Although the initial breakout of the new deadly swine flu was hit with a quick response to try to limit its spread from Mexico, it has escaped into the general population in the U.S. in milder forms. Many other countries are reporting cases and now there are thousands of confirmed infections.
H1N1 is spreading fast and is on the way to being a global pandemic, though the U.N.'s World Health Organization doesn't want to panic people prematurely with its highest level alert 6. For one thing the H5N1 bird flu outbreak of 2006 never materialized into the global threat that many anticipated with governments ordering tons of antivirals and protective masks while scientists were trying to rush through a new vaccine. It's still an ongoing threat with 11 avian flu H5N1 outbreaks last year.
Now researchers are saying the H5N1 though extremely deadly doesn't propagate well as the human nose is too cold for it to enter the respiratory system. Nevertheless H5N1 has spread widely in a milder form and might evolve still into a more infectious type by recombining with other influenza viruses, even with the new H1N1.
But the fear that H1N1 will become a plague is now thought to be unlikely as nearly all cases outside of Mexico have been mild, with few deaths reported. Perhaps the WHO is basing their strategy on this fact, that this strain will accommodate itself to the human population by becoming less virulent which is generally the case in epidemics that fizzle out. It has to do with a survival mechanism: the virus or bacteria to be successful needs to spread quickly by not killing its hosts, as if viruses and bacteria have this sort of intelligence to dilute themselves into less of a threat for their maximum survival.
But in many pandemics initial virulence has been sustained for years, wiping out populations wholesale like the old plagues of Europe, the Black Death and others. The most recent was the Spanish Influenza of 1918-1919, which also was a swine flu and alarmingly an H1N1 type like today's swine flu, but the Spanish Influenza killed millions worldwide, some estimates going as high as a 100 million deaths.
The Spanish Influenza did follow this model towards less virulence and disappeared into the morass of other milder influenzas. At that point its survival today can't be measured easily as you'd have to test a lot of people with common flu symptoms to see if it's in the general population. It is the ultimate source of the alarming new variant we've seen in Mexico and possibly not transmitted via pigs but from human to human perhaps exclusively.
The Spanish H1N1 has evolved into the Mexican H1N1, through admixtures of genes from other flus. Scientists and the media haven't broadcast the connection as the new H1N1 isn't the old Spanish H1N1. This could panic more people as some would assume they could expect another deadly pandemic like the Spanish Flu of 1917-1918. Though it is a possibility. The new H1N1 could be as devastating. In the last decade the Spanish H1N1 has been genetically sequenced from some poor samples taken from victims who died during the pandemic, partially preserved in their frozen bodies buried in the arctic. Some other samples were also discovered in the US Army medical collections in Washington, which also helped the sequencing projects. Scientists now have been able to compare them as the new virus has been under intense and rapid scrutiny since the Mexican outbreak.
To complicate matters the new H1NI is a mystery in itself, as no swine in Mexico have so far been reported as animal hosts of this influenza. So where did it come from? And how? Now the Centers for Disease Control in Atlanta are saying that a mild precursor of the new H1N1 did infect some Americans as far back as September 2008. So it's not clear if the March outbreak in Mexico of its most deadly form is ultimately from Mexico. No pigs in Mexico involved so far.
Though somewhere along the line there has to be an animal host, scientists presume, and like the earlier Spanish Flu, it was pigs. No pigs in the US have been confirmed as the source of the American infections either though researchers are saying there is evidence of a precursor in American pigs though lacking the full compliment of genes. N1H1 is a swine flu but the swine can't be found. Yet the panic about swine as a source of infection has started, with the Egyptian government ordering the killing of all swine in Egypt, some 300,000 and other countries banning imports of pigs and pork.
Consumption of pork properly cooked has never been linked to influenza transmission to humans. This has prompted the WHO to rename the influenza as H1N1, rather than the misunderstood and media spread swine flu.
Recently the first pigs infected were found in Canada, with a swine herd in Alberta diagnosed with the current H1N1, though cases of humans infected there haven't come to light.
If all of this is a cause of major concern, the oddest thing of all is the cautious approach of the WHO and other government agencies that fight infectious diseases to the link to the Spanish Influenza. Probably to limit a panic. But is that wise? It's not only that the two viruses are similar, it's that there is no guarantee that the new H1N1 will melt away into a less virulent strain as many hope. The most unsettling thing is the Spanish Influenza according to an excellent history on the subject* by Gina Kolata, wasn't a sudden and spectacular disease that swept Europe at the end of WWI out of nowhere.
