Deadly Waterborne Bacteria Are Surging Because of Climate Change


Climate experts have long warned about the myriad ways that warming temperatures can negatively affect human health. Now that global temperatures are predicted to increase by 1.5°C by the 2030s, that risk is becoming increasingly real.

One long-held prediction that appears to be coming true—according to the results of a new study—is how climate change can potentially expand concentrations of bacteria that thrive and spread through warm U.S. waters and cause an infection with a particularly high fatality rate.

In a paper published in Nature Scientific Reports, scientists at the University of East Anglia in the U.K. analyzed infections that were reported to the U.S. Centers for Disease Control and Prevention (CDC) from 1988 to 2018 caused by Vibrio vulnificusa type of bacteria that lives in sea or brackish waters warmer than 68°FVibrio vulnificus kills approximately 20% of the healthy people, and 50% of those with weakened immune systems, that it infects—though it’s rare in the U.S. (for now). People can get infected either by eating raw shellfish such as oysters or by exposing small cuts or wounds to waters where the bacteria live; eating infected shellfish can cause diarrhea vomiting, fever and chills, while infected wounds can lead to serious skin infections. There is no strong evidence that antibiotics can control the infection, but doctors may prescribe them in some cases.

The researchers focused on wound-based infections, since those are easier to pinpoint to specific locations. They then created models predicting the pattern of new infections over the next few decades. One model assumed a more sustainable trajectory, in which emissions would be relatively low and the rise in global temperatures would be slower. Another assumed more of a worst-case scenario, in which containing emissions and addressing warming were low priorities for nations around the world.