Associate Professor Nick Wilson from the Department of Public Health says a just published review of climate change studies and infectious diseases in NZ shows there are significant gaps in our knowledge.
“While climate change is having impacts on the environment, it is also critical to understand its current and potential impacts on human health, including infectious diseases” he says.
Over a quarter (26%) of acute hospitalisations in NZ result from infectious diseases, which is well up on the rate in the early 1990s when it was 18%.
“A warmer, wetter and stormier climate has the potential to make this burden of serious illness significantly worse because of the biological and ecological origins of many infectious diseases. This potentially means both additional human suffering and additional costs to the tax-payer funded health system.”
One of the highest priorities identified by the study is the need for closer consideration of the risk of new mosquito-borne diseases, such as dengue fever, carried by mosquitoes from tropical countries. There are many habitats in NZ which could be colonised by new mosquito species, as temperatures and rainfall increase.
“Given that NZ recently spent around $70 million on eradicating the Southern Salt Marsh mosquito – it is important that we maximise our prevention efforts to protect health and to save costs,” Wilson says.
Studies have indicated that food-borne disease from salmonella infection is related to warmer temperatures. However, the evidence for links between increased temperature/rainfall and diseases caused by campylobacter, cryptosporidium and severe E. coli infections is much less clear for NZ. If increased rainfall and flooding do occur, then it is likely to be the many communities without reticulated water supply that will be most vulnerable to water-borne diseases.
The increase in serious skin infections causing hospitalisations, may also have a link to warmer temperatures and higher humidity. “This is another area that urgently needs further research,” says Associate Professor Michael Baker, a co-author of the study.
The review also found that relevant NZ Government agencies had little on their websites about climate and health. Only one of five such agencies had a document related to climate change and health, and this document was published in 2001.
The authors reported that there is one research project currently underway on the climate and health issue in NZ, but this only covers some of these potential diseases.
“Given the potential scale of the climate change problem, NZ dramatically needs to lift its response in this area,” says Wilson.