About cameronwebb

Dr Cameron Webb is a Medical Entomologist with Pathology West - ICPMR Westmead and The University of Sydney. His research is focused on the management of mosquitoes and mosquito-borne disease risk associated with constructed, rehabilitated and natural wetlands in Australia.

Ross River virus in Melbourne, how did that happen?

aedesnotoscriptus

Health authorities in Victoria have been warning of mosquito-borne Ross River virus for much of the summer. The state is experiencing one of its worst outbreaks of the disease but cases have mostly been across inland regions. Now it’s hit Melbourne. How has this happened?

Ross River virus is the most commonly reported mosquito-borne disease in Australia. There are usually about 5,000 cases across Australia. However, in 2015 there was a major spike in activity with around 9,000 cases reported. It is a common misconception that the disease is only found in northern regions of Australia. I’m often told “I heard the disease is moving south from QLD?” That’s not the case.

The virus is just as much a natural part of the Australian environment as the mosquitoes and the wildlife that maintain transmission cycles.

While there are generally more cases in northern Australia, nowhere is safe. Some of the largest outbreaks have occurred in southern regions of Western Australia, South Australia, Victoria and even Tasmania.

The virus is widespread but is generally associated with rural regions. A driving factor in determining the activity of Ross River virus is that more than just mosquitoes are involved in outbreaks. The virus is maintained in the environment in native wildlife, especially kangaroos and wallabies. Even when and where there are high numbers of mosquitoes, without wildlife, outbreak risk is low. This is the reason why any clusters of locally infected cases in metropolitan regions are typical in areas where there are wetlands, wildlife and mosquitoes occurring together. We’ve seen this on the urban fringe of Sydney and Perth in recent years.

The announcement of locally acquired cases in the suburbs of Frankston and Casey, in Melbourne’s south-east, has taken many by surprise. Should it have?

Victoria is no stranger to mosquitoes and outbreaks of mosquito-borne disease. There are mosquito surveillance and mosquito control programs in place in many regions and historically there have been major outbreaks of mosquito-borne disease. From freshwater flood plains of the inland to the tidally flooded estuarine wetlands of the coast, Victoria has diverse and often abundant mosquitoes. But cases in the metropolitan region are rare.

Victorian mosquitoes are not all bad but over a dozen different mosquito species can spread Ross River virus.

The region where these cases have been identified are in proximity to bushland and wetland areas. There is no doubt plenty of mosquitoes and suitable wildlife too. While this is the first time local transmission has been documented, that doesn’t mean the virus hasn’t circulated in the past, or even that cases may have occurred.

For individuals infected but only suffering mild symptoms, the illness can be easily discounted as nothing more than a mild case of the flu. Without appropriate blood tests, these cases never appear in official statistics. For this reason, many mosquito researchers believe that the number of notified cases across the country is just the tip of the iceberg with many milder infections going diagnosed.

But why in Melbourne now?

It is difficult to know for sure. The two most likely explanations are that either environmental conditions were ideal for mosquitoes and suitable populations of wildlife were present so that the virus was much more active in the local environment than previously. The second explanation is that the virus may have been introduced to the region by a traveller or movement of wildlife. In much the same way Zika virus made its way from SE Asia to South America in the last few years, mosquito-borne viruses move about in people and animals, much less so than mosquitoes themselves (but that isn’t impossible either).

Victoria (as well as inland NSW) is experiencing one of its largest outbreaks of Ross River virus on record following significant flooding of inland regions. With so much activity of the virus in the region, perhaps an infected bird or person travelling to the metropolitan region brought the virus with them. When bitten by local mosquitoes, the virus started circulated among local mosquitoes and wildlife.

Most people infected by Ross River virus are bitten by a mosquito that has previously fed on a kangaroo or wallaby.

Once it’s made its way to metropolitan regions, the virus can be spread from person to person by mosquitoes. Common backyard mosquitoes, especially Aedes notoscriptus, can transmit the virus but as these mosquitoes are not particularly abundant, don’t fly vary far and will just as likely bite animals as humans, they’re unlikely to drive major urban outbreaks of the disease. This mosquito doesn’t pack the same virus-spreading-punch as mosquitoes such as Aedes aegypti that spreads dengue, chikungunya and Zika viruses. Aedes aegypti isn’t in Victoria.

