After decades away, dengue returns to central Queensland



Australia’s dengue cases are usually limited to far north Queensland.
Shutterstock

Cameron Webb, University of Sydney

The Queensland city of Rockhampton was free of dengue for decades. Now, a case of one of the most serious mosquito-borne diseases has authorities scratching their heads.

Over the past decade, dengue infections have tended to be isolated events in which international travellers have returned home with the disease. But the recent case seems to have been locally acquired, raising concerns that there could be more infected mosquitoes in the central Queensland town, or that other people may have been exposed to the bites of an infected mosquito.

What is dengue fever?

The illness known as dengue fever typically includes symptoms such as rash, fever, headache, joint pain, vomiting, diarrhoea, and abdominal pain. Symptoms can last for around a week or so. Four types of dengue virus cause the illness and they are spread by mosquito bites.

Once infected, people become immune to that specific dengue virus. However, they can still get sick from the other dengue viruses. Being infected by multiple dengue viruses can increase the risk of more severe symptoms, and even death.

Hundreds of millions of people are infected each year. It is estimated that 40% of the world’s population is at risk given the regions where the virus, and the mosquitoes that spread it, are active. This includes parts of Australia.




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The last significant outbreak in Australia occurred in far north Queensland in 2009, when more than 900 people were infected by local mosquitoes.

Only a handful of locally acquired cases have been reported around Cairns and Townsville in the past decade. All these cases have two things in common: the arrival of infected travellers and the presence of the “right” mosquitoes.

The dengue virus isn’t spread from person to person. A mosquito needs to bite an infected person, become infected, and then it may transmit the virus to a second person as they bite. If more people are infected, more mosquitoes can pick up the virus as they bite and, subsequently, the outbreak can spread further.

Why are mosquitoes important?

Australia has hundreds of different types of mosquitoes. Dozens can spread local pathogens, such as Ross River virus, but just one is capable of spreading exotic viruses such as dengue and Zika: Aedes aegypti.

Aedes aegypti breeds in water-holding containers around the home. It is one of the most invasive mosquitoes globally and is easily moved about by people through international travel. While these days the mosquito stows away in planes, historically it was just as readily moved about in water-filled barrels on sailing ships.

Aedes aegypti is the mosquito primarily responsible for the spread of dengue viruses.
By James Gathany – PHIL, CDC, Public Domain

The spread of Aedes aegypti through Australia is the driving force in determining the nation’s future outbreak risk.

The mosquito was once widespread in coastal Australia but since the 1950s, it become limited to central and far north Queensland. We don’t really know why – there are many possible reasons for the retreat, but the important thing now is they don’t return to temperate regions of the country.

Authorities must be vigilant to monitor their spread and, where they’re currently found, building capacity to respond should cases of dengue be identified.




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Is climate change to blame for outbreaks of mosquito-borne disease?


What happened in Rockhampton?

Last week, for the first time in decades, a locally acquired case of dengue was detected in Rockhampton, in central Queensland. The disease was found in someone who hasn’t travelled outside the region, which suggests they’ve been bitten locally by an infected mosquito.

This has prompted a full outbreak response to protect the community from any additional infected mosquitoes.

While the risk of dengue around central Queensland is considered lower than around Cairns or Townsville, authorities are well prepared to respond, with a variety of techniques including house-to-house mosquito surveillance and mosquito control to minimise the spread.

These approaches have been successful around Cairns and Townsville for many years and have helped avoid substantial outbreaks.

The coordinated response of local authorities, combined with the onset of cooler weather that will slow down mosquitoes, greatly reduces any risk of more cases occurring.

What can we do about dengue in the future?

Outbreaks of dengue remain a risk in areas with Aedes aegypti mosquitoes. There are also other mosquitoes, such as Aedes albopictus (the Asian tiger mosquito), that aren’t currently found on mainland Australia but may further increase risks should they arrive. Authorities need to be prepared to respond to the introductions of these mosquitoes.




