TRANSCRIPT of July 9, 2019, CDC Vital Signs: Nationwide Outbreak of Acute Flaccid Myelitis—United States, 2018

Press Briefing Transcript

Thursday, July 11, 2019

Please Note: This transcript is not edited and may contain errors.

OPERATOR: Good morning, and thank you all for holding. Your lines have been placed on a listen-only mode until the question-and-answer portion. At that time, to ask a question, please press star-1. I would remind all parties, the call is being recorded. If you have any objections, please disconnect at this time. And I would now like to turn the call over to Kathy Harben.

Thank you. You may begin.

KATHY HARBEN: Thank you, Elan, and thank you all for joining us today for the release of a new CDC Vital Signs. This month’s Vital Signs is about acute flaccid myelitis, also known as AFM, a rare but serious illness that causes limb weakness, mostly in children. We are joined today by CDC’s Principal Deputy Director, Dr. Anne Schuchat and by Dr. Tom Clark, a pediatrician and lead investigator for CDC’s AFM team. They’ll discuss what CDC has learned about AFM and our continued work to better understand this syndrome. I’d like to turn the call over now to Dr. Schuchat.

ANNE SCHUCHAT: Thank you Kathy, and thank you all for joining us today to discuss CDC’s Vital Signs report. Each month, we focus on the latest data about a critical health issue facing our nation, and what can be done about it. Acute flaccid myelitis, or AFM, is a devastating illness for patients and their families. We know families are facing uncertainties when it comes to their child’s recovery from AFM, and we want parents to know that we are keeping their children front and center and working with our partners to better understand this illness, the risk factors, and ways to treat and prevent it.

AFM affects the spinal cord and causes limb weakness, mostly in children. There have been three nationwide outbreaks of AFM, starting in 2014 when CDC started tracking this illness. We’ve seen a seasonal pattern to this illness–most patients develop AFM between August and October. Most patients had a mild respiratory illness or fever less than a week before they developed arm or leg weakness. These are important pieces of evidence that point to viruses, including enteroviruses in particular, playing a role in AFM.

Today, in our Vital Signs report, we summarize: what CDC has learned about AFM from the cases confirmed in 2018, and actions that doctors can take to better respond in the future.

Doctors and other clinicians across the United States play a critical role. We ask for your help with early recognition of patients with AFM symptoms, prompt specimen collection for testing, and immediate reporting of suspected AFM cases to health departments. When specimens are collected as soon as possible after symptom onset, we have a better chance of understanding the causes of AFM, these recurrent outbreaks, and developing a diagnostic test. Rapid reporting also helps us to identify and respond to outbreaks early, and alert clinicians and the public. AFM has serious consequences for otherwise healthy children. AFM is a priority for us at CDC. We are working with local and state public health departments to investigate AFM by reviewing each case, testing every specimen we receive, analyzing seasonal patterns, and collaborating with universities and the National Institutes of Health to conduct research. Our sustained work will help lead to more answers about this serious illness, such as why some children develop AFM and why these outbreaks are occurring. CDC’s AFM Task Force of national experts is also playing a critical role in the AFM investigation by evaluating the current understanding of causes of AFM and strengthening the knowledge base about the best ways to support patients through treatment and rehabilitation.

Now, I’ll turn the briefing over to Dr. Tom Clark, who’s leading the CDC’s AFM investigation from our Division of Viral Diseases. He’ll summarize what we’ve learned in 2018 and to discuss the way forward.

TOM CLARK: Thank you again to everyone for joining us today.

In 2018, CDC confirmed that 233 patients in 41 states had AFM. This was the third and largest outbreak since we started our surveillance of AFM in 2014. Similar to the AFM outbreaks in 2014 and 2016, most AFM cases were in young children; the average age was 5 years. The patients were severely affected by AFM with 98% of them being hospitalized; 60% being admitted to intensive care units, and 27% requiring machines to help them breath. We tested all the available specimens that we received from patients with AFM. All the stool specimens we tested were negative for poliovirus. Of the respiratory and stool specimens tested, about half were positive for enterovirus or rhinovirus, including EVA-71 and EVD-68. The spinal fluid was positive in two cases. One had evidence of EVA-71, and one had evidence of EVD-68. Since 2014, we have tested spinal fluid of most AFM cases, and in only a few have we identified a pathogen. When a virus is found in the spinal fluid, it is good evidence that this was the cause of a patient’s illness.

