Pediatric complications and deaths with swine flu

Yesterday CDC's Morbidity and Mortality Weekly Report (MMWR) carried an a note about neurologic complications in children with swine flu. Central nervous system effects -- seizures, encephalitis, encephalopathy, Reye syndrome, and other neurologic disorders -- are known to occur with seasonal influenza in children, but whether they are more or less common with the swine flu variant is unknown at the moment. The MMWR reports four cases from Dallas County, more as a reminder that these kinds of complications can occur and should be considered whenever a child with influenza-like illness (ILI) presents with unexplained seizure or mental status changes. It's also a reminder of something else. That influenza, whether seasonal or pandemic varieties, presents different clinical pictures in different age groups, but pandemic flu shifts the age distribution of ill cases towards the younger age groups. The difference is not necessarily a clinical difference but an epidemiological one. First, the clinical picture:

This is the first report describing patients with neurologic complications associated with novel influenza A (H1N1) virus infection. The severity of the neurologic disease in the four patients described in this report was less than the typical disease described in two studies of neurologic complications associated with seasonal influenza (1--2), which included reports of severe static encephalopathy and death. Only two of the four patients described in this report had seizures, and none died or had neurologic sequelae at discharge. Considering that clusters of influenza-associated encephalopathy in children have been reported during previous community outbreaks of seasonal influenza and that children appear to be infected with novel influenza A (H1N1) virus more frequently than adults, additional neurologic complications in children are likely to be reported as the pandemic continues. Clinicians should consider influenza associated encephalopathy in the differential diagnosis of children with ILI and seizures or mental status changes, and remain aware of the potential for severe neurologic sequelae associated with seasonal or novel influenza A (H1N1) virus infection. (MMWR, CDC [cites omitted])

If that sounds vague reassuring, it is important to remember that influenza infection is always potentially dangerous. Seasonal flu kills mainly those over 65, but pandemic flu targets the young, and while most "just have a case of flu" (in itself potentially nasty as the cases reported above show), every year children die and this year's flu season was no exception. For several years CDC has been trying to keep track of pediatric flu mortality and the striking thing about this year is the appearance of pediatric swine flu as a distinct second season. Here is a chart from last week's CDC surveillance report where it is easy to see that this year's pediatric mortality from seasonal flu looks very much like the three previous years (although last year was a very bad flu year), but that in addition pediatric deaths are occurring this year during weeks when there are no, or almost no, pediatric deaths in the previous seasons. This is another key marker of an influenza pandemic:

i-b9f827eadbf10bae51f67503b47bcd8f-IPD27.jpg

Source: CDC, Influenza-associated pediatric mortality

Of the 90 pediatric deaths this year (there were 88 last year), 23 are from swine flu. Not all of the children had specimens collected, but of the 40 that did (all deaths, not just swine flu), about a third (15) had bacterial co-infections that contributed to their deaths, and Staph aureus was the organism in 9 of them (60%). Of these 9, 5 were MRSA, i.e., antibiotic resistant (see our post of the other day). This year, as in past years, the children with bacterial co-infections have been the older ones, most over 5 and two-thrids over 12 years old. Of the 9 swine flu fatal cases in children where specimens from normally sterile sites were obtained to see if there was bacterial co-infection, only one had a positive bacterial culture. It is still too early to say if this difference is a real difference in the likelihood of bacterial co-infection because no specimens were obtained from the majority (14 of 23) of the fatal swine flu cases.

The swine flu pandemic continues to be described in some quarters as "mild." In our view, "mild" is not a word that should be used in connection with influenza outbreaks, whether seasonal or pandemic.

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Of the 90 pediatric deaths this year (there were 88 last year), 23 are from swine flu.

As sad as those total numbers are: They also reassuringly put things into perspective about the severity of the novel H1N1 pandmic relative to a "regular" flu season.
For the numbers suggest that the first pandmic wave (of which we have probably already seen a substantial part in the US) actually causes significantly less deaths among children then did last years "regular winter flu wave" (and this even though considering pandmic H1N1's 'preference' for the young).

