Turning Our Backs on Pandemic

Emerging infections diseases of the SARS/Ebola/HIV type are on the rise and, unfortunately, we in the affluent West are looking in the wrong direction. A team of scientists has studied the development of infections disease from 1940 to 2004 and your suspicions were right, the incidence and spread of these diseases is increasing.

Their study, published in the journal Nature, has identified a disease highway that begins in nature and then spreads through wildlife to livestock to humans. The past decades have witnessed rapid infringement on the environment, forest clearing for example, and a massive increase in livestock populations. In the result, what once was a 2-lane road has been transformed into a disease superhighway.

The researchers have produced a map (above) showing where the next major diseases are most likely to develop. These hotspots are those depicted in red while the least active regions are in green. They contend the West needs to put its disease focus on these tropical hotspots instead of simply worrying too much about what is happening at home.

While we tend to think of diseases such as HIV and SARS, the scientists identified 335 "emerging diseases" during the 64-year span of their study and they're sure there are plenty more to come.

“We are crowding wildlife into ever-smaller areas, and human population is increasing,” said coauthor Marc Levy, a global-change expert at the Center for International Earth Science Information Network (CIESIN), an affiliate of Columbia University’s Earth Institute. “The meeting of these two things is a recipe for something crossing over.” The main sources are mammals. Some pathogens may be picked up by hunting or accidental contact; others, such as Malaysia’s Nipah virus, go from wildlife to livestock, then to people. Humans have evolved no resistance to zoonoses, so the diseases can be extraordinarily lethal. The scientists say that the more wild species in an area, the more pathogen varieties they may harbor. Kate E. Jones, an evolutionary biologist at the Zoological Society of London and first author of the study, said the work urgently highlights the need to prevent further intrusion into areas of high biodiversity. “It turns out that conservation may be an important means of preventing new diseases,” she said.

While new diseases are most likely to come from the tropics, the West has played a huge role in the evolution of the most lethal diseases. We have been so undisciplined in our use of antibiotics that we've created new, increasingly drug-resistant strains. At the same time, modern transportation and industrial agriculture have accelerated the spread of emerging diseases.

The report argues that the West needs to take a more prophylactic approach to emerging diseases, pushing the front lines of detection and intervention to the hotspots themselves instead of waiting for these diseases to arrive at our own borders. We also need to explore the role that conservation of remaining tropical forests can play in reducing the rate of disease emergence.