Update 4/30/09, 2 p.m.: This post is getting a lot of hits; I’d like to suggest that your next stop be Effect Measure at Science Blogs, which I’ve found to have the most valuable current analysis of the public health ramifications of the swine flu threat. Also, in the post below I criticize WHO for not moving up to phase 5 quickly enough; they’ve since rectified this.
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Don’t panic, says the White House. Don’t panic, says the CDC. Don’t panic, says the WHO.
I don’t want them to panic either, but the people at those agencies had better be worried sick about the emerging swine flu. While the unknowns still overshadow the knowns, there’s one very troubling development that suggests why our government and public health authorities should be treating the swine flu as a far, far greater threat than 9/11 ever was.
Buried deep in a New York Times report is this nugget of information:
In each year’s flu season, most deaths are in infants and the aged, but none of the first ones in Mexico were in people over 60 or under 3 years old, a W.H.O. spokeswoman said. When a new virus emerges, deaths may occur in healthy adults who mount the strongest immune reactions. Their own defenses — inflammation and leaking fluid in lung cells — can essentially drown them from inside. [My emphasis.]
I don’t hold a degree in public health or epidemiology, but as a historian of medicine who’s familiar with the 1918 flu, I know that this is very, very alarming news. (And since I’m not a public health expert whose job entails keeping people calm, I feel free to speak bluntly about it.)
In 1918/19, the mortality pattern was exactly as the WHO describes. Historian John M. Barry describes this pattern in The Great Influenza: The Epic Story of the Deadliest Plague In History
It was the worst infectious disease epidemic ever, killing more Americans in just a few months than died in World War I, World War II, the Korean War and the Vietnam Wars combined. Unlike most flu strains, which kill predominantly the very old and the very young, this one — a bird flu, as it turns out — struck young adults in their 20′s, 30′s and 40′s, leaving children orphaned and families without wage earners.
To the best of my understanding, the reason less-novel flu viruses don’t provoke such deadly immune responses is that by adulthood, most of us have encountered enough flu viruses that we have some partial immunity to the average new mutations. There’s no need for our immune system to go into overdrive. When a radically new mutation pops up, however, our immune system resorts to the nuclear option. An otherwise healthy young person’s lungs can be destroyed in the course of the resulting inflammatory process – a cytokine storm, if you want the technical term. (Here’s an accessible description of how this works in bird flu; if the swine flu deaths are indeed due to cytokine storm, as seems likely, the mechanism would be similar.) Ironically, healthy young adults are the most vulnerable, because their immune systems are the most robust.
So this mortality pattern plus the other data available so far suggest several conclusions:
- We really are seeing a novel virus.
- It’s at least moderately deadly. However, its virulence could be variable, since the U.S. has seen milder cases than Mexico, and the less extreme cases in Mexico may be flying under the radar. Remember, though, that a virus can mutate to become more or less virulent during the course of an oubreak.
- It is transmitted from human-to-human. It appears much more contagious than SARS or the bird flus that epidemiologists have tracked in recent years.
- It has shown up in far-flung parts of North America and Europe. Today, we learned that the swine flu has turned up in Lorain County, Ohio – not quite my neck of the woods, but way too close for comfort. (The infected boy is recovering well, but his school is closed in hopes of containing the outbreak.)
The only reason this swine flu is not being labeled a pandemic is because it’s not widespread enough. Not yet. Give it a week.
Here’s one example of where exhorting people to stay calm seems to be trumping the actual science. Technically we ought to be at phase 5 of pandemic preparedness – one notch short of a full-blown pandemic – if you look at this WHO graph. Officially, we’re at phase 4, but that doesn’t square with the WHO definition:
Phase 5 is characterized by human-to-human spread of the virus into at least two countries in one WHO region. While most countries will not be affected at this stage, the declaration of Phase 5 is a strong signal that a pandemic is imminent and that the time to finalize the organization, communication, and implementation of the planned mitigation measures is short.
The only reason not to panic is because losing it would make our response even less effectual. I’ve always admired Obama’s calm; his unflappability is one of his most attractive and reassuring traits. But I hope our decision-makers are at least a little scared, because so far, complacency has not concentrated anyone’s mind. Nor has it funneled adequate dollars to the fight against flu. Republicans actually fought to keep flu funding out of the stimulus – gee, thanks! (h/t Pudentilla at Skippy the Bush Kangaroo) Perhaps more damningly, eight years of GOP veto power have left us only marginally more prepared than were were when the anthrax attacks redefined public health as a national security issue!
It’s already a few years too late for the kind of preparation we would have needed: enough doses of antivirals to rein in a true pandemic, and a rapid-response system for developing, producing, and distributing a vaccine. But we need to recognize that the swine flu is poised to create a global emergency. We need to find the resources to fast-track a vaccine. How is it that we can find a trillion bucks to prop up the banks, yet we only have two labs in North America capable of identifying this vaccine – one in Atlanta, the other in Winnipeg? (This is being rectified, but it too will take time.)
Another lesson from 1918: The virus mutated some months into the pandemic and became radically more virulent in the fall of 1918, just when the world was hoping for a respite. In the end it killed somewhere between 20 and 100 million people. Every week of further delay in creating a vaccine for this new flu could cost thousands or even millions of lives.
