A sizable shift in people's diets could help prevent the brewing influenza pandemic
We’ve heard it before: Eating less meat is better for the planet.
In May, China’s health authorities went so far as considering this in their new dietary guidelines, which advised a 50 percent reduction in meat consumption. (It isn’t actually doing anything to enforce this advice, just suggesting it.)
The announcement was lauded for its potential impact on stemming climate change and keeping global warming under the levels agreed upon in 2015’s Paris accords.
The notion that we share a collective responsibility, that a change in something as simple as what we consume could move the needle on an accelerating global crisis, was powerful. Yet, hidden in the guidelines was an unanticipated but equally powerful benefit. It’s not just climate change that could stand to benefit from meatless plates. This same action could spark positive change in addressing another defining challenge of our time: pandemic influenza.
In early June, a live bird market in Hong Kong turned up positive for the H7N9 influenza virus, shuttering the market and triggering the destruction of thousands of birds. In April, another worrying signal from the region—a suspected cluster of human cases from eastern China, hinting at possible human to human spread, a pre-condition for pandemic emergence. Authorities are closely watching this virus, wary of the experience from 2009 when an H1N1 virus turned up in Mexico, and within six months, had achieved near global distribution as the first influenza pandemic of the 21st century.
Nearly 20 years ago, Hong Kong was present at the birth of a different influenza virus: H5N1 avian influenza. That virus remains entrenched in poultry across Asia, charting a slow-burning course that has exacted a devastating toll: 450 human deaths, over 400 million birds destroyed, and global losses exceeding $20 billion.
There is a rhythm to the influenza pandemic clock, keeping time with machine-like precision. Time rolled out in long sheets and then ruptured with disturbing regularity: 1918, 1957, 1968, 2009. It’s tempting to be lulled into complacency by that rhythm, to awake only in response to the occasional piercing alarm, which history tells us is sure to come. But what if we could slow, or even halt, the clock? What if we could permanently silence the alarm?
As China’s new guidance demonstrates, a preventative approach aimed at disrupting the drivers of global threats, including pandemics, is achievable. But it will take our individual and collective action, and a proactive investment in strengthening systems.
To appreciate the efforts necessary to mitigate pandemic influenza risk, we must consider from where—and how—these viruses emerge. Influenza viruses are largely of animal origin, and their road to pandemic emergence requires transmission from animal to human. In fact, influenza pandemics of the last century all directly, or derivatively, originated in animals, primarily poultry and swine.
There is a rhythm to the influenza pandemic clock, keeping time with machine-like precision.
Influenza is a highly unstable virus with a propensity for mutation and the ability to produce new variants from mixing two or more strains. A regular dance of viral genes capable of finding their way into a suitable vessel—a pig or duck, say—before pairing in a volatile mix to produce a new variant. Many of these variants will be only marginally capable of infecting humans. Others will be exquisitely suited: the pandemic candidates. This is what viruses do. Infect. Copy. Repeat. The virus has time on its side. Like a machine, it will continue casting out variants—new strains potentially capable of human-to-human transmission—until conditions are in place to grind it to a halt.
Today, global conditions favor the virus in unprecedented ways. The human population has soared to over 7.3 billion and is on track to reach 9.7 billion by 2050. As both population and wealth increase, so too does the demand for animal protein. Between 2000 and 2030, demand is expected to leap 150 percent and 200 percent for pork and poultry, respectively, in Southeast Asia. To feed this demand, we are producing more animals at a faster rate than at any time in the history of animal domestication. This places more of us in frequent contact with the livestock that are among the sources of new influenza viruses. The farmer tending to sick hogs and the butcher slaughtering infected chickens in an open market where scores of people transit—each an opportunity for an influenza virus to cast its lot with a new host: us.
