Environmental change and the increasing threat of infectious diseases

“Although the direct threat from climate-related infectious diseases in the UK is likely to be limited to food and waterborne disease,” says Professor Hunter, “mass migration of peoples displaced from developing nations that are more severely affected, is likely to have a far greater impact: causing a rise in cases of diseases like tuberculosis and HIV.”

Professor Hunter will make his comments on Tuesday as part of ‘Environmental change and the increasing threat of infectious diseases’, an event at the BA Festival of Science in Norwich. The Festival is taking place at the University of East Anglia from 2-9 September and will bring together over 300 of the UK’s top scientists and engineers to discuss the latest scientific developments with the public.

Professor Hunter suggests that the most serious impacts of climate change on infectious disease will be felt in the poorer countries of the world, but may also influence the ecology and distribution of species that are host to disease. For instance, while increases in summertime temperatures and the frequency of hot summers will boost bacterial growth rates in food and may cause a noticeable rise in cases of food poisoning, decreasing rainfall will reduce the availability of water and may lead to an increased reliance on poorer quality water sources and waste water. In developing nations without the appropriate water treatment technology this will lead to increasing outbreaks of diseases associated with contaminated water supplies (e.g. cholera, Hepatitis A and malaria) in addition to famine, large-scale displacement of people and wars over access to water before the end of the century.

Of more concern to developed nations, such as the UK, is the fact that more frequent flooding and extreme rainfall increases the likelihood of waterborne disease outbreaks. Particularly notable are reports of wound infections in Germany caused by Vibrio vulnificus (a marine water organism that only grows in warm water and was previously most problematic in areas bordering the Gulf of Mexico) and cryptosporidium and E. coli O157:H7 outbreaks in the UK and Canada as a result of heavy rainfall and associated flooding.