenge that we have is that by giving antibiotics, in many ways we're continuing to disturb the normal bacteria in the bowel so it's not a perfect solution. The challenge arises when you have a toxin-forming type of C-difficile where your colon becomes so damaged that it is, "a," very painful and, "b," puts your life at risk because it starts leaking potentially dangerous bacteria into the bloodstream. And when that happens, it's not just a matter of a frustrating long course of infection and recurrent treatment, but it's also a matter of going in and having the damaged part of the colon actually removed. So, now not only do you have the frustration of the infection, but you have the very real issue of becoming a surgical patient with a missing part of colon. That definitely changes your life because now you'll have a diversion as they call it where your bowels have to empty into a bag, a colostomy bag, and it may be years before things can be re-attached appropriately. So it's a devastating impact on a human being's life. One of the things that holds out some promise, and you may have heard about, is fecal transplantation. What we know is that returning the bowel to its normal state in terms of the types and variety of bacteria that live there normally is one way that we can return a person to health. And the sooner that happens, the less likely they are to have recurrences of C-difficile infection. So, originally this was sort of a last-ditch desperation-type treatment. I think increasingly we're seeing it move earlier into the process. I'm going to hand it over, again, to our C-difficile expert Dr. Cliff McDonald to say a little bit more about the micro-biome issue. 

CLIFF MCDONALD: I think that’s exactly right and that it’s a range of outcomes and a range of problems. Some people do just fine with the antibiotic treatment that Dr. Bell mentioned. And it is -- but it is a problem that we're using an antibiotic to treat a disease that really occurs because someone got an antibiotic in the first place. It just so happens the antibiotics we use to treat them are active against the C-difficile organism, but they're also just like any antibiotic disrupting the normal ecology in the bowel and that leads to one in five individuals across the board getting recurrences. And also some individuals not even going to the point of recurrence, but even dying or losing their colon to the initial disease. But there's also a large subset that do find with the first treatment and they get over it and it's usually ten days of the antibiotic treatment. It's frustrating. You hear this a lot, that it often takes several days for the diarrhea to get better and sometimes the diarrhea is very, very severe. In fact, it is generally a severe disease, the diarrhea, I shouldn't say just sometimes. C-difficile marks itself as being a more severe diarrhea. Most severe cases people are having bowel movements almost continuously or ten times a day just miserable during those days in the acute illness and often six days required to start to see a real recovery from that diarrhea. But then most of them still do go on and resolve and don't recur. But one in five will recur. And some of those, then, go on to this multiple recurrent cycle that results in people getting fecal transplants and whatnot. 

EBEN BROWN: I wanted to further clarify my question. If someone has this infection and they go through their first round of having C-difficile and they -- is there any anything they can do to prevent a recurrence? You know, I’m talking about lifestyle. I'm talking about prevention, you know, what does the patient do? Or is there nothing they can do? 

CLIFF MCDONALD: Well, the big thing, of course, is not to take antibiotics if they're not prescribed and making sure that your clinician know that you've had C-difficile in the past. That antibiotic taken in that recovery phase or in especially the weeks after recovering from the C-difficile infection increases the likelihood of having the recurrence. And, of course, antibiotics are lifesaving if they have to be given, they're given. Some people say can we take probiotics, is there anything like that yet? Not at this time. There's plenty of probiotics on the market, of course, they're sold as a nutritional supplement, none of them have an FDA implications for specifically preventing C-difficile, it's a little bit of a shot in the dark. Generally for most people those probiotics are going to be safe and they can take them, they can take yogurt or whatever, but we can't at this point in time give a clear recommendation of which one to take and how to take it. I think hopefully that will change in the future. Other than avoiding antibiotics, I think there are certainly general things. Taking a diverse diet. We don't know enough yet, but we know a little bit to know that dietary diversity probably helps with a diverse microbiome and things like that. But the big thing is avoiding unnecessary antibiotics and not pushing for antibiotics if they're not truly needed. 

EBEN BROWN: Thank you. 

BENJAMIN HAYNES: Next question, please. 

OPERATOR: Next question comes from Tara Terregino, Cronkite news. 

TARA TERREGINO: Thank you for taking my call. I was wondering is C-difficile more prevalent in a certain area of the country? Do we have any state numbers on this? 

MICHAEL BELL: That's a great question, and I think the work that Dr. Lessa has done might shed some light on that. Fernanda? 

FERNANDA LESSA: Sure, absolutely. So, this study was done across ten U.S. states. And we saw some states that had higher -- higher numbers of community associated C-difficile infection and other states with higher numbers of health care associated infections, so in particular Minnesota was the state with the highest incidence of community associated C-difficile infection. And on the health care associated infection site, New York was the state with the highest rate of health care associated infection. 