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How we kept disease-spreading Asian Tiger mozzies away from the Australian mainland


While a changing climate may play a role in increasing the risk, increasing international travel, which represents pathways of introduction of “dengue mosquitoes” into new regions of Australia, may be of greater concern.

There is more that can be done, both locally and internationally. Researchers are working to develop a vaccine that protects against all four strains of dengue virus.

Others are tackling the mosquitoes themselves. Australian scientists have played a crucial role in using the Wolbachia bacteria, which spreads among Aedes aegypti and blocks transmission of dengue, to control the disease.

The objective is to raise the prevalence of the Wolbachia infections among local mosquitoes to a level that greatly reduces the likelihood of local dengue transmission.

Field studies have been successful in far north Queensland and may explain why so few local cases of dengue have been reported in recent years.

While future strategies may rely on emerging technologies and vaccines, simple measures such as minimising water-filled containers around our homes will reduce the number of mosquitoes and their potential to transmit disease.The Conversation

Cameron Webb, Clinical Lecturer and Principal Hospital Scientist, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Expanding gas mining threatens our climate, water and health


Melissa Haswell, Queensland University of Technology and David Shearman, University of Adelaide

Australia, like its competitors Qatar, Canada and the United States, aspires to become the world’s largest exporter of gas, arguing this helps importing nations reduce their greenhouse emissions by replacing coal.

Yes, burning gas emits less carbon dioxide than burning coal. Yet the “fugitive emissions” – the methane that escapes, often unmeasured, during production, distribution and combustion of gas – is a much more potent short-term greenhouse gas than carbon dioxide.




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A special report issued by the World Health Organisation after the 2018 Katowice climate summit urged governments to take “specific commitments to reduce emissions of short-lived climate pollutants” such as methane, so as to boost the chances of staying with the Paris Agreement’s ambitious 1.5℃ global warming limit.

Current gas expansion plans in Western Australia, the Northern Territory and Queensland, where another 2,500 coal seam gas wells have been approved, reveal little impetus to deliver on this. Harvesting all of WA’s gas reserves would emit about 4.4 times more carbon dioxide equivalent than Australia’s total domestic energy-related emissions budget.

Gas as a cause of local ill-health

There are not only global, but also significant local and regional risks to health and well-being associated with unconventional gas mining. Our comprehensive review examines the current state of the evidence.

Since our previous reviews (see here, here and here), more than 1,400 further peer-reviewed articles have been published, helping to clarify how expanding unconventional gas production across Australia risks our health, well-being, climate, water and food security.




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This research has been possible because, since 2010, 17.6 million US citizens’ homes have been within a mile (1.6km) of gas wells and fracking operations. Furthermore, some US research funding is independent of the gas industry, whereas much of Australia’s comparatively small budget for research in this area is channelled through an industry-funded CSIRO research hub.

Key medical findings

There is evidence that living close to unconventional gas mining activities is linked to a wide range of health conditions, including psychological and social problems.

The US literature now consistently reports higher frequencies of low birth weight, extreme premature births, higher-risk pregnancies and some birth defects, in pregnancies spent closer to unconventional gas mining activities, compared with pregnancies further away. No parallel studies have so far been published in Australia.

US studies have found increased indicators of cardiovascular disease, higher rates of sinus disorders, fatigue and migraines, and hospitalisations for asthma, heart, neurological, kidney and urinary tract conditions, and childhood blood cancer near shale gas operations.

Exploratory studies in Queensland found higher rates of hospitalisation for circulatory, immune system and respiratory disorders in children and adults in the Darling Downs region where coal seam gas mining is concentrated.

Water exposure

Chemicals found in gas mining wastewater include volatile organic compounds such as benzene, phenols and polyaromatic hydrocarbons, as well as heavy metals, radioactive materials, and endocrine-disrupting substances – compounds that can affect the body’s hormones.

