A Quick Primer on Flu Strains

This Reuters article posted today gives a quick primer on different strains of avian flu, how dangerous they are, and where they can spread. It also explains the technical term "pathogenicity"--important to know to distinguish among how relatively dangerous different strains are.

The Risk of Pandemic Flu from Human Error

Emergency hospital during 1918 influenza epidemic, Camp Funston, Kansas
(U.S. Army photographer; photo in public domain).
It is estimated that 50 million or more people worldwide died during this pandemic

Today in the online magazine Business Insider, an article by Kevin Loria depicts what I consider to be one of the greatest risks regarding the rise of pandemic flu: the escape from a research lab of a flu virus engineered for maximum contagiousness and lethality.

Science fiction, you say? Couldn't happen, you say? Guess again.

Yes, this has often been a theme of science fiction (as in Stephen King's 1978/1990 novel The Stand, later a 1994 television miniseries). But although a fictional treatment is certainly no proof that something could actually occur, the converse is also true: the fact that something has been treated as a theme in fiction is no proof that it could not actually occur.

Just this week, as Loria's article notes, the U.S. Centers for Disease Control and Prevention (CDC) reported that it had kept a supply of smallpox virus in a lab that was not sufficiently prepared to guard the public from an accidental release of the virus. Smallpox virus, of course, is so dangerous that, by international agreement, only two laboratories in the world are allowed to possess it. Yet this location was not one of those two laboratories!

As Loria reports, labs worldwide are engaging in flu research--including the engineering of flu viruses that are modified to increase their contagiousness and lethality. However, as Loria notes:

In a New York Times op-ed on the risks of some current flu studies, [Harvard professor Marc] Lipsitch points out that "between 2003 and 2009, there were 395 'potential release events' and 66 'potential loss events' in American labs involving select agents, a category that includes many of the most lethal bacteria and viruses."

Considering whether such mistakes could actually lead to widespread infection is not just hypothetical. In fact, the best current explanation for a 1977 H1N1 outbreak in China and Russia is that the virus escaped from a lab.

The bottom line: whenever human judgment and action are involved, mistakes and accidents will happen. When these mistakes or accidents involve deadly flu viruses, the consequences could be catastrophic. With such risks around us, we would be wise to be prepared to survive pandemic flu.

Commentator Down Temporarily

Your commentator has the 72-hour Yucks. (Not swine flu.) Will be unable to update "The Basics, Part 1" for another day or two. When I return, will address some questions being bandied about the media: Is the danger over? What does it mean to say that the 2009 A1H1 virus does not have the same genetic virulence as Spanish flu of 1918? There's more to be concerned about than might appear on the surface. (Do see post re the second wave.)

Don't Be Taken In By Stylish Dismissal of the Threat of Pandemic Flu

Some people become overly catastrophic at the slightest hint of threat. That is a bad thing. On the other hand, some people err in the opposite direction, and that is a bad thing as well.

It is stylish to be dismissive of concerns raised by the media. Such a dismissive attitude can be seen in an opinion piece by Wesley Pruden, appearing in The Washington Times on Tuesday, April 28. Mr. Pruden, editor emeritus of the paper, pointed out that, in recent years, the media alerted people to threats that did not, in fact, kill everyone in sight, threats like "AIDS, SARS, bird flu, poisoned peanut butter," and so on.

There is much to criticize in Mr. Pruden's op-ed piece, such as the way he mocks the caution with which global and national health authorities have qualified their warnings. (Well, of course they have to use words like "may" and "might," in reference to this threat. If we wait until a pandemic definitely develops before we raise warnings, then it will be too late to do anything; that would be the medical equivalent of the way the federal government dealt with Hurricane Katrina.) However, I would like to focus on the very worst section of Mr. Pruden's piece, the part most likely to cause actual harm. As he put it:

About 2,000 persons in Mexico are down with flu, and about 150 have died. That's a mortality rate of about 7 percent. Sad, even tragic, but not exactly the most lethal flu virus we've ever seen.

The lordly manner with which this op-ed piece dismisses the apparent mortality rate seen in the recent Mexican flu cases disguises a monumental misunderstanding of the medical significance of these statistics. It is a misunderstanding that has potentially lethal consequences.

The most lethal flu pandemic of which we have certain knowledge is the so-called Spanish flu of 1918. The low-end estimates of the number of people killed by this flu pandemic are 40 million around the world--in a single year. As noted in probably the best book on this pandemic, John M. Barry's The Great Influenza, the mortality rate of the Spanish flu was 2%. (Mr. Barry repeats this statistic in his own op-ed piece, which also appeared on April 28, in The New York Times.) At 2%, the Spanish flu showed a much higher mortality rate than the normal annual flu, which has a mortality rate that is a fraction of 1%. That, in addition to the Spanish flu's relatively high infection ratio (it infected one-quarter or more of those exposed to the virus), made the Spanish flu the worst pandemic disease killer of recorded history, beating out the Black Death of Europe.