In parallel, we are increasingly living in dense urban megacities connected by a network of democratized air travel that can place anyone, anywhere within 24 hours. These megacities are mirrored by intensive livestock production systems that house tens of thousands of animals together. Historically, limited infrastructure and less-intensive production hindered a pandemic-capable virus from onward spread. The borders of its empire were the farm gates or the edge of town. But from the vantage of a newly minted influenza virus today, our livestock production systems, megacities, and their urban sprawl have effectively become untapped rivers, deltas, and great oceans of hosts, with little to no pre-existing immunity. Today, the empire has no limits.
History reminds us that such a pandemic influenza event is not hypothetical. Both the threat, and the magnitude of expected impact, are excruciatingly real—and larger than many other issues at the forefront of the collective conscious. Recent work places the cost attributable to a moderately severe influenza pandemic at $570 billion annually, or 0.7 percent of global income. By comparison, the authors highlight, the cost from the impact of global warming has been estimated at 0.2 to 2 percent of annual global income.
So what can we do to limit the risk?
First, we should rethink our diets. Are we consuming too much meat? Per unit of nutrition, livestock are energy-hungry commodities. Livestock production requires land clearance. And over 50 percent of emerging diseases such as influenza have been attributable to land-use change and agricultural intensification. A growing body of research has demonstrated that dietary preferences favoring more plant-based foods and less animal protein improve individual health, but importantly, also yield planetary health dividends: protection of land and fresh water resources, enhanced biodiversity conservation, reduced carbon output, and, yes, mitigated risk from pandemic disease like influenza. We have the power to shift this dynamic at every meal.
Second, we need to reimagine our existing food-processing systems. Reducing the amount of meat we consume will only be partially effective if animals are still produced and processed in manner that favors viral spillover. Throughout much of the world, people maintain intimate contact with their livestock from rearing through slaughter and consumption. Each interaction is an opportunity for influenza to move from animal to human. Where possible, a shift toward central slaughter and processing will minimize risk. Government and industry dialogues, supported by the U.S. Agency for International Development and Australian Department of Foreign Affairs and Trade, and brokered by the Food and Agriculture Organization of the United Nations, are underway across Asia to consider how systems can be made safer. If we instead continue to use 19th century marketing structures to feed a 21st century population’s dietary demands, we can expect more of the same.
Where this shift is not feasible, there are still tools in the kit. Nearly two decades of experience with avian influenza in Asia has shown what works to reduce risk of viral spillover from animals to humans in markets.
Third, we must be prepared to rapidly detect and contain new emergence events. This means adequately resourced and robust public health infrastructure inclusive of both human and veterinary capacities. It means targeted surveillance in the highest-risk livestock and wildlife populations—and the people who interact with them. It means expanding coverage to fill gaps where surveillance systems are inadequate or nonexistent. It means investigating clusters of unusual illness wherever and whenever they arise. And it means that diagnostic testing does not start and end with influenza, but screens for other viruses of pandemic potential to capture them at their earliest debut on the global stage.
The still-smoldering Ebola epidemic in West Africa serves as exhibit A that viruses will exploit weak systems wherever they are present. Based in part on reviews following these recent events, the World Bank launched in May a Pandemic Emergency Financing Facility intended to provide immediate resource availability to address a localized outbreak before it spirals into a pandemic. Embedded in the facility are structures to incentivize a systems-strengthening approach—enhancing preparedness, and boosting national capacities to rapidly identify and contain future outbreaks.
We should be under no illusion that achieving such change will be simple or inexpensive. The World Bank estimates a $3.4 billion annual investment in national public health systems is needed to achieve these capacities globally. Yet, even when only half of pandemics are averted that investment produces an annual rate of return between 44 percent and 88 percent, outpacing most global equity indices over the last decade: impressive returns for financing a global public good. The alternative—to await the alarm and scramble a containment effort—will be more challenging and costly by orders of magnitude.
Influenza viruses aren’t going anywhere. The endgame is not eradication. But we have a shared responsibility for securing a future where the existential threat of a pandemic seems absurd. And as China demonstrated in May, we have the capacity—individually and collectively—to channel the course of events, to slow and halt that seemingly immutable clock.
Read the original article on Slate. Copyright 2016. Follow Slate on Twitter.