Scientists studying oysters along America's Atlantic Coast have discovered a possible link between climate change and an increase in the number of seafood lovers getting sick from eating shellfish.
Researchers at the University of New Hampshire (UNH) have found a new strain of the bacteria vibrio parahaemolyticus, the world's leading culprit of contamination in shellfish that, when eaten, causes diarrhoea, vomiting and abdominal pain. In rare cases, people have died from contracting lethal septicaemia.
Cheryl Whistler and her colleagues discovered the new strain ST631 and detailed their findings in the Journal of Clinical Microbiology and the findings build on earlier studies showing the role climate change is playing in the spread of pathogens like vibrio parahaemolyticus.
"We were surprised to learn that it was so widespread," she said, adding that ST631 can thrive in a range of water temperatures from Florida to Prince Edward Island and the Gulf of Maine, suggesting a link to climate change.
Previously only one strain of the bacteria was blamed for this type of food poisoning, which Whistler said is on the rise in New England and already is responsible for an estimated 45,000 cases in the US each year.
"It wasn't understood that there was a strain that lived in the Atlantic already that was causing increasing infections," said Whistler, the director of the university's Northeast Center for Vibrio Disease and Ecology.
Rita Colwell at the University of Maryland did not participate in the UNH research but led the study published in the Proceedings of the National Academy of Sciences, and praised Whistler's work. She said the UNH study contributes to a growing body of evidence that global warming has "a measurable human effect."
"They have done a very nice job doing sequencing of the DNA and getting the DNA fingerprints so to speak," Colwell said.
"The important aspect of it is they have good evidence that the strain that is circulating in the US is in fact different from strains that are circulating globally ... They have also been able to track infections with it."