It had a precursor that was floating around Europe in a milder form though of the bad flu type that didn't raise any alarm as the war was going on. What appears to have happened is the Spanish Influenza used human hosts to develop its virulence before bursting forth and slaughtering more people than the war did. That's accepted science in disease outbreaks, that infectious diseases evolve from milder strains.
Is this what's happening now? Is this virus on a two stage attack plan? The milder and earlier cases of H1N1 in the U.S. would seem to confirm it. The later Mexico fatalities might be traceable to the U.S. outbreak. Tourists nowadays are the big vectors for new influenzas and other infectious diseases. American tourists with mild cases of H1N1 might have brought it into Mexico where it evolved into it's deadly form. Though this would be hard to prove even if this etiology is being studied anywhere by government agencies.
What if the milder forms are still recombining with other influenza viruses in these people infected, as some researchers expect, for a new outbreak like the Spanish Influenza? Are changes to the virus being monitored? To some extent, but it's extremely difficult to see if any of these current mild infections now affecting perhaps a hundred thousand people in the U.S. alone are mutating. Virus and virus subtypes are extremely difficult to detect with precision if you bother looking. Studying an evolution of H1N1 from mild to virulent must be an over-riding concern, but there's hardly time and the resources when you have the real McCoy to worry about. Oddly too, so far the virus shows remarkable consistency in samples studied. Viruses are extremely tiny and it's difficult even if you have a good sample of a suspected altered virus to find it under an electron microscope, unless you laboriously culture it first to concentrate it for study.
The major focus of research has been to sequence the new swine flu genome and in this way compare it to other strains. The idea is to understand how it formed and how it works, and then counter it with a vaccine. Today, a science paper on the new H1N1 was released, providing a complete picture of what is known. A team of 59 researchers collaborated on the project led by the CDC and the University of Cambridge.
What they found was bits of genetic material from various swine and other flus combined. The new strain of H1N1 goes back to the first isolate of swine flu discovered back in 1930, an H1N! that was a close relative of H1N1 Spanish Influenza of 1917-1918 which was also a swine flu. Ultimately the new strain derives from the original H1N1, but it has new features from other flu viruses. Here's the recap from Science, the highly respected publication of the AAAS:
The paper explains that this novel H1N1 has two genes from an avian virus that entered Eurasian swine in 1979, three from the old-fashioned H1N1 in North American swine, two genes from the triple reassortants in North American swine, and the final one from humans transmitted to us from birds in 1968.Just how all this happened is rather a mystery. Did it form in humans or swine or in some other host? We still don't know. Also strangely, the researchers note:
Many of the molecular markers predicted to be associated with adaptation to a human host or to the generation of a pandemic virus, such as in 1918 H1N1 or highly pathogenic H5N1, have not been identified in the 2009 H1N1 viruses characterized here.So the new H1N1 is not identical to Spanish Influenza H1N1, but its potential is similar enough through its rapid spread and its virulence, as we've seen worldwide, to be a major threat. It could mutate, now that it is widespread in the human population, into a more virulent form with a great many people infected worldwide and new infections still soaring. In the Spanish Influenza pandemic in just two years about one in five died out of an estimated 500 million who were infected. The rock bottom estimate was half that or 50 million dead, 250 million infected. It's important to know just how similar the original H1N1 is to today's H1N1, not only in structure but in mechanisms of infection and propagation. With all the research findings we now have, it's possible to find out.
Oddly again, the researchers who studied the 76 isolates of the new swine flu, from victims in Mexico and the U.S. have found that so far there is a remarkable consistency or just one major form of the virus. This is good news for producing a vaccine more simply and more quickly. But it raises another question. If there is such a consistency in the virus both in lethal and non lethal cases, why does it kill some and not others? Do some people have a partial immunity due to previous swine flu exposures or swine flu vaccines commonly used in the U.S. but not in Mexico?
In any case the advice on current swine flu vaccines is they are ineffective in providing immunity to the new virus.
The spread of the virus is so rapid, we might see new lethal outbreaks perhaps where we don't expect them. There's the wait and see approach in pandemics to gauge how they are evolving. We don't have a vaccine yet and mass quarantines and restrictions on travel would be extremely disruptive, maybe unnecessary, maybe spreading more panic. When other people get more seriously ill who have been in contact with mild cases, then the alarm bells will ring out everywhere.