This wastewater can find its way into aquifers and surface water through spillage, injection procedures, and leakage from wastewater ponds.

The environmental safety of treated wastewater and the vast quantities of crystalline salt produced is unclear, raising questions about cumulative long-term impacts on soil productivity and drinking water security.

Concern about the unconventional gas industry’s use of large quantities of water has increased since 2013. Particularly relevant to Australian agriculture and remote communities is research showing an unexpected but consistent increase in the “water footprint” of gas wells across all six major shale oil and gas mining regions of the US from 2011 to 2016. Maximum increases in water use per well (7.7-fold higher, Permian deposits, New Mexico and Texas) and wastewater production per well (14-fold, Eagle Ford deposits, Texas) occurred where water stress is very high. The drop in water efficiency was tied to a drop in gas prices.

Air exposure

Research on the potentially harmful substances emitted into the atmosphere during water removal, gas production and processing, wastewater handling and transport has expanded. These substances include fine particulate pollutants, ground-level ozone, volatile organic compounds, polycyclic aromatic hydrocarbons, hydrogen sulfide, formaldehyde, diesel exhaust and endocrine-disrupting chemicals.

Measuring concentrations and human exposures to these pollutants is complicated, as they vary widely and unpredictably in both time and location. This makes it difficult to prove a definitive causal link to human health impacts, despite the mounting circumstantial evidence.




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Our review found substantially more evidence of what we suspected in 2013: that gas mining poses significant threats to the global climate, to food and water supplies, and to health and well-being.

On this basis, Doctors for the Environment Australia (DEA) has reinforced its position that no new gas developments should occur in Australia, and that governments should increase monitoring, regulation and management of existing wells and gas production and transport infrastructure.The Conversation

Melissa Haswell, Professor of Health, Safety and Environment, School of Public Health and Social Work, Queensland University of Technology, Queensland University of Technology and David Shearman, Emeritus Professor of Medicine, University of Adelaide

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Explainer: what is Murray Valley encephalitis virus?


Ana Ramírez, James Cook University; Andrew Francis van den Hurk, The University of Queensland; Cameron Webb, University of Sydney, and Scott Ritchie, James Cook University

Western Australian health authorities recently issued warnings about Murray Valley encephalitis, a serious disease that can spread by the bite of an infected mosquito and cause inflammation of the brain.

Thankfully, no human cases have been reported this wet season. The virus that causes the disease was detected in chickens in the Kimberley region. These “sentinel chickens” act as an early warning system for potential disease outbreaks.

What is Murray Valley encephalitis virus?

Murray Valley encephalitis virus is named after the Murray Valley in southeastern Australia. The virus was first isolated from patients who died from encephalitis during an outbreak there in 1951.

The virus is a member of the Flavivirus family and is closely related to Japanese encephalitis virus, a major cause of encephalitis in Asia.

Murray Valley encephalitis virus is found in northern Australia circulating between mosquitoes, especially Culex annulirostris, and water birds. Occasionally the virus spreads to southern regions, as mosquitoes come into contact with infected birds that have migrated from northern regions.




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How serious is the illness?

After being transmitted by an infected mosquito, the virus incubates for around two weeks.

Most people infected don’t develop symptoms. But, if you’re unlucky, you could develop symptoms ranging from fever and headache to paralysis, encephalitis and coma.

Around 40% of people who develop symptoms won’t fully recover and about 25% die. Generally, one or two human cases are reported in Australia per year.

Since the 1950s, there have been sporadic outbreaks of Murray Valley encephalitis, most notably in 1974 and 2011. The 1974 outbreak was Australia-wide, resulting in 58 cases and 12 deaths.

It’s likely the virus has been causing disease since at least the early 1900s when epidemics of encephalitis were attributed to a mysterious illness called Australian X disease.