Yes, there are worse mortality rates, for agents like the Ebola virus--but Ebola and the like have never become pandemic. (Good thing, too, as then we'd be in Stephen King, end-of-civilization territory.) The Spanish flu, with it's 2% mortality rate, wins the prize for deadliest pandemic virus.

But 2% does not hold a candle to 7%, now does it? Actually, a mortality rate of 7% really would be the most lethal flu virus we've ever seen, and by a very large margin, at that.

The figures coming out of Mexico are more than a bit sketchy. It will take at least a few more days to clarify the actual infection rate and mortality rate of the new swine flu seen in Mexico. However, if--and may the Divine Powers in heaven forbid this--if the new swine flu does indeed have a mortality rate of 7%, then it will have over three times the mortality rate of the Spanish flu, the worst flu pandemic of recorded history until now, all without the necessity of the virus mutating from what it is today.

This is why the health authorities of the globe are so concerned. This is why they are taking serious steps, even in the early stages when the available data are still so sketchy. This is why Mr. Pruden's op-ed is so irresponsible, and dangerous--for by misrepresenting the meaning of the very statistics he quotes, he encourages people to ignore this threat.

One might expect Mr. Pruden to know the meaning of these statistics. After all, he does cite the Spanish flu; his piece even features a photograph of Seattle in the grip of the Spanish flu (above). However, having taught dozens of class sections of statistics at the college level myself, I can understand how easy it is to misunderstand the impact of these statistics. (Think about this for a minute. Seven percent is about one person in fifteen. Have you ever experienced an illness that killed one person out of every 15 infected? That's worse than the mortality rate from combat for the Union troops in the Civil War.)

But now you know that impact. I hope that, over the course of the next few days, we'll come to know the true mortality rate of the new swine flu. If it is well below 1%, that will mean one thing. On the other hand, if it is 2%, or worse, then we are in Spanish flu range, and that worked out quite badly for the unprepared world of 1918. If it is actually 7%--frankly, we would be in a lot of trouble. Let's hope (and pray) for a lower number--but let us prepare for a worse scenario.

. .

-----UPDATE

. .

The Washington Times published my response to Mr. Pruden as a Letter to the Editor in their May 1 issue. I did not choose the title ("Fear the Flu"); I write this blog so that you won't do that. But at least a response is in print.

(The photo, of Seattle during the 1918 pandemic, was obtained from the website of The Washington Times. The photo itself is in the public domain.)

Bring Up Your Questions Here

I plan to write some of the future posts on this blog to respond to questions that you bring up. You may bring up questions in one of two ways:

1. Make comments on blog posts--especially this one. This is the first place I shall look for your questions.
2. E-mail your questions. You may send questions to flu_mekr@yahoo.com . (That is an underscore "_" between "flu" and "mekr.")

I look forward to receiving your questions.

The Basics, Part 2: Why You Should Be Concerned

What is the big deal with this new swine flu? After all, at least in the United States, no one is dying from this. Nothing came of the bird flu scare of 2006. The swine flu scare of 1976 turned out to be nothing.

Let me address each of these objections. Then I have some other things to point out.

"At least in the USA as of April 27, no one is dying from this."

This is quite true. As of suppertime on Monday, April 27, no one in the United States was determined or even rumored to have died from the new swine flu. Unfortunately, this should not give us any comfort.

It is in the nature of viruses that their genetic material has the potential to mutate into different forms. However, different viruses have different degrees of potential, when it comes to mutation; some will mutate frequently, and into radically different forms, while others will mutate infrequently, and not change too much. The new swine flu is caused by a virus that is composed of a previously unseen combination of elements of four other viruses. No one knows how this virus will change, or what it's potential is. It is entirely possible that it will not mutate at all, or mutate into a less dangerous form, or mutate into something even more lethal and more contagious.

It is true that one of the big mysteries at present is why so many have died in Mexico, and no one in the United States. There are a couple of possibilities here, none of them cause for comfort:

• The "Too Soon" Hypothesis. It might simply be the case that the virus has been active in the United States for too short a period of time to have killed anyone. Mexico has seen about 1,995 documented cases of flu recently (since some time in March), with 149 recent flu deaths. Let's take one of the worst-case scenarios: all of the flu cases and fatalities were caused by the new swine flu. This would yield a fatality rate of almost 7.5%--an astonishingly high fatality rate for influenza. However, we only have about 48 cases of flu in the USA that we know were caused by the new swine flu. Even with a similarly high fatality rate, we would only expect to see maybe 3 or 4 deaths, and that would not be for some time, either. Basically, there may not have been enough time for fatalities to show: this is the alternative scenario, the "Give It Time" hypothesis.

