The pathogens cause infections that kill millions of people each year and often go undiagnosed. Even when identified, a growing number of infections is resistant to the current crop of drugs.
Climate change is pushing temperatures higher in states with large numbers of farmworkers, says one researcher. Current rules are inadequate to address the threats to safety.
Globalization and ecological disturbances have knocked down many of the natural barriers that keep viruses at bay. Smart conservation practices can change that.