CLIFF MCDONALD: Could I just jump in here, too? This is Dr. McDonald again. This paper was -- this study that we're talking about was performed in our emerging infections program.  The ten sites that its strength it gives us the opportunity to see the full continuum of where these infections occur including these community-associated cases. However, we also have the national health care safety network where we get data from hospitals in all 50 states. And so there you can actually find if you're from some other state that was not involved in these, was not one of these ten regions that was included in the emerging infections program, you can actually go to the hospital compare website. Or actually I should say even simpler, more straightforward, look at our recent progress report on the CDC website where hospital rates of C-difficile or performance or levels of infection are reported from all 50 states. That's called our standardized infection ratio, so if you're interested specifically in where a particular region is affected at least from a hospital standpoint, that that's available as well. 

BENJAMIN HAYNES: Rebecca, we have time for two more questions. 

OPERATOR: Our next question comes from Elizabeth Mechcatie with Internal Medicine News.

ELIZABETH MECHCATIE: You mentioned that medical and dental offices are one source of community acquired infections, and I’m wondering if you have any idea how it's getting transmitted in the offices and what doctors can do to reduce that risk, like better hand washing or --

MICHAEL BELL: Right, that's a great question. Certainly in all health care settings we want all health care professionals to be meticulous about hand hygiene, not just for c-diff, but for countless reasons. That's a basic part of correct medical practice. But remember that C-difficile is special in that there are two steps to becoming infected. There's one, you have to be exposed to the spore or the bacterium and that can certainly happen in health care settings. But also you need to be given antibiotics so that you can open the path for the C-difficile to take hold. And, you know, I think what we saw was that the exposure in outpatient medical settings and dental clinics seemed to also correlate with the antibiotic piece of that as well. So, it's not entirely clear that this was where they actually were exposed to the bacteria. This may have been mainly where they were exposed to the antibiotics that let the bacteria take hold.  But I’ll also check, Dr. Lessa, do you have additional details that you want to add to that? 

FERNANDA LESSA: No, Dr. Mike bell that was perfect. And you're absolutely right that the outpatient setting can be the place where the patient can get exposed to the antibiotics or can be exposed to the C-difficile spores. And that has implications that showed identification of C-difficile spores on those outpatient settings. Dr. Mike --

ELIZABETH MECHCATIE: You mean they found it in -- actually found it in the settings? 

CLIFF MCDONALD: Yeah, yeah. I'll just jump in here. Yes, there's a study from a VA clinic where patients who recently were discharged from the hospital and they maybe had c-diff while they were in the hospital, they recovered from their diarrhea, but they continued to shed these spores for weeks to a couple months after resolution of the diarrhea. And so they were -- they found that, yes, in fact, examination tables and other ambulatory sites were contaminated with C-difficile spores. So, that is something that we're very interested in understanding is, as Dr. Bell, you know, laid it out, is it the exposure to the antibiotics, they receive the prescription in the doctor's or dentist's office that led them to be vulnerable to C-difficile or was it also that they were exposed to the spores in that setting. And what should we do about that if that's the case. And so there's actually a study ongoing right now, again, in this emerging infections program that we have ongoing, a case control study, to look at risk factors in the community, where C-difficile is, to better understand that, especially that, the role of health care exposures and how that may play a role in what we should be doing about that. 

MICHAEL BELL: And this is Mike Bell again. Just to clarify, these studies that we're talking about today, they're undertaken in a number of locations around the country. But these particular studies don't include every last state, so when we talk about where we had high rates and low rates, please do bear in mind that those are amongst the participants. The information that Dr. McDonald pointed you towards earlier on the CDC website for national reports is a better place to look at data representing sort of national pictures in terms of where these things are being found. 

BENJAMIN HAYNES: Last question, please, Rebecca. 

OPERATOR: Your last question from Jilda Unruh, CBS Miami. 

JILDA UNRUH: Thank you very much. I'm going to make this real quick. Are you talking about all antibiotics, or are you talking about a certain class of antibiotics like fluoroquinolones. 

MICHAEL BELL: That’s a very good question. I’m afraid it’s not as easy as saying one class is bad. As we look more closely at the bewildering number of bacteria that live in your colon. What we are realizing is that probably 70 percent of them have never been grown and even named before. There's a huge amount that we're able to do now with our advanced technology that's shedding light on this issue. And common antibiotics like vancomycin, for example, which ironically can be used to treat C-difficile also does a tremendously effective job of wiping out some of these hidden bacteria that we think might be very important in terms of maintaining the normal state of the bowel and preventing C-difficile. Suffice to say any antibiotic that we take can disrupt the normal flora and when that happens, we believe there's risk. Again, I’ll ask Dr. McDonald to weigh in on this as well. 

CLIFF MCDONALD: I don't have anything to add. That's great.  

JILDA UNRUH: Thank you. 

BENJAMIN HAYNES: Thank you, Dr. Bell. Thank you, Mr. Lillis, and everybody else that answered questions. This is going to conclude today's briefing. I want to remind you that all materials are embargoed until 5:00 p.m. eastern. A transcript will be available at www.cdc.gov/media. If you have further questions, please e-mail media @cdc.gov. Thank you. 

OPERATOR: Thank you for attending today's conference. You may now disconnect.  

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U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES