Football, ticks, mozzie vaccinations and big budget repellents: The year ahead in medical entomology

IMG_6223The new year is off and running. What twists and turns will mosquitoes and other biting arthropods provide in the year ahead? Here are just a few of the things I’ll be keeping my eye on.

Ross River virus along the east coast of Australia

Ross River virus is the most commonly acquired mosquito-borne infection in Australia. It causes a potentially serious illness with flu-like symptoms and, although not fatal, can be seriously debilitating. There are around 5,000 cases of disease reported each year with cases reported from across the country. It is something of an urban myth to suggest that “Ross River virus is moving south from Queensland”. In fact, some of the largest outbreaks in recent years have been in southern states. South-west Western Australia has had considerable activity in recent years.

Along the east coast, activity has actually been reasonably low. Flooding of inland regions during 2010-2012 resulted in some substantial activity west of the Great Dividing Range but along the coast, not that much has been happening. One explanation is that the average to above average rainfall the east coast has experienced in recent times is not conducive for the major pest mosquitoes associated with coastal wetlands. With drier conditions forecast for this summer, conditions improve for these mosquitoes. The recent king tides that occurred in the first week of 2014 have provided an opportunity for a major emergence of mosquitoes. This may get the ball rolling for a big year of mosquito activity along the coast.

While we can forecast a rise in mosquito populations, predicting an outbreak of Ross River virus is much more difficult. The key reason for this is that mosquitoes don’t hatch out of the wetlands infected with the virus, they must bite an infective animal (most commonly kangaroos and wallabies) first. This means that complex interactions occur between mosquitoes, environmental conditions and wildlife ecology. We don’t quite understand how all these factors interact just yet. What we do know is that it is unusual to have more than a couple of years without at least a minor outbreak of Ross River virus and with a combination of suitable environmental conditions, could the Autumn of 2014 see a surge in cases of disease?

Tri Nguyen Island, Vietnam. The site of release of Wolbachia infected mosquitoes as part of the Eliminate Dengue project (Photo: Eliminate Dengue)

Will the Eliminate Dengue project eliminate dengue?

The Eureka Prize winning Eliminate Dengue project has many excited by the prospect that mosquitoes could be “vaccinated” against dengue infection. There have been some great results from Cairns, Australia, where field released Wolbachia-infected mosquitoes have natural spread through study sites and successfully replaced large percentages of “wild” mosquitoes. However, it is one thing to have a well resourced field study looking at the spread of Wolbachia infected mosquitoes alone, will they actually reduce rates of dengue? To test the effectiveness in a dengue-endemic region, the Eliminate Dengue project is currently undertaking field testing in Vietnam.

Unfortunately, 2014 hasn’t got off to a good start to the project. News of some small, but not insurmountable, hurdles has come through from Vietnam where populations of Wolbachia-infected mosquitoes on Tri Nguyen Island aren’t persisting at forecast levels. While the rate of Wolbachia-infected mosquitoes reached close to 80% in August 2013, the rate had fallen to below 65% by early December 2013. Whether the falling prevalence of infected mosquitoes is due to higher mortality rates of infected mosquitoes (or at least some degree of reduced competitive advantage) or other environmental factors is yet to be determined. Hopefully better news will come later in the year.

The tick responsible for most bites along the east coast of Australia, the paralysis tick, Ixodes holocyclus. (Photo: Virginia Bear/Sydney Morning Herald)

Pulling ticks and pushing Lyme in Australia

Ticks, and their health impacts, in Australia are gaining some increasing notoriety. We’ve always known that ticks can pose a potentially serious health impact due to bite reactions. There is also the fascinating “tick induced red meat allergy” that is being seen more commonly around Sydney. However, the controversy around the potential presence of a pathogen causing Lyme Disease, or a Lyme-like illness, spread by local ticks has focused the attention of local authorities and communities where ticks are abundant.

It will be interesting to see what comes out of the Tick-induced Allergies Research and Awareness (TIARA) group and the federal government’s Clinical Advisory Committee on Lyme Disease over the coming year. In addition, the largest study into tick-borne pathogens is currently underway at Monash University with specimens being processed from across the country in an effort to find, identify and (hopefully) culture any pathogens present so that we can better understand the complex issues surrounding tick-borne illness.

Even if new tick-borne pathogens are documented, the advice provided by local authorities on avoiding tick bites is unlikely to change significantly. However, what has been missing from the promotion of tick bite prevention methods is some good quantitative evidence on the best measures to prevent bites as well as how best to remove a tick once it has attached. Many of the products promoted for use haven’t been registered by the Australian Pesticides and Veterinary Medicines Authority (APVMA) for use against ticks; creating difficulties for health authorities to recommend their use. Also, despite some recent guidelines on tick removal from Europe, these guidelines may not be appropriate against local ticks that have the potential to cause anaphylaxis and paralysis. So, do you just pull off attached ticks or kill them first with an insecticide? We’re expecting some guidelines from the TIARA group this year (in the meantime, stay tuned for a blog post about this from me in coming weeks).

Dengue & FIFA World Cup in Brazil

There wouldn’t be a better place to be for a football loving entomologist than the FIFA World Cup in Brazil in June & July 2014. Enjoy some football; research some dengue!

Brazil has been a focus for dengue research for many years. With tens of thousands of travelers planning to visit Brazil for the world cup, concerns have been raised regarding the possible risk to travelers of dengue. Those risks are well founded as, not only is dengue endemic in the country, but many of the travelers to Brazil may not be fully aware of the risks and the appropriate personal protection measures they should take. We’ve seen this in recent years with a rise in the number of imported cases of dengue and Chikungunya virus with Australian travelers returning from SE Asian destinations. I’ve written about the need to educate travelers on avoiding mosquito bites in these dengue-endemic regions here.

While there is obviously a risk to travelers, a risk often overlooked is the possibility that travelers returning to their home countries may inadvertently introduce dengue viruses to local mosquito populations. As is the case in Australia, there are regions where suitable mosquitoes are present that can transmit dengue viruses but the disease is not endemic. Sporadic, and occasionally significant, outbreaks are triggered by infective travelers. Could we see locally acquired cases of post-World Cup dengue in North America, Europe or Australia? Conversely, could travelers import a new mosquito-borne virus into South America? (see below)

St Vincent: Holiday destination and location of first Chikungunya cases in the Americas (Telegraph)

Chikungunya in the Americas

2013 was the year that Chikungunya really made its presence felt in Australia. This was due to the Asian Tiger Mosquito knocking at the door of mainland Australia and raising the risk that a temperate climate tolerant mosquito may one day be widespread in Australia and, as a key vector of Chikungunya virus, could pose a serious health risk. Despite no known locally acquired cases of the infection in Australia, the numbers of infected travelers returning from Chikungunya endemic regions jumped dramatically in 2013 with over 100 cases reported compared to an average of about 25 cases for the previous two years.

It was at the end of 2013 that the virus was first detected in the Americas. By the first week of 2014 almost 100 cases now reported from Caribbean island of St Martin. Now with effective vectors of Chikungunya virus throughout much of South America and many parts of North America the question of whether more outbreaks are likely to occur should be asked. With increased travel to South America in conjunction with the FIFA World Cup (and additional tourism activity prompted by the tournament), perhaps the greatest risk is posed by travelers introducing the virus to other countries where suitable vectors are present. Perhaps Zika virus may pop up too in South America too…

Repel_illustration_DSMouthwatering mozzie repellents and a move away from topical formulations

The media love news of a new mosquito repellent. There is likely to be a steady stream of news stories this year about the discovery of new mosquito repellent chemicals. Considerable research is going into the discovery of chemicals, derived from a range of botanical and non-botanical sources, that may hold potential as mosquito repellents. Some neat computational analysis is being done that includes “molecular field topology analysis, scaffold hopping, and molecular docking” to uncover new repellent products. A recent study identified a few “nice” smelling chemicals that may be effective and more user friendly repellents. There also seems to be a focus on products derived from “food grade” substances, I assume as a way to avoid some of the registration obstacles and/or allow greater marketability for the “natural” repellent market. I expect to see many more announcements over the course of the year….but very few new products being made available that will make much of a differences “in the real world” (at least this year).

These “discoveries” are usually framed within the context that N,N-diethyl-3-methylbenzamide (DEET) based repellents are unsafe or unpleasant to use. This argument lacks substance when you considered that the safety of DEET is demonstrated time and time again. In addition, most circumstances call for the use of only a low or moderate concentration DEET-based repellent. A formulation that only contains about 10% DEET will still provide a few hours protection. Interestingly, a lot of the commercial “low dose” DEET-based repellents are being replaced by picaridin-based (a product considered more “user friendly”) repellents here in Australia.

Rather than new active ingredients, what we really need is better formulations. A move away from topical repellents would be a great move and overcome the difficulties in “user compliance” to get the most effective results. The most promising product in this regard is metofluthrin. This product has recently been registered for use by the APVMA in Australia so I’m looking forward to seeing it available in local stores. It has proven to be effective in preventing mosquito bites. What is most interesting is that the product is usually included with battery operated “clip on” devices that individuals wear. They may not prevent bites when mosquito populations are high (e.g. close to wetlands) but could be a useful alternative to topical repellents when mozzies are just causing a mild annoyance.

The half a million dollar mosquito repellent – Kite Patch

$600,000 would buy a lot of mosquito repellent!

One of the most amazing things to happen last year was the phenomenal support provided to a crowd-funded mosquito repellent patch that purported to make the wearer invisible to mosquitoes. The company raised almost US$600,000 for filed testing of their patches in endemic regions of Africa. Yep, over half a million dollars.

I’ve written about what is required to evaluate new mosquito repellents (it was easily the most read post on my blog last year). Field tests of the Kite Patch are scheduled to commence in Uganda in January 2014 so I will be keeping a keen eye out for any updates. Most importantly, I’m keen to see some published peer-reviewed papers reporting on field and laboratory testing of these new repellents. Hopefully we’ll know by the end of the year whether the “dream” of an effective non-topical repellent can become a reality. The next interesting development will be when the patches are sent out to supporters of the crowd funding campaign. This isn’t expected to be until late 2014 or early 2015 (after the completion of Uganda field tests and EPA approvals).

QLDControl1949Australian mosquito researchers head west

The 11th Mosquito Control Association of Australia conference will be held in Mandurah, Western Australia on 7-10 September 2014. The conference will be held at The Sebel Mandurah and is shaping up to be an exciting forum. Mandurah is located an hour south of Perth and plays an important role in mosquito ecology, being located on the Peel and Harvey estuaries with large areas of tidal saltmarsh habitat. Management of mosquitoes and mosquito-borne disease has been an important issue for local authorities.

The theme of the 2014 conference is “Bringing good science to strategic programs” will bring together research entomologists, field biologists, and vector control specialists in a unique networking environment designed to promote collaboration and partnerships to improve preparedness, prevention, and control of vector-borne diseases of medical importance. Keep an eye on the MCAA website for more details in the next month.

So, it looks like there will be plenty of medical entomology stuff to keep an eye on for 2014, I wonder what surprises will be tossed up….

And the winner is…me! How the Sydney Olympics got me hooked on mosquito research

winnerissydneySomething happened 20 years ago that set the wheels in motion for my life in the swamps. On September 24 1993 International Olympic Committee President Juan Antonio Samaranch announced that Sydney had successfully won the right to host the Olympic Games in the year 2000. With those now famous words, “and the winner is…Sydney”, my path towards a life of research into mosquitoes and wetland rehabilitation had begun. Not that I realised this at the time.

In September 1993 I was nearing the completion of a BSc at Macquarie University. Although I was thinking about continuing with Honours the next year, a PhD was still a long way from my mind. I was probably worrying more about securing tickets to the following year’s Big Day Out to see Teenage Fanclub and the Breeders than launching my research career. I certainly had no idea at the time how important the 2000 Olympics announcement would be for me.

Although the area around Homebush Bay had been earmarked for redevelopment for a long time, it was the announcement that this was to be the central location for the 2000 Olympics that really kicked off the transformation of the site. Most importantly for me, it wasn’t just the sporting and accommodation facilities that were being built that was important, it was the major wetland rehabilitation projects planned that provided me with a life changing opportunity.

IMG_7562Mosquitoes had been a problem around Homebush Bay, and parts of the Parramatta River, for a long time. There had been reports of nuisance-biting problems and mosquito control programs in the local region since the 1920s. There was even a push from the community in 1929 to spray kerosene on local wetlands from an aeroplane to control mosquitoes!

During the 1980s, the pest mosquito problems began to intensify as local communities around Homebush Bay complained to local authorities about how unpleasant life had become during the summer months. One of the problems, as I would find later during my PhD candidature, was that the unusually high mosquito populations were really symptomatic of the poor health of the estuarine wetlands. The shoreline along Homebush Bay and the Parramatta River had been heavily modified and this had restricted the flow of tides and rainfall runoff into and out of the wetlands. The wetlands had become clogged with large areas of stagnant water. As well decreasing the health of the wetlands, it enhanced conditions for the production of pest mosquitoes.


The saltmarsh mosquito, Aedes vigilax. (Photo: S. Doggett)

The most important pest mosquito was the saltmarsh mosquito, Aedes vigilax. This species is a severe nuisance-biting pest, disperses many kilometres from wetlands and is closely associated with outbreaks of mosquito-borne disease. Along the east coast of Australia, this species has been identified as playing a key role in the transmission of Ross River virus and Barmah Forest virus during epidemics.

Along the Parramatta River, the risks of mosquito-borne disease are minimal as there are no native animals (i.e. kangaroos and wallabies) that act as reservoirs for the mosquito-borne viruses. However, large populations of these mosquitoes can still cause a problem due to their nuisance-biting.

newingtonA large section of wetlands at Homebush Bay was contained within the Royal Australian Navy Armament Depot (RANAD) Newington (commonly known as the Newington Armory). This site was operated as a ammunition depot from 1897 through until 1999. With a desire to better understanding the environmental drivers of pest mosquito populations and to develop environmentally sustainable strategies to reduce the mosquito populations, the Australian Government Department of Defence provided funds to support a PhD project through the University of Sydney.

I had just finished my BSc (Hons) at Macquarie University investigating the response of ant populations in rehabilitated coastal sand dunes and the role of mosquitofish in Sydney’s declining frog populations. I’d developed a love of research and started looking around for projects. I was originally interested in a project studying bird populations associated with rehabilitated urban streams but that didn’t quite work out. Someone passed on the details of a PhD scholarship with the University of Sydney to investigate mosquitoes. I was fortunate to be awarded that scholarship and haven’t looked back.