Of course the impact of the next pandmic wave in the fall/winter will be probably higher. Say as dramatically as ten times the impact of the current summer wave : But even then the projected number of pediatric deaths (e.g. ten times 20 ~ 100, if the trend continues) of the pandmic will be still "only" twice that of a regular flu season.

By h1n1_watcher (not verified) on 24 Jul 2009 #permalink

Barney: These are all guesses at this point. The figure you cite assumes an event twice 1957, which is certainly possible. How likely, I have no idea, but it is a worst case scenario. None of this is a question of logic. There are too many uncertainties here. I don't know if the US figures are good news or bad news. For me they are just news, i.e., data points. I don't know that what we see in the US in the spring has any bearing on what we will see at some other time, or if it does, what the relationship will be. But I would say that pediatric deaths "off season" don't particularly reassure me, no matter what their magnitude.

I have taken care of numerous kids with this novel H1N1. Most flew past the illness without problems. However, several had major problems and one required a prolonged ICU stay (My shop only admits adults so I had to ship her to a pediatric hospital for PICU). Follow up with mom reveals her course was complicated by myocarditis. She had no medical problems. I fear these high hospitalization rates we experienced in the spring will be even higher in the second wave. My state alone (MA) will need to come up with an additional 3400 beds based upon HRSA recommendations and quite frankly I see no way no how of this happening even if we were in great financial times. We should stop wasting money and start making sponge bob cartoons having good ole sponge himself washing his hands or have Hanna Montana sing a song on how to wash your hands and that would go a long way in minimizing spread.

Recent personal experience that scares the bejesus out of me regarding complacency: I recently flew on southwest airlines and no one other than my family were washng there hands and the bathroom on the flight had no running water. To add insult to injury, they shut the ventilation system completely off with 138 souls onboard during deplaning and I got stuck with a C boarding pass which translated to getting stuck in the very back of the plane. So we have an aviation industry that prefers, like the govt, to react rather than be proactive despite being the major vehicle of spread.

By BostonERdoc (not verified) on 24 Jul 2009 #permalink

Boston-Here are some suggestions and the legislation is being prepared now for Tenn. if it becomes necessary.

The south has a lot of penal farms and jails, maybe you too. Its time to play lets make a deal. Crims facing 11 months and 29 days (misdemeanors) before hitting the hard time prison will jump at the chance to reduce their time in the box if they are offered 2 days for every one worked in a flu environment.

Yep, you will have to mask them up, but there are a lot of Army/AF masks out there that could be used. They dont need suits, just a good decontamination shower afterwards. It will provide you with necessary manpower and most of them will do it because of the reduction, the others will do it because they will be helping family members as the hood is where its going to hit worst.

Simple stuff like mopping floors, move this guy up to this floor or that floor, take this tray down to so and so. Using them also opens up the facilities for sick people. The crims can live in tents outside in the cleaner air. Anyone inside of those jails and other penal facilities should be sick.

There are hundreds of available beds in those places. The crims can clean them as they vacate and then keep them clean. We wont have the money to keep them in prison anyway afterwards as the estimate is a 24% reduction across the board in revenues for taxes, businesses etc. It will give them a new chance and an early shot at being out for the non-violent and the short term violent to release. They arent as a rule just going to walk away. Where are they going to go in this stuff? They would be picked up again and then get harder time.

Prisons? Even the violent offenders with less than two years left should be given the opportunity. Fact is that most of those people when they are given direction, which is what they never got as kids work very well. I have done levee building with some real hard cases. You talk to them like they are just another joe blow and they give no hassles. No shackles, manacles or any of that stuff. We will need every able bodied man and woman. No sex offenders or extreme cases, but again this will open up hundreds of beds and we can tent facility the ones that will work.

Equipment-Boston, you know as well as I do that there aint no way. Those same crims can take turns using SPURS to pump air into those people in rotations. They can clean them too. Not much chance at infecting a new patient with a used flu bag when they already have the flu. Someone just needs to take them apart and wash them in phenolic and rinse them down.

Then there is the harder fact. We also know that there is no proof that the new vax is going to work, especially with a 75% titer level after two months of vaccinations and using LAIV. That live stuff bothers a lot of people and indicates its a lot worse than we have been led to believe.

