Vibrio cases have been found to surge along with the temperatures of the Baltic Sea. (Photo: Stock File/FIS)
Climate change directly linked to spikes in bacterial infections
Wednesday, July 25, 2012, 04:10 (GMT + 9)
New research shows that man-made climate change is the main factor behind an emergence of bacteria in seawater in Northern Europe and other parts of the world.
An international group of researchers related those recent cases of gastroenteritis that affected people who have consumed raw or undercooked seafood exposed to seawater in the Northern European with the outbreak of the bacteria Vibrio. In general, these pathogens develop in tropical and warm marine environments and can cause cholera and gastroenteritis-like symptoms.
The paper has been published in the journal Nature Climate Change.
The team -- comprised of researchers from Britain, Finland, Spain and the US -- examined the temperatures of the Baltic Sea’s surface in combination with satellite data and statistics on Vibrio cases in Northern Europe.
They found that the number of Vibrio cases surged along with the temperatures of the Baltic Sea: a one degree rise in water temperature corresponded with a nearly 200 per cent spike in the number of Vibrio cases in the region.
“The big apparent increases that we’ve seen in cases during heat wave years (…) tend to indicate that climate change is indeed driving infections,” said Craig Baker-Austin with the Centre for Environment, Fisheries and Aquaculture Science (CEFAS) and one of the paper’s authors, Reuters reports.
Climate change caused by greenhouse gas emissions have made surface temperatures across the world’s oceans increase by 0.17 degrees celsius from 1980 to 2010, previous research has shown.
Of all these oceans, the Baltic Sea has experienced the greatest instances of warming at a rate of 6.3 to 7.8 degrees celsius per 100 years.
“(It) represents, to our knowledge, the fastest warming marine ecosystem examined so far anywhere on Earth,” the paper reads.
Several aspects have led up to this Vibrio-rich environment: As the climate changes and the seas get warmer, rainfall becomes heavier and more frequent, which reduces the salt content in coastal wetlands and estuaries. In turn, this creates a warm, low-saline environment where numerous marine bacteria can flourish.
As the oceans continue to get warmer, these Vibrio-friendly conditions will begin to expand across Northern Europe and, thus, the scientists believe Vibrio outbreaks will begin to emerge in new areas.
These kinds of outbreaks have even started to appear in typically cold-water areas such as Chile, Israel, Peru and the US Pacific Northwest. These outbreaks have been blamed on special conditions or sporadic events, but now these researchers are discovering that gradual global warming could be the culprit.
“Very few studies have looked at the risk of these infections at high latitudes,” Baker-Austin said. “Certainly the chances of getting a vibrio infection are considered to be relatively low, and more research is focused on areas where these diseases are endemic or at least more common.”
By Natalia Real