American high school teacher implementing sustainable mosquito control project in the Maldives

“For most people in Siskiyou County, mosquitoes are no more than a nuisance. But in the Maldives, where they breed rapidly and transmit painful and sometimes deadly Dengue fever, they’re much more of a problem”, Californian publication Mount Shasta Herald  reports.

“Former Mount Shasta High School teacher Trudy Rilling-Collins is working to control mosquitoes in the Maldives in an environmentally friendly way. She recently enlisted help from MSHS graduate Sydney Miller to implement sustainable mosquito control projects with local islands in the Maldives, a double chain of 26 atolls consisting of 1,200 islands off the coast of India and Sri Lanka.

Rilling-Collins hopes to create a project model that will empower the Maldivian people to effectively control mosquitoes on their own. Not only will this benefit the people – both local Maldivians and tourists – but it will also help the environment, she explained.”

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‘Mosquito Lady’ and local community combine to deter unwanted guests on Kuda Huraa

Pest control consultant Trudy Rilling-Collins, better known as the ‘Mosquito Lady’ has been working closely with Four Seasons Kuda Huraa resort and the local community of neighbouring Boda Huraa to introduce sustainable and environmentally friendly mosquito control procedures.

As the South-West monsoon season reaches the Maldives, wetter weather will bring rain to replenish the water tanks that provide safe drinking water for the people of the islands. But it is not just the human population who will be glad to see the clouds rolling overhead.

The increased rainfall is also particularly appealing to the country’s mosquito population, which will take full advantage of any available water in which they can lay their eggs. Any stagnant body of water will be most appreciated by Aedes aegypti and her cousin Aedes albopictus, the mosquito species that carry the dengue virus which has been afflicting Maldivians in increasing numbers in recent years.

Aedes aegypti will utilise any water available in which to lay her eggs. She will live for only one month, but in that time her larvae will take full advantage of any accommodating bucket, well, puddle, blocked drain or water tank.

She will sustain herself during this period by feeding exclusively on human blood, unlike her cousin who will happily feed off any red-blooded creature.

Aedes aegypti is a particular fan of mid-market tourism, preferring to find accommodation in close proximity to the local community. Eager to ingratiate herself with her human food supply, she can visit up to five people per blood meal, potentially passing the dengue virus to all she acquaints herself with.

She will be able to lay four lots of eggs in her lifetime which is more than long enough to see her young grow into fully grown biting adults, a process that takes only one week.

Fully booked

One place where Aedes aegypti and her kin will not receive a hospitable welcome this year, however, is on the resort island of Kuda Huraa in North Male’ Atoll and the inhabited island of Bodu Huraa next door.

The resort has this year enlisted the help of Trudy Rilling-Collins, otherwise known as ‘Mosquito Lady’, to ensure that its hospitality extends only to the human guests.

Trudy runs her own consultancy, specialising in environmentally responsible pest control, and has been working closely with Four Seasons Kuda Huraa and the Bodu Huraa community to ensure that there are no vacancies for dengue spreading visitors.

The resort on Kuda Huraa and the local community share a symbiotic relationship. The resort provides around 13 percent of the registered population in Bodu Huraa with jobs and has provided vital infrastructure to the local population.

The town’s sewerage system was provided by Four Seasons and the company has even assisted in providing fresh water to Bodu Huraa during the current dry season.

This close relationship is not lost on the mosquitos, who can easily travel the short distance between the islands, to feed happily from tourists and locals alike.

Trudy studied the biological control of insects and became disillusioned with the extensive use of harmful pesticides in what she sees as often futile attempts to control pests.

The use of pesticides in a diesel fuel carrier, referred to as fogging, is widely practised in the Maldives and throughout the tropical regions, although Four Seasons Kuda Huraa, which also pays for mosquito control in the two islands, has not fogged since Trudy’s arrival in April.

“The neurotoxins present in pesticides used for fogging on the islands have the same effects on humans that they have on the insects, it just takes far higher doses to affect humans,” said Trudy.

