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Human health needs a common defense. Too bad we blew it

Antibiotic-resistant microbes highlight our overuse of the world’s shared resources

K. pneumoniae bacteria in a respiratory tract.

It began with a broken leg. On a long journey through India, a Nevada resident in her 70s fractured her femur. Complications took her to several Indian hospitals. Eventually, she returned to the United States, but her problems followed her home. In August of last year, she had to be hospitalized once again. In Reno, she presented with systemic inflammatory response syndrome — a condition that can produce a racing heart, frantic breathing, and other symptoms. The syndrome often marks a powerful immune response to an infection. So her doctors looked for a microbe that might have provoked her increasingly devastating response.

They found it: Klebsiella pneumoniae, a bacterium that occurs naturally in soils and can live quite peaceably in human guts, mouth, or skin. If it makes its way elsewhere, it can cause disease — often pneumonia, but a number of other conditions as well. Until recently, the treatment for a K. pneumoniae infection was simple and effective: Give the patient one of a range of common antibiotics. Accordingly, her medical team tested the patient’s bacterial samples to see which drug would work.

The answer came back: none of them. Her microbes were resistant to all 14 antibiotics available in Reno. The hospital sent samples to the federal Centers for Disease Control and Prevention, and the tests there showed that these bugs were resistant to 12 more drugs. That was it. There was nothing else available in the United States that could touch this disease. (For more details on this unsettling case, see Helen Branswell’s coverage in The Boston Globe’s sister publication, STAT.)

In January, the CDC reported that the woman had died in early September, killed by a superbug for which there is no cure.


Each death, of course, is a private grief for a family and community. This one has broad public meaning as well. It’s possible to say it was just bad luck: A traveler falls and then happens to come into contact with a microbe too tough for modern medicine to handle. But it’s just as true to say that billions of human choices made over the last 70 years killed this woman.

Told that way, the story of this death is a tragedy, in the classical sense of the term: not simply an individual loss, but the last act in a series of events that remorselessly progressed to a terrifying conclusion. After their introduction in the 1940s, antibiotic drugs seemingly crushed the scourge of microbial disease that had until then been humanity’s most formidable killer. This catalog of drugs, available across national borders, became a shared resource for all. But over time, the overuse of antibiotics allowed drug-resistant microbes to emerge, thereby putting that resource at risk.

There’s a name for this sort of loss: the “tragedy of the commons,” a phrase coined by the American biologist Garrett Hardin. The term “commons” has its roots in communally used land in feudal England; the Boston Common has a similar origin. Antibiotic resistance is just one of many examples of a modern common in crisis.


Together, these crises have created new threats to human well-being and, as a death in Reno confirms, have resurrected some old ones, too. Collective action is required to address them. Tragically, current American politics is thoroughly ill-placed to provide it.

The idea of the commons is deeply woven through the history of the English countryside. Shakespeare captured this idyllic approach to nature’s wealth in “As You Like It,” when the shepherd Corin explains to the cynic Touchstone the joys of his life. “I earn that I eat, get that I wear,” he says, adding that “the greatest of my pride is to see my ewes graze and my lambs suck” — in the unowned, readily shared Forest of Arden.

There can be trouble in such an Eden, as Hardin pointed out in an influential 1968 paper. Hardin asked what would happen if access to a commons were truly unfettered — if Corin and every other villager ran as many sheep as they could there. In such cases, Hardin argued, the endgame is obvious: Too many animals would eat too much fodder, leaving the ground bare, unable to support any livestock at all.

The evolution of resistance to antibiotics fits that story perfectly. The first modern bacteria-killing drug, penicillin, came into widespread use in 1944, as American laboratories raced to produce millions of doses in time for D-Day. The next year, its discoverer, Alexander Fleming, used his Nobel Prize lecture to describe precisely how this wonder drug could lose its power, telling the sad tale of a man who came down with a strep infection. In his tale, Mr. X didn’t finish his course of penicillin, and his surviving microbes, now “educated” (Fleming’s term), infected his wife. When her course of penicillin failed to eradicate these now-resistant microbes, Mrs. X died — killed, Fleming said, by her husband’s carelessness. It took just one more year for this fable to turn into fact: In 1946, four American soldiers came down with drug-resistant gonorrhea, the first such resistance on record.


Since then, human decisions, most importantly the overuse of antibiotics in agriculture and over- and mis-prescription of the drugs for human patients, have created the future that Fleming feared. Multi-drug-resistant tuberculosis is a global scourge, and the first recorded deaths from TB untouchable by all known agents occurred in 2003. In 2015, E. coli displaying a novel resistance mechanism to the antibiotic colistin showed up in pigs, in raw meat, and in a handful of human patients in China — and colistin-resistant microbes have since spread to countries around the globe, including the United States.

This is potentially disastrous. Colistin is a drug of last resort for several classes of infections. In the language of the commons, we have drastically overgrazed our communal field of antibiotics, and humankind will pay the price. A team of experts convened by the British government reported last May that the evolution of resistance in microbes kills at least 700,000 people worldwide each year. Unremedied, that toll will worsen. By 2050, the same study warns, the loss could balloon to 10 million a year — more than the expected death toll from cancer.