A deadly outbreak as in Mexico might arise again but from contact with carriers of the milder type who didn't have obvious symptoms or had ordinary flu symptoms, but still due to the new virus. So the deadly H1N1 could surface in a population that hasn't been detected as harboring the less virulent virus as its hard to spot with so many ordinary influenzas around. In any case it takes only one virulent case to start a chain reaction. The deadly virus might jump out without any warning anywhere as it did in Mexico. We wait and see.
What happens next is anyone's guess. No doubt the correlations with Spanish Influenza are known to researchers and agencies, though the more recent discovery of an incubation period in the old Spanish Influenza in Europe isn't generally known.
One way of checking Spanish Influenza easily enough with Mexican is to see what age groups are infected and who dies. In the Spanish Influenza it was generally healthy adults aged 20-40 who died en mass. Are epidemiologists studying who's getting the Mexican variety? Obviously, but why not tell us publicly if there is or isn't a correlation? Why aren't reporters too asking the right questions? Problem always is few know enough about a topic to cover it really well.
It seems in order not to spread panic the WHO is not publicizing any connections to the Spanish Influenza plague, in the same way as they have downplayed the severity of the current pandemic. The WHO isn't sure where it will go. It went overboard justifiably in its dire warnings on H5N1 that never panned out. Embarrassing to be wrong, but they might have been right. Now the WHO seems to be more cautious in predicting risk. The new policy might backfire though as the Mexican government has just lifted restrictions that went into place to limit exposure to this swine flu, now with new deadly cases not spreading as quickly, the Mexico epidemic isn't as alarming.
A full scale alarm from the WHO might have stopped this quick return to business as usual in Mexico, with the tourist industry a leading pressure factor. If the WHO and Mexico are wrong, we're in trouble. Does politics and business play a role?
It looks that way. The WHO is no doubt planning for the worst and has assembled a consortium of pharmaceutical giants to tackle a new vaccine and mass production of it, just in case.
But there's been some fudging anyway by government agencies on the earlier bird flu H5N1 threat, with the claim that this was a new virus not previously seen. It wasn't. H5N1 surfaced in Hong Kong 3 years earlier in 2003 and it was extremely deadly. If you had it then chances were about 100% you'd die, but it wound up only killing a Hong Kong resident and 3 people in Vietnam. But even now it seems no one cites the work of Keiji Fukuda of the CDC who confirmed the first case of H5N1 avian influenza in Hong Kong in 1997, nine years before Bush's official announcement.**
George W Bush made the first public statement on the antecedents of H5N1 well into the big scare of a new influenza plague, which wasn't new. Doesn't make any sense either that Bush would make the announcement. I'd followed the story and couldn't figure out why the WHO or the CDC didn't tell us about the earlier cases of H5N1. Then Bush told us. Had it been made public before the big bird flu scare, it might have dampened enthusiasm for the medical mega reaction and stockpiling of drugs and masks. Politics of preparedness? Here was a threat that surfaced back in 1997 that never went anywhere, probably because 1.5 million chickens were slaughtered in Hong Kong to stop the epidemic, but a lot of money was spent on it after it the first U.N. alarm in late 2005, the virus proving as deadly but with remarkably few deaths ensuing considering the U.N. outcry of millions potentially dying. Kill rate of those infected is still alarming, from 17% to 100% depending where you get it. But why keep it quiet when on the other hand killing 1.5 million chickens is a big alarm in itself? Because nothing was done since the first outbreak from 1997 to 2005?
It's an odd fudge factor maybe with no correlation to the big spending that followed. Now what we have is another fudge factor at the WHO: Don't cry wolf again 2005, and again 1976-- remember President Ford marshaling America for swine flu then, if you're not sure. And cross your fingers.
First Detailed Report of New Virus's Promiscuous Past, in AAAS Science
Latest H1N1 Swine Flu News, in AAAS Science
Influenza A virus subtype H5N1, in Wikipedia
2009 swine flu outbreak, in Wikipedia
*Book: Flu; The Story of the Great Influenza Pandemic of 1918 and the Search for the Virus That Caused It, by Gina Kolata 1999, Touchstone
**Book: Secret Agents: the menace of emerging infections, by Madeline Drexler 2002, Penguin Books, p174 ff on Keiji Fukuda's discovery of H5N1 in 1997