“Fogging kills only a small percentage of adults, five to ten percent if you’re lucky, and over time results in increased resistance,” she added.

Trudy believes that the key to mosquito control lies in making the area inhospitable to the pests: “80-90 percent of the problem can be sorted by eliminating standing water where mosquitoes breed.”

The effects of these chemicals are also harmful to the local environment, a particular concern for SEAMARC, a Maldivian an environmental consultancy that works closely with Four Seasons.

Alban Viaud, a marine biologist on Kuda Huraa, explained that the fogging chemicals which are quickly washed into the ocean are harmful to marine health: “Only a few parts per million can kill fish.”

Trudy has been working closely with the resort, the local council, schools and the community to implement a sustainable, effective and environmentally friendly way to keep mosquito numbers down.

Strength in numbers

After having visited the islands, there is a strong understanding emerging that, rather than chemicals, it is the community that is the strongest weapon in making Aedes aegypti feel unwelcome.

Measures have been taken to clear breeding grounds during Trudy’s time on Bodu Huraa. She has worked with the islanders to identify and eliminate as many breeding grounds as possible.

Of particular concern were the islands old septic tanks, long since replaced by the sewerage system supplied by the resort, but still capable of retaining water through gaps in the paving slabs. After water collects in such areas, Aedes aegypti is sure to follow.

Covering these gaps with concrete eliminates the tanks as another potential holiday home for the mosquitoes.

A similar, and innovative, method to prevent mosquitoes checking in to household water tanks was in full swing when Minivan News visited Boda Huraa.

Ringed hoses, filled with sand were being constructed in order to secure a fine mesh over the top of the water tanks, allowing access to rainwater but not to mosquitoes.

In the shade of the local council building, three resort employees could be found steadily working on the project. With around 250 tanks on the island, the team had a long way to go but seemed enthusiastic.

One of the men working on the rings was resort employee Rafeeq, who has been assigned the vital task of checking, sampling and clearing potential breeding areas. The job will require four hours of Rafeeq’s time every day, for six days every week.

The town’s households have been surveyed and divided into eight zones, meaning that each house should be checked three times in each one month cycle.

Around the corner, another simple and sustainable method was being used for removing larvae from water supplies. Fish are a far more welcome guest in the ground wells. No room service is required as they feed largely off any larvae they can find in water, which the townsfolk no longer use for drinking. One type of fish often found in the wells can eat up to 40 mosquitoes in three minutes.

Community action

“Energy and action are key components  the success of this project. I try to push for simple sustainable solutions,” said Trudy.

“But it takes someone on the ground to create action,” she added.

A vital part of her mission in Bodu Huraa has been to raise awareness and create enthusiasm for the eradication scheme. This has involved numerous presentations given to all sections of the community, from the employees at the resort to the children in the local school.

Shafyga Arif, the island’s Community Health Officer noted that there had been a big reduction in the mosquito population since the scheme had begun.

She also noted that the community would be important in keeping numbers low, with leaders appointed within each of the project’s eight zones. “They have to do it themselves. Each person should take responsibility. People had some previous awareness but didn’t care before,” said Shafyga, who has herself pledged nine hours of her working week to the project.

Back at the council building, the Island’s Council President Abdel Rahman Saleh explained that a local task force comprising fifty members of the local community had been formed to work on the scheme.

The task force members are working on a volunteer basis as there is no space in the council’s current budget for the scheme. Saleh said that he had requested more funds for such projects for next year.

“The task force will work. The government requested that we continue the project for twelve weeks, but we intend to continue it forever,” he added.

The appreciation of the health and environmental benefits of these sustainable methods appeared to be widespread as Trudy neared the end of her time on the islands.

Of equal importance was the realisation that the fight against the mosquitoes will only be as strong as its weakest link, and that the resort, the local government and the community must continue to patrol and eradicate potential breeding sites.

With the entire community working together and remaining vigilant, it is hoped that Kuda Huraa and Bodu Huraa will be receiving poor reviews from Aedes aegypti for the foreseeable future.