Our 2018 data show that patients suspected to have AFM quickly received medical care. On average, patients were hospitalized within one day after they started experiencing limb weakness and an MRI was performed within two days. Specimens were collected for virus testing with 2 to 7 days on average. However, suspected cases were reported to CDC anywhere from 18 to 36 days after onset of limb weakness. This delay hampers our ability to understand the causes of AFM.

As Dr. Schuchat mentioned, CDC urges healthcare providers to recognize AFM symptoms, collect specimens early, and immediately report all suspected cases to their health department. CDC is working diligently to investigate every case, test every specimen, and conduct research to understand AFM and find better ways to diagnose, treat, and prevent it. Thank you for your attention. Thank you for your attention. And Elan, I believe we’re ready for questions.

OPERATOR: Thank you. And at this time, if you would like to ask a question, please press star 1. Please unmute your phone and record your name clearly when prompted. Once again, if you would like to ask a question, please press star 1. One moment, please, for the first question. And once again, if you would like to ask a question, please press star 1. Our first question today is from Eben Brown from Fox News.

EBEN BROWN/FOX NEWS: Hi. Good afternoon and thank you for doing the call today. I have to ask the obvious question — is there any belief, or even if not documented, but a belief or a working idea that the increased alarming number of parents choosing not to vaccinate against certain childhood diseases is any way related to the rise in AFM cases? I know that it’s not something that is normally vaccinated for, but is there anything that you think is contributing to this?

ANNE SCHUCHAT: Thank you for that question. The rise in vaccine preventable diseases is of great concern. Obviously, we’ve been talking about the increase in measles this year with record levels unfortunately linked to individuals who haven’t been vaccinated as appropriate. There’s not any known association with this outbreak that we’ve been seeing of AFM and parental choices about vaccines, but thank you for the question. Next question, please.

OPERATOR: And our next question is from Mike Stobbe from the Associated Press.

MIKE STOBBE/AP: Hi. Thank you for taking my question. Two, if I could. Could you update us on how many confirmed cases there have been this calendar year? And then also, Dr. Schuchat had said something about it affects the spinal cord and causes limb weakness, mostly in children. Could you say more about the best understanding of why it’s mostly children who are affected and not so much adults? And if adults have been affected, how many? Thanks.

ANNE SCHUCHAT: Thank you for those questions. I’ll begin and let Dr. Clark continue. In 2019 so far, there have been 11 confirmed cases of AFM reported to us, and they come from eight different states. In terms of the pediatric occurrence, I don’t think we have all the answers. There may be some issues about children’s immune systems and what they’ve already been exposed to, but let me see if Dr. Clark wants to add to that.

TOM CLARK: Thanks, Dr. Schuchat. So, we do want to remind everyone that AFM can occur year round and it does occur in odd-numbered years, not just even-numbered years. So, we maintain surveillance year round. And the testing and investigations we propose are important in every case. I think there probably is — we really do suspect viruses play a role, and enterovirus is among the leading suspect. And so, these are really ubiquitous infections common in childhood, and as you age, you’ve had many of them, so it may be that adults are less susceptible, whereas children are more susceptible. But we have a lot to learn through the research we’ve proposed in understanding what triggers AFM in some children, while most recover from these common infections. Overall, about roughly 93%-95% of the cases occur in kids, but a handful do occur in adults.

KATHY HARBEN: Okay. Next question, please.

OPERATOR:  Thank you. Our next question is from Maggie Fox, who is an independent journalist.

MAGGIE FOX: Hi, thanks very much. You talked about it’s good for the kids to get in as soon as possible. Can you talk about what treatment options there are, and has anyone found a way to slow the progression of the paralysis? Thanks.