We’re unlikely to see significant spread of Ross River virus across Melbourne but that doesn’t mean Victorians should be complacent. As there is no cure for Ross River virus disease, the best approach is to avoid being infected in the first place. Preventing mosquito bites is the best approach. For my tips and tricks on avoiding mosquito bites see this recent paper in Public Health Research and Practice as well as my article for The Conversation.

Keep an eye on the website of Victoria Health for more information.

 

 

 

 

 

West Aussies versus the local mozzies

This is a special guest post from Dr Abbey Potter, Senior Scientific Officer, Environmental Health Hazards, WA Health. I’m currently mentoring Abbey as part of The Public Health Advocacy Institute of WA (PHAIWA) Mentoring Program. Its been a great experience as we navigate through some of the strategies to raise awareness of mosquito-borne disease and advocate for better approaches to addressing the public health risks associated with mosquitoes.

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Living in WA, we’re all too familiar with the pesky mosquito. We know they bite but what we often don’t consider is that they can transmit serious and sometimes deadly diseases. In fact, a recent survey of locals indicated that knowledge of mosquito-borne disease is pretty limited, particularly among younger adults aged 18-34 years and those living in the Perth Metro. It’s pretty important we’re aware of the risks posed by these pint-sized blood suckers and how you can avoid them… and here’s why!

The Facts

On average, more than 1,000 people will be infected with a mosquito-borne disease in WA every year. Our mossies can transmit Ross River virus, Barmah Forest virus, West Nile virus (Kunjin substrain) and Murray Valley encephalitis virus. All four cause diseases that are debilitating at best, causing weeks to months of symptoms. Murray Valley encephalitis is limited to the north of the State but is so serious it can result in seizures, coma, brain damage and even death.

Forget the bush, most people bitten in their own backyard. West Aussies are all very prone to getting eaten alive while socialising outdoors but if you’re up in the north of the State, you’ve also got a much higher likelihood of being bitten while boating, camping or fishing or working outside, compared to the rest of the state.

And don’t think you’re off the hook when you head off on holidays. A further 500 WA residents return from overseas travel with an exotic mosquito-borne disease every year. Heading to Bali? Beware of dengue, especially young adult males who return home with the illness more than others. There is limited mosquito management in many overseas countries where disease-transmitting mozzies can bite aggressively both indoors and throughout the day. This catches West Aussies off guard, as we are accustomed to mozzies biting outdoors, around dusk and dawn. When you’re in holiday mode it’s likely that you’ll be relaxing, having a couple of drinks and not thinking about applying repellent. Oddly enough, mosquitoes may actually be more attracted to people whose body temperature is higher. This happens naturally when you consume alcohol, so best pull out the repellent before you crack your first beer.

Despite our attractiveness to mosquitoes, we aren’t really aware of the most effective ways to avoid bites or how we can do our bit to reduce breeding in our own backyards. If you live by the mantra Cover Up. Repel. Clean Up you’ll have no problems!

mandurah_sep2014

Western Australia has some amazingly beautiful wetlands but these saltmarshes around Mandurah can produce large populations of nuisance-biting mosquitoes!

Cover Up

If you know you are going to be outdoors when mosquitoes are active, wear loose, long-fitting clothing that is light in colour. Believe it or not, mosquitoes can bite through tight pants as tough as jeans – I’ve witnessed it!

If you’re staying in accommodation that isn’t mosquito-proof, consider bed netting.

Try to keep children indoors when mosquitoes are most active. If exposure can’t be avoided, dress them appropriately and cover their feet with socks and shoes. Pram netting can also be really useful.

Admittedly, it’s not always practical to wear long sleeves during our warm summer nights, so there are going to be times when you need to use repellent. Choose a product that actually works and apply it appropriately so it does the job. Despite our best intentions, this is where we often go wrong. There are a few basic things to cover here, so stick with it!

Ingredient: Science tells us that the best active ingredient for repelling mosquitoes is diethyltoluamide (DEET for short) or picaridin. You need to look for either one of these names on the repellent label under the ‘active constituents’ section.

Unfortunately, natural repellents and anything wearable (e.g. bands, bracelets or patches) have very limited efficacy. Experts don’t recommend you use them and I consider this very wise advice. It only takes a single mosquito bite to become infected and chances are you will receive at least one if you rely solely on a product of this nature. It just isn’t worth the risk.

