The old adage about not eating oysters in months that contain the letter “R” may have to be updated.
Two foodborne pathogens — Vibrio and Cryptosporidium — are becoming more prevalent as a result of climate change, according to a report from Nutrition Action Healthletter, the flagship publication of the Center for Science in the Public Interest, a consumer advocacy nonprofit.
Vibrio are bacteria that can infect shellfish in coastal waters. The bacteria cause vibriosis, a form of food poisoning that causes an estimated 80,000 illnesses and 100 deaths annually, according to the Centers for Disease Control and Prevention. Some forms of vibrio are also responsible for cholera, and the bacteria can also cause a skin infection.
Typically, Vibrio becomes more common in the summer months between May and October, and health experts generally recommend avoiding raw shellfish during those times.
Foodborne bacteria have been traveling further north
But because the bacteria are so sensitive to temperature changes in water, they’ve been spreading further north and increasing in prevalence over the last 50 years.
“We’re finding Vibrio farther up both the West and East Coasts of the United States and even in Alaska,” Glenn Morris, director of the Emerging Pathogens Institute at the University of Florida, told Nutrition Action Healthletter.
Heavier rainfall also helps spread microscopic parasites
Scientists are also concerned about how weather affects another water organism, Cryptosporidium. Heavier rainfall as a result of climate change could wash these microscopic parasites out of contaminated soil and into drinking water supplies and groundwater, researchers found.
The parasite causes the diarrheal disease cryptosporidiosis — the symptoms of which can be especially severe — and even fatal — for people with compromised immune systems.
Previous research has suggested that other foodborne pathogens could become more common as a result of climate change. A study released in 2012 by the European Centre for Disease Prevention and Control indicated that salmonella, campylobacter and E. coli all thrived in warmer temperatures.
However, not all hope is lost: the European Centre for Disease Prevention and Control report indicated that public health efforts have nonetheless been successful in reducing the infection rates from these pathogens, suggesting that humans may be able to counteract climate change’s impact in this arena successfully.