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.

Summer summary of mosquito media madness

Webb_ABC24_Zika_Media

Summer is always a busy time for me. As well as plenty of time sloshing about in the wetlands, there is often lots of interest from mosquito-curious media. There has been some intense bursts of activity in previous summers but the 2015-2016 was particularly interesting.

I certainly covered some new ground this summer. I responded to over 160 individual media requests in the past 6 months. From flies and food safety to the emergence of Zika virus. Here is a wrap from my media adventures and some valuable lessons learned for future science and public health communication.

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The good news of new virus discoveries

Usually, the discovery of a new mosquito-borne virus brings with it new concern for public health. This time though, there was some good news.

Towards the end of 2015, a paper reporting on a collaborative research project between University of Queensland, QLD Health and University of Sydney was published in Virology. This was the first publication detailing the discovery of Parramatta River virus, an insect specific virus that exclusively infects the mosquito Aedes vigilax. This virus does not infect people and poses no health risk.

A joint media release was issued by University of Queensland and University of Sydney and there was plenty of media attention. Not surprising given the usual negative associations with mosquito-borne pathogens!

There were dozens of articles, much of the attention focused on the team at University of QLD. Dr Jody Hobson-Peters was kept busy with local media including ABC and Brisbane Times. It was a great experience sharing the research with colleagues in Queensland, particularly great seeing so much exposure for PhD student Breeanna McLean and her newly published research.

I was surprised at how little attention there was in the news from Sydney media. The lesson here though was more about bad timing than uninteresting research. A couple of weeks after the initial media release, I forwarded around a few emails and sent out a couple of tweets and next thing you know, we made the front page of the local newspaper, the Parramatta Advertiser (see above). It was some great local coverage, not only about the virus discovery but it also provided an opportunity to raise awareness of mosquitoes and mosquito-borne disease on the eve of summer!

Lesson learned: A good reminder that if your research isn’t picked up immediately, give it another shot a few weeks later. Timing may make all the difference but perseverance does too!

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To stop sickness, swat or spray

Just in time for Christmas lunch and summer holiday picnics, I published an article on flies and food safety at The Conversation. I really expected this article to slip under the radar of most people. Coming out on Christmas eve doesn’t seem likely many would be clicking about on the internet but within a few days over 600,000 people had clicked on the piece!

Many of those clicks were thanks to the article being shared by IFLS but there was also plenty of interest from local media and I was busy with interview requests from ABC Local Radio across the country. Who doesn’t love hearing about how flies poop and vomit on your food? I was even interviewed by Grey Nomad Magazine!

Lesson learned: Applying a little science to seasonal urban myths and common uncertainties can prove popular and may be a good opportunity to promote a little science!

wetweather_Jan2016

Rain, rain everywhere with mozzies soon to come

With all the talk of El Nino and predictions of a hot and dry summer for the east coast of Australia, the summer was actually reasonably mild and extremely wet. Sydney was particularly battered by a series of storms and intense rainfall early in 2016.

More water generally means more mosquitoes. In response to the rain, many media outlets were interested in chatting about the prospects of a bumper mosquito problem. As well as talking about the prospects of an increase in mosquito-borne disease risk, it was a great opportunity to talk about personal protection measures.

There were some radio, print and tv spots that provided opportunities to talk about how to choose and use the right repellents.

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In 2015 I published a paper in the Medical Journal of Australia explaining that health authorities need to provide more guidance on how the community can get mosquito repellents working more effectively.

Typical health warnings and media release from health authorities (usually limited to grabs on news bulletins) but when there is an opportunity to do longer form radio interviews, there is a chance to put an emphasis on aspect of public health messages. The hook to get these longer spots is giving more than just warnings, by mixing up some interesting things about mosquitoes, you can catch a little extra attention and sneak in the public health messages between the fun and fascinating facts about mosquitoes!

One news outlet was really insistent in grabbing a hold of me for some comments ahead of the evening bulletin. They even sent a crew to meet me in the city while I was taking the kids along to the Sydney Festival!

Lesson learned: When doing tv for the evening news, it is ok to wear a t-shirt, shorts and runners just so long as you have a rain jacket handy to make you like like you could have just stepped straight out of the wetlands!

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From African forests to South American cities

While many of us were keeping our eyes on the developing outbreak of mosquito-borne Zika virus in South America towards the end of 2015, it wasn’t until February 2016 that the situation really grabbed the attention of the world’s media.