SOPA_mangrovesfloodedWhat I love most about working with mosquitoes is that they’re a link that connects many aspects of environmental science, entomology, public health and scientific communications. Mosquitoes, particularly Aedes vigilax, are Australian native animals that have adapted to a specific, and particularly harsh, ecological niche. These estuarine wetlands, particularly saltmarshes, where the mosquitoes are found are also important and threatened ecosystems. Perhaps the mosquitoes are also vital components of these ecosystems as a food source for insectivorous animals?

While it is certainly true that large populations of mosquitoes can be produced from healthy natural wetlands, I am finding that unusually large mosquito populations are often found in association with degraded wetlands, particularly those in urban areas. The work I’ve done documenting the ways in which degraded wetlands can be rehabilitated, while reducing mosquito populations, will hopefully assist in the development and willingness of local authorities to undertake rehabilitation projects.

mozzielarvaeI’ve come to realise that mosquito management needs to be a key component of wetland management. Notwithstanding the duty of care wetland managers have to reduce potential public health impacts, engaging the community to care about wetlands and their conservation will always be much harder if visitors are chased away by swarms of biting mozzies. Effective mosquito management can help wetland conservation!

Together with the Sydney Olympic Park Authority, I’ve had an opportunity to incorporate my ongoing research into the development of ecologically sustainable mosquito management strategies. We’ve conducted a number of projects that have restored tidal flushing to degraded areas of mangroves to improve the health of the wetlands while also reducing the need for mosquito control. In areas where mosquito control is required, a detailed surveillance and assessment program is in place that ensures that mosquito population increases are minimised without any adverse impacts to the local environment.

Webb_Mangroves2The other benefit of working closely with the Sydney Olympic Park Authority has been the opportunity to work with them on educating the community and a range of professionals on the importance of wetland conservation. Whether it is public lectures, speaking to school groups or coordinating workshops on wetland management techniques, it has been a pleasure to share my experiences and knowledge with new groups of people.

I think that there was a time when mosquito control operations were perceived as being at odds with wetland conservation but I argue strongly at every opportunity that an integrated approached to wetland management, that includes mosquito management, is critical. Once wetlands were drained or filled to control mosquitoes, now tidal flows and predator populations are promoted to reduce the suitability of wetlands for pest mosquitoes.

Now, on the 20th anniversary of that historic announcement by Juan Antonio Samaranch, I’m taking some time to reflect on what turned out to be a very fortunate opportunity for me. That opportunity introduced me to the world of mosquitoes and has allowed me to continue that work in one of the most interesting wetland rehabilitation projects in Australia.

Social Media and Hospital Week

webb_birdThe Westmead Association “Hospital Week” 2013 runs from 7-9 August. There are many symposiums, debates and social functions that showcase some of the clinical research, innovation and expertise displayed by the professionals associated with Westmead Hospital. Symposium topics include diabetes, cannabis & cannabinoids, infectious diseases and psychiatry.

As part of the Hospital Week Research Symposium, I will be presenting a poster titled “Can social media increase the exposure of medical research and public health messages?”

ABSTRACT. Increasing the exposure of public health messages and medical research is critical. Could the use of social media provide an avenue to increased exposure of new research and improve engagement with the wider community? The aims of this study were to determine if promotion and engagement via social media influenced how online information is accessed.

A recently published paper in an online open access journal was promoted on social media platforms (e.g. Twitter and Facebook). Changes in daily page views and downloads compared to another five publications were recorded for a three week period. The publication that received the most mentions on social media platforms was also the most viewed and downloaded.

A Twitter account was set up to disseminate public health messages and engage the community and traditional media outlets. The total weekly exposure of “tweets” was measured for six months. On average, approximately 40,000 people per week received tweets with maximum exposure of almost 190,000 people in a single week. 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.

The results highlight the potential for social media to increase exposure of both newly published research and public health messages. 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 must take advantage of these new opportunities. In particular, the ability to easily engage with traditional media outlets further increases exposure beyond online communities.

I’ve taken this opportunity to present something a little different to my usual research (almost always related to mosquito-borne disease management) in the hope of sparking a little interest in the use of social media to both spread public health messages and promote newly published research. I’m also hoping to encourage a few of my colleagues to jump into the world of Twitter too.

This poster pulls together work presented in more detail in a couple of previous blog posts on my use of social media. Could social media help beat the bite of mosquito-borne disease? and Can social media increase the exposure of newly published research?

You can download the PDF of my poster here.

The London (down) underground mosquito

Culex_molestus_Photo_StephenDoggettOur latest publication in the Australian Journal of Entomology marks the end of a three year research project investigating the biology of a unique introduced mosquito species, Culex molestus, in Australia.

We generally think of nuisance-biting mosquito problems being confined to tropical regions, or at least warm summer conditions. Well, imagine you’re in London in late September 1940. You’re taking shelter in the underground during The Blitz. It is crowded and cold. You’re bitten by mosquitoes too. You’re being bitten by Culex molestus. It is often commonly referred to as the London Underground mosquito and has already been the subject of some fascinating research that has shown how the mosquito has adapted to life within the London underground.

Culex molestus was first described from Egypt in 1775. The mosquito is unique in that it is closely associated with subterranean habitats across the temperate regions of the world, from underground train networks to flooded basements to septic tanks. The species has adapted to these habitats by gaining the ability to mate without the need to swarm (a phenomenon known as stenogamy) and by dropping the requirement of a blood meal to develop the first batch of eggs (a phenomenon known as autogeny). You can read about our previously published work on this here.

Londoners take refuge in the Underground during the Blitz. Taken from “The Tube 150 Anniversary: London Underground, Its Life In Pictures ” Huffington Post UK

The Culex pipiens subgroup of mosquitoes includes a number of globally important vectors of disease-causing pathogens but there are distinct genetic and biological differences between these species that influence their role in transmission cycles. There are four member of the Cx. pipiens subgroup in Australia, Culex australicus, Culex globocoxitus, Culex quinquefasciatus and Culex molestus.

The last of these species, Cx. molestus, had not been the focus of substantial research for over 50 years until a research project by the Department of Medical Entomology and University of Sydney commenced in 2010. The project was designed to address the gaps in our knowledge of these species with a view to assisting in the assessment and management of disease risk associated with this species.

This work was primarily undertaken by Nur Faeza Abu Kassim as part of her PhD candidature with generous support from Ministry of Higher Education Malaysia and Universiti Sains Malaysia.

How did the mosquito get to Australia?

The most cited theory to explain the introduction of Cx. molestus into Australia is that it was through military movements into Melbourne during World War II. This was based on an absence of this species in Victoria during the pre-WWII period. Our research supported this theory.

There were no reports of this species in Australia prior to the 1940s. A review of distribution records for this species confirmed the presence of the species at over 230 locations confirmed that the mosquito has spread throughout the southern parts of Australia and in coastal regions as far north as Tweed Heads (NSW) and Geraldton (WA). No specimens have been reported from Queensland or Northern Territory.

Molecular analysis of specimens collected from throughout Australia, with reference to specimens from Asia, North America and Europe, indicated that Australian Cx. molestus shared the strongest genetic similarity with specimens from Asia. Perhaps the mosquito hitched a ride from Japan into the Pacific and then, with US military, in Australia?