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Percentage: The next thing to consider is the percentage of the active ingredient. This can range anywhere from 7% to 80% which can make choosing a repellent confusing. Just remember, the higher the percentage, the LONGER the product will remain active for. It doesn’t mean it will repel mosquitoes better.

A repellent containing 16-20% DEET will provide around 4-6 hours of protection, and is a good place to start. Repellents labelled ‘tropical strength’ usually contain greater than 20% DEET – they are useful when you spend longer periods exposed to mosquitoes or if you are heading to a region where dengue, malaria or Zika is problematic. Kids repellents usually contain picaridin or <10% DEET.

Sometimes it can be tricky to work out the percentage of the active ingredient. You can see the Bushmans example below states this clearly, but the other bottles list the ingredient in grams per litre (g/L). No need for complex maths – just divide by 10 and you have the magic number! For example, the RID label below reports the product contains 160g/L of DEET. This would convert to 16% DEET – easy!

You can see a few examples here of effective repellents:

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How to Apply: No doubt we would all prefer if repellents didn’t feel quite so gross on our skin or didn’t smell so bad. Even I have to admit that before I moved into this field, I was guilty of putting just a dab here and a dab there. Unfortunately, this is flawed logic that will only result in you being bitten!

Repellents must be applied correctly to be effective. That means reading the label and applying it evenly to all areas of exposed skin. Remember to reapply the product if you are exposed to mosquitoes for longer than the repellent protects you for. You’ll also have to reapply the repellent after sweaty activity or swimming.

For more information on repellent use in adults and children, click here.

Clean Up

Mosquitoes need water to breed, but only a very small amount. Water commonly collects in a range of things you may find in your backyard including pot plant drip trays, toys, old tyres, trailers and clogged up gutters. Mosquitoes also love breeding in pet water bowls, bird baths and pools if the water is not changed weekly or they are not well maintained. Rain water tanks can also be problematic so place some insect proof meshing over any outlets. When you’re holidaying, cover up or remove anything that may collect water.

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If you need more official info from WA Health about mosquito-borne disease or simple ways to prevent being bitten click here. And if you want to read more about how much West Aussies know (or don’t know) about mossies, check out Abbey’s excellent paper here! Joint the conversation too on Twitter by following Abbey and Cameron.

Preserve and protect? Exploring mosquito communities in urban mangroves

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This is a special guest post from Dr Suzi Claflin. Suzi found herself in Sydney, Australia, (via Cornell University, USA) in 2015 to undertake a research project investigating the role of urban landscapes in determining mosquito communities associated with urban mangroves. She was kind enough to put this post together to celebrate the publication of our research in Wetlands Ecology and Management!

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Sometimes you’ve got to make hard choices for the greater good. These situations can arise anywhere, but here – as usual – we are concerned with mosquitoes. There’s a balancing act carried out by public health officials and wetland managers trying to both preserve endangered habitat and protect human health. In this guest post, I’ll explain the science behind research I recently published in collaboration with Dr Cameron Webb, and suggest one way forward for addressing human and environmental health concerns in urban wetlands.

During my PhD, I studied how the landscape surrounding small-scale farms affects the spread of a crop virus and the community of insect pests that carry it. When I came to Australia to work with Cameron, I was surprised to find myself applying the same type of landscape ecology to mosquitoes and mangroves in urban Sydney.

The misfortune of mangroves

Mangroves are real team players. They provide a range of services to the surrounding ecosystem and to the humans lucky enough to live near them. Mangroves are extremely effective at protecting the shoreline (but this can sometimes be a problem). They prevent erosion by gripping the soil in their complex root systems and buffer the beach by serving as a wave break. By filtering sediment out of the water that flows over them, mangroves also prevent their neighbouring ecosystems, such as coral reefs and seagrass forests, from being smothered.

Despite all their good work, mangroves have an almost fatal flaw; they prefer waterfront property. Unfortunately for them, so do humans. Urban and agricultural development has eaten away at mangroves, leaving them highly endangered.

The mosquito menace

Mozzies are a public health menace, because they spread human diseases like Ross River virus (RRV). Because of this, public health officials rightly spend time considering how to supress mosquito populations in order to reduce the risk of disease transmission.

Here’s where things get tricky: mangroves are great for mosquitoes.

