The Microbiological Havoc of the Anthropocene

In the summer of 2004, many passengers traveling aboard the Spirit of Columbia, a 143-foot cruise ship in Alaska's Prince William Sound, unexpectedly came down with intense bouts of nausea, vomiting, and—it got pretty gross—explosive, watery diarrhea. Seasickness is one thing. This was much worse. According to a study later published in the New England Medical Journal, epidemiologists traced the cause to a disease found in raw oysters, Vibrio parahaemolyticus. It was an unprecedented outbreak; the microbe had never been seen that far north.

“This is one of the first instances we’re seeing of a waterborne disease actually changing its range, and that’s what’s so significant,” Paul Epstein, a director of Harvard Medical School’s Center for Health and the Global Environment, told me. “It’s part of a larger picture of infectious diseases on land changing their ranges.”

Global climate change is undeniably reshaping the world around us, melting ice caps, causing coastal flooding, fomenting storms with increasing intensity, and leaving indelible stratigraphic signals in ice cores and sedimentary rocks. But the associated risks are rippling through the world’s microbial community—Salmonella, Giardia, and Fasciola—with a measurable impact on our food supply. As Dr. J. Glenn Morris, the director of the Emerging Pathogens Institute at the University of Florida, told me, “Vibrio are the poster child for the impact of climate change on pathogens.”

In his latest book, Changing Planet, Changing Health, Epstein writes that extreme weather affects the timing and intensity of infectious diseases, contributing to everything from E. coli to Cryptosporidium. Warming has been linked to increases in asthma, allergies, and mycotoxins in corn and peanuts.

So, more than just crop failures and the associated rise in food prices, unchecked, global warming poses clear threats for safe food. And yet the process is only beginning to play out.

Top image via Janice Carr/CDC. Bottom image via "Climate anomalies and the increasing risk of Vibrio parahaemolyticus and Vibrio vulnificus illnesses" ©2010 Elsevier.