The hyperbolic response to the recent bout with swine flu reveals how much our antiquated public health policy motivates fear. Neither the number of deaths attributed to the H1N1 virus nor the geographic distribution of cases makes this a worrisome epidemic. But with flu policy guided by a horror vision of a return of the “Spanish flu,” which caused tens of millions of deaths worldwide in 1918, even the present mild outbreak looks like a fearsome challenge.
Despite a wealth of knowledge not available in 1918, we still deal with each new outbreak of flu as if the virus were an invading army and the US population its target. We meet each year’s flu with immunization, “stockpiles” of Tamiflu and a command and control center at the CDC. A few programs normally held in reserve, like school closings and airport screenings, are brought up to the front lines when we’re feeling particularly menaced. Each year, we win a Pyrrhic victory–there are piles of casualties on our side, but the enemy deserts the field. Then, when flu returns the following year, we do the same thing all over again.
The traditional armamentarium works against flu only in the limited sense of reducing casualties in developed countries. It doesn’t work if we recognize that our policy of arming ourselves against communicable diseases allows us to ignore them when they devastate the world’s poor. It doesn’t work if we consider the costs to poor farmers’ economic welfare and physical health when flocks or herds are slaughtered to protect rich-country livestock from flu. And it fails utterly if we count the long-term costs of letting flu viruses infest herds and flocks, recombine and start the cycle again.
In order to break out of this cycle and invigorate a broader approach to public health, we must dispense with the naïve notion that fighting flu is an annual battle and begin to think in terms of management. Whether we want to change this situation because it threatens us or out of a deeper sense of obligation to the world’s welfare, we have to regard flu as a resident of an ecosystem humans share with animals. We have to equip ourselves to understand not only how flu crosses species barriers but how the many interactions in a complex system of agriculture, climate, land use, food production, commerce and human behavior influence the development of new flu strains.
Flu viruses drift in a wide web of connections among their many hosts: humans, swine, birds and some wild animals (waterfowl, ferrets, feral cats and others). The links in the web are sometimes intimate and direct–farmers breathe the same air as their pigs, for instance. Often, though, viral connections are mediated by subtle forces in the environment: shifts in climate alter species balances and bring once-separated animal populations into contact; the endless competition between strains of microbes (bacteria, notably) affects the health of animals and humans, and that microscopic struggle responds to minuscule changes in social ties within or between species.
The dimensions and connectivity of this wide web are further affected by economic and political factors that normally receive short shrift in discussions of (and research on) human disease. Wealth disparities can force poor farmers to raise more stock on less land. When farmers live close to the animals they raise and slaughter, microbial dynamics shift and create opportunities for viral movement. When the poor are displaced altogether, a globally mobilized proletariat offers a vehicle for the spread of contagion far more worrisome than flu-infected travelers on airplanes.