That leaves public health officials and wetland managers in a difficult position. On the one hand, mangroves are delicate, at-risk ecosystems that need to be preserved. On the other, mangroves and surrounding habitats potentially harbor both the animal carriers of the RRV (e.g. wallabies) and a load of mosquitoes, which means that people nearby may need to be protected.

How can we do both?

 

claflin_mangroves

Dr Suzi Claflin trapping mosquitoes in the mangroves along the Parramatta River, Sydney, Australia.

 

The potential power of prediction

This is a hard question to answer. One approach is prediction: using measurements of the environment, like rainfall and tide level, to estimate what the mosquito community will look like in a given region. The mosquito community determines what management actions, like spraying an insecticide, need to be taken, based on the threat it poses to public health.

We set out to explore how the way we use land (e.g. for residential areas or industrial areas) near urban mangroves affects the mosquito communities that live in those mangroves. The project involved dropping over retaining walls, slipping down banks, and tromping through muddy mangroves along the Parramatta River in Sydney. We set mosquito traps (billy cans of dry ice with a container on the bottom) and left them overnight to capture the mozzies when they are most active. We did this at two points in the summer, to see if there was any change over time.

We found that yes, the way we use land around a mangrove makes a difference. Mangroves with greater amounts of bushland and residential land in the surrounding area had fewer mosquitos, and fewer species of mosquitos. On the other hand, mangroves with greater amounts of industrial land surrounding them had a greater number of mosquito species, and those surrounded by greater amounts of mangrove had more mosquitos.

And, just to muddy the waters a bit more (pun intended), several of these relationships changed over time. These results show that although prediction based on the surrounding environment is a powerful technique for mangrove management, it is more complicated than we thought.

Another way forward: site-specific assessments

Our work suggests another way forward: site-specific assessments, measuring the mosquito community at a particular site in order to determine what management approaches need to be used. This is a daunting task; it requires a fair number of man-hours, and mangroves are not exactly an easy place to work. But it would be time well spent.

By assessing a site individually, managers can be confident that they are taking the best possible action for both the mangroves and the people nearby. It turns out that the best tool we have for striking a balance between environmental and public health concerns, the best tool we have for preserving and protecting, is information. In mangrove management—as in everything—knowledge is power.

Check out the abstract for our paper, Surrounding land use significantly influences adult mosquito abundance and species richness in urban mangroves, and follow the link to download from the journal, Wetlands Ecology and Management:

Mangroves harbor mosquitoes capable of transmitting human pathogens; consequently, urban mangrove management must strike a balance between conservation and minimizing public health risks. Land use may play a key role in shaping the mosquito community within urban mangroves through either species spillover or altering the abundance of mosquitoes associated with the mangrove. In this study, we explore the impact of land use within 500 m of urban mangroves on the abundance and diversity of adult mosquito populations. Carbon dioxide baited traps were used to sample host-seeking female mosquitoes around nine mangrove forest sites along the Parramatta River, Sydney, Australia. Specimens were identified to species and for each site, mosquito species abundance, species richness and diversity were calculated and were analyzed in linear mixed effects models. We found that the percentage of residential land and bushland in the surrounding area had a negative effect on mosquito abundance and species richness. Conversely, the amount of mangrove had a significant positive effect on mosquito abundance, and the amount of industrial land had a significant positive effect on species richness. These results demonstrate the need for site-specific investigations of mosquito communities associated with specific habitat types and the importance of considering surrounding land use in moderating local mosquito communities. A greater understanding of local land use and its influence on mosquito habitats could add substantially to the predictive power of disease risk models and assist local authorities develop policies for urban development and wetland rehabilitation.

Dr Suzi Claflin completed her PhD at Cornell University exploring environmental factors driving the spread of an aphid-borne potato virus on small-scale farms. She is now a postdoctoral research fellow at the Menzies Institute for Medical Research in Hobart, TAS. In her spare time she runs her own blog, Direct Transmission, focusing on disease and other public health issues (check it out here). To learn more about her doctoral research, follow this link!

Do outbreaks of mosquito-borne disease always follow floods?

webb_deepwater

Water, water everywhere…and mosquitoes soon to follow. It makes sense that with more water you’ll get more mosquitoes and with more mosquitoes you’ll get more mosquito-borne disease. Right? Well, not always.

With floods hitting parts of inland NSW, health authorities have issued warnings about mosquitoes and mosquito-borne disease.