New bug kills young to stop dengue

An experiment by British biotechnology company Oxitec Limited has yielded mosquitoes genetically engineered to prevent the spread of dengue fever by killing their own offspring.

The mosquitoes, formally termed aedes aegypti RIDL strain, transmit a lethal gene to their offspring which kills them before they reach maturity. Only male mosquitoes carry the gene.

The engineered mosquitoes were first released in the Cayman Islands in 2009 in a 25-acre area. A report published yesterday (October 30) revealed signs of success.

According to the traps, genetically engineered male mosquitoes accounted for 16 percent of the total male population in the test area, while 10 percent of the larvae contained the lethal gene. Scientists concluded that although genetically engineered males were half as successful at mating as normal mosquitoes, their activities would still suppress the population in dengue-endemic areas.

A larger trial on Grand Cayman island in 2010 reduced the targeted mosquito population by 80 percent for three months, Oxitec has reported.

“The results, and other work elsewhere, could herald an age in which genetically modified insects will be used to help control agricultural pests and insect-borne diseases like dengue fever and malaria,” the US’ New York Times reported today.

The insects have also been released in Brazil and nearby Malaysia.

Dengue is reported in between 50 and 100 million cases each year, and accounts for an estimated 25,000 deaths. According to Oxitec, dengue threatens 50 percent of the world’s population and costs the global economy US$4 billion annually.

The new bug could prove useful to the Maldives. Though it ranks number one on South-East Asia’s list of malaria-free zones, the Maldives continues to combat dengue fever annually.

This year, hospitals documented the highest number of fatalities when Ahmed Shinah of Vaadhoo in Gaaf Dhaal Atoll succumbed to the disease in July. An Oxitec report shows a steady increase in cases weekly since 2009.

Director General of Health Services Dr. Ibrahim Yasir said health officials are aware of Oxitec’s experiment but are awaiting confirmation that the mosquitoes are a valid solution.

“We have heard about it, but we are not discussing the experiment at a policy level right now,” Yasir said. “We are waiting to see how it works in other countries first.”

Yasir was unable to say if the Maldives would be able to genetically modify its own mosquitoes, but noted that the environmental parallels between Malaysia and the Maldives gave officials confidence in Malaysia’s results.

“We will not pilot the experiment here, but I think the way they are exploring it in Malaysia will help us decide if it safe for the Maldives. It could certainly be a cutting edge solution to dengue,” Yasir said.

The Maldives is particularly vulnerable to the impact of dengue. Using Maldives as an example, Oxitec reported that dengue cases had occurred more frequently this year than in the two years previous in tourism-dependent countries. Travel warnings were issued by various government and international health organisations for these areas.

The economic impact of even a warning can be significant for tourism-dependent countries such as the Maldives, Oxitec claims. A paper by Mavalankar et al. found that French Réunion lost 40 percent of its tourism traffic in the year following the 2005-2006 chikungunya oubreak. The paper estimated that a country such as Thailand could lose US$363 million annually for every four percent drop in tourism traffic.

Deputy Director General of Tourism Hassan Zameel said dengue had never been reported on resorts in the Maldives, and was not expected to become a concern.

“Of course dengue is a problem if it becomes widespread and cannot be controlled, but the government has given this lots of thought and emergency mechanisms are in place,” he said, adding that emergency procedures were carried out effectively for the outbreak in July and August.

“Cases are mostly reported on local islands. Resorts have their own methods involving sprays and smoke to counter the spread of mosquitoes. They’re doing very well at controlling it. But I don’t think it will be an issue moving forward,” Zameel added.

Oxitec lately opened a new facility to serve further experiments in Brazil and Malaysia. However, the program is also being criticised for possible health and environmental risks.

Unlike an antibiotic, mosquitoes cannot be recalled once they have been released. Some scientists interviewed by the Times said the insects could develop a resilience to the gene and survive. Todd Shelly of Hawaii’s Agricultural Department said 3.5 percent of the insects in a lab test survived the gene and matured into adulthood.