A train in Mexico City, ground zero of the epidemic; photo by Flickr user Eneas, used under a Creative Commons license.
Patron cat of Kittywampus (1985-2001)
[...] Well, my sweetheart and I gave this idea a whirl today, but with a twist. (Don’t worry, I’m not about to inflict TMI on you.) We went to our local big-box store … and shopped for emergency supplies in case pandemic flu comes to our corner of Ohio. I don’t think this is quite what Parker-Pope had in mind but it had all the elements she mentions: novelty (we don’t do this every day), a new location (definitely my first date at Wal-Mart), and of course a frisson of fear (y’all know I’m nervous about the swine flu). [...]
Hmm, my husband works at a hospital, I going to ask him to bring home some masks, if they haven’t run out already. This is frightening.
Hi Nat! Thanks for stopping by. I think it’s probably smart to have some masks at home, lots of imperishable food, and a good supply of Tylenol and ibuprofen. Beyond that, we just need to wash our hands and get the people around it to do the same. My husband and I talked to our kids’ principal this morning to ask what plan is in place, and to request that the kids do more handwashing.
Maybe this really won’t be a catastrophic pandemic, globally. If you live in Mexico, it’s already plenty bad. But we know enough about the flu virus to realize it’s only a matter of time. If it’s not this H1N1 swine flu, it might be another mutation that becomes highly virulent. We need to prod our leaders to prepare better, and we also need to care for our families as best we can. I’m just frustrated that the official response appears to be erring on the side of “business as usual.”
Please come by again; I’m not always so doom and gloom!
Right now, the swine flu appears to be about 40 times more deadly than the regular flu, which would result in about 1.2 million deaths if it became pandemic here in the US. *but*: It does not appear to be anywhere as virulent as the regular flu. It’s hard to pass on to other people, it seems, or we’d already see the bodies stacking in Mexico. So the current stance of the Obama administration — concern, preparation, but no panic — seems justifiable by the nature of the outbreak.
That said, it would take only one mutation for virulence for there to be a *lot* of dead bodies, easily surpassing the 20 million worldwide of the 1918 pandemic… you can bet that there are some people at the CDC having sleepless nights over that possibility.
Hi Badtux. I don’t want the government to panic, just to be on top of this – and yep, that definitely means losing sleep over it. Today Janet Napolitano said something that made me feel better: that they’re treating this flu as if it will become a pandemic. I’m encouraged that they’re starting to release stockpiled Tamiflu. I still want to see them pull out all the stops on developing a vaccine, because – as you say – this could mutate into something nastier yet. That’s just what happened in the fall of 1918, when the public and government officials believed the pandemic was winding down. If a vaccine were ready in 4 months (that’s the best-case scenario) it would be available in September, when schools resume, people are starting to stay indoors more, and the odds of transmission increase.
I’m most worried that a “business as usual” attitude will discourage people from any steps that might be necessary but disruptive – closing schools and businesses, for instance. I understand that humans basically suffer from inertia, and I understand that people don’t want to do anything to hurt an already fragile economy. But the cities that fared best in 1918 were those that implemented “social distancing.” I’m a historian by training, and I’m skeptical about people’s ability to learn from history.
I think “don’t panic” is advice for the general populace rather than the attitude of the agencies in question.
A population in panic about an infectious disease is proven to increase the rate of spread of infection, and this has also been demonstrated in an incident in a MMORPG in which a deadly infectious disease was introduced by the creators of the game, intended to be a low-level hazard in the game environment. Instead, when infected people panicked, the disease spread much more rapidly than ever anticipated. Because the characters were all controlled by human intelligences invested in the survival of their characters, this incident presents clear evidence on the ways people tend to behave when faced with an epidemic, and the ways in which this affects the spread of the disease.
I agree that the decision-makers worldwide should be treating this as a test for how they deal with a real crisis even if they don’t believe this is the real deal. As you say, we know enough to say that it’s only a matter of time before something really bad happens.
Oh, you’re definitely right that the advice was aimed at the populace. One problem we’re already seeing is that people are clogging ERs with minor infections that are no way, no how flu.
But this illustrates the broader problem of how the U.S. is fundamentally underprepared. It’s not just that our per capita stocks of antivirals are lower than, say, Great Britain’s. It’s not even just that we have no real capacity to produce flu vaccine domestically! Our entire public health infrastructure has been woefully neglected. Many ERs were already running above their capacity *before* the threat of pandemic flu emerged. If a true pandemic arrives, our health system will break down completely. Similarly, we are less prepared than other western nations to convince people to stay home when they’re ill, because at many jobs people don’t get sick days.
Fortunately, the authorities are reacting to the threat, more than when I wrote the post at the start of the week. Sometime this week, for instance, Ohio will have the ability to test for H1N1 2009 in-state instead of sending all the samples to the CDC in Atlanta. So that’s real progress. However, the bigger infrastructural problems remain. Such an irony in the place that spends a bigger share of its GDP on medicine than any other country!
I too see this as a test – and hopefully that’s what it will remain, only a test. But then we’ll have to worry about whether people will take the next threat seriously.
[...] This is cause for worry. Medical historians believe that most deaths in 1918 resulted from direct injury to the lungs, and they believe that cytokine storm may have played an important role. [...]