Western NSW, has been substantially impacted by flooding this month and the region has been declared a natural disaster zone. The Lachlan River at Forbes has reached a level not seen for 25 years. There is a lot of water about. 35,000 mega litres of water has also been released from Wyangala dam resulting in further flooding. There could be more to come as “Superstorm 2016” continues to bring rain to south-east Australia. Evacuations continue.

The flooding has come at a time when the weather in warming up and there are already reports of mosquito numbers increasing. The biggest concern is that once the flood water recede, how long will pools of water remain, have mosquitoes got a “jump start”on the season?

On the other side of the world, Hurricane Matthew is threatening Florida. The Bahamas and Haiti have already been hit and more than 2 million people in the US have been told to evacuate their homes. Flooding is expected.

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Mosquitoes need water

There is no doubt that mosquito populations can increase rapidly following flood. There is even a group of mosquitoes commonly called “floodwater mosquitoes“. The desiccation resistant eggs of these mosquitoes are laying dormant in the cracks and crevices of flood plains, just waiting for the water to arrive. When it floods, the eggs hatch and in about a week or so, swarms of mosquitoes emerge.

For the most part, it isn’t immediately following the flooding, but in the weeks and even months following that can provide the most ideal conditions for mosquitoes. If temperatures aren’t high enough to drive rapid evaporation of ponding (or if additional rainfall keeps them topped up), mosquitoes can start building impressing population abundances. With more mosquitoes, the risk of mosquito-borne disease outbreak can increase.

bom_rainfalljulyseptember2016

Rainfall records provided by the Bureau of Meteorology indicate that over the three months to September 2016, some regions of NT, QLD, NSW and Victoria received some of their highest rainfall on record for the period. (Bureau of Meterology)

A look back to floods and mosquito surveillance

In 2011-2012, QLD, NSW and Victoria saw incredible flooding. For those of us working in the field of mosquito-borne disease, we’re well aware of what that flooding can cause. Our attention was sparked when stories starting coming out from locals about this being the biggest flooding since the 1970s. Why was this important? Following flooding in the 1970s, we saw one of the biggest outbreaks of the potentially fatal Murray Valley encephalitis virus Australia has seen. This outbreak, and the response to the actual and potential health impacts, was essentially the genesis of many mosquito-borne disease surveillance programs across the country.

One of those programs was the NSW Arbovirus Surveillance and Mosquito Monitoring Program. Following the flooding in early 2012, there was a huge jump in mosquito populations in western NSW and one of the largest collections of mosquitoes in the history of the program was recorded with over 18,000 mosquitoes collected! Fortunately, we didn’t see any substantial activity of Muray Valley encephalitis virus but elsewhere in Australia, cases were reported.

mve_1974

Mosquito-borne disease outbreaks need more than just mosquitoes

There is little doubt you need mosquitoes about for pathogen transmission. However, for many mosquito-borne diseases, the pathogens that cause the illness in people are naturally found in wildlife. Person to person transmission may occur but for pathogens such as West Nile virus, Ross River virus or Murray Valley encephalitis virus, the mosquitoes that inject their virus-filled saliva into people have bitten birds or mammals previously.

The role of wildlife is important to consider as the flooding may influence mosquito populations but they can also influence wildlife. While kangaroos and wallabies may be adversely impacted by floods, flood waters can provide a major boost for waterbirds.

In some instances, as is the case for Murray Valley encephalitis virus, floods provide ideal conditions for both mosquitoes and birds!

HexhamSwamp_stilts

Do floods really cause outbreaks of mosquito-borne disease?

There are few studies that have demonstrated that outbreaks of mosquito-borne disease always occur following floods.

Studies in North America had previously concluded that there wasn’t a direct link between hurricanes and flooding and mosquito-borne disease. But, that doesn’t mean there won’t potentially be a boost in nuisance-biting mosquitoes following flooding.There is often widespread spraying to control these pest mosquito populations.

Interestingly, after Hurricane Katrina hit New Orleans in 2005, there was an increase in mosquito-borne disease with more than a 2-fold increase in West Nile neuroinvasive disease. However, other reports noted no significant increase in cases of either West Nile or St. Louis encephalitis viruses. Surveillance for 6 weeks following the hurricane, authorities found no arboviruses circulating in local mosquito populations. These results highlight that much more than water and mosquitoes are required for outbreaks of disease.

