An Epidemic Epidemic
These disease outbreaks are part of a disturbing global pattern. Earlier in this century, most infectious diseases were thought to be under control. Yet outbreaks are now occurring all over the world, in ever-greater numbers. Infectious and parasitic diseases are now responsible for almost half the deaths in developing countries.
Some of the diseases are emergent, like the viruses that cause Rift Valley Fever and Hepatitis C. Most of these emergent diseases are zoonotic, meaning that they can pass from animals to humans. Others are old enemies now reappearing in force, like tuberculosis, malaria, the plague, and measles. This is no surprise to scientists like Gretchen Daily and Paul Ehrlich, biologists at Stanford University who write, “Bacteria have such rapid life cycles, extraordinary abilities to swap genetic material, and intrinsic mechanisms of resistance derived from their evolutionary experience that the surprise really is that they did not all become resistant to our puny efforts sooner.”
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