An example of subterranean habitats closely associated with the presence of Culex molestus

Buzzing (and biting) about all year long?

One of the interesting findings of our research was that the mosquito was active throughout the winter months around Sydney. Analysis of weekly trapping over a 13 month period indicated that the species does not display diapause. As well as generally being a cool-temperate climate mosquito species, perhaps the subterranean habitats provided a little “insulation” from the cold, keeping water temperatures just a little warmer than above ground pools and ponds?

Most of the other nuisance-biting pests disappear during the cooler months. There will occasionally be a few about, particularly during warmer winter days. However, for most local pest mosquitoes, it seems to be the minimum daily temperatures that drive mosquito activity more than maximum daily temperatures. In the case of Cx. molestus, they soldier on regardless.

What about the public health risks?

One of the last unanswered questions regarding the potential public health impacts of Cx. molestus is in relation to the ability of this mosquito to spread local and/or exotic viruses. While local viruses (e.g. Ross River virus) have been isolated from field collected specimens, there is yet to be a thorough investigation of the ability of this species to transmit endemic pathogens such as Murray Valley encephalitis virus or Kunjin virus.

I was involved in a research project assessing the risks posed in eastern Australia due to potential introduction of West Nile virus. Laboratory investigations and field collections provided some valuable information but, due to prevailing environmental conditions at the time, there were very few Cx. molestus collected during the study. We need to complete some of this work to gain a better understanding on how important a role Cx. molestus may play in local disease risk.

One of the key implications of our research is that it highlights the need for urban planners and engineers to consider the risks posed by above and below ground water storage for creating mosquito habitats. While much of my work previously has concentrated on the creation of wetlands and rehabilitation of other habitats in association with urban development, rainwater and storm water storage structures should be adequately designed to reduce mosquito risk.

The full reference for our most recent paper is below:

Kassim NFA, Webb CE and Russell RC (2013) Australian distribution, genetic status and seasonal abundance of the exotic mosquito Culex molestus Forskal (Diptera: Culicidae). Australian Journal of Entomology 52: 185-198 [online]

ABSTRACT. Culex molestus was probably introduced into Australia in the 1940s and represents a potentially important nuisance-biting pest and vector of disease-causing pathogens in urban areas. The aims of this study were to review the literature to determine the current and historical distribution of Cx. molestus in Australia, analyse the genetic similarity of specimens collected from various locations in Australia with reference to specimens from North America, Asia and Europe, and document the seasonal abundance of this mosquito in the Sydney region. Results showed that Cx. molestus is common in southern Australia, but there was no evidence that this mosquito is found north of latitude 28.17°S. Molecular analysis indicated that specimens from various locations throughout Australia shared strong genetic similarity and that it was most likely introduced from Asia, possibly through multiple introductions over the past 70 years. Analysis of the seasonal abundance of Cx. molestus indicated that the species does not display diapause during the cooler months. Consideration should be given to the unique biology and ecology of this species when assessing the public health risk and the surveillance methods required in the management of Cx. molestus within urban areas of Australia.

You can read a media release from the University of Sydney here. Our research was picked up by the local and international media in the past week or so too. You can read about our work in the Daily Telegraph, Newcastle Herald and Sydney Morning Herald.

Previous publications as part of this research project include:

Kassim NFA, Webb C.E. and Russell RC (2012) The importance of males: larval diet and adult sugar-feeding influence reproduction in the mosquito Culex molestus. Journal of the American Mosquito Control Association 28: 312–316

Kassim NFA, Webb C.E. and Russell RC (2012) Is the expression of autogeny by Culex molestus Forskal (Diptera: Culicidae) influenced by larval nutrition or by adult mating, sugar feeding or blood feeding? Journal of Vector Ecology 37: 162–171

Kassim NFA, Webb C.E. and Russell RC (2012) Culex molestus Forskal (Diptera: Culicidae) in Australia: colonisation, stenogamy, autogeny, oviposition and larval development. Australian Journal of Entomology 51: 67-77

Making music from environmental sounds

Ward Pound Ridge Nature Preserve

I normally only post about my mosquito/medical entomology related activities but since World Listening Day 2013 is just around the corner, i thought I’d post about one of my hobbies, sound recording. Over the last 10 years or so I’ve had the opportunity to turn my love of environmental sound recording into a (mostly) self supporting hobby through the release of records under the name Seaworthy.

I wish I had the time to devote to studying the more academic aspects of acoustic ecology. Perhaps in the years to come, when I have more spare time, I’ll be able to delve into this pursuit. I will have more spare time in the future right? For now, I thought I’d write a short piece on the background to a recently released album, “Wood, Winter, Hollow”. Although not a purely an album of field recording, many of the sound sources were recorded in the local environment.

I recently had the good fortune to visit Westchester County, New York. I had the opportunity to stay with a friend and fellow musician (not to mention a wonderful photographer), Taylor Deupree. This was intended as a quick visit while i was on my way to Atlantic City for the American Mosquito Control Association meeting. I’d never had the chance to visit New York City but it was nice to also get out of the city and into a part of the world I’d only ever read about before. It was also the first time I had visited a region of the world with endemic Lyme disease (but I wasn’t there to study ticks this time around).

I visited in February. Winter. The local countryside was a world away from the Australian summer. The woodlands of (mostly) leafless tree were sparse and silent. There was a healthy snow cover and the ponds and lakes dotted throughout the countryside were mostly frozen over. Very few animals to be seen besides a few birds and deer. Despite what may sound a little like desolation, it was really quite beautiful.

Taylor and I took the opportunity to do some recording while I was there. What started out as just being an opportunity for me to record some of the wintery environmental sounds of Westchester County, turned into a couple of days of rapid fire recording.

PoundRidge_WWHFB_June10eMuch of our time was spent in the nearby Ward Pound Ridge Nature Preserve/Reservation. The park covers over 3000 acres and, as well as containing a number of historic buildings, is a biodiversity reserve containing extensive woodland and grassland habitats dissected by creeks and wetlands. I have no doubt that these environments are alive with sound during the summer but during winter there really is an eerie silence.

The relatively silent ambiance can force you into listening to most subtle sounds. Tiny crackles of water flow beneath a frozen stream surface or the faint rustle of those last few leaves clinging to otherwise barren branches. The otherwise incidental sounds like these can take on much more significance during winter where they would otherwise be drowned out during the buzz of insects, birds and frogs during the summer.

In these circumstances, it is often impossible to actually sit and listen to these sounds. You can only really appreciate them when they’re amplified or captured with special microphones. In particular, much of my recording is done using hydrophones. These are underwater microphones most commonly associated with the recording of whale songs. These can also be useful in recording aquatic arthropods too. The real joy for me though is recording the crackle and rattle of small streams where water is rushing through debris and rocks and tiny bubbles fizz creating the most wonderful sound. These types of recordings are even more abstract when made beneath the frozen water surface.

PoundRidge_WWHFB_June10fI usually approach environmental recordings from two perspectives. Firstly, it is impossible to switch off my “science” brain from searching and analysing the recordings to identify the source of the sounds. What animal is making that sound? What species of bird is it? What type of call is it? (One of my first ever research projects required analysis of sound recordings to identify the diversity of frogs across Western Sydney) Even amongst the abstract sounds recorded with the hydrophone, I’m trying to determine what physical processes are underway beneath the water surface to create the changes in water direction or pressure waves.