In Australia, a recent review looked at the influence of flooding on cases of Ross River virus disease. They found that the evidence to support a positive association between flooding and RRV outbreaks is largely circumstantial. The trouble in predicting outbreaks of Ross River virus disease is that there can be complex biological, environmental and climatic drivers at work and, irrespective of local flooding, there may be other region-specific issues that either increase or decrease the potential for an outbreak.

What should we expect in Australia as summer approaches?

There is no doubt mosquito repellent will come in handy over the coming months. There are already reports of increased mosquito populations in some parts of the country. While nuisance-biting impacts will be a worry, if mosquito populations further increase following flooding, authorities need to remain mindful of a range of other health risks too.

The good news is that unless higher than normal mosquito populations persist into the warmer months, we may not see major outbreaks of disease. It typically isn’t until November-December that we start to see pathogens circulate more widely among wildlife and mosquitoes. Hopefully, if some hot weather arrives, the flood waters will quickly evaporate and abundant mosquitoes populations won’t continue.

Current outlooks suggest that between now and December 2016, south-eastern regions of Australia are likely to receive above average rainfall. Temperatures, though, are likely to be a little cooler than normal. We’re probably lucky that this cooler weather will keep the really big mosquito population increases that we saw a few years ago at bay.

On balance, we’re expecting plenty of mosquitoes to be about as summer starts, hopefully not “mozziegeddon” but enough to ensure the community should stay aware of the health risks associated with mosquito bites and how best to avoid their bites.

Have you seen mosquitoes about already this season? Join the conversation and tweet some shots of local mosquitoes!

Could a podcast stop mosquito bites?

podcasting_mozziebites

This week I’m attending OzPod 2016: the Australian Podcast Conference, a workshop at the ABC, Ultimo. Celebrating International Podcast Day, the workshop brings together podcasters for “an event for the expanding podcast industry to escape the studio or office and meet with peers to share experiences, information, insights and ideas around audience acquisition and retention, new technologies, the rise of the podcast in traditional media, monetizing and of course the fine art of storytelling.”

 So, why am I going? I don’t even have a podcast!

I may not have a podcast now but I hope to start playing around with the platform soon as a complement to my other efforts to spread the word on science communication and public health awareness.

I’ve been thinking about kicking off a podcast for a while but have been a little reluctant due to time commitments. More importantly, I’ve also wanted to have a clear idea of what exactly I want to do.

In a previous life, I co-hosted a radio show on FBI Radio (during their test broadcast days) with my wife called “Good Morning Gidget”. It was a Saturday morning show of surf music and interviews with professionals involved in a wide range of coastal-based activities, from marine biologists to surf shop owners. Despite the early start on a Saturday morning, it was a load of fun. I’d also worked behind the scenes producing a couple of music shows. If I had more time, I really would have liked to pursue more work with community radio.

Perhaps podcasting will be the backup plan.

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It’s great to listen back to packaged interviews with radio, like the Health Report (I’m talking zika virus) but I was also lucky enough to have a chance to contribute to a few podcasts this year. I spoke with Science On Top about the outbreak of Zika virus and the implications it has for Australia, Flash Forward on what will happen if we eradicate mosquitoes from the planet and ArthroPod on what its like to study mosquitoes for a living!

All these were a lot of fun and were really motivating for me to want to get started with podcasting myself.

I feel like my experience with sound recording and ongoing engagement with media provides a solid background in most of the technical skills I need to get started. I’m hoping I’ll leave the OzPod 2016 conference with a few more tips on story telling and structuring a podcast too.

What I’ve been struggling with is format. I like the conversational nature of most podcasts but as I’ll probably be doing everything myself, perhaps a more structured and edited podcast is the go?

There are very few podcasts I listen to that are built around a one-person show. I’m not sure I could pull it off. Does anyone really want to listen to me ramble on for 20 mins about mosquitoes? 40minutes?

Sometime over the coming summer I hope to launch a short series of podcasts covering some of the basics of mosquito biology and how that relates to the ways we protect ourselves and our families from mosquito bites and mosquito-borne disease. I want to share my fascination with mosquitoes and explore some of the gaps in our understanding of mosquitoes, particularly their role in our local environment. 