Warning people. Jesus H. Christ-this is a media job and we certainly aint getting it from this administration. Bush did a much better job, but this a different bug too with an incredible world onset. If they dont follow the protocols then we are going to get whacked but good here in the US.

Schools? Even the UK is leaving theirs in session even in light of 30% absenteeism. How does one pass when they are feverish, coughing, snotting up? When do you call it off? When the numbers tip over for the state funding because there are too many absentees? Doesnt seem to be what is happening. By calling it mild, watching it go to severe and then calling it is criminal in my book.

To be proactive rather than reactive? Good luck on that one. All of this is news to most people still. They think its gone.

I actually had a woman tell me I was crazy just today because swine flu happened only in Mexico.

By M. Randolph Kruger (not verified) on 24 Jul 2009 #permalink

On what scientific basis do you pronounce an event "twice 1957" to be a worst case scenario? Dr. Niman, for one, is saying that this is the first time since 1918 that a swine flu virus has jumped to humans with efficient transmissibility, and that so far this pandemic is developing similarly to the one at that time. Then, there's H5N1 still endemic in some countries and nobody knows what will happen when people or pigs or ? get coinfected with both.

Unless you can present a solid scientific basis for that evaluation I don't think you're being realistic.

By Jon Schultz (not verified) on 24 Jul 2009 #permalink

Jon: I was referencing the UK estimate, not giving my own. I don't have one of my own. The origin of the 1918 virus remains in doubt, but even if it was swine, that doesn't make the two pandemics the same by any "solid scientific basis" that I know of (unless you want to call analogy a solid scientific basis). We don't know what made 1918 the way it was, but the fact it came from swine probably wasn't it. Henry is entitled to his opinion, which remains that. But the issue with 1918 isn't transmissibility, it's virulence, which is not the same thing. No one has a "solid scientific basis" for an opinion at the moment. Not even you, if you will excuse me saying so.

Revere: No, you said, "The figure you cite assumes an event twice 1957, which is certainly possible. How likely, I have no idea, but it is a worst case scenario." That means that in your opinion twice 1957 is a worst case scenario. If you meant something else then you can simply amend the statement without implying that I implied I had a solid scientific basis for an opinion, which I did not. I simply feel, from my intuition, that Dr. Niman is a knowledgeable and honorable man, and I, among others, am watching what he says (not only on his website but at FluTrackers) with great interest. Perhaps you should too.

By Jon Schultz (not verified) on 24 Jul 2009 #permalink

Many assumptions, speculations, 1918 analogies here...
But if we follow revere's advice given in a recent blog post to just "look out of the window" instead,( i.e. take a look at the big picture published each week at FluView/MMWR ) we can clearly see the overwhelming evidence that this first pandemic wave has not been more severe (in terms of total numbers of deaths) than typical regular winter flu waves.

According to [1] the total number of deaths attributed to regular seasonal flu epidemics is in the range of 300-1000 in the less-than-65 age group alone.
Comparing this to the 300+ swine flu deaths reported so far (most of which in the less-than-65 age category too) again strongly supports that the severity (in terms of age specific morbidity) of the first pandmic wave is about equal to that of a mild-moderate regular seasonal flu wave.

So the question remains: how much more severe will the second (main) pandmic wave be ?
How likely is it that the virus A) mutates and B) the mutation leads to a more severe form ?
BTW.: there is no conclusive scientific evidence that the increase in severity observed for the second wave in 1918 was due to a change in the viru's severity CFR itself. The increase in total fatalities could be simply due to the much larger number of people becoming infected during the second wave instead of a more dangerous virus)

-----------------------
[1]L. Simonsen "Pandemic versus Epidemic Influenza Mortality: A Pattern of Changing Age Distribution"

By h1n1_watcher (not verified) on 24 Jul 2009 #permalink

that Dr. Niman is a knowledgeable and honorable man,

That may be true. He is also a bit of a loon. Niman has been calling for numerous catastrophes and the end of the world anytime for years. I suppose if you predict it long enough it will come true eventually. Our sun is due to Nova in a few billion years.