Traditional monitoring of mosquito-borne diseases relies on the collection of mosquitoes using specially designed traps baited with carbon dioxide.
Cameron Webb

Early warning system

Given the severity of Murray Valley encephalitis, health authorities rely on early warning systems to guide their responses.

One of the most valuable surveillance tools to date have been chooks because the virus circulates between birds and mosquitoes. Flocks of chickens are placed in areas with past evidence of virus circulation and where mosquitoes are buzzing about.

Chickens are highly susceptible to infection so blood samples are routinely taken and analysed to determine evidence of virus infection. If a chicken tests positive, the virus has been active in an area.

The good news is that even if the chickens have been bitten, they don’t get sick.

Mosquitoes can also be collected in the field using a variety of traps. Captured mosquitoes are counted, grouped by species and tested to see if they’re carrying the virus.

This method is very sensitive: it can identify as little as one infected mosquito in a group of 1,000. But processing is labour-intensive.




Read more:
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How can technology help track the virus?

Novel approaches are allowing scientists to more effectively detect viruses in mosquito populations.

Mosquitoes feed on more than just blood. They also need a sugar fix from time to time, usually plant nectar. When they feed on sugary substances, they eject small amounts of virus in their saliva.

This led researchers to develop traps that contain special cards coated in honey. When the mosquitoes feed on the cards, they spit out virus, which specific tests can then detect.

We are also investigating whether mosquito poo could be used to enhance the sugar-based surveillance system. Mosquitoes spit only tiny amounts of virus, whereas they poo a lot (300 times more than they spit).

This mosquito poo can contain a treasure trove of genetic material, including viruses. But we’re still working out the best way to collect the poo.

Mosquito poo, shown here after mosquitoes have fed on coloured honey, can be used to detect viruses like Murray Valley encephalitis.
Dagmar Meyer

Staying safe from Murray Valley encephalitis

There is no vaccine or specific treatment for the virus. Avoiding mosquito bites is the only way to protect yourself from the virus. You can do this by:

  • wearing protective clothing when outdoors

  • avoiding being outdoors when the mosquitoes that transmit the virus are most active (dawn and dusk)

  • using repellents, mosquito coils, insect screens and mosquito nets

  • following public health advisories for your area.

The virus is very rare and your chances of contracting the disease are extremely low, but not being bitten is the best defence.The Conversation

Ana Ramírez, PhD candidate, James Cook University; Andrew Francis van den Hurk, Medical Entomologist, The University of Queensland; Cameron Webb, Clinical Lecturer and Principal Hospital Scientist, University of Sydney, and Scott Ritchie, Professorial Research Fellow, James Cook University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How do we save ageing Australians from the heat? Greening our cities is a good start



File 20190227 150698 rrobo4.jpg?ixlib=rb 1.1
A shade tree makes a big difference to the comfort of this couple.
Nancie Lee/Shutterstock

Claudia Baldwin, University of the Sunshine Coast; Jason Byrne, University of Tasmania, and Tony Matthews, Griffith University

Heatwaves have killed more Australians than road accidents, fires, floods and all other natural disasters combined. Although recent research shows extreme cold is a worry in some parts of Australia, our hottest summer on record points to more heat-related deaths to come. The record heatwaves have highlighted the damaging effects of heat stress. Understandably, it’s becoming a major public health challenge.




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The risk of extreme heat events and the adverse impacts on older people has been extensively discussed in research. Remarkably, very little attention has been paid to the role of urban greenery in reducing heat stress for seniors.

Older people are particularly at risk of heat stress. Pre-existing medical conditions and limited mobility increase their vulnerability. Deaths of older people increase during extreme heat events.

The physical features of urban areas shape the capacity of older adults to engage in many activities when it’s hot. These include vegetation volume and coverage, thermal design, and the extent of shading in public areas and walkways. Increasing urban greenery may offer a way to improve older people’s comfort and social experience.