Hopefully I can recruit some of my colleagues from around Australia for a chat too so we can share a little about the science behind our public health messages and what life is like to be chasing mosquitoes around swamps all summer

Sound like a good idea? Join the conversation on Twitter and let me know what you think, would you listen to a podcast about Australian mosquitoes?

 

 

 

 

 

 

Social media and blood suckers showcased at the International Congress of Entomology

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Digital technology is changing a lot about how we undertake entomological research and communicate the results of that research to the community and policy makers.

This week in Orlando, Florida, is the International Congress of Entomology (ICE). A huge gathering of entomologists from around the world. While it was a great pleasure to be invited to participate, I couldn’t get over there this time.

I will, however, have a chance to present my work in the Symposium “Entomology in the Digital Age”  Friday, September 30, 2016 (01:30 PM – 04:45 PM), Convention Centre Room W222 A.

In the presentation I’ll share some of the reasoning behind my use of social media to engage the community with both entomological research and public health communication. Most importantly, it will focus on some of the metrics I’ve recorded alongside my use of social media, maintaining a blog of research and writing for outlets such as The Conversation.

I’ve written about my use of social media and how it can help extend the reach of public health messages and presented on the topic alongside a range of great speakers at the 2014 Entomological Society of America meeting in Portland.

This time around, technology is playing an even more direct role in my presentation! I’ve pre-recorded my presentation and it will be shown to the audience on the day among other presentations. I’ll also be checking into the session to answer questions. Despite the fact I’ll need to be up around 1:30am due to time differences, it should be fun.

See the abstract below…

Taking entomological research from the swamps to the suburbs with social media

Cameron E Webb

Connecting scientists and the community is critical. This is particularly the case for medical entomologists working in the field of mosquito-borne disease where the translation of entomological research into improved public health outcomes is a priority. While traditional media has been the mainstay of public health communications by local authorities, social media provides new avenues for disseminating information and engaging with the wider community. This presentation will share some insights into how the use of social media has connected new and old communications strategies to not only extend the reach of public health messages but also provide an opportunity to promote entomological research and wetland conservation. A range of social media platforms, including Twitter, Instagram, and WordPress, were employed to disseminate public health messages and engage the community and traditional media outlets. Engagement with the accounts of traditional media (e.g. radio, print, television, online) was found to be the main route to increased exposure and, subsequently, to increased access of public health information online. With the increasing accessibility of the community to online resources via smartphones, researchers and public health advocates must develop strategies to effectively use social media. Many people now turn to social media as a source of news and information and those in the field of public health, as well as entomological research more generally, must take advantage of these new opportunities. doi: 10.1603/ICE.2016.94611


If you’re at ICE, you can also catch up with my PhD student David Lilly who’ll be presenting our research into the development of insecticide resistance in bed bugs as part of the symposium “New Insights into Biology, Resistance Mechanisms, and the Management of the Modern Bed Bug” Friday, September 30, 2016, 01:30 PM – 04:45 PM, Convention Center, West Hall F4 (WF4).

Novel insecticide resistant mechanisms in the common bed bug, Cimex lectularius

David Lilly, Cameron E Webb and Stephen Doggett

Introduction: Research on field strains of Cimex lectularius from Australia has identified widespread resistance to pyrethroid insecticides, but variability in the magnitude expressed. To determine if differences in resistance mechanisms exist, collected strains were examined for the presence of metabolic detoxification and/or cuticle thickening. Methods: The presence and relative contribution of detoxifying esterases or cytochrome P450 monooxygenases were assessed. Bed bugs collected from Parramatta (NSW), Melbourne (VIC) – 2 strains, ‘No.2’ and ‘No.4’, and Alice Springs (NT) were exposed in topical bioassays employing deltamethrin and two pyrethroid synergists: piperonyl butoxide (PBO) and EN16/5-1. PBO inhibits both monooxygenases and esterases, whereas EN16/5-1 will inhibit esterases only. Thus in a comparative bioassay, the results can infer the dominant enzyme system. The Parramatta strain was then selected to study the potential presence of cuticle thickening. Nine-day-old male bed bugs were exposed to filter papers treated with the highest label rate of Demand Insecticide®(200mL/10L of 25g/L lambda-cyhalothrin) and were grouped according to time-to-knockdown (< 2 hours, ≥ 4 hours, and survivors at 24 hours). Measurements of mean cuticle thickness at the transverse midpoint of the second leg tarsus were taken under electron microscope. Results/Conclusion: All strains possessed resistance that was inhibited by the synergists, with the Parramatta and Melbourne No.2 indicating esterase-dominance, and Alice Springs and Melbourne No.4 indicating cytochrome P450 monooxygenase-dominance. Cuticular measurements demonstrated that bed bugs surviving deltamethrin exposure had significantly thicker cuticles, denoting a novel form of resistance in these insects. doi: 10.1603/ICE.2016.92553