Antibiotics are not the only modern-day commons at risk. The atmosphere is another. It can be disrupted at the local level — just ask the masked pedestrians making their way through literally deadly air pollution in any number of megacities. Globally, the cumulative impact of every drive to work, each cooking fire, and every gallon of oil burned to heat a home can be read in the daily measurements of atmospheric carbon dioxide at the observatory on the flanks of the Mauna Loa volcano in Hawaii: 408.28 parts per million as I write this, up from 404.2 a year ago (and 315 as first observed in 1958).

While the full consequences of this use — or abuse — of a truly global commons will only emerge over time, new risks emerge with ever passing year: increasingly damaging storms, droughts, and floods. Yet more fundamental shifts in the earth’s climate system are in sight, too. Potential changes in the circulation of the ocean or atmosphere would radically alter the weather patterns on which human societies have come to depend.

There are other modern commons that are less immediately visible, but remain at risk. The CDC lists 16 vaccine-preventable diseases children face — measles, mumps, whooping cough, and more. Vaccination against such illnesses doesn’t just protect the kid getting jabbed. When enough of any group is immune to a given illness, so-called herd immunity emerges. The disease agent can’t get enough of a foothold in a community to threaten those who haven’t been vaccinated (such as infants too young for the shots or people with compromised immune systems). Those who choose not to vaccinate exploit the communal immunity others’ shots produce.

But that only works as long as vaccination rates remain high. Over the last two decades, objections to vaccination have spread, partly in response to a false claim of a vaccine-autism link published in 1998, and outbreaks of preventable illnesses have begun to recur. Here, the commons is the public’s willingness to accept vaccination; the exploitation lies in the use of others’ immunity to protect oneself without vaccination. The tragedy of this commons would come if herd immunity were to fail. If that happens, more and more people will fall ill needlessly. Some will die.


The actual experience of traditional commons suggests that, under the right circumstances, a commons can be remarkably robust. Garrett Hardin’s hypothetical villagers had unfettered access to the commons, much as doctors and farmers have been little deterred in their use of antibiotics. But access to the village green in historic England was never so unrestricted. Specified rights were clearly defined and explicitly allocated. There were rights of pasture — the allowance to run different kinds of livestock in specified numbers — and rights to fish, gather wood, cut sod, and so on, with each household’s share explicitly constrained.

Anyone reckless enough to take more than their share could face swift and rough correction. Just ask the rabbit-keepers of Charnwood forest in Leicestershire. Some of the wealthiest landowners around that commonly held woodland expanded their commercial rabbit operations, which led to the overgrazing of the best pasturage. The local villagers rioted and marched, advancing through the common and declaring that “all rabbits are vermin.” They dug up the warrens and killed and sold any rabbits they could catch. When this defense of traditional rights went to court, the rioters won.

Long-lived commons were always regulated. Those who depended on them had to accept restraints on their freedom of action, and such agreements had to extend to all those with access to whatever was being protected. Contemporary global commons require the same: international regimes and broad agreements to preserve what individual nations cannot own but could wreck. Market-based responses can work in certain circumstances. It’s possible, sometimes, simply to privatize formerly public resources. That’s what happened when most English commons were “enclosed” and divvied up among local landowners, and it is the theory behind, for example, proposed responses to the traffic jams of a commonly shared free road that would impose toll payments that allow some drivers to rent access to private, open lanes.

Whatever one may feel about the justice or social consequences of such approaches — Harvard philosopher Michael Sandel’s “What Money Can’t Do” has made a powerful argument against such solutions — many crucial modern commons don’t readily privatize. Cash can encourage the building of more roads, but it’s difficult indeed to price microbial resistance. Enclosing the atmosphere or the ocean is impossible, so it will take some international form of regulatory constraint to slow or stop the accumulation of carbon in the world’s climate system. Herd immunity can’t readily be “owned.”

To ensure the long-term health of each of today’s commons — our shared systems of survival — the way we use them has to be constrained. How that regulation occurs can vary. A carbon tax, essentially putting a price on pollution, may be an effective way to address climate change. Preserving the antibiotic commons may likely require multiple approaches, from boosting support for research into new antimicrobial drugs and treatments, to negotiating international agreements restricting antibiotic use in agriculture and uncontrolled distribution of antibiotics to the public, to training doctors to avoid prescribing unneeded or ineffective drugs.

To save certain human goods, we must accept the idea of restricting some human choices.

Such a commitment does not now exist at the center of American power. President Trump’s paint-by-numbers approach to rule-making — his order that federal agencies cut two regulations for every new one they issue — makes a mockery of the notion of regulatory goals to deal with crises within our physical and biological habitats. “America First” rhetoric is utterly at odds with the global nature of critical dangers. Microbes trade resistance from strain to strain and know no borders; winds blow to and from wherever they will; the same oceans lap against every shore. Nothing in the statements of the Trump administration or the Republican leadership in Congress suggests that the current American government recognizes such natural systems as inherently global and jointly held inheritances, in need of explicit care.

Last fall, a woman in Reno died of a disease that until recently was easy to cure. That’s sad. But this death was not inevitable, if only America and nations around the world had acted on a problem that was understood more than 70 years ago. Given what we know now, how many more such tragedies are we willing to tolerate?

Thomas Levenson is a professor of science writing at MIT and an Ideas columnist. His latest book is “The Hunt for Vulcan.”