On Beyond Zika

Like everyone else who has heard the news about it, I find the rapid spread of the Zika virus extremely alarming. The newly recognized capacity of this virus, which historically has caused mild, self-limited infections in adults, to induce microcephaly, a terrible birth defect, is nothing less than devastating. To date, Brazil has borne the brunt of this development, with thousands of newborns affected. But the virus has now been identified in at least 20 countries in the Americas. As I write this, the World Health Organization is scrambling to catch up with the global proliferation of this emerging infectious disease, and poised to declare a public health emergency.

As inevitably occurs when a new health threat emerges, this one is generating lots of media attention, with coverage in both the scientific literature and popular press. Predictably, much of that attention is specific to the Zika virus itself, with relatively less addressing the general circumstances that foster our vulnerability to such crises. Both topics matter.

This particular virus was originally identified in Uganda some 70 years ago, first in monkeys, then in people. That likely makes it a zoonosis at the start, a disease transmitted to our species from another. The vector shuttling between the two was the Aedes mosquito, the bite of which transmits the virus. The first human who got Zika, in other words, was likely stung by a mosquito that had drawn blood from an infected monkey not long prior. For the past half century, Zika has generally been limited to Uganda and Tanzania, with isolated outbreaks seen occasionally in other parts of the world.

That there is no specific treatment for Zika, named after the forest in Uganda where it was first identified, and no vaccine, is because until now the virus has not inspired much global concern, partly because it was not all that serious, and partly no doubt because it was “over there.”

Exactly why this infection, in the same family with the viruses that cause yellow fever and dengue fever, is suddenly implicated in an epidemic of birth defects is a work in progress. One likely explanation, for which there is evidence, is an evolutionary change in the virus itself. That may be compounded by exposure of new human populations, with perhaps different genetic vulnerabilities; transmission at a new scale; or other factors yet to be determined. We are currently on the steep part of the learning curve, racing to catch up with current events.

That’s a familiar race. We ran it for Ebola, too; and SARS, and MERS. Whatever the next outbreak is, we will likely need to run it again. We keep getting left behind.

For now, practical advice about Zika is limited, and mostly of the “easier said than done” variety. Countries mired in the outbreak are advising against pregnancy. We are all encouraged to avoid mosquito bites. Travel advisories are being issued.

As we confront Zika, but mostly fail to think beyond it, I am tempted to compare this predicament to its analogy in the space I work in all the time, nutrition. For decades, we have shifted from one nutrient fixation to the next- fat, carbohydrate, sugar, gluten- and generally been left behind by the big picture. The result has been a flurry of misguided, mono-nutrient activity, and no meaningful improvement in our prevailing vulnerability to the marketing of junk food. We just keep encouraging the invention of new varieties of junk food, and reaping what we sow. At present, we have sown a bumper crop of gluten-free junk.

The situation with emerging infections is much the same. We react to each as if the particular bug is the entire problem, while paying far less attention to fundamentals of public health practice and preparedness that account for vulnerability not just to the last outbreak and the current one, but the next. That same tendency- the neglect of public health until we have cause to think about panic, outrage, or both- is on display in Flint, Michigan as well.

The implications of the Zika crisis are not confined to this particular pathogen, for there will be a next, and a next. I am reasonably confident that an acute concentration of resources and ingenuity on Zika will result in a vaccine. Welcome though that will be, perhaps even by some prone to misguided railing against vaccination, it will do nothing to resolve our basic vulnerability.

As the climate changes, and we are past the point of debating the fact of it, the distribution of pathogens is changing too. We have seen this many times already, and are thus forewarned: we will be seeing it again. Whether or not we are forearmed depends on how we react, and allocate resources.

There is, thankfully, ever more attention to how the more than 7 billion of us Homo sapiens are roughing up the planet’s remaining pristine places. There is less, however, to the ramifications of it. For one thing, more people in more places inevitably means more encounters with bugs formerly unencountered. For another, the disruptions of ecosystems often circle back to bite us.

Another issue, relevant to almost every major peril our species now faces, is the very fact that there are more than 7 billion of us, and rising fast. There aren’t just humans in ever more places, there are ever more humans in ever greater concentrations everywhere. Whatever else we may be, we are just one, vast Petri dish to our pathogens. Plagues are a product of dense populations and unprecedented population densities will predictably mean new plagues.

And then finally, there is our proclivity to disperse into our competing factions: nations, religions, political parties, and so on. The distinctions between “us” and “them” may matter enormously to us, and them, but to the Zika virus, we are all the same, accommodating host.   From the bug’s eye view, there is no “over there.” In a world of increasing global travel, the bug is right.

In our fantasies, we acknowledge that. The usual scenario is a science fiction adventure in which humanity is attacked by a scourge from without- an extraterrestrial menace- and that common threat provides common cause, and unifies us. We overcome our differences to defend our home, and our shared humanity.

From what we know about the universe, the probability of extraterrestrial visitation, hostile or otherwise, seems vanishingly remote- for reasons entirely unrelated to the probability of life on other planets. If interested in the mind-boggling barriers to such inter-stellar concourse, I recommend Lawrence Krauss’ book, A Universe from Nothing, as a good place to start.

But the threats to us all, threats blind to the borders of nations, and deaf to the distinctions of ideology, are already here. They have no need to traverse the distance between stars.

The faults we must overcome for our own security lie not with exotic perils from distant stars, but with dangers evolving right here at home. The faults lie most particularly with ourselves. Ironically, Zika is named after a forest, and one of our great liabilities is the recurrent failure to see the forest through the trees. We react to each new pathogen, while doing little to anticipate the next.

We often fail as well to perceive and prioritize our common humanity. We rally to the defense of it when fighting the threats of science fiction fantasy, but miss the opportunity to do so in the face of real, clear, present, and inevitably recurrent danger.

-fin

David L. Katz, MD, MPH, FACPM, FACP, FACLM

Director, Yale University Prevention Research Center; Griffin Hospital
President, American College of Lifestyle Medicine

Founder, The True Health Initiative

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