• The "Poorer Nation" Hypothesis. It may be that the relatively poorer level of nutrition and health care in Mexico, relative to the United States, is to blame here. However, this will be no protection for the US. The first identified cases in the United States were business or pleasure travellers to Mexico, who had the financial resources, not only to go abroad, but to get good, attentive health care. However, the US has millions of people who have no health coverage, and who are suffering economically from the Great Recession; they may be relatively malnourished, and may be trying to tough out the flu without health care at all--at this very moment. They wouldn't appear on the radar of the health authorities until they seek health care, and that may not happen for many of these people for some time. (Even if you, the reader, have health coverage, that won't necessarily protect you as much as you'd like: if the less fortunate get the flu, they may develop secondary infections such as pneumonia, which can be passed on to you along with the flu.) Thus, it may be that there are many more infected in the US than we know about, people too poor to seek health care; this is the alternative scenario, the "Hidden Infections" hypothesis.

• The "Just Lucky" Hypothesis. Perhaps we're just lucky, and the virus mutated to a less powerful form before it infected the cases in the US. I don't think so, and here's why. Normal flu kills people, but usually a fraction of 1% of those infected, and those are mostly those with compromised or immature immune systems: infants, the elderly, people on immunosuppresant drugs, and so forth. The Mexican authorities noted that their flu fatalities were primarily among the healthy and strong young adult population, aged 20-40. This is troubling because this is precisely the population that has been hit in previous flu pandemics, most notoriously the so-called "Spanish Flu" of 1918. (In a future post, I'll explain why this group is hardest hit; briefly, their immune systems are so vigorous that they go into overtime and actually overwhelm the body of the young adult.) Details are skimpy, but the people known to be infected in the US by the new swine flu so far seem to fall outside the target age range for pandemics: over half the US cases are just a bit too young (high schoolers in Queens, NY), and the business travelers may well be older. Thus, the people most at risk were not among those first infected in the US, although they may very well be infected at this point. This is the alternative scenario, the "age range" hypothesis.
  

In sum, yes, no one has died of the new swine flu in the USA yet. However, this should not make us complacent at the moment.

"Nothing came of the bird flu scare of 2006."

Yes, lots of people got scared because of the avian or bird flu incident of 2006, and yet nothing came of it. However, if you go back and look at the news pieces that emerged from that incident, you'll see that there was a good reason for that, a reason that does not apply with the new swine flu of 2009. The bird flu of 2006 was never shown conclusively to be transmissible from human to human; to put it simply, infection seems to have required some sort of physical contact with infected birds (like being a chicken farmer). However, in 2009, we have conclusive proof that human-to-human transmission is happening. That is why the United Nations World Health Organization (WHO) raised its pandemic threat level to Level 3, and then to Level 4. (It's a six-point scale, where Level 6 is a full-blown pandemic.)

"The swine flu scare of 1976 turned out to be nothing."

Yes, the swine flu scare of 1976 turned out to be nothing; more people died of bad reactions to the flu vaccine than from the flu. However, although the name is the same, the 2009 organism is different from the one seen in 1976. The organism that we are seeing in 2009 combines genetic components of human flu, avian or bird flu, and two strains of swine flu, in ways that have never been seen before by scientists. It is just an accident that it happens to have the same public label--'swine flu'--as the weak organism seen in 1976.

Further Reasons To Be Concerned

I wish that were it, but it is not. There are troubling echoes in the 2009 swine flu incident that reminds epidemiologists of what may have been the worst pandemic seen in recorded history: the 1918 Spanish flu. In the course of a single year (1918-1919, the tail end of World War I, which overshadowed the flu in the news), this pandemic killed between 20 million and 100 million people around the world (almost certainly much closer to the high end than the low end of that estimate). This is more people than were killed during the Black Death of 14th century Europe--and all within the bounds of a single year.

(The photo above shows police in Seattle during the 1918 epidemic, wearing face masks.)

For the last thirty or forty years, as biomedical science has come to understand viruses better, epidemiologists have been predicting that it is just a matter of time until something like the Spanish flu appears again, causing a global pandemic that could be even worse--because modern transportation can help the virus travel farther and faster; because now more people are crowded together into cities, making infection much more efficient. Although we now have antiviral agents to fight the flu, we only have a few. (Antibiotics work against bacteria, not the much, much smaller viruses.)

So, is the new swine flu of 2009 like the Spanish flu of 1918? There are two areas in which there is an unfortunate resemblance:

1. Infection patterns. The Spanish flu was a shock to medical workers, as it killed healthy young adults. As I pointed out above, this is the same pattern seen in the new swine flu.
2. Fatality rates. The Spanish flu killed about 2.5% of those whom it infected, a fatality rate at least three to five times higher than the fatality rate of normal human flu. As I pointed out above, although data are sketchy, the new swine flu seems to have a fatality rate in the range of Spanish flu--and maybe worse.