ANNE SCHUCHAT: You know, I’ll begin again and let Dr. Clark expand. CDC has worked together with clinicians and experts around the country to develop interim considerations for treatment. There are not yet proven strategies that significantly change the outcome, but there’s a lot of work going on. And one of the promising areas that we’ve been hearing about recently is early institution of rehabilitation or physical therapy, but let me let Dr. Clark talk in a little bit more detail about the possible ways to treat or recover.

TOM CLARK: Thanks. That’s right, we do have information for health care providers on our website that summarizes the experience that experts have had in using different types of treatment in patients with AFM. Unfortunately, we don’t have good evidence for the benefits of any of those treatments. This is an important question for us and why we’re working to identify every case and collaborating especially with the National Institutes of Health on a prospective study to better understand the treatments that are given and what might improve the outcomes. We really do think that early and aggressive physical therapy and rehabilitation holds good promise to help kids strengthen the function that they have after AFM and regain as much strength and function as possible.

KATHY HARBEN: Next question, please.

OPERATOR: Thank you. Our next question is from Alison Aubrey from NPR.

ALISON AUBREY/NPR: Do you know what percentage of the kids who get this have permanent paralysis? And also, another thing is just the unusual biannual feature of it. You mentioned you do have cases in odd years, but you tend to get them — we tend to get them in even years. I can’t think of something else that works that way, where it comes every two years.

ANNE SCHUCHAT: Thank you. Let me take the questions in reverse order. The every-other-year pattern is intriguing. I want to say that we cannot assume that it’s a long-term pattern, because we’ve really only been tracking this since 2014, and we want clinicians and parents to be ready for a possible significant outbreak this year. It’s one of the reasons that we’re reporting these results right now in July, because it is every August that we start to see an uptick. There are some conditions an every-other-year pattern has been seen, for instance in rotavirus infections, that’s what we see. But we don’t right now have an explanation for the every-other-year pattern, and we really need to be ready to rapidly detect, report, and investigate each case this year and be ready for possibly a bad year this year. The issue of the outcome of paralysis, I’ll let Dr. Clark let you know what we know so far.

TOM CLARK: There’s been published experience from some of the cases that have occurred since 2014, and unfortunately, it’s 70% or 80% or more of kids that had ongoing limb weakness several months after onset of AFM. You know, one of the things that the parents of affected children taught us last year is that, you know, we were focused on cases of AFM as they occurred, but there are families and children living with AFM, and so, it’s a gap in our understanding and an important thing we’ve set about addressing, so we’re going back to all of the cases that occurred in 2018 to assess their muscle function and strength and ability to perform activities of daily living up to 6 and 12 months after their illness onset. So we’ll learn a lot more about the persistence of limb weakness after AFM.

I would just say that we do — the biannual pattern is something that points us towards viruses, certainly, and we have strengthened our surveillance for enterovirus D68 in this network of seven children’s hospitals we mentioned. And so, we have two years now of additional experience. In 2017 not much, EV-D68, not much AFM. In 2018, more EV-D68 and more AFM. So, this is something that’s got us focused on EV-D68, but we still have a lot to learn about how it plays a role in triggering AFM in certain kids.

KATHY HARBEN: Next question, please.

OPERATOR: Our next question is from Michelle Cortez from Bloomberg News.

MICHELLE CORTEZ/BLOOMBERG NEWS: Thanks so much for taking the question. I’m wondering how many patients we’ve seen, if you have a good idea of how many across the board that there have been, and wondering if you think that because it had been increasing, did we see more in 2016 than we saw in 2014, and do you think that that pattern will continue, and until everyone’s been exposed to this virus, do we have any idea of what percentage of people who have been exposed to a virus or something else might actually develop this?