The Reveres and a few tens of thousands of MDs and Ph.D.s aren't knowledgeable and honorable? Sorry, you aren't inducted into the axis of evil or even the Illuminati just because you have an advanced degree and practice medicine. As a member of the Illuminati I can tell you that you also have to have superpowers. If you weren't born on Krypton or bitten by a radioactive spider, forget it.

Every cloud has its silver lining and the swine flu has been a boon to several groups. The End of the World crowd is ecstatic. This could be the one and billions will die. The anti-vaxxers are going crazy. It's all a plot by the New World Order to kill 80% of the human race and turn the rest into zombie slaves.

Jon: I'll just say again, I was citing your cite of the worst case scenario that was cited in the link (I thought) we were both talking about. You can tell me what I meant all you want but now, at least, you have my testimony as to what I said and can believe it or not. As for what you believe or others believe at FluTrackers (a flu forum with many smart and knowledgeable and honorable people who participate) that's not particularly relevant to this point, nor is what Henry believes. For Henry just about anything is a cause for concern. Some of them are also a cause for concern for me, some of them are not. Every day at work I lunch with a colleague who is an economist, whom I have written papers with and who is one of the smartest people I know. We disagree often and enjoy arguing about what we disagree about. I try to give people who come here a little value added to news or science pieces about flu they can read about anywhere, not just here. That's our "value added" over the (already considerable value) of a news filter about flu. I am not terrified about the flu or even a bad pandemic. But I am enormously respectful of it as an adversary. I've seen people suffer or die in respiratory failure, even seasonal flu. It may be I take it more seriously than those that fear it without having that experience. But fear and respect are different. You never defeat an adversary by overestimating or underestimating it. While this virus isn't likely to kill you, it can kill you or make you desperately ill or just miserably ill or maybe you won't even notice. What the mix will be I don't know, you don't know and Henry doesn't know. But in my estimation (based on what we see and past experience) it is more likely to be like 1957 or in some places like 1951 (a non-pandemic year) than 1918. Anyone who disagrees and no one who agrees has the kind of "solid scientific evidence" you ask for.

Raven has said that swine flu has been a boon to several groups and lists the conspiracists whom none really takes seriously - do they?

An article from the Guardian business section by Richard Wachman 22 July 09, has reported that GSK is preparing to sell £3bn worth of Swine flu drugs this year. GSK was keen to stress that this figure would be much lower once development costs were taken into account and that they are also donating 50m doses to the WHO to distribute to poorer countries.

While doomsday sayers will always serve to rachet up the fear in times of uncertainty, it's good to know that the economy may well get the boost it needs and that those living in extreme poverty will be saved from 'mild' flu symptoms, if the malaria doesn't get them first that is.

Revere: All I meant is that if anyone is going to call "twice 1957" a worst-case scenario, that simply isn't believable, in light of what Dr. Niman and some other very intelligent people are saying, without a convincing argument to that effect, which I haven't seen. And I think that making that kind of statement is a serious public disservice considering that we are possibly on the verge of a 1918-level or worse world catastrophe - which I believe, if I understand you correctly now, you do agree is the worst-case scenario that we should consider reasonably possible, even if there is no solid scientific evidence at this point for considering it particularly likely.

By Jon Schultz (not verified) on 25 Jul 2009 #permalink

Jon: No, saying something is possible or a cause for concern is not the same as saying I think that is something I think could reasonably happen. I don't think so, in this case, and it is just as reasonable to say that people who raise the specter of 1918 are also doing the public a disservice. No one has a convincing argument that any particular outcome will happen but people have hunches or judgments -- to which they are entitled providing they don't go beyond the pale. You are persuaded by one scientist and not another for reasons other than science. We all do that. Just because I'm a scientist (or Henry is) doesn't mean we are correct, and in this case we don't agree. It is a basic misunderstanding that when two scientists disagree, one of them must be wrong or deliberately trying to mislead or prejudiced or whatever. This is a perfectly normal situation, what philosophers of science call "underdetermined," that is, that the available data don't determine which of competing views, if any, are more correct. Learn to live with it. And, no, you do not understand me correctly.

"It is a basic misunderstanding that when two scientists disagree, one of them must be wrong..."

Good, I'll remember that.

By Jon Schultz (not verified) on 25 Jul 2009 #permalink

Raven has said that swine flu has been a boon to several groups and lists the conspiracists whom none really takes seriously - do they?