Secondly, I’m very attracted to the abstract sounds. I rarely set out to record the pure sound of particular species as you may hear in audio field guides (e.g. birds, frogs). I tend to generally record the ambient soundscapes through a filter of recording hardware and the placement of the microphones. I particularly enjoy the sounds that aren’t immediately identifiable. These can often be “happy accidents” where the microphone has picked up my own movements or may be due to some technical short comings on my behalf on operating the equipment! While these sounds may not strictly be “environmental sounds”, there is no doubt that I would be unable to recreate them in the studio. These sounds can sometimes be the most inspiring, or at least can trigger other ideas to investigate at another time.

PoundRidge_WWHFB_June10Unlike many other sound artists who work purely with environmental recordings (some of my favourites are Jana Winderen, Tom Lawrence and Chris Watson), I tend to incorporate my recordings with more traditional instruments. There are many other artists that pursue this methodology, many incorporate electronics or process the original recordings to such an extent that they may no longer become recognisable. A few of my favourite artists that fall into this category are Lawrence English, Marcus Fisher, Simon Scott, Stephen Vitiello and Matt Rosner.

Back in Westchester County, once a collection of environmental recordings were made, it was back to the studio to compose a series of music pieces. These were generally built on top of a bed of sounds and textures recorded from the woodlands and creeks of Ward Pound Ridge. For the most part they were improvisational but certainly many of the seeds of ideas were planted out in the field and in direct response to the recorded sounds. Once various instruments were layered, additional environmental recordings were then interwoven throughout the pieces.

IMG_6973Overall, it was a great experience and this release will forever be a perfect reminder of my time in Westchester County. Working on a project like this is not dissimilar to working on a collaborative research project. The opportunity to work with other people, who each bring a difference perspective and skill set typically results in a better outcome than if working alone. I know that many of my scientific publications would have been much poorer if it hadn’t been for the statisticians or microbiologists that brought their skills, that I lack, to the table.

The release of a CD is a lot like finally getting your research project published too. Perhaps music reviews aren’t quite as critical as the reviews of a newly submitted manuscript but, at least at this stage, a couple of people have enjoyed the music (Folk Radio UK and Fluid Radio). If you’re interested in reading more about this release and listening to some sound samples, please visit the 12k website.

If you’re interested in reading more about acoustic ecology, field recording and soundscapes, there is an excellent series of recent posts by Caleb Kelly up on the Sound Thoughts blog. One of the most cited references on the topic is “The Soundscape: Tuning of the World” by R. Murray Schafer (originally published in 1977). There is also nice article on soundscape ecology here.

You can also visit the Environmental Sounds blog run by Matt Rosner and myself that contains a number of recordings from both the east and west coast of Australia. We’re both trying to dedicate some more time to keep that blog updated!

Can social media increase the exposure of newly published research?


What can we learn about the benefits of social media by comparing the popularity of research into seals and mosquitoes? (Photo: Andreas Trepte,

There are many proposed benefits associated with the use of social media by scientists. There have been a couple of excellent pieces recently published that provide an overview of social media and some of the potential benefits of its use. Last month I wrote about tracking the exposure and reach of my tweets to measure the potential impact of public health awareness activities. Twitter seems to work well in providing exposure for public health messages, could it be used to increase exposure of new publications?

The role of social media in the promotion of research and publications has already received some attention. A study published in the Journal of Medical Internet Research (JMIR) measured the quantity of tweets linking to publications in JMIR. The authors found that 4208 tweets cited 286 distinct JMIR articles and concluded that “highly tweeted articles were 11 times more likely to be highly cited than less-tweeted articles”. Similarly, a study analysing access to and citation of pre-print publications posted to the arXiv database ( found that “the volume of Twitter mentions is statistically correlated with arXiv downloads and early citations just months after the publication of a preprint”.

There have also some interesting observations by Melissa Terras on her blog about the use of social media to increase exposure of publications. Melissa found that publications she blogged or tweeted about had at more than 10 times the number of downloads than her other publications. In particularly, Melissa posted a nice piece on increased access to one of her recently published open access papers after she had tweeted about it.

I’ve been planning to do something similar with my publications but just hadn’t had an opportunity to do it. One of the other issues is that I generally don’t publish in open access journals. I’ve been guilty of simply submitting articles to journals that I had previously published in or that were considered the key journals of mosquito research or were of regional importance (e.g. Australian Journal of Entomology, Journal of the American Mosquito Control Association, Journal of Vector Ecology).

On 7 May 2013, a publication that I was co-author on was published online in the open access journal PLoS ONE (Gonsalves L, Law B, Webb C, Monamy V (2013) Foraging Ranges of Insectivorous Bats Shift Relative to Changes in Mosquito Abundance. PLoS ONE 8(5): e64081. doi:10.1371/journal.pone.0064081). I was looking forward to the publication of this paper. It presented some of the research from a very exciting project investigating the ecological role of mosquitoes in coastal environments. I was also excited about publishing in PLoS ONE and having some research more widely (and freely) available.

Since PLoS ONE provide metrics on each of their publications, I thought I’d take the opportunity to track some of the basic metrics to see if activity on social media may influence exposure of the publication. Each day, for almost four weeks, I made a record of the page views, downloads and “social shares” (Facebook and Twitter mentions). I made a conscience effort to split my “self-promotion” tweeting into three distinct periods, the first few days after publication, a week or so later and then an additional week later.

Rather than just track our paper, I thought I’d also track some other papers published on the same day. I choose two “mosquito-related” papers, one “general health” related paper and two “ecology” papers. In selecting these papers, I simply browsed the list of publications to see what else had been published that day, I didn’t give any consideration to what impact or “newsworthiness” these papers may inherently have.

 The five additional papers selected were:

Kim J-Y, Ji S-Y, Goo Y-K, Na B-K, Pyo H-J, et al. (2013) Comparison of Rapid Diagnostic Tests for the Detection of Plasmodium vivax Malaria in South Korea. PLoS ONE 8(5): e64353. doi:10.1371/journal.pone.0064353 [the “malaria” paper]

Villabona-Arenas CJ, Mondini A, Bosch I, Schimitt D, Calzavara-Silva CE, et al. (2013) Dengue Virus Type 3 Adaptive Changes during Epidemics in São Jose de Rio Preto, Brazil, 2006–2007. PLoS ONE 8(5): e63496. doi:10.1371/journal.pone.0063496 [the “dengue” paper]

Winkvist A, Bertz F, Ellegård L, Bosaeus I, Brekke HK (2013) Metabolic Risk Profile among Overweight and Obese Lactating Women in Sweden. PLoS ONE 8(5): e63629. doi:10.1371/journal.pone.0063629 [the “lactation” paper]

Jessopp M, Cronin M, Hart T (2013) Habitat-Mediated Dive Behavior in Free-Ranging Grey Seals. PLoS ONE 8(5): e63720. doi:10.1371/journal.pone.0063720 [the “seal” paper]

Moody EK, Sabo JL (2013) Crayfish Impact Desert River Ecosystem Function and Litter-Dwelling Invertebrate Communities through Association with Novel Detrital Resources. PLoS ONE 8(5): e63274. doi:10.1371/journal.pone.0063274 [the “crayfish” paper]

On the day of publication, as is usually the case with new publications, I tweeted about the paper and provided a link to PLoS ONE. I also sent an email around to my “mosquito research” colleagues. In addition, I wrote a blog post, the buzz of bat conservation, that put the paper into context with the broader research project. I tweeted about that too, in fact I probably tweeted links to the blogpost more than the paper directly during those first few days. The paper’s lead author, Leroy Gonsalves, tweeted about the paper and blog post too.