In late January, I published a piece at The Conversation titled “Does Zika virus pose a threat to Australia?” It prompted a little interest but it was the media conference coordinated by University of Sydney Media and Communications together with Australian Science Media Centre (AusSMC) that coincided with the announcement of the World Health Organization that the Zika virus outbreak was a Public Health Emergency of International Concern.

Together with colleagues from the University of Sydney’s Marie Bashir Institute of Infectious Disease and Biosecurity, I spoke at a media conference broadcast nationally on ABC News 24. There was a huge amount of media stories stemming from this media conference with over 500 individual articles identified across radio, tv, print and online. During the days and weeks following, I felt like I was spending more time at the ABC studios in Ultimo than I was in our lab! There were days when I spent hours on the phone doing radio interviews.

There were a couple of great longer form interviews that I really appreciated the opportunity to contribute to such as ABC Radio National’s Health Report and Rear Vision. There were also a couple of podcasts too, check out Science on Top and Flash Forward.

This flood of media requests also exposed me to a few more new experiences. There were live tv appearances on Sunrise, ABC News 24 and Sky News but probably one of the most interesting was my spot on Channel Ten’s The Project. It was interesting for a number of reasons.

Firstly, I was warned early on that one of the guests on the panel was comedian Jimmy Carr, a somewhat controversial figure notorious for jokes a little too close to bad taste. I’m not typically one to play the “wacky scientist” during interviews but what I was most cautious of was not being seen to be treating a very serious disease outbreak too lightly. I was determined to play the straight guy. In the end the interview turned ok but there were a couple of awkward moments that, luckily, ended up being edited out.

Secondly, simply doing the interview was unusual. It was a pre-recorded interview with me in a tiny room at the Channel Ten studio in Sydney and the panel in the Melbourne studio. I was sitting in front of a green-screen, staring down the camera with an earpiece blasting away in my ear. I have done live crosses before but they’re all been one-on-one interviews. This time it was with the panel and I found it incredibly difficult to get the feel for each of the panelists when they were asking questions. Missing that eye-to-eye contact was a disconcerting experience. Luckily, all turned out well in the end.

Lesson learned: Lots (I mean LOTS) learned while dealing with the interest in Zika virus! Probably another post in itself…but I would say that managing this volume of media wasn’t easy and it did eat up a lot of time (even though communicating public health messages is central to my “day job”) but this was important work.

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A morning with Dr Karl!

When it comes to science communicators in Australia, there are few with a higher profile than Dr Karl Kruszelnicki. We’d spoken on a number of occasions about mosquitoes but I’d never actually met him in person before. “Dr Karl” invited me to hang out for a morning recording interviews for ABC News 24, ABC Local Radio and also guest on his national “Science Talk” segment on Triple J’s Mornings Show with Zan Rowe.

The experience of a behind-the-scenes perspective on Karl’s hectic schedule and how he manages the frenetic pace of work at the ABC was an eye opener. Doing the hour long segment on Triple J was great, enlightening to get questions from a slice of the Australian community I don’t usually cross paths with when doing the usual community engagement. I good reminder of just how much anxiety there can be within the community when news of international disease outbreaks occur. Not surprising given the thousands of Australians travelling to South America each month….with more to come later this year when the Rio Olympic Games kick off!

You can listen to the segment here and you can also follow Dr Karl on Twitter.

Lesson learned: From a public health perspective, this is a great reminder that the concerns and anxieties around infectious disease can change depending on the sector of the community you’re dealing with. The core messages may remain the same but you’ll always need to consider your audience when fine tuning your public health messages.

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So, was all this worth it?

It was stressful. It was fun. It eroded much of my time that may have been spent in other ways but I see this as “doing my job” perhaps a little more than pure research scientists do. But how does all this convert into tangible metrics. How do you measure the reach and economics of all these media activities?

I’m fortunate to be supported by the University of Sydney media and communications team that helps out by providing some data on the metrics of my media activities each summer. What was all this time and effort worth?

Between November 2015 and Match 2016, I was quoted in over 160 media items. This adds up to a cumulative audience of around 8.9 million people, that is quite some reach! How much was it worth? Based on current advertising rates, about $1.6 million.

I’ve written before about how we can better value science and public health communication. Collecting these types of metrics can be useful for a range of purposes. Recently, I’ve been including media engagement as an “in kind” contribution to grant applications with valuation calculated on average media coverage that may be expected.

The lesson here is to take the time to record your media activities, not just so you have a list to demonstrate quantity but also so you can assess audience and value to your media activities. Work with your media and communications departments to see what extra information you can collect.