The conspiracists take themselves very seriously. Every few months one or another goes out and kills people. So far this year we've had the guy in Pitsburgh who killed three cops because Obama was going to take away his guns, the guy who killed a guard at theHolocaust museum because the Jews run the world, and the Xian Terrorists who murdered George Tiller in a church. Among others.

As to numbers, who knows? If you add up the 9/11ers, Obama Birthers, New World Orderers, FEMA concentration campers, moon hoaxers and so on, you might be looking at 20% of the population.

The anti-vaxxers are going crazy. The vaccine is full of mercury, killer adjuvants, and cancer viruses, will be mandatory, and the swine flu was genetically engineered by whoever is the current bogeyman.

I left out another group that finds the swine flu a huge benefit. Medical quacks. You can buy cures for the swine flu over the internet. I recommend the ionized water.

You are persuaded by one scientist and not another for reasons other than science. We all do that. Just because I'm a scientist (or Henry is) doesn't mean we are correct, and in this case we don't agree. It is a basic misunderstanding that when two scientists disagree, one of them must be wrong or deliberately trying to mislead or prejudiced or whatever. This is a perfectly normal situation, what philosophers of science call "underdetermined," that is, that the available data don't determine which of competing views, if any, are more correct. Learn to live with it.

Simply brilliant !

Frame this and hang it above the entrance to every discussion forum :-)

By h1n1_watcher (not verified) on 25 Jul 2009 #permalink

Raven. I've not taken into account how mad things can get in the USA but if you have a culture that insists on arming everyone, including crackpots, then what do you expect? Peace and harmony? Sure medical quacks exist, they always have and always will. But to be taken in by one is whose problem exactly? I think that believing in praying to God for help in an illness or going to Lourdes for a medical miracle is also quackery.

I've read today about escorts for women attending health centres where abortions are carried out. Now that really does creep me out.

However prevention and preparedness are still more important that ever. This flu is in its early stages and may still worsen.

h1h1: A turd in the best french bread does not a good sandwich make. Two scientists can propose alternate hypotheses to explain an event or predict its future course, but if they are mutually exclusive then only one of them can be correct.

Dr. Niman is a virologist who, to my understanding, has accurately predicted specific viral genomic acquisitions and who is willing to publicly debate his unorthodox explanation of how influenza viruses evolve, so his opinion is not to be taken lightly. This morning, at FluTrackers, he is talking about the possibility of a "doomsday scenario" whereby infection with the current pandemic virus could perhaps prime the immune systems of those infected in such a way that subsequent reinfection - after the virus further adapts to human beings - could trigger the cytokine storm which is theorized to have affected so many in 1918. He analogizes this to the need for two shots in the administration of the hopefully coming vaccine, with the first shot acting to prime the immune system in preparation for the second. I'm sure that explanation contains inaccuracies and can be improved on.

Maybe you guys are just testing, to see if there's any interest in truth around here. I hope so.

By Jon Schultz (not verified) on 26 Jul 2009 #permalink

Jon: I don't want to start a flame war here about Henry Niman. The history of flublogia is littered with destructive Niman controversies that go nowhere except to set people against each other. Scientists have their own forum for testing truth and it's in the scientific literature through peer reviewed publication. As for the logic of your opening remark, it betrays a lack of understanding of how science is done in the real world. Explanations can be mutually exclusive and both can be correct (consider complementarity in quantum mechanics); neither can be correct; one and not the other; they can be saying apparently different things that are really equivalent (ala Heisenberg and Schrodinger); etc. The number of ways your statement is wrong is too long to include everything here. I just picked a couple of things at random. But please do not start a Niman battle here. One of the reveres engaged in that in the past and he/she regretted the effect it had on a reasonably civil community. We have decided we won't do it any more. You've got your own forum for that. Feel free to use it but please don't use this one for that purpose.

Revere: I have no interest in promoting Dr. Niman, I'm only interested in the truth of what is going on with the pandemic and whether you are ignoring reasonable concerns that we could be on the verge of a truly major catastrophe which dwarfs the 1957 pandemic.