ANNE SCHUCHAT: Thanks for those questions. The cumulative total reported confirmed AFM cases to date, our figures is 570. And the 2018 outbreak was the largest so far with 233. In 2016, there were 149. And in 2014, 120. Now, it’s important to say that we have strengthened the surveillance and increased attention, and I think parents and clinicians have also increased attention, but we do believe the 2018 outbreak was the largest yet. Does that mean 2019 or 2020 that or will be even bigger? We really can’t say. I think it’s keen for us to make sure that we detect all the cases and that they’re promptly cared for and we learn as much as possible, but I think it’s too early in the course of this condition for us to understand fully what will happen in the future. One thing we’re trying to do is be better prepared to learn as much as possible so that we can better treat and rehabilitate children who experience this and possibly work towards prevention or cures.

OPERATOR: And our next question is from Jeremy Olson from the Minnesota Star Tribune.

JEREMY OLSON/STAR TRIBUNE:  Two questions. One, I didn’t know — I haven’t seen a list of the seven hospitals where surveillance is being done. But my main question is, what is the list of possible things in common that differentiated the children who suffered these AFM due to common viruses, apparently? I mean, what’s the possible things they had in common that could explain why they got so sick and experienced limb weakness, whereas other kids just cleared the virus with little problem?

ANNE SCHUCHAT: The list of hospitals I think we could probably get after the call, make that available in terms of the collaborating pediatric centers. And that question that you ask about why this child and not the other child, why not the sibling who also had the respiratory infection, where we’re pretty sure that the same virus was running around the family, those are critical questions and one of the reasons for the prospective investigations that are being developed, to better characterize risk factors, such as whether there are genetic predispositions that differ even within a family, but we don’t actually have information right now about why this child. Most of the children that have been reported were previously healthy kids.

TOM CLARK: That’s right, and we’re also going back to all the cases in 2018 to do some structured interviews to look at potential risk factors. We’ve done this in the past and really haven’t found anything unusual. Dr. Schuchat said, these mostly have been healthy children, no unusual patterns of exposures. And there are some studies that collaborators are working on to look for things like genetic or innate risk factors that might predispose to AFM.

KATHY HARBEN: Next question, please.

OPERATOR: And our next question is from Jill Daley from the Pittsburgh Post-Gazette.

JILL DALEY/PITTSBURGH POST-GAZETTE: Well, thank you. I have three questions the first kind of follows up on what we were just talking about, genetic predispositions. Hasn’t there been any thought to families that might have had ancestors that had polio, that the children might have had grandparents, say, that had polio, whether that would be some susceptibility? And my other two quick questions are, is there another disease that children might have been diagnosed with, instead of AFM, that would have looked differently, and so, they weren’t undiagnosed in the past? And my third question is just the spinal cord sampling is there a possibility that instead of attacking the spinal cord, the virus had hit a different part of the body, neurologically affecting the child instead of coming through the spinal cord?

ANNE SCHUCHAT: The question of genetic predisposition and family history is I don’t think we have that kind of information yet, but one thing to say is that there are a number of infectious pathogens that have a spectrum of conditions where some people are asymptomatic, some people have mild illnesses and some people have very severe consequences, and in fact, with polio myelitis virus, many infections are asymptomatic, and yet, some patients get paralyzed. So, with viruses, we have seen that before, but we don’t know right now exactly what’s going on with the AFM outbreaks that we’ve been seeing. In terms of misdiagnosis, there are a variety of rare neurologic conditions that are on the differential, and one reason that experts in transverse myelitis got involved in this is that they were being called upon to consult on these children. Diseases like Guillain-Barre Syndrome, other rare neurologic conditions may be there. But there’s also a number of viruses, including enteroviruses that can cause a variety of clinical syndromes, some neurologic manifestations and fever and other conditions. You probably heard us talking about Zika virus and about West Nile Virus as conditions where there can be very severe neurologic complications, but most people have viral or even asymptomatic conditions. Dr. Clark will expand.

TOM CLARK: One of the reasons that MRI is so important to us in the diagnosis of AFM is that it gives you a really specific picture of the part of the spinal cord that is involved in these cases. And so, it’s kind of diagnostic of AFM. It’s also important to remember that it’s a challenge — I think you were asking about a biopsy, for example, of a spinal cord or nerves to make a diagnosis, and it’s a challenge to do that in kids who are previously healthy when your goal is to preserve function and help them regain strength. And so, that’s really not been an option for diagnosing AFM or for researching AFM.