I think it is important to note that, much to my disappointment and notwithstanding media releases from both the Australian Catholic University and University of Sydney media offices, I am not aware of any substantial coverage of our paper in the online or traditional media. All the promotion for this paper seemed to come from social media.

 So, what happened?

 Firstly, how much exposure did our publication get via social media? The chart below shows the total daily blog post views and “social shares” of the publication itself. You can see the results of my tweeting about the blog post early on. I guess it is hard to say how many people who read the blog post then went on to view or download the paper. There were, however, also number of tweets linking to the paper directly over the first few days. The additional periods of active “tweet promotion” were between 15-17 May and 24-25 May and you can see the resulting increase in “social shares” during those periods. It is also interesting to note that “social shares” on the 19 May too that, from what I understand, was not prompted by any active tweeting on my behalf.

The total daily blog post views and social shares of our publication

The total daily blog post views and social shares of our publication

How did this change the exposure of the publication?

Looking at the chart of cumulative page views, you can see that, as expected, all the papers had a quick jump in the first couple of days following publication and then the number of page views remained the same for the rest of the week. A couple of interesting observations from that first week. Our paper, along with the “malaria” paper, had the most page views at around 400. While we had put our efforts into social media (with plenty of tweets and a total of 14 “social shares”), there were no “social shares” of the “malaria” paper. The paper with the most “social shares” was the “seal” paper with 28 but less than 200 page views had occurred in that first week.

Total daily page views of our publication along with five additional papers published on the same day.

Total daily page views of our publication along with five additional papers published on the same day.

After a week or so, I put some effort into tweeting about the paper, this time linking directly to the publication. I also tried tweeting at times when people in the US and UK may be more likely to be online. Over this time, there was approximately another 20 “social shares” of our paper. The chart shows the resulting boost in page views over that next week or so. While all the other papers maintained a relatively consistent number of page views, ours jumped substantially so that by the end of the second week we’d had almost twice as many page views. There was no substantial boost in social shares of the other five papers.

A week or so later (now about two weeks after publication), I repeated the same amount of tweets with links to our publication. This third burst of tweets failed to repeat the noteworthy increase of earlier efforts. Why? Perhaps by the time I got around to my third burst of tweeting, any of my followers who were interested in this work had already checked out the paper or had already retweeted my messages on earlier occasions.

There is also the possibility that the spike in page views of our article may not have been the result of that second batch of tweeting. Perhaps there was some kind of delay between people seeing the links and accessing the paper? Could you trace that spike in interest back to the initial “social media push”?

Clicking a link is one thing but was the paper downloaded?

It is interesting to compare the cumulative rates of page views to the cumulative rate of downloads. In the chart of cumulative daily downloads of our publication below, you can see that a very similar trend is followed. After an initial rise and plateau, there is a secondary jump in downloads. There is a similar increase in the number of downloads of all the papers but it is quite dramatic in ours. However, after two weeks or so, and despite additional tweets with links to the paper, downloads grow at a very slow rate. This trend is also shown in the download data of the other publications.

Total daily downloads of our publication compared to five other publications published on the same day

Total daily downloads of our publication compared to five other publications published on the same day

Putting aside the debate around the timing of tweets their resulting influence on metrics, at the end of the three week period, our paper had received almost twice as many “social shares” as any of the other papers, and subsequently, substantially more page views and downloads. Surely the social media effort assisted in this result? I don’t want to draw too much from this relatively simple analysis but I think the resulting increase in exposure of the publication has been worth the relatively small amount of time invested in spreading the word via Twitter.

Lastly, I think it is important to make a note about the importance of the “traditional” media. As I mentioned earlier, I was both surprised and disappointed at the lack of coverage the publication received. I thought a new study that contributes some answers to one of the most commonly asked questions I get, “are mosquitoes good for anything?”, would have generated more interested. I guess all researchers think their research will attract wider interest!

So what happens when a paper is picked up and widely publicised? It is interesting to look at another recently published paper in PLoS ONE. Smallegange RC, van Gemert G-J, van de Vegte-Bolmer M, Gezan S, Takken W, et al. (2013) Malaria Infected Mosquitoes Express Enhanced Attraction to Human Odor. PLoS ONE 8(5): e63602. doi:10.1371/journal.pone.0063602 was published a week or so after ours on the 15 May. It is a great study with an interesting story. The researchers found that mosquitoes infested with malaria parasites are more attracted to humans than non-infected mosquitoes. It was really no surprised that it has been picked up by media outlets across the globe. There have been around 60 news items online that reference the paper, 325 “social shares” and the paper has been downloaded over 700 times. Could these numbers have been generated by social media alone? I have a sneaking suspicion that traditional media played a significant role in the promotion of this publication but social media, and the spread of links to both news coverage and the paper directly, must have played a role as well.

 UPDATE [6 March 2014]

It has now been around 10 months since our paper was published so I thought I’d revisit the metrics for all these papers to see if the trend we observed over the first few weeks continued.

Cumulative page views and downloads of six scientific papers published in PLOS ONE and respective "social media" shares

Cumulative page views and downloads of six scientific papers published in PLOS ONE and respective “social media” shares

It is interesting to see that our “Bats” paper received the most page views (2,186) over that time while the others ranged from 715 through to 1312. However, there wasn’t such a dramatic difference in the number of downloads with our paper downloaded 342 times compared to the 298 of the “Malaria” and 252 of the “Dengue” papers.

There is no doubt that our paper received the most “social shares” but it is also worth noting that there were plenty of Facebook shares of the “Seal” paper but that didn’t result in a boost to either page views or downloads compared to the other papers. In fact, there wasn’t much difference compared to papers with minimal or no “social shares”.

What does this mean almost a year on from publication? With regard to our paper, “social shares”, particularly Twitter, seemed to boost the number of page views we received. Given the result with the “Seals” paper, it is tempted to suggest that Twitter shares are more important than Facebook shares but I suspect I may be drawing a long bow on that one.

I don’t see anything in this analysis that suggests it isn’t worth putting in a bit of effort to promote new publications via social media. It would have been interesting to see what these metrics were like had one of these six papers tracked had been picked up by traditional media outlets. I suspect that working closely with your institution’s media office will be just as important, probably more so, than just relying on send out a few tweets.

Mozzie bites and tweet tracking

One of my favourite artists, Nat Russell, painted a wonderful portrait of me a couple of years ago

One of my favourite artists, Nat Russell, painted a wonderful portrait of me a couple of years ago. Perhaps think of this as me wading out into the sea of social media?

Could social media help beat the bite of mosquito-borne disease?

Social media won’t do it alone but I think it is definitely something Australian authorities should embrace. The only problem is, how do you measure the success of social media activity? Taking my activity on Twitter as a case study, I monitored the changes in follower number, “tweet type” and estimated reach and exposure of tweets over a six month period. This was during a time when I would normally be active in the media responding to  mosquito-borne disease outbreaks or general interest questions about mosquito biology.

