Manmade climate change may be driving tummy bug outbreaks in Europe, claim scientists
Vibrio bacteria, which is normally found growing in warm and tropical waters, now thrives in the Baltic Sea Bacteria strains will multiply as seas warm, predict researchers
The bacteria causes illnesses from cholera to gastroenteritis
09:55 GMT, 23 July 2012
Tummy troubles: There is increasing concern that climate change may be driving bacterial waterborne infectious diseases
Climate change is driving the growth of a group of water-borne bacteria in northern Europe that can cause illnesses from cholera to gastroenteritis.
An international team examined sea surface temperature records and
satellite data, as well as statistics on Vibrio cases in the Baltic.
Vibrios is a group of bacteria which usually grow in warm and tropical marine environments. The bacteria can cause various infections in humans, ranging from cholera to gastroenteritis-like symptoms from eating raw or undercooked shellfish or from exposure to seawater.
The researchers found the number and distribution of cases in the Baltic Sea area was strongly linked to peaks in sea surface temperatures. Each year the temperature rose one degree, the number of vibrio cases rose almost 200 per cent.
Study author Craig Baker-Austin from the UK-based Centre for Environment, Fisheries and Aquaculture Science, said: 'The
big apparent increases that we've seen in cases during heat wave
years… tend to indicate that climate change is indeed driving
Climate studies suggest that rising greenhouse gas emissions made global average surface temperatures increase by about 0.17 degrees Celsius a decade from 1980 to 2010.
The Vibrio study focused on the Baltic Sea in particular because it warmed at an unprecedented rate of 0.063 to 0.078 degrees Celsius a year from 1982 to 2010, or 6.3 to 7.8 degrees a century.
'(It) represents, to our knowledge, the fastest warming marine ecosystem examined so far anywhere on Earth,' the paper said.
Many marine bacteria thrive in warm, low-saline sea water. In addition to warming, climate change has caused more frequent and heavier rainfall, which has reduced the salt content of estuaries and coastal wetlands.
Vibrio cholerae – some strains can cause cholera: Each year the temperature rose one degree, the number of vibrio cases rose almost 200 per cent
As ocean temperatures continue to rise
and coastal regions in northern regions become less saline, Vibrio
bacteria strains will appear in new areas, the scientists said.
Vibrio outbreaks have also appeared in
temperate and cold regions in Chile, Peru, Israel, the northwest U.S.
Pacific and northwest Spain, and these can be linked to warming
patterns, the scientists said.
Rising temperatures: The Baltic Sea represents the 'fastest warming marine eco-system examined so far anywhere on earth'
'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,' he added.
Previous Vibrio outbreaks in colder regions have often been put down to a sporadic event or special conditions rather than a response to long-term climate change.
This is because the effects of global warming can be more pronounced at higher latitudes and in areas which lack detailed historical climate data, the study said.
Writing in the journal Nature Climate
Change the authors, from Britain, Finland, Spain and the U.S., said: 'There is increasing concern regarding the role
of climate change in driving bacterial waterborne infectious diseases.'
However Baker-Austin added a note of caution saying there are still 'huge data gaps in that area which need addressing.'