Read more:
Building cool cities for a hot future


Ageing adds urgency to greening

It is expected 20% of the global population will be older than 60 by 2050. The figure for Australia is even higher, at 23%. This means that by 2050 around one in four Australians will be more vulnerable to extreme heat.

Older people are more vulnerable to heat stress.
PorporLing/Shutterstock

Climate change may make the problem worse by fuelling even more extreme heat events.

Planning our urban centres to meet the needs of a rapidly ageing population is a matter of urgency. Urban greening to reduce their vulnerability to heat stress should be central to this agenda. It can also improve people’s quality of life, reduce social isolation and loneliness, and ease the burden on health systems.

An important task is matching the design of communities with the needs of an ageing population. Where older adults live and the quality of their local areas strongly influence their lived experiences. Yet recent research found the experiences of seniors were often not accounted for in research on neighbourhood design.




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What about aged care?

People face choices about where they live as they age. The common choices are to “age in place” or to move into aged care.

Ageing in place includes living in one’s own home or co-habiting with relatives or friends. Around 90% of Australian seniors choose this option, with the remainder opting for aged-care facilities.

If one in ten Australian seniors live in aged-care facilities, it is clear these should be designed to minimise heat stress. This isn’t just good for residents; it may also benefit operators by lowering health-care and electricity costs.

While these facilities are purpose-built for older people, many in Australia were built well over a decade ago, when heat stress was not such a large concern. Many more facilities are being built now and will be into the future. Yet it is uncertain whether they are being actively designed to reduce the impacts of heat.




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What has our research found?

We recently conducted a focus group to investigate this issue. Participants were senior managers from four large corporate providers of aged care in Australia. We investigated if and how providers try to minimise heat stress through design. We also sought to understand the rationales used to support these design approaches.

Several participants reported on refurbishments that they expect will have cooling effects. Cited design approaches included green roofs and walls, as well as sensory gardens. Other expected benefits included reducing anxiety and improving the mental health of residents.

The fact that single design interventions could produce multiple benefits improved the potential for corporate buy-in. Participants expected that increasing green space and green cover would give their facilities a competitive advantage by attracting more clients and providing a better working environment for staff.

Participants also reported on challenges of including greening in their projects. For example, the benefits of trees were weighed against concerns about roots disrupting footpaths and becoming trip hazards. Species selection was another concern, with fears that inappropriate plants could die and undermine support for greening programs.

Our research suggests that more can be done to make cities hospitable for older people, especially during extreme heat. Urban greening is a start. Encouraging aged-care providers to adopt green infrastructure will have benefits. But we should also consider reforms to planning systems and urban design to better protect older people who choose to age in place.




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If planners understand it’s cool to green cities, what’s stopping them?


The Conversation


Claudia Baldwin, Associate Professor, Urban Design and Town Planning, Sustainability Research Centre, University of the Sunshine Coast; Jason Byrne, Professor of Human Geography and Planning, University of Tasmania, and Tony Matthews, Senior Lecturer in Urban and Environmental Planning, Griffith University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How Australian wildlife spread and suppress Ross River virus



File 20181230 47292 1isykoi.jpg?ixlib=rb 1.1
Mozzies feed on many native species, including the Nankeen Night Heron.
Janis Otto/flikr

Eloise Stephenson, Griffith University; Cameron Webb, University of Sydney, and Emily Johnston Flies, University of Tasmania

Ross River virus is Australia’s most common mosquito-borne disease. It infects around 4,000 people a year and, despite being named after a river in North Queensland, is found in all states and territories, including Tasmania.

While the disease isn’t fatal, it can cause debilitating joint pain, swelling and fatigue lasting weeks or even months. It can leave sufferers unable to work or look after children, and is estimated to cost the economy A$2.7 to A$5.6 million each year.

There is no treatment or vaccine for Ross River virus; the only way to prevent is to avoid mosquito bites.




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Explainer: what is Ross River virus?