Got any other tips? Share them via Twitter!

 

 

 

 

 

Lessons from the dengue outbreak in Hawaii

Hawaii_1There are millions of cases of mosquito-borne disease world wide every year so why should we care about a few dozen dengue cases in Hawaii?

Hawaii is no stranger to dengue. There have been outbreaks first dating back to the 1840s. Travellers, including returning residents, are diagnosed with dengue routinely. However, this is the first outbreak of locally-acquired infection since 2011.

As of 17 November 2015, Hawaii Department of Health reports there have been approximately 65 locally acquired cases on Hawaii Island (aka Big Island) including both residents and visitors. Why has this happened and what lessons can be learned from the outbreak?

[update: As of 29 January 2016, there have been 242 confirmed cases of locally acquired dengue.]

Hawaii provides a fascinating example of the implications (as well as study of spread) of exotic mosquito invasions. With no endemic mosquito species, the pest species found in the Hawaiian islands have all been introduced from elsewhere.

The first mosquito to make it to Hawaii was Culex quinquefasciatus. It is thought to have arrived on a boat from Mexico in the mid 1820s. Interestingly, with no native mosquitoes in Hawaii, there was no word to describe them so they were initially referred to as “singing flies”.

In recent years, it has been the role of Culex quinquefasciatus in the spread of avian malaria that’s been grabbing the headlines. However, in the last few weeks, it has been Aedes aegypti and Aedes albopictus playing a role in the local spread of dengue virus in the spotlight. These two container-inhabiting mosquitoes are the key vectors of dengue viruses (as well as chikungunya, yellow fever and zika viruses) internationally. They’re driving the outbreak now as they have in the past.

There was an outbreak of dengue in 2001 with a total of 122 locally acquired cases. Cases were reported from Maui, Oahu and Kauai with the outbreak thought to have been triggered by travellers from French Polynesia where there was a major outbreak underway at the time. Between 1944 and 2001, the only cases of dengue reported in Hawaii were imported with travelers. Firstly, this highlights how important it is to understand the pathways of infected people, this can help guide assessments of risk.

This was also done from the potential introduction of West Nile virus into Hawaii. Analysing the movement of travelers from regions of endemic mosquito-borne disease has also been used to assess the risk of chikungunya virus introduction to North America.

It was believed that Aedes albopictus played an important role in this 2001 outbreak. This mosquito was not a significant presence in Hawaii until the 1940s. More importantly, Aedes albopictus is not exclusively found in water-holding containers in urban area. Unlike the other vector of dengue viruses, Aedes aegypti, Aedes albopictus is also found in bushland habitats. This makes mosquito control just a little more difficult when authorities need to look beyond the backyard.

Previous dengue outbreaks in Hawaii were thought to have been driven by Aedes aegypti. These outbreaks were significant with an estimated 30,000 cases in the early 1900s followed by approximately 1,500 cases around Honolulu in the period 1943-1944. While not necessarily easy to manage, outbreaks of dengue driven primarily by Aedes aegypti can be strategically targeted by residual insecticide treatments and community education. That education focuses on raising awareness of the public health risks associated with mosquitoes and the need to remove opportunities for mosquitoes to be breeding around dwellings. This model is essentially what is in place to address occasional outbreaks of dengue in Far North Queensland, Australia.

The current outbreak has raised concern in the community. Shelves of stores have been emptied of insecticides and repellents. Community meetings have been held by local authorities to provide information on dengue and address concerns on the Big Island. You can watch some of the meetings here. You can see some of the health promotion (aka “Fight the Bite”) flyers here.

Community engagement is important. An indirect impact of this engagement though is that the total number of confirmed cases of dengue on the Big Island is likely to rise over coming weeks. Not necessarily due to new cases but a greater likelihood that older cases will now be diagnosed through blood tests. Even those who may be suffering a mild illness are likely to be tested for infection and may end up in official statistics.

This dengue outbreak is a reminder to authorities across the world that where suitable mosquitoes are present, a risk of mosquito-borne disease outbreak is possible. The mosquitoes provide the tinder and it only takes the spark of an infected traveler to ignite an outbreak. We saw this in 2014 with the first outbreak of dengue in Japan for 70 years. We’ve seen it this year with local transmission of chikungunya virus in Spain and other outbreaks across Europe.

For Australian authorities, ensuring there are strategic responses in place to address the risk of exotic mosquito introduction, as well as outbreaks of disease, is critical. What this outbreak in Hawaii reminds us is that if Aedes albopictus becomes established in our major cities, it is only a matter of time before we see local outbreaks of dengue, chikungunya or Zika viruses.