 

You can also see Stephen Doggett (co-author and photographer of A Guide to Mosquitoes of Australia) speaking on photographing mosquitoes to in the symposium “Insect Photography Symposium: Bringing the Small to the World.


You can join the conversation on Twitter and keep an eye on all the fun in Orlando by keeping an eye on the tweet stream!

 

Taking Australian wetland research to China

jayne_mosquitotrap

My PhD student Jayne Hanford has been super busy this year. Not much more than a year into her candidature and she has already locked away a summer of research and has been presenting her findings at conferences here in Australia as well as overseas.

After recently sharing our research at the Society for Wetland Scientists Annual Conference held in Corpus Christi, Texas, USA and the Mosquito Control Association of Australia conference on the Gold Coast, Jayne is off to China for the 10th INTECOL International Wetlands Conference.

Her research is focused on understanding the links between wetland vegetation, aquatic biodiversity and mosquito populations. Better understanding of these links will assist management strategies that minimise actual and potential pest and public health risks associated with mosquitoes and urban wetlands.

Our abstract for the conference is below:

Is the Biodiversity Value of Constructed Wetlands Linked to their Potential Mosquito-Related Public Health Risks?

Jayne Hanford1, Cameron Webb2, Dieter Hochuli1

1School of Life and Environmental Sciences, The University of Sydney, Australia; 2Department of Medical Entomology, Westmead Hospital and The University of Sydney, Westmead, Australia

 Stormwater treatment wetlands constructed in cities can enhance the sustainability of urban biodiversity by providing wildlife refuge areas and habitat connectivity. However, the creation of wetlands for stormwater infrastructure can increase risks to public health and wellbeing by proliferating nuisance-biting and pathogen-transmitting mosquitoes. In severe cases, this proliferation can erode goodwill in the community for creating and protecting valuable wetland systems.  We compared mosquito assemblages at 24 natural and constructed urban wetlands in the greater Sydney region, Australia. Our aim was to determine if stormwater wetlands constructed with the goal to support high biodiversity value also had reduced associated mosquito risks. Wetlands were located across a gradient of urbanisation determined by surrounding human population density, and included sites with different aquatic and riparian habitat complexity and availability. Adult and larval mosquitoes and aquatic macroinvertebrates were sampled on two occasions through summer and autumn. Aquatic macroinvertebrates were used to derive health indices, as well as being a relative measure of aquatic diversity.  Diversity of adult mosquito species was high, and abundance varied greatly between wetlands. Macroinvertebrate assemblages were also highly variable between sites. Wetlands with greater habitat complexity had lower adult mosquito abundance and greater mosquito species diversity, compared to stormwater-specific wetlands with minimal available habitat. As expected, mosquito assemblages did not respond to urbanisation and aquatic macroinvertebrate assemblages per se, but appeared to respond to a complex suite of coarse and fine-scale features that may affect a wetland’s biodiversity value.  Effectively integrating wetlands into cities requires balancing their design for water infrastructure purposes, biodiversity resources and public health and wellbeing requirements. Understanding the risks as well as the benefits will enhance the value of constructed urban wetlands in sustainable cities while minimising public health risks posed by mosquitoes.

Jayne will be speaking in the “The next generation of wetland science: ecosystems, applications, and engineering” session in the Nanhu Room 1520-1530 on Wednesday 21 September.

You can keep an eye on whats happening in China by following Jayne on Twitter and checking the hashtag

westernsydneywetlands

The Society for Wetland Scientists Annual Conference held in Corpus Christi, Texas, USA back in May included a paper by Jayne titled “Risky Wetlands? Conflicts between biodiversity value and public health” and prompted some great feedback and discussion among wetland scientists at the meeting. It was a successful trip and a timely reminder that I must get to one of the SWS meetings sometime soon, perhaps Puerto Rico?

Keep an eye out for Jayne’s research publications soon!