Mosquitoes pick up the disease-causing pathogen by feeding on an infected animal. The typical transmission cycle involves mosquitoes moving the virus between native animals but occasionally, an infected mosquito will bite a person. If this occurs, the mosquito can spread Ross River virus to the person.

Animal hosts

Ross River virus has been found in a range of animals, including rats, dogs, horses, possums, flying foxes, bats and birds. But marsupials – kangaroos and wallabies in particular – are generally better than other animals at amplifying the virus under experimental infection and are therefore thought to be “reservoir hosts”.

The virus circulates in the blood of kangaroos and wallabies for longer than other animals, and at higher concentrations. It’s then much more likely to be picked up by a blood-feeding mosquito.

Kangaroos are a common sight around Australia’s coastal wetlands.
Dr Cameron Webb (NSW Health Pathology), Author provided

Dead-end hosts

When we think of animals and disease we often try to identify which species are good at transmitting the virus to mosquitoes (the reservoir hosts). But more recently, researchers have started to focus on species that get bitten by mosquitoes but don’t transmit the virus.

These species, known as dead-end hosts, may be important for reducing transmission of the virus.

With Ross River virus, research suggests birds that get Ross River virus from a mosquito cannot transmit the virus to another mosquito. If this is true, having an abundance of birds in and around our urban environments may reduce the transmission of Ross River virus to animals, mosquitoes and humans in cities.

Other reservoir hosts?

Even in areas with a high rates of Ross River virus in humans, we don’t always find an abundance of kangaroos and wallabies. So there must be other factors – or animals yet to be identified as reservoirs or dead-end hosts – playing an important role in transmission.

Ross River virus is prevalent in the Pacific Islands, for instance, where there aren’t any kangaroos and wallabies. One study of blood donors in French Polynesia found that 42.4% of people tested had previously been exposed to the virus. The rates are even higher in American Samoa, where 63% of people had been exposed.




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It’s unclear if the virus has recently started circulating in these islands, or if it’s been circulating there longer, and what animals have been acting as hosts.

What about people?

Mosquitoes can transmit some viruses, such as dengue and Zika between people quite easily.

But the chances of a mosquito picking up Ross River virus when biting an infected human is low, though not impossible. The virus circulates in our blood at lower concentrations and for shorter periods of time compared with marsupials.

Stop mozzies biting with insect repellents.
Elizaveta Galitckaia/Shutterstock

If humans are infected with Ross River virus, around 30% will develop symptoms of joint pain and fatigue (and sometimes a rash) three to 11 days after exposure, while some may not experience any symptoms until three weeks after exposure.

To reduce your risk of contracting Ross River virus, take care to cover up when you’re outdoors at sunset and wear repellent when you’re in outdoor environments where mosquitoes and wildlife may be frequently mixing.




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The Conversation


Eloise Stephenson, PhD Candidate, Griffith University; Cameron Webb, Clinical Lecturer and Principal Hospital Scientist, University of Sydney, and Emily Johnston Flies, Postdoctoral Research Fellow (U.Tasmania), University of Tasmania

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Why naming all our mozzies is important for fighting disease


File 20180223 108139 lvidlr.jpg?ixlib=rb 1.1
And you can be…Susan.
from http://www.shutterstock.com

Bryan Lessard, CSIRO

Notorious for spreading diseases like malaria and Zika virus overseas, mosquitoes contribute to thousands of cases of human disease in Australia each year. But only half of Australia’s approximately 400 different species of mosquitoes have been scientifically named and described. So how are scientists able to tell the unnamed species apart?

Climate change means population change

Mosquito populations and our ability to predict disease outbreaks are likely to change in the future. As climates change, disease-carrying mozzies who love the heat may spread further south into populated cities.

As human populations continue to grow in Australia, they will interact with different communities of wild animals that act as disease reservoirs, as well as different mosquito species that may be capable of carrying these diseases. The expansion of agricultural and urban water storages will also create new homes for mosquito larvae to mature, allowing mosquitoes to spread further throughout the country.