The mosquitoes are also sorted by hand according to gender, leaving room for error which could be signficant when thousands are released over an area.

One possible solution is modifying female mosquitoes, which do not carry the lethal gene, to stay grounded.

Chief Scientist at Oxitec Dr. Luke Alphey deemed the new approach safe because it releases only males, while only females bite people and spread the disease. He said it should have little environmental impact, reports the Times.

Meanwhile, authorities in Florida, United States hope to conduct an experimental release of the bugs in December.


Comment: Dengue fever, a problem for everyone

Although the MNDF has been drafted in to help combat the problem of dengue fever that is affecting Male and several other atolls, it is important that people don’t stand back and think that this action alone will solve the problem.

Experience in many other countries has shown that a ‘top-down’ or vertical campaign against dengue fever is only part of the solution to preventing outbreaks of the virus from getting worse.

Most people know that dengue fever is spread by a mosquito that takes the blood of an infected person. The blood contains a virus that causes dengue fever and this is passed on to a new person when they are bitten in turn by the mosquito. The mosquito seems fine – but people infected by the virus may become very seriously ill and a small proportion may die.

Most action to prevent the spread of dengue fever is aimed at the mosquito itself. If the mosquitoes are stopped from breeding then the transmission of the dengue virus from person to person will be interrupted and no new cases will occur. Often the strategy against the mosquito relies on spraying chemicals and treating water storage containers. But without having fully integrated community involvement, this strategy has failed almost everywhere in the world that it has been tried. The mosquitoes will always find ways to outwit their human adversaries unless locally tailored eradication programmes are implemented.

Community involvement is key to the success of the eradication programme and every member of the community should be involved in understanding the problem of controlling the mosquitoes (vector control). Within each community the local community leaders should be involved in forming a dedicated steering committee that can create formal task forces or community working groups that will undertake environmental management. The working groups will need to know in detail exactly what they are supposed to be doing and precise training sessions need to be organised. Every locality is different so each community task force needs to identify the exact local conditions in which their mosquitoes will be breeding. Precise local knowledge is the most important resource for beating the disease. In particular waste water needs to be evacuated efficiently; water pipelines and water storage containers must be protected and communal waste collection improved.

A research programme in Cuba compared the usual ‘top down’ ways of combating dengue fever with a community activist approach as described above. They found that the community based environmental strategy was much more effective that the usual eradication programme. You can read more about this research on:

Garbage: a special problem throughout the Maldives

The mosquitoes love little collections of water. When I was in the Maldives as a volunteer for the Friends of Maldives health programme I noticed that outside almost every house there is a little collection of garbage. This includes plastic drink containers, tins, discarded tyres, containers and invariably a pile of half coconuts. These are ideals breeding sites for the mosquitoes that carry dengue fever. Unless each and every one of these piles is cleaned up, dengue fever will continue to be a problem throughout the Maldives in urban and rural areas.

Mosquitoes love the little collections of water that form in garbage piles.

Dr Tom Heller is a Senior Lecturer in the Open University’s Faculty of Health and Social Welfare.  He has previously visited the country as a medical volunteer for the UK-based NGO, Friends of Maldives.

All comment pieces are the sole view of the author and do not reflect the editorial policy of Minivan News. If you would like to write an opinion piece, please send proposals to [email protected]


Comment: Winning the war on Dengue

The news that dengue is hitting the Maldives hard has reached the Netherlands, along with other parts of the world from which your beautiful country attracts large numbers of tourists.

That Maldivian children are dying of dengue is distressing and of course a horrific experience for the families affected, but there will surely be broader ramifications for the country. The blame culture that followed these deaths, fuelled by emotional debates in the press is affecting your country badly. Negative press will influence the tourism sector and may have a major economic impact.

