future mosquito-borne disease threats in australia
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Future mosquito-borne disease threats in Australia
Dr. Cameron Webb
Department of Medical EntomologyMarie Bashir Institute of Infectious Disease & Biosecurity
University of Sydney& Pathology West – ICPMR Westmead
Westmead Hospital, Westmead NSW 2145
Australian Society for Microbiology, 12-15 July 2015, Canberra #2015ASM @mozziebites
cathy wilcox (@cathywilcox1)http://www.smh.com.au/photogallery/federal-politics/cartoons/cathy-wilcox-20090909-fhd6.html
Will the response of mosquitoes to a changing climate increase the risks of disease?
Difficult to predict future changes in mosquito-borne disease risk with climate change #2015ASM @mozziebites
Australia has annual activity of endemic mosquito-borne pathogens
Exotic vectors and pathogens have potential to shift disease risks from the swamps to the suburbs
Local risks shift from swamps to suburbs with exotic mosquitoes #2015ASM @mozziebites
Surveillance and mosquito control strategies will need to adapt to changing landscape of mosquitoes and pathogens
We need to change the ways we catch and kill mosquitoes #2015ASM @mozziebites
The Yellow Fever Mosquito (Aedes aegypti) is a day-biting pest and vector in tropical regions
Dengue outbreaks are driven by the presence of Aedes aegypti but are triggered by infected travellers
Stephen Doggett (Medical Entomology, Pathology West – ICPMR Westmead)
Only one mosquito in Australia can spread dengue viruses. It’s in FNQ backyards #2015ASM @mozziebites
Newcastle Morning Herald and Miners' Advocate (NSW),31 December 1927
Look back to see the dengue risk ahead of us in Australia #2015ASM @mozziebites
The Asian Tiger Mosquito (Aedes albopictus) is an invasive, severe day-biting species of tropical and temperate regions
Stephen Doggett (Medical Entomology, Pathology West – ICPMR Westmead)
Arrival of Asian Tiger Mosquito will be a game changer for temperate regions #2015ASM @mozziebites
Hill, M. P., Axford, J. K. and Hoffmann, A. A. (2014), Predicting the spread of Aedes albopictus in Australia under current and future climates: Multiple approaches and datasets to incorporate potential evolutionary divergence. Austral Ecology, 39: 469–478.
Asian Tiger Mosquito could easily adapt to life along the east coast of Australia #2015ASM @mozziebites
Nicholson, Ritchie, Russell, Zalucki and van den Hurk (2014) Ability for Aedes albopictus (Diptera: Culicidae) to Survive at the Climatic Limits of Its Potential Range in Eastern Australia. Journal of Medical Entomology 51:948
Recent studies show immature stages don’t survive a “Sydney winter”…but eggs will survive and hatch in spring…going on to proliferate in summer
Cold winters are no barrier to the Asian Tiger Mosquito in temperate regions #2015ASM @mozziebites
Recent studies demonstrate competition from local mosquitoes is no barrier to establishment or spread
Nicholson, Webb , Ritchie and van den Hurk (2015). Effects of cohabitation on the population performance and survivorship of the invasive mosquito Aedes albopictus and the resident mosquito Aedes notoscriptus (Diptera: Culicidae) in Australia. Journal of Medical Entomology [in press].
Asian Tiger Mosquito can co-exists with mosquitoes in temperate regions #2015ASM @mozziebites
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Knope et al. 2013. Increasing notifications of dengue in Australia related to overseas travel 1991-2012. CDI 37: 55-59
Australian travellers increasingly returning to Australia infected with dengue #2015ASM @mozziebites
Asian Tiger Mosquito provides the tinder in temperate zones waiting for the spark provided by an infected traveller…
Introduction and spread of Asian Tiger Mosquito “sets the scene” for future outbreaks #2015ASM @mozziebites
Japan experienced the biggest outbreak of dengue in 70 years in 2014
Webb (2014) What can the outbreak of dengue in Japan tell us about future mosquito-borne disease risk? https://cameronwebb.wordpress.com/2014/09/15/what-can-the-outbreak-of-dengue-in-japan-tell-us-about-future-mosquito-borne-disease-risk
Dengue outbreaks in temperate regions a risk when Asian Tiger Mosquito active #2015ASM @mozziebites
Future mosquito-borne disease risk will be determined by more than just temperature, tides and rainfall (or exotic mosquitoes)
Drivers of outbreaks may include wildlife conservation, wetland rehabilitation and urban developments
Future mosquito-borne disease outbreaks driven by wetlands and wildlife #2015ASM @mozziebites
Role of native wildlife in endemic mosquito-borne disease outbreaks requires research #2015ASM @mozziebites
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Number of notifications of Ross River virus infection, received from State and Territory health authorities in the period of 1991 to 2014 and year-to-date notifications for 2015
(National Notifiable Diseases Surveillance System – Accessed 12 July 2015)
Mean national monthly notifications of Ross River virus disease
2015 outbreak of Ross River virus disease biggest on record #2015ASM @mozziebites
Why so much Ross River virus disease in 2015?
• Warmest spring on record• Wet start to Summer• Rainfall above average
Summer and early Autumn• Abundant (and diverse)
vector populations in coastal NSW/QLD
• Macropods?
Webb (2015) “Is climate change to blame for outbreaks of mosquito-borne disease?” The Conversationhttp://theconversation.com/is-climate-change-to-blame-for-outbreaks-of-mosquito-borne-disease-39176
Warm spring and wet summer drivers of Ross River virus outbreak #2015ASM @mozziebites
What does all this mean?
When it comes to the future risk of mosquito-borne disease in Australia, perhaps the climate change debate is a distraction from what we need.
Surveillance. Management. Education.
Strategic regional responses required to reduce future mosquito-borne disease risk #2015ASM @mozziebites
Visit my website: http://cameronwebb.wordpress.com
Email: [email protected]
Join the conversation on Twitter: @mozziebites
Mosquito illustration on opening slide provided by Golly Bard https://www.etsy.com/shop/GollyBard