What is it like if a loved one comes down with dengue? Check out the channel of YouTube stars Charles Trippy and Allie Wesenberg as they document their brush with mosquito-borne disease during this outbreak.

[Update: Implications for potential Zika virus spread] The recent spread of Zika virus in the Americas has raise concerns by health authorities. In particular, the spread of the virus to North America. What about Hawaii? There has already been one case of microcephaly in Hawaii with a baby born on Oahu to a mother who had been residing in Brazil. The pregnant women was infected in South America, not Hawaii. However, authorities should be on alert as travellers from the Americas, or the Pacific, have the potential to introduce the virus and the mosquitoes currently present in Hawaii spreading dengue viruses are the same that spread Zika virus.

 

 

 

 

 

 

 

What can the outbreak of dengue in Japan tell us about future mosquito-borne disease risk?

dengue_japantimesConsidered free of dengue for around 70 years, Japan is now facing an outbreak of mosquito-borne dengue virus centered around a popular Tokyo city park. How could this happen?

Dengue is typically associated with tropical regions. However, outbreaks of dengue have occurred in temperate regions historically. That includes major outbreaks in Japan. In fact, dengue has been a notifiable disease in Japan since 1999; regulated by the Infectious Disease Control Law.

The last major outbreak was in 1942-1945. Breaking out in Nagasaki in August 1942, over 200,000 cases were suspected to have occurred, making it one of the largest temperate zone dengue outbreaks on record. It is interesting that, at the time, there was an extensive network of water tanks to enable response to fires triggered by bombing during the war. These tanks supported “innumerable” populations of the Asian Tiger Mosquito, Aedes albopictus. Also contributing to the problem was an inability to undertake large-scale insecticide applications at the time.
Then, for around 70 years, dengue disappeared. Until 2014.
Local authorities This picture taken on August 28, 2014 shows a worker spraying insecticide at the Yoyogi park, one of the largest open spaces in central Tokyo, believed to be the source of the mosquito-borne dengue fever. An outbreak of dengue fever in Japan -- the first since World War II -- could have affected up to 20 people, media reported on September 1, as officials confirmed three more cases.      (Photo Source: AFP via ABC News)

Local authorities undertake spraying in Tokyo’s Yoyogi Park. (Photo Source: AFP via ABC News)

The first case of dengue in this current outbreak was reported at the end of August 2014 but in the space of a week or so, many more cases were identified. To date (9 October 2014) there has been a total of 151 confirmed locally acquired cases of dengue (this includes an Australian traveller). The majority to these cases have been centred around the popular Yoyogi Park in Tokyo.

[update 1 November 2014] Tokyo’s Yoyogi Park finally reopened after the outbreak was first detected but it was closed for 57 days. As well as a serious inconvenience to the people of Tokyo, there is little doubt this has had a substantial economic impact on the city. It would be fascinating to know if the outbreak impacted tourism.

[update 5 December 2014] A newly published paper reports on the molecular analysis of isolates of dengue virus from 19 confirmed cases of infection from Tokyo. The analysis showed that the outbreak was triggered by a single incursion of dengue virus type 1 (DENV-1) and that analysis of the envelope protein genome sequence from 3 patients revealed 100% identity with the strain from the first patient.

Some of the media coverage has focused in the role that climate change may have played on triggering this outbreak. However, the outbreak is not the result of a changing climate. International travel and a cool climate tolerant mosquito are to blame. Perhaps complacency regarding the risks associated with this mosquito predisposed the region to this outbreak too?

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The Asian Tiger Mosquito, Aedes albopictus. (Source: Stephen Doggett, Pathology West – ICPMR Westmead)

The Asian Tiger Mosquito, Aedes albopictus, is a cool climate tolerant mosquito closely associated with water holding containers in urban environments. The mosquito is a severe nuisance-biting pest and second only to the Yellow Fever Mosquito (Aedes aegypti) in its importance in transmitting dengue virus. It is also very effective at transmitting chikungunya viruses. The expanding range of Aedes albopictus internationally is of critical importance to outbreaks of the disease. It is raising concerns regarding the transmission of chikungunya virus in North America this year.

Aedes albopictus provided the tinder that an infected traveller ignited to kick off this dengue outbreak.

There were warnings this was coming. Much of the media coverage has emphasised that this is the first local outbreak of dengue in 70 years. In fact, there was an intriguing case last year that should have put local authorities on notice.