Conclusion

I have given reasons why you should be concerned about the new swine flu. Even if the new swine flu of 2009 peters out, as we all hope it will, it is still just a matter of time until something like the Spanish flu emerges again. New swine flu or new Spanish flu, you need to prepare now to deal with this threat. I describe how to do that in the post "The Basics, Part 3: What You Can Do." (It will appear in this blog just above this post, if you are looking at the blog in its entirety.)

(The photo, of police officers in Seattle, December 1918, wearing masks made by the Red Cross during the influenza pandemic, was obtained from Wikimedia Commons, and is in the public domain in the United States.)

The Basics, Part 1: The Current Threat

The "current threat" at any given time is evolving, so I will be editing this blog post on an ongoing basis, even though the first version was composed on the afternoon of Monday, April 27, 2009.

The Situation as of the Mid-Afternoon, Wednesday, April 29, 2009

At this point (2:45 p.m., but see update below), there are many cases of the new swine flu, confirmed by laboratory analysis, in the United States. In the USA, 50 cases had been confirmed as of Monday, and 64 as of Tuesday. At present, there are 91 confirmed cases in the USA, including the states of New York (51 confirmed cases, by far mostly in NYC), Texas (16), California (14), Kansas (2), Massachusetts (2), Michigan (2), Arizona (1), Indiana (1), Nevada (1), and Ohio (1). There are also laboratory-confirmed cases in Mexico (49 cases ), Canada (13 cases), Spain (10), as well as in the United Kingdom, New Zealand, Germany, Israel, Costa Rica, South Korea, and Austria (fewer than 10 cases each).

It would be easy to be misled by these figures. There are only a very few laboratories in the world that can confirm a case of the new swine flu. Thus, there almost certainly are many, many more actual cases of the new swine flu around the world, and in the United States. Let us consider overall how many cases of flu there are currently around the world.

Overall, there are 2,547 cases of flu in Mexico, but it is unknown at present how many of these are of the new swine flu (beyond the 49 confirmed cases, mentioned above), because testing is not complete. In Mexico, over 160 people have died of flu; 7 of these have been shown to be fatalities from new swine flu, but it is currently unknown how many of the others may have resulted from the new swine flu as well. Mexico is largely shut down, with its schools and many businesses closed, and police patrolling with face masks (pictured).

There are reportedly hundreds of suspected flu cases just among schoolchildren in New York City; there are also unconfirmed cases of flu at Teachers College, Columbia University, and at the Ernst and Young accounting firm, at Times Square in Manhattan. Officially, in the US, there are over 277 cases of flu where the new swine flu is suspected but not yet confirmed. (As mentioned above, 91 confirmed cases of swine flu are known to exist in the USA.) So far, there has been just 1 fatality from the swine flu in the United States.

(4:45 p.m. update:) As reported by the Associated Press, the United Nations World Health Organization (WHO) has just upgraded its pandemic alert level to Phase 5. This means the following:

• Larger clusters of flu infections, involving 25-50 people in each cluster, have appeared, lasting from two to four weeks in duration.
• Person-to-person transmission is occurring.
• Although this person-to-person transmission is still somewhat confined to specific locations, the virus appears to be increasingly adapted to humans.
• "There is a substantial risk of a pandemic."
  

(The above is paraphrased and quoted from page 11 of the December 2005 edition of WHO Outbreak Communication: WHO Handbook for Journalists: Influenza Pandemic [WHO/CDS/2005.37].)

Phase 6 would indicate a full-fledged pandemic flu.

The United States federal government has been making preparations for a full-scale pandemic--although the government is not yet predicting a full-scale pandemic. Simply put, no one knows what direction this pattern of infections will take. However, as reported on Tuesday by the Associated Press, the feds are preparing for a worst-case scenario.

The big question now is, is this 'the big one,' or not? For many years, epidemiologists have warned that it was just a matter of time until a highly contagious and potentially fatal organism spread in a global pandemic. Is this the case with the new swine flu? That is unknown at present.

Sometimes infections like this peter out; at other times, they become pandemic. Given what we know right now, it could go either way.

It is important to point out that the authorities have noted troubling characteristics regarding this virus. These characteristics have implications concerning what you should do. For the characteristics of this virus, see "The Basics, Part 2: Why You Should Be Concerned." For what you should do, see "The Basics, Part 3: What You Can Do."


(The photo, "Mexican police officers with masks on [for] swine flu," by Sari Huella, April 25, 2009, was obtained from Wikimedia Commons under Creative Commons Attribution License 2.0.)