Pigs Do Fly! Implications for Influenza

The influenza genome is segmented. Eight pieces of single-stranded RNA encode for 11 proteins: PB2, PB1, PB1-F2, PA, HA, NP, NA, M1, M2, NS1, and NS2. The segmentation allows influenza of different subtypes infecting the same host to trade segments like card players on a Friday night. Most of the resulting viruses will express phenotypes for the worse, but a small subset may be transformed into strains more infectious in their usual hosts or to a new host species.

This reassortment accounts in part for the origins of this year’s pandemic. Livestock pigs have long hosted their own version of seasonal H1N1, evolutionarily related to our own. From 1930-1998 the pig version evolved only slightly. But starting in 1998, the virus was subjected to a series of reassortment events. In North America, an aggressive swine H1N1 emerged with internal genes of a human H3N2 virus and an avian influenza. That virus subsequently spread across pig populations, with limited transfer to humans, usually to farm workers, who routinely offer the influenza virus human test subjects every step in its evolution.

Breeding Influenza: The Political Virology of Offshore Farming

What better way to medicate against a holiday’s genocidal origins and the hunger now swelling worldwide in the wake of a banker-brought recession than with a bellyful of turkey, stuffing, yams, and pumpkin pie? Despite its dark ambiguities, Thanksgiving remains my favorite American holiday. Take a breath, eat well, love your family, make time for friends, and, a few drinks later, curse God, badmouth your boss, and regroup for the descent into winter. Here in Minneapolis, dusk is approaching its solstice nadir. Five in the afternoon and pitch black.

Thanksgiving obviously reminds us too of the pathogens the livestock breeding that produces the birds most of us will be chowing on also offers. If the bone breaks your way, you might with sardonic irony wish for a way out of this and subsequent pandemics. It isn’t, of course, merely a matter of a little luck (although that would help). There are due causes for the bad things that happen, often specifically related to the decisions people in power and in the money make. I believe we can think through these fixes and with enough courage to act in the face of threats to life and fortune change the world’s course.

A Visitation of the Influenza

In seeping through the world’s every nook and cranny, pandemics have a way of forcing themselves into our lives as a lurking presence. Even the most insular of functionaries, who typically makes his living solving problems by ignoring them, straightens up and takes notice.

As an epidemic wave arrives, each of us faces intimate decisions we may have thought a concern only for someone somewhere else far, far away. Should my family flee, vaccinate, wear masks, scrub regularly, shun crowds, isolate itself, drink brandy-infused elderberry, or, for the jittery among us, just crawl into bed until 2011? Others, on the other hand, may ask whether we should even bother worrying.

The answers are as variable as the people who arrive at them. Over the past two weeks I’ve heard friends and family heatedly talk through their positions online and in the real world. I’ve overheard strangers in cafes, on buses, and on the street wrestle with what were months ago only abstract possibilities better left to the eggheads.

‘Biosecure’ Farms Not So Biosecure

There are times when perniciously false premises are treated as the criteria by which truth is determined. We lose the argument before it’s begun. And where does that leave us in our efforts to control mortal dangers of our own making?

An article of faith among veterinarians and epidemiologists is that large industrial farms are both biosecure and biocontained: livestock pathogens such as highly pathogenic influenza can’t check in, and if they do, they can’t check out. The premise is so engrained that international health agencies have codified levels of biosecurity by the size of farming sectors alone. The operational standard is the bigger the farm, the better its protection.

A paper published last year cuts against the grain. Graham et al.’s review shows industrial farming can promote the spread of pathogens to other farms, to the outside environment, and to farm workers. All three modes can expose surrounding communities to daily doses of the latest and greatest in xenospecific bugs, some of which, as this spring’s swine flu pandemic attests, may take root as widespread human outbreaks.

Yes, Swine Flu Is Worse Than Seasonal Influenza

Although most cases of swine-origin H1N1 influenza have been ‘mild’, half of those hospitalized with severe illness have none of the pre-existing conditions that might complicate an influenza infection: asthma, heart disease, hepatitis, immunosuppresion, pregnancy, among others.

A new study explains why. Itoh et al. demonstrate swine-origin H1N1, now pandemic, to be intrinsically more virulent than previously assumed. Indeed, the infection expresses characteristics of some of the more deadly influenzas, including highly pathogenic H5N1, the bird flu virus.

Itoh and colleagues tracked the pathogenesis of the new H1N1 infection. They conducted experiments on mice, ferrets, pigs and macaques, comparing the effects of swine-origin H1N1 and recent strains of seasonal H1N1. The team discovered,

The Hog Industry Strikes Back

Swine flu H1N1 appears at one and the same time moving full-boar and on its cloven heels. The World Health Organization reports 15,510 official cases in 53 countries, with new countries regularly reporting in. An order or two more cases are likely unreported and together represent an atypical spring surge for influenza. At the same time, the strain’s virulence appears presently no more than along the lines of a bad seasonal influenza.

One of the mistakes we need avoid is to assume we’ve been victimized by a media-fueled hysteria. Given the mortality rates reported at the beginning of the outbreak in Mexico—exceeding that of the 1918 pandemic—it looked like we were in for it. Previous pandemics teach us that preparing for the worst is the prudent option. Imagine the reaction if only feeble preparations were made in the face of a truly deadly pandemic. The cost of a Type II error, thinking no pandemic possible with one imminent, is catastrophically greater than that of its Type I sibling, thinking a pandemic imminent with none in the offering.

The NAFTA Flu

Cases of swine flu H1N1 are now reported in Honduras, Costa Rica, Brazil, Argentina, Austria, Thailand, Israel, etc. Can’t keep up at this point.

H1N1 is making its way across the world by hierarchical diffusion. By the world’s transportation network it is bouncing down a hierarchy of cities defined by their size and economic power and their interconnectedness to Mexico City, the international city closest to the initial outbreak. It’s no coincidence that New York and San Diego were among the first cities hit. The virus is also engaged in contagious diffusion, spreading out within each new country hit.

For the most part only a few cases have been reported in countries other than Mexico. But as influenza, unlike SARS, can transmit before symptoms show, there may be no way to stop H1N1 now. New York now reports hundreds infected.

What is clear is that the more countries affected, the more likely the virus will find chinks in the world’s epidemiological armor. The new strain may develop the right epidemiological momentum once it reaches those countries whose public health infrastructures are underdeveloped or undermined by structural adjustment programs. On the other hand, that may have happened from the start. Since the early 1980s Mexico has been subjected to IMF-specified truncations in animal and health infrastructure.