Disease 'migrates' as world warms

Posted: 12 October 2006

Climate change is exacerbating the spread of infectious diseases, according to new research.

Warming temperatures are causing organisms to migrate, Professor Paul Hunter told a conference in the UK. In Europe, ocean swimmers have been infected with illnesses normally associated with warmer waters.

And Professor Hunter warned not enough was being done to monitor the spread, due to the warming of the Earth, of big killers such as malaria in Africa.

Malaria mosquito
Malaria mosquito
Climate change may cause malaria-carrying mosquitoes to migrate. Photo credit: Population Media

Professor Hunter, head of health protection at the UK's University of East Anglia, presented research tracking the movement of disease-causing organisms in Europe and North America to the Festival of Science in the UK city of Norwich. "There are already significant indications of disease burden occurring in Europe as a result of climate change," he told the conference.

One organism on the move is Vibrio vulnificus, which can cause severe illness - and in some cases death - in humans, the research found. It only grows in warm waters, such as those in the Gulf of Mexico - but has now been reported as far north as the Baltic Sea in Europe, and killed one person in Denmark.

In Italy, 100 holidaymakers had been taken ill after coming into contact with an organism called Ostreopsis ovata which had extended its habitat because of warmer waters, Professor Hunter said.

And Congo Crimea Haemorrhagic Fever - which causes bleeding from the skin, mouth and nose - had also began to appear in areas where it was previously unknown, he said. Prof Hunter said the spread of such organisms was probably due to milder winters rather than warmer summers. But he emphasised that "the burden of climate change will fall on the poorest countries in the world, and the tropical countries. "We actually have very little information about health and infectious disease statistics for many of these countries.

"In Europe we're getting worried about three or four cases of rare disease associated with the Baltic Ocean - but in Africa we're talking about potentially many millions of cases of malaria occurring as a result of climate change which might not have occurred earlier."

The migration of ticks and midges also caused diseases like malaria to spread, he said.

The researchers also believe that infectious diseases borne by humans, such as TB and HIV, are likely to spread more widely as people migrate to escape drought and other effects of climate change.