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Mosquito larvae need a body of water to mature in.
James Gathany, CDC

Agents of disease

Mosquitoes like the native Common Banded Mosquito (Culex annulirostris) are known to spread human diseases such as Ross River virus, Barmah Forest virus, Dengue fever and Murray Valley encephalitis.

It’s not the adult mosquito itself that causes the disease, but the viruses and other microbes that accumulate in the mosquito’s saliva and are injected into the bloodstream of the unsuspecting victim during feeding.

The mosquitoes that bite humans are female, requiring the proteins in blood to ripen their eggs and reach sexual maturity. Male mosquitoes, and females of some species, are completely vegetarian, opting to drink nectar from flowers, and are useful pollinators.

The life cycle of a mosquito.
from http://www.shutterstock.com



Read more:
Common Australian mosquitoes can’t spread Zika


The name game

Mosquitoes belong to the fly family Culicidae and are an important part of our biodiversity. There are more than 3,680 known species of mosquitoes in the world. Taxonomists, scientists who classify organisms, have been able to formally name more than 230 species in Australia.

The classification of Australian mosquitoes tapered off in the 1980s with the publication of the last volume of The Culicidae of the Australasian Region and passing of Dr Elizabeth Marks who was the most important contributor to our understanding of Australian mosquitoes.

She left behind 171 unique species with code numbers like “Culex sp No. 32”, but unfortunately these new species were never formally described and remained unnamed after her death. This isn’t uncommon in biodiversity research, as biologists estimate that we’ve only named 25% of life on earth during a time when there is an alarming decline in the taxonomic workforce.

Dr Marks’ unnamed species are still held in Australian entomology collections, like CSIRO’s Australian National Insect Collection, Museum Victoria and the Queensland Museum. Although all the major disease-carrying species of mosquitoes are known in the world, several of Marks’ undescribed Australian species are blood feeding and may have the capacity to transmit diseases.

How do we tell mozzies apart?

Naming, describing and establishing the correct classification of Australia’s mosquitoes is the first step to understanding their role in disease transmission. This is difficult work as adults are small and fragile, and important diagnostic features that are used to tell species apart, like antennae, legs and even tiny scales, are easily lost or damaged.

CSIRO scientists, with support from the Australian Biological Resources Study, Government of Western Australia Department of Health, and University of Queensland, have been tasked with naming Australia’s undescribed mosquitoes. New species will be named and described based on the appearance of the adults and infant larval stages which are commonly intercepted by mozzie surveillance officers. New identification tools will also be created so others can quickly and reliably identify the Australian species.

A 100 year old specimen of the native Common Banded Mosquito Culex annulirostris, capable of spreading Murray Valley encephalitis virus, one of 12 million specimens held in CSIRO’s Australian National Insect Collection in Canberra.
CSIRO/Dr Bryan Lessard



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Scientists are now able to extract DNA and sequence the entire mitochondrial genome from very old museum specimens. CSIRO are using these next generation techniques to generate a reliable DNA reference database of Australian mosquitoes to be used by other researchers and mozzie surveillance officers to accurately identify specimens and diagnose new species. CSIRO are also digitising museum specimens to unlock distribution data and establish the geographical boundaries for the Australian species.

By naming and describing new species, we will gain a more complete picture of our mosquito fauna, and its role in disease transmission. This will make us better prepared to manage our mosquitoes and human health in the future as the climate changes and our growing human population moves into new areas of Australia.The Conversation

Bryan Lessard, Postdoctoral Research Fellow, CSIRO

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Heatwaves threaten Australians’ health, and our politicians aren’t doing enough about it


Paul Beggs, Macquarie University; Helen Louise Berry, University of Sydney; Martina Linnenluecke, Macquarie University, and Ying Zhang, University of Sydney

Extreme heat affects the mental health of Australians to the same degree as unemployment, yet Australia’s policy action on climate change lags behind other high-income countries such as Germany and the United Kingdom.