As broad scale mosquito control programs are generally limited, Australian health authorities typically rely on the communication of personal protection strategies to reduce mosquito-borne disease risks. These personal protection strategies may include avoiding known mosquito habitats, wearing long sleeved shirts and long pants to create physical barriers to biting mosquitoes and the use of insect repellents. Messages are usually relayed to the public via media releases or online fact sheets.

I started using Twitter in September 2010 with the expectation that I could use the service to distribute those public health messages as well as news on mosquito and mosquito-borne disease research. I generally tweet material that is related to my position with NSW Health/Westmead Hospital/University of Sydney but my account is not an official source of information from those organisations. I generally keep “personal” tweets to a minimum.

I’d already had some experience with public health communications working groups. I consider my activity on Twitter to be an extension of that work. In particular, my work with the “Living with Mosquitoes” group in the Hunter region investigated new ways to raise awareness of mosquito-borne disease risk and communicate more effectively the benefits of personal protection strategies. A couple of the options we tried were the incorporation of “mosquito risk periods” into free tide charts and stickers designed for primary school students. We even briefly (unsuccessfully) experimented with using myspace to host some information.

Using Twitter to spread the message

How did I go about using Twitter to help spread the word on mosquito-borne disease? At first I was expecting to build a following directly with the public by growing the number of followers. What I’ve found, however, is that the greatest benefit of Twitter has been when it is used in association with traditional media activities. Tweets can be exchanged between myself and the presenter/broadcaster/publisher, particularly links to online resources/fact sheets, and then subsequently retweeted to their followers.

You can read more background about my use of Twitter for spreading mosquito-borne disease awareness in this article, “Can the buzz of mosquitoes be replaced with a tweet?”, recently published in “Mosquito Bites” – the newsletter of the Mosquito Control Association of Australia.

While I initially thought a large number of followers was important, I now realise that engagement with the media (as well as other active users of Twitter) may be the best way to enhance the way health messages can be promoted. It is our local media that play the primary role in disseminating public health information to the local community, perhaps Twitter is best used to build communication lines between journalists, scientists and local authorities?

Assessing activity on Twitter

I started to think of ways I could better assess my use of Twitter to help answer some of these questions. I first starting thinking about this after reading a great paper by Thackery et al. in 2012 titled “”Adoption and use of social media among public health departments”. The paper describes the social media activity of health departments and highlights that very few use social media to engage the community. Their use of social media is, as is the case for traditional media, a one-way direction of information. There is very little active engagement. The authors argue that the departments need to develop a strategic communication plan to expand their reach while fostering interactivity and engagement.

This is very much the case in Australia too. If you have a quick look at state health department Twitter accounts (e.g. NSW Health, QLD Health), there is very little (if any) engagement with other Twitter accounts (i.e. very few RTs or Replies).

Before the start of the 2012-2013 “mosquito season”, I decided to try and document some of my activity on Twitter using some free online analytics services. I am the first to admit, this was a pretty rough and ready way to collect data. It was really just an experiment to see what kind of data could be collected to document how my activity on Twitter changed over the course of the season.

Most of the information was collected weekly from TweetReach. This website collects data on your account including estimated reach (total number of unique accounts that receive tweets) and exposure (total number of times tweets are received by any account) as well as a breakdown of “tweet type” (e.g. tweets, retweets and replies). It samples the last 50 of your tweets to collect this data. I logged in every Saturday morning and downloaded the data. I tweet more than 50 times a week (on average over this period I tweeted about 70 times per week) so the data represented what was going on towards the end of each week. I started in early November 2012 and stopped at the end of April 2013.

So, what did the analysis of my Twitter activity reveal?

Firstly, did my followers change over this time? There was a steady increase in the number of my followers as shown in the chart below. Followers increased from 916 to 1406 over the six month period. I’m not exactly sure what this reveals but since there were no notable falls in the number of followers, perhaps it suggests that most followers find the tweets of interest (or at least not annoying enough to “unfollow”).

A chart showing the weekly growth in my Twitter followers from November 2012 through April 2013

A chart showing the weekly growth in the number of followers from November 2012 through April 2013

Secondly, what did analysis of my “tweet types” show? There is generally a three way split in my activity between tweets, RT and replies. The trend remained fairly consistent over the six month period as shown in the chart below. Many of the RTs were tweets from various health authorities providing information on mosquito-borne disease outbreaks or other health related matter (e.g. infectious disease outbreaks, vaccination information, general health advice). It was generally a quiet season for mosquito-borne disease activity. The start of the season was marked by local activity of dengue in FNQ and the end of the season by activity of Ross River virus and Barmah Forest virus in SE QLD as well as SW WA. As a result, there was substantially less coverage of “mozzie stories” in the traditional media this season compared to previous years.

A chart showing the mix of "tweet types" in 50 of my weekly sampled tweets

A chart showing the mix of tweets, retweets and replies in 50 of my weekly sampled tweets

Many of the replies I tweeted were promoted by questions directed towards me following my tweets. Some were requests for more information or clarification on mosquito-borne disease activity or for my thoughts on recently published studies or news reports. I made an effort to respond to everyone who tweeted me. Interestingly, a recent paper by Neiger et al. (2013) titled “Evaluating social media’s capacity to develop engaged audiences in health promotion settings: Use of Twitter metrics as a case study” identified the number of questions and interaction between a user and their followers as a measure of “medium engagement”.

Finally, what was the reach and exposure of my tweets over this six month period? This was some of the most surprising information. Despite a relatively modest number of followers, my average weekly reach as approximately 19,000 and estimated exposure approximately 45,000. Much of the added reach and exposure came from multiple RT of my messages, not only accounts with large followers (e.g. media outlets) but from RTs by multiple users with similarly modest follower counts. I think this information shows the power of a small but engaged group of followers.

Chart showing the "reach" and "exposure" of the 50 tweets in my weekly sample

Chart showing the “reach” and “exposure” of the 50 tweets in my weekly sample

What influenced changes in reach and exposure?

Following the release of a health warning by NSW Health in mid-December 2012 (it is typical of health departments to release a warning about the start of the mosquito season every year) combined with a piece on mosquitoes on The Conversation, I was asked to do a series of radio interviews, mostly with stations in the ABC radio network. All had Twitter accounts that retweeted my link to repellent use guidelines following the interview. There would also often be some additional questions and comments tweeted about following the interview that I could respond to.

It is also easy to often forget who is following these accounts. In the case of 702 Sydney, whose account has over 20,000 followers, following an interview on why some people are bitten more by mosquitoes than others, I even received a tweet from the NSW Premier.

The peak in estimated exposure of my Twitter account came in early January. This was following an appearance on the Today show (a nationally broadcast tv breakfast show). Following an appearance to talk about mosquito repellents and their use, I had a tweet of mine retweeted by the producers and host of the program and this was subsequently retweeted by a number of their followers too. It provided exposure of a link to my guidelines for mosquito repellent use to almost 100,000 unique twitter accounts (with estimated exposure of approximately 188,000). As a result, I had over 200 visitors view the guidelines within a couple of days. That may be less than 1% of the people that saw the original link but still a substantial jump in the amount of people who would have otherwise visited the guidelines. I wonder how many people visit the “mosquito fact sheet” on the NSW Health website after a media release goes out?

So, what does all this mean for the potential benefits of Twitter?