KATHY HARBEN: Okay. Next question, please.

OPERATOR: And our next question is from Leigh Ann Winick from CBS News.

LEIGH ANN WINICK/CBS NEWS: Thank you. I’m wondering if you could characterize the awareness among pediatricians of the first line of defense for these kids. Does it vary regionally based on where the cases have been?

ANNE SCHUCHAT: Just to say that while this is a relatively rare condition, we have had reports from practically every state so that the — this isn’t just, you know, a southern disease or a northern disease. However, the vast majority of pediatricians will never have taken care of a patient with this, and that’s one of the reasons for the clinical consultation service that has been developed by the neurologic specialists who really want to help a pediatrician who’s wondering whether that’s what they have in terms of patients that they’re seeing and what are the best ways to care for this. So, in terms of the broader pediatrician awareness, Dr. Clark can make some comments.

TOM CLARK: Yeah, and just to add that, you know, we mentioned that kids who present with limb weakness are hospitalized quickly and the MRI is done quickly and the specimens are obtained quickly for virus and other testing. But this delay of 18 days or more to report — you know, among the many things the doctor who’s caring for a child with AFM in the hospital has to do — we want one of those things to be call the health department. We’re also working with the doctors on the front lines who might see a child with AFM, for example, in an urgent care facility or just in their clinic. So, we’re working with the partners we’ve always worked with and reaching out to additional partners and provider organizations to make everyone aware and consider AFM and understand that it’s important that it be reported to the health department.

ANNE SCHUCHAT: And maybe just to close that out — as a disease that occurs seasonally, there may have been great awareness among pediatricians last October when the media was covering this extensively, but October was a long time ago, and so, we do hope that today’s report will be a reminder to clinicians and parents that the season for enteroviruses is coming, and you know, if your child develops arm weakness or leg weakness, please seek medical care right away. If you’re a clinician caring for such a child, remember that getting specialty assistance through neurology and infectious disease and the service that’s been developed is important, and please do report to your health department so that we can understand what is going on across the country.

KATHY HARBEN: We have time for two more questions.

OPERATOR: Thank you. Our next question is from Molly Walker from Med Page Today.

MOLLY WALKER/MEDPAGE TODAY: Hi. Thank you for taking my question. Following up on a couple of questions, but do you have data for what it looked like in 2017? You said 11 cases in 2019, is this year trending like 2017 or is it higher so far?

TOM CLARK: This year looks like the past off years. So, so far as we said 11 cases in 2019, there were 35 total in 2017, and 22 cases in 2015. So, these really are distinctive peaks in the even-numbered years. But AFM does occur year-round. We confirm cases year-round and in the odd-numbered years. So, it’s important always to think about it.

KATHY HARBEN: Final question, please.

OPERATOR: And our final question today is from Tom Avril from the Philadelphia Inquirer.

TOM AVRIL/PHILADELPHIA INQUIRER: Hi. Thank you so much. So, I realize that the culprit hasn’t been nailed down for sure, but has any thought been given to possibly developing a vaccine against one of those enteroviruses, such as EVD-68?

TOM CLARK: Thanks for that question. So, you know, it’s a long road to a vaccine, to develop and license a vaccine. It’s important to really understand the cause of AFM or causes first, and so, we’re focusing on enteroviruses and EVD-68, and especially, you know, we know certain viruses can cause AFM. We really want to know what explains this epidemiology we’ve talked about of AFM. Collaborators are working on proof of concept sort of studies or vaccines, but there’s a lot to learn before we really have an effective prevention strategy.

KATHY HARBEN: Thank you Dr. Schuchat and Dr. Clark for joining us today. Thank you also to the reporters who have called in. If you have follow-up questions, you can call the CDC press office at 404-639-3286 or email us at This concludes our call. Thank you.


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Page last reviewed: July 11, 2019