As Australia approaches another summer, we face the inevitability of deadly heatwaves. Our report published today in the Medical Journal of Australia concludes that policy inaction, particularly at the federal level, is putting Australian lives at risk.

The report, The MJA–Lancet Countdown on health and climate change: Australian policy inaction threatens lives, builds on an earlier publication in The Lancet medical journal, which concluded climate change is the biggest global health threat of the 21st century.




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Australia is the first to prepare its own country-level report. Developed in partnership with the Lancet Countdown – which tracks the global connections between health and climate change – it adopts the structure and methods of the global assessment but with an Australian focus.

How Australians’ health suffers

Australians are already facing climate change-related exposures that come from increasing annual average temperatures, heatwaves and weather-related disasters. Australian deaths during the 2014 Adelaide heatwave and Melbourne’s 2016 thunderstorm asthma event are examples of the risk climate poses to our health.




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Our report was produced by a team of 19 experts from 13 universities and research institutes. We aimed to answer what we know about climate change and human health in Australia and how we are responding to this threat, if at all.

To do this, our team examined more than 40 indicators that enable us to track progress on the broad and complex climate change and human health issue. Health impact indicators included the health effects of temperature change and heatwaves, change in labour capacity, trends in climate-sensitive diseases, lethality of weather-related disasters and food insecurity and malnutrition.

We also developed an indicator for the impacts of climate change on mental health. This involved examining the association between mean annual maximum temperatures and suicide rates for all states and territories over the last ten years.

We found that, in most jurisdictions, the suicide rate increased with increasing maximum temperature. In Australia’s changing climate, we urgently need to seek ways to break the link between extreme temperature and suicide.

Across other indicators, we found workers’ compensation claims in Adelaide increased by 6.2% during heatwaves, mainly among outdoor male workers and tradespeople over 55 years.

And we found the length of heatwaves increased in 2016 and 2017 in Australia’s three largest cities – Sydney, Melbourne and Brisbane. Heatwave length varied from year to year, but between 2000 and 2017, the mean number of heatwave days increased by more than two days across the country.

Policy action we need

Australia’s slow transition to renewables and low-carbon electricity generation is problematic, and not only from a climate change perspective. Our report shows that pollutants from fossil fuel combustion cause thousands of premature deaths nationwide every year. We argue even one premature death is one too many when there is so much that we can do to address this.

Australia is one of the world’s wealthiest countries with the resources and technical expertise to act on climate change and health. Yet Australia’s carbon intensity is the highest among the countries we included in our comparison – Germany, United States, China, India and Brazil.

A carbon-intensive energy system is one of the main drivers behind climate change. Australia was once a leader in the uptake of renewables but other nations have since streaked ahead and are reaping the benefits for their economies, energy security and health.

Despite some progress increasing renewable generation, it’s time we truly pull our weight in the global effort to prevent acceleration towards dangerous climate change.

Policy leaders must take steps to protect human health and lives. These include strong political and financial commitments to accelerate transition to renewables and low-carbon electricity generation. The government lacks detailed planning for a clean future with a secure energy supply.




Read more:
What would a fair energy transition look like?


Our MJA-Lancet Countdown report will be updated annually. Now that Australia has begun systematically tracking the effects of climate change on health – and given its poor performance compared with comparable economies globally – further inaction would be reckless.The Conversation

Paul Beggs, Associate Professor and Environmental Health Scientist, Macquarie University; Helen Louise Berry, Professor of Climate Change and Mental Health, University of Sydney; Martina Linnenluecke, Professor of Environmental Finance; Director of the Centre for Corporate Sustainability and Environmental Finance, Macquarie University, and Ying Zhang, Associate Director, Teaching and Learning, Sydney School of Public Health, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.