In short, I think it Twitter provides a complementary route of community engagement to traditional methods. It certainly doesn’t replace any of the traditional methods of community or media engagement but I think it will become increasingly important in the future. From my experience, the ability to engage with local media outlets greatly increases the potential reach and exposure of information you can provide. This is particularly the case when links can be tweeted (and hopefully retweeted) that direct people to credible sources of public health information. The more people are aware of the risks associated with mosquito-borne disease, and the strategies available to reduce those risks, the better the public health outcomes.

The analysis of the reach and estimated exposure of my tweets demonstrates how, even from a Twitter account with a modest number of followers, messages can reach a much larger audience. That audience can be increased by being more engaged with followers. It isn’t just the Twitter accounts of media outlets and journalists. I’ve found that there are many active Twitter users who tweet and retweet material covering a wide range of topics. These users are actively engaged with a large cross section of other users and when they retweet material, messages are received by accounts that may not even think to seek out an account tweeting about mosquito-borne disease!

I am confident that the use of Twitter can assist in getting the community more engaged in public health issues, not only mosquito-borne diseases! Developing better strategies for the use of social media (by both health departments and individuals) as well as an assessment of whether those strategies are successful is required.

Getting Off Track with Radio National


I had the pleasure of being interviewed by Joel Werner (pictured above) from Radio National’s Off Track program a couple of times over the past 12 months. Not surprisingly, it was about mozzies!

The first show was broadcast back in May 2012 and concentrated mostly on our work in the laboratory and some of the background to our field-based research into the development of strategies to reduce the risks of mosquito-borne disease in coastal Australia. Joel did a great job recording our interview in the noisy surrounds of our insectary at Westmead Hospital!

The second show was broadcast in March 2013. It was recorded out in the field. Joel and I took a stroll through the saltmarsh at Sydney Olympic Park and chatted about the various techniques of mosquito sampling. While Joel was able to get his feet wet out in the wetlands, I think he got off quite lightly when it comes to mozzies. I don’t think he got a single bite!


I was really happy with how both radio shows came together. They provide a really nice and informative overview of the work I do, combining some of the laboratory and field components of my day-to-day work. You can download each of the programs by following the links above.

Off Track is broadcast Saturday 1:30pm (Repeated: Sunday 6:30am) on Radio National (ABC). You can follow Joel on Twitter too for some insight into how the show is put together.

Mosquitoes, Beer & Australia Day


This Saturday, 26 January 2013, is Australia Day, the official national day and commemorates the arrival of the First Fleet at Sydney Cove in 1788. For many Australians, it is all about BBQs, ferry races, cricket and the Hottest 100. To say beer drinking is common is probably an understatement. Do beer drinkers attract more mosquitoes? Could there be a more perfect story for our local media on the eve of Australia Day?

Besides rain, about the only thing that can spoil the day is a swarm of mosquitoes. Unfortunately, late January is at the peak of the local mosquito season. This year, Australia Day falls about two weeks after some major tidal flooding of our coastal wetlands (particularly the east coast of Australia). This is a major trigger for mosquito activity. This summer has already been marked by ideal conditions for our major nuisance-biting pest and vector of Ross River virus, Aedes vigilax (the saltmarsh mosquito). Current mosquito numbers along the NSW coast are the highest they’ve been this summer and local authorities have issued health warnings.

While the idea that beer drinkers attract more mosquitoes is a quirky story and is bound to spark some media interest, the phenomenon is more than just folklore. There have been a couple of studies looking at the role of alcohol in influencing the attraction of mosquitoes. A Japanese study published in the Journal of the American Mosquito Control Association  demonstrated that drinking 350ml of beer increased the landing rates of mosquitoes.

One of the most recent, and perhaps well publicised, studies was by Lefèvre et al. (2010) “Beer Consumption Increases Human Attractiveness to Malaria Mosquitoes”. In their study, Anopheles gambiae (probably one of the world’s most important malaria vector) were used in Y tube-olfactometer tests to see if their host-seeking behaviour changed in the presence of beer drinking and non-beer drinking volunteers. The results showed that 15 minutes after drinking 2 pints of beer (a little less than 3 schooners by Australian standards), beer drinking volunteers attracted more mosquitoes. The reason for this result was unclear but it wasn’t due to either a change in the temperature of the volunteers or increases in exhaled breath (two factors that are generally thought to increase an individual’s attractiveness to mosquitoes).

There have been many studies over the years that have demonstrated a difference in the attraction of mosquitoes in response to humans. It is a subject that fascinates many people and has lead to many urban myths about mosquito attraction and repellency. While the exact reason why some people attract more mosquitoes than others hasn’t quite been nailed down, it is thought to have something to do with the “smell” of the chemical cocktail of microbes on our skin. There are thought to be over 300 different chemicals on our skin and that their “blend” influences how many more mosquitoes we attract compared to our friends. It is possible that drinking beer changes that blend and, consequently, beer drinkers end up attracting more mosquitoes. In reality, based on recent studies, after a few beers you’ll probably not notice the mozzies and you’ll be a little less effective in swatting them away.

The key issue here though is to remember that not all mosquitoes share the same tastes for humans. Just because Anopheles gambiae is more attracted to beer drinkers, it doesn’t mean that the Australian saltmarsh mosquito will be too. The difference in host-seeking behaviour may be most vividly demonstrated in studies that showed that Anopheles gambiae was attracted to Limburger cheese. This smelly cheese contains bacteria closely related to bacteria found on our feet. While this has been shown to attract mosquitoes with a preference for biting humans, mosquitoes with broader preferences, such as Aedes vigilax, are less likely to be attracted to the stinky cheese.

What does all this mean for beer-drinkers on Australia Day? To be honest, you couldn’t be certain that drinking beer will result in more mosquitoes being attracted to you. However, there is little doubt that there will be plenty of mosquitoes about over the weekend and unless you take precautions to avoid mosquito bites, you’ll end up with a few extra itchy bites on your return to work or school and, at worst, increase the risk of catching a mosquito-borne virus such as Ross River virus. You can find some tips on avoiding mosquitoes here.

Summer mozzie media buzz

Trapping mosquitoes in the mangroves along the Parramatta River (from SMH 21 December 2012)

There is usually a bit of media interest in mosquitoes during the summer months.  As most people start thinking about lazy coastal holidays and endless BBQs, the topic of mosquitoes isn’t far from mind so it is no surprise that there is interest in the topic.

I was involved in two recent articles in local media. The Sydney Morning Herald ran a piece by Julie Power on my mosquito research and its contribution to understanding the health risks associated with coastal mosquito populations. This was a timely piece as NSW Health had recently issued a public health warning about mosquito numbers along the coast and the possible increased risk of Ross River and Barmah Forest virus during the holiday period.

The second article was by Matthew Kelly in the Newcastle Herald on my research project with Hunter-Central Rivers Catchment Management Authority on the Hexham Swamp Rehabilitation Project. After two years under relatively cool and wet La Nina weather patterns, mosquito populations associated with most coastal wetland areas were generally pretty low. The Newcastle Herald had run a story in early 2012 reporting our findings that mosquito populations associated with Hexham Swamp were actually relatively low. The shift back towards hot and dry El Nino conditions mark an increase in the suitability of habitats for the saltmarsh mosquito Aedes vigilax. We’re expecting to see increases in the abundance of this mosquito along the east coast of Australia over the coming summers. It will be interesting to see how populations of this mosquito associated with the Hexham Swamp Rehabilitation Project respond to these conditions.