In January 2014 there was news that a German tourist had contracted dengue. In Japan.

In a published case report, a woman sought treatment in a hospital in Berlin, Germany, in after returning from two weeks of travel in August-September 2013 to Honshu Island, Japan. Her travel route was via Frankfurt International Airport to Tokyo Narita International Airport and return. She did not visit any regions considered to have endemic dengue activity. The authors note that this case was “the first recognised case of locally acquired dengue (DENV) infection in Japan for more than 60 years”.

Following this reported case, authorities undertook surveys that revealed high population densities of Aedes albopictus within the urban areas of Japan. It is interesting to note that, despite using a surveillance method that is typically not effective at collecting Aedes albopictus (carbon dioxide baited light traps), some of the largest densities of mosquitoes were collected from Tokyo. Interestingly, a 2010 study into the blood feeding behaviour of Aedes albopictus in Japan showed that over 68% of mammalian blood meals identified were human and the authors concluded that the mosquito may play a role in outbreaks of dengue and chikungunya viruses.

I cannot find any reports of mosquito control, either source reduction or insecticide treatment, were undertaken in response to these findings.

Average number of Aedes albopictus collected using human bait collection and CDC miniature traps in urban areas of Japan (Source: International Journal of Infectious Diseases)

Average number of Aedes albopictus collected using human bait collection and CDC miniature traps in urban areas of Japan in September 2013 (Source: International Journal of Infectious Diseases)

There are clearly some warnings that authorities, both in Japan and elsewhere, should take from this event. Most importantly, the presence of Aedes albopictus should not be underestimated in increasing the risk of local dengue outbreaks. While the published report of the dengue infection in the German tourist prompted debate (see here and here) about the future of local dengue outbreaks in Japan, it is clear now that where Aedes albopictus occurs, so does the risk of dengue. Control of this mosquito should be undertaken, not only to reduce the nuisance-biting impacts but to also reduce public health risk. Clearly, August and September seem to be a high risk period around Tokyo.

While locally acquired cases of dengue were unknown since the 1945, Japanese travellers were regularly returning home infected with the pathogens. A recent study of 540 Japanese travellers demonstrated that, not only was Indonesia and the Phillippines destinations of high risk, but that August and September were peak periods when infected travellers were returning home from these endemic regions. An eerie coincidence considering the cases in August/September in both 2013 and 2014. Where these traveller, not climate change, triggered outbreaks in Japan? (the debate about climate change driven dengue outbreaks in other regions of SE Asian could be left for another day)

Rate of reported dengue cases per 100 000 travellers by month and countr y visited,* Japan, 2006–2010

Rate of reported dengue cases per 100 000 Japanese travellers by month and country visited, 2006–2010. It is interestign to note that only data for 2010 on travellers to Indonesia is reported. (Source: Western Pacific Surveillance Response Journal)

Australian authorities should take note of what has happened in Japan. While understanding the routes of entry of Aedes albopictus into new regions is critical, developing strategic surveillance and control responses to the introduction of the mosquito are of equal importance.

Since the discovery of Aedes albopictus in the Torres Strait in 2005, there has been much debate, together with data crunching and computer modelling, with regard to the possible spread of the mosquito across the mainland. There is evidence that the mosquito can survive at cooler climates in Australia and can spread some of our local pathogens. What will it mean for Australia to have a severe nuisance-biting pest and potential vector of dengue and chikungunya viruses inhabiting our major cities such as Brisbane, Sydney, Melbourne and Perth?

We should be mindful that this mosquito may not naturally spread south from the north, it may sneak in through the back door. It already has. The mosquito was discovered, and fortunately eradicated, from Melbourne in 2012. Exotic mosquitoes continue to be intercepted at our ports.

Perhaps we can’t stop Aedes albopictus reaching mainland Australia. Efforts continue to keep the mosquitoes at bay but, in reality, we may be overwhelmed. We cannot fill enough cracks to stop them slipping through.

What we need are strategic responses to the incursions of the mosquito. Authorities need to build capacity for quick response surveillance and control. Traps and insecticides are cheap, expertise on the ground by those responsible for catching and killing the mosquitoes is not. The traps and control measures currently used to control pest mosquitoes associated with wetlands will not be easily be transferable to the control of container-inhabiting mosquitoes. We need to review our approaches to mosquito control should Aedes albopictus be introduced. Time may be on our side for the moment but for how long? Will we one day see outbreaks of dengue in Sydney’s Centennial Park?

Why not join the conversation on Twitter?