Who can forget the SARS scare? Back in February 2003, Dr. Carlo Urbani, a physician with the World Health Organization (WHO), diagnosed a 48-year-old businessman in Vietnam with a new infection he named severe acute respiratory syndrome. Within six weeks of that diagnosis, SARS had infected people on six continents, killing both the businessman and Urbani along the way. The WHO issued an unprecedented travel advisory and released daily updates tracking the wildfire spread of the bug; by mid-year it had claimed some 800 lives.
SARS was later traced to an animal called the palm civet (a small mammal found throughout Southeast Asia), and while the threat was eventually contained, the chilling possibility of the modern global pandemic had come to stay. Research released this month at a conference I attended on agriculture and nutrition in New Delhi, India, suggests the likelihood for similar epidemics will only grow. One factor: Growing populations and higher incomes in the developing world are leading to more intensive animal-production and increasing numbers of domestic livestock.
It might be hard at first to see the connection between livestock and pandemics, but it’s there. Over the last four decades, said John McDermott, the deputy director general for research at the Nairobi-based International Livestock Research Institute, rising demand for meat, milk, and eggs among urban consumers in the developing world has fueled an enormous spike in livestock production. In Asia and Southeast Asia, for example, the number of chickens has gone from 1 billion in 1961 to an astonishing 9.6 billion today.
Such numbers, combined with rapid urbanization (as of 2008, fully half the human population lived in cities), raise the threat of so-called “zoonotic” diseases -- those transmissible between animals and humans. No less than 61 percent of all human pathogens, and 75 percent of new human pathogens, are zoonotic. Avian influenza, for example, was spread primarily by domesticated birds in high-density operations, and the Nipah virus spilled over to people from backyard pigs.
Livestock diseases threaten food security in the developing world, where protein availability is already limited, but when they “jump” from their animal hosts to humans, they pose a risk to us all.
Wealthy countries have invested heavily in surveillance and risk-reduction schemes to deal with such diseases -- a response, you might imagine, to a World Bank report saying an avian influenza pandemic could cost the global community some $3 trillion -- but in Africa and Asia, said McDermott, “the capacity of veterinary services to track and control outbreaks is lagging dangerously behind livestock intensification.” The challenge is to establish regulatory programs that will protect public health while avoiding the imposition of anything so onerous as to drive the world’s 450 million smallholder farmers underground.
Given the health issues that have resulted from our own voracious appetite for animal protein (antibiotic-resistant superbugs, anyone?), American consumers are maybe not in the best position to be dictating agricultural policy, but it seems reasonable to hope that as developing countries consider their animal-husbandry sectors moving forward, they’ll put concerns for human-health right up there with those for production size and profit.