I know nothing of quantum mechanics and the phenomena which can be observed or deduced to exist at microscopic and macroscopic levels, but if you discount the logical principle of mutual exclusives being mutually exclusive then I think you destroy the basis of rational discourse upon which, to an enormous extent, science is based.

By Jon Schultz (not verified) on 26 Jul 2009 #permalink

I'm afraid that discussion to arrive at the truth of things, on the one hand, and trying to build or maintain a "community," on the other, are mutually exclusive endeavors.

By Jon Schultz (not verified) on 26 Jul 2009 #permalink

Jon: Suit yourself. But anyone who says, "I don't know much about quantum mechanics, but I know all about scientific method" is missing something. As for mutually exclusive, it just means the events are disjoint, not that they are inclusive and even in non quantum logic, events overlap and their union isn't inclusive so if you want to confine yourself to 19th century logic you are wrong. You want to argue with me about Henry's opinions. Why? To get at "the Truth"? How would you recognize it? We're talking about things everybody is guessing about. Henry has made a million predictions. Some of them even happened. Same for us. We're trying to figure it out like lots of other people. While I'm not going to do it the way you want me to, you're welcome to follow along. Or not.

Since you belong to no community whatsoever then not being part of this one is a given, just as you aren't part of the FluTracker community (because, according to you, you are a seeker after Truth and that's mutually exclusive -- your words -- from being part of a community). I'm not trying to mock you. I'm trying to make you see that things aren't as simple as they might appear.

Revere: I don't want to argue with you at all. Please stop putting words in my mouth. I do not think I implied "I know all about scientific method;" I simply expressed an opinion, which us laymen are entitled to have. I also did not say that I wanted you to try to figure out the truth in any way other than to be open-minded, and I said nothing about belonging to communities which spontaneously form, only about the intention to create communities (for other than pragmatic reasons) which I think invariably results in some degree of cultism where truth becomes less important than the emotional comfort the members of the community derive from being a part of it.

I don't understand your point about mutual exclusives and 19th century logic, so I can't respond to it, but you raise an interesting issue with regard to how laymen can decide which of disagreeing scientists to trust. As I said above, it is simply my intuition that Dr. Niman is someone worth paying attention to, as it is that you are.

I was hoping you would comment on the idea which Dr. Niman enunciated this morning - and I have no idea if he originated it or picked it up from someone else - about one wave of a pandemic possibly priming peoples' immune systems so that they might be more susceptible to a cytokine storm reaction upon reinfection in a subsequent wave. I think that's important because you have to wonder if some of the decisions which have been made - i.e. the reopening of schools - were in fact based on the idea that it is better that people get infected in the first wave of the pandemic so that they will have greater immunity later on. I know the health agencies have been publicly dismissing the idea of "swine flu parties," but perhaps liability issues have influenced that.

By Jon Schultz (not verified) on 26 Jul 2009 #permalink

Jon: I consider Henry to be speculating, spinning a tale. I don't have any idea if it is true or not, nor does he. We don't understand the dysregulation called cytokine storm hardly at all. I've written quite a lot about the science of it here, what we know of it. I personally don't think speculating in that fashion is particularly useful as there is no evidence to support it, but we all do it to some extent. For the record, it doesn't sound plausible to me. But then I've just said no one knows how this works, which is why I don't want to get into a discussion about pure speculation. The problem -- and the history -- is that you can't comment on Henry's speculations without starting a food fight. So this comment from me is the last of it and I already think it will start something unproductive.

As for whether you said you understood how science works, you did most certainly say so, if not in so many words, in essence. It is an extremely common notion. Lots of people, many of them scientists, say similar things Very few scientists have much or any knowledge of how science works outside their own field or in general. They are like fish who know how to swim but nothing about hydrodynamics. I picked on you because the idea that one can decide between seemingly differing statements among scientists and that all it takes is common sense is very prevalent. I've thought (and written) a fair amount about this, which doesn't make me right but it certainly gives me the advantage that comes from thinking about it a lot.

Revere: What you say may be true but the fact is that laymen have to decide which of the experts to trust, especially in an emergency...

Thanks for the gentler tone.

By Jon Schultz (not verified) on 26 Jul 2009 #permalink