When the Indian Ocean island La Reunion was struck by an outbreak of Chikungunya virus – also transmitted by dengue mosquitoes – in 2005/6, it suffered losses of tourism income amounting to €225 million (US$325 million). The French government had to inject €76 million to keep the tourism industry alive. With 1.2 million tourists per year, surely the Maldives cannot afford to wait for such a thing to happen.

So how can the war against dengue be won and can it be done quickly? In my opinion this is possible by doing just one thing well: learning from the past.

In the absence of a vaccine and specific medicines, the sole option to contain or eliminate dengue is through controlling the mosquito that transmits it. It is this option where many countries are failing miserably. Whereas in the middle of the last century, the responsibility for mosquito control remained in strong government hands and was rigorously organised and meticulously executed, a gradual shift of responsibility to the general population in recent decades has yielded disastrous outcomes.

Community awareness and engagement in controlling potential mosquito breeding sites has at best been partially effective, but remains hopeless in most countries with endemic dengue. The result at present: 2,5 billion people at risk, and an estimated 100 million cases of infection per year. These numbers keep growing steadily.

By 1947, the same mosquito that is causing havoc in the Maldives today had invaded 11 million square kilometres of Central and South America. The Pan-American Sanitary Bureau then took the decision to eliminate it. By 1962, these efforts had succeeded in 21 countries, an area encompassing 8.5 million square kilometres. I repeat, 8.5 million square kilometres. Compare that to the size of Male’, or even the Maldives at large, and one wonders why we have forgotten past successes and not simply repeated these.

Back then, these huge successes were based on intensive campaigns to search for breeding sites and either remove or treat them with insecticides to kill mosquito larvae. Large teams of inspectors moved from house to house, and all they did was that. Clean up trash and kill mosquito larvae. These teams were well organised, well funded, well trained, motivated, and well paid.  Much of that has changed, and with the shift of responsibility away from governments, so has the capacity and know-how to deal with outbreaks waned.

Pro-activism to control dengue mosquitoes is gone. Instead, waiting for things to go wrong and then act has become the norm for policy. Why is that?

First, it’s a money issue, and the lack of willingness of governments to put money on the table when prevention is the issue. Politicians like to solve problems that are visible but shy away from spending money on something that may strike one day. Further complicating chronic underfunding are five other factors that contribute to the failure of dengue vector control programmes.

These factors are:

  • The desire to find easy solutions
  • Degradation of technical and managerial skills
  • The increasing scope of the problem
  • The shortness of human memory
  • Expectation of failure

I emphasize that the most important factor in achieving successful control of dengue mosquitoes is a programme led by a high calibre administration and staffed by well-trained, supervised and motivated personnel. Most countries suffering from dengue lack precisely these things and call upon experts from the World Health Organization (WHO) when disaster strikes. Beyond the WHO’s advisory role, which mostly emphasizes strategies based on community participation of which we know that they don’t really work, there isn’t much it can do.

When the experts fly home, you remain with the problem and responsibility to execute their well-meant advice. They will not do it for you. Setting up a high-level response team is certainly a good thing, but meetings do not control epidemics.

What is needed are highly competent control staffs that know how to systematically cover areas and reduce vector breeding; staff that go out into the country and are capable of containing transmission of the virus and to prevent further misery. Although this should be done in a military style, this is not the same as mobilising the military as is now being done in the Maldives.

We have taken a different approach to the persistent problem of dengue by building on the hugely successful campaigns of the past, and augmenting the old strategies with the latest scientific knowledge and modern tools. The successes of the past were accomplished without computers, mobile telephony, satellite imagery, modern monitoring and surveillance tools, and so on.

We have these now, and should use them to the full. Not just to control outbreaks, but solve the problem permanently, in a sustainable and green manner.

We are discussing this approach with various islands in the Caribbean at present, and consider the Maldives as another great example of where dengue mosquitoes can be eliminated for good.

Now you are facing bad press, political turmoil, and deaths. A public-private partnership holds the key towards avoiding this from happening every few years, and if given an opportunity we are ready to lend a helping hand with our team that holds some of the world’s leading mosquito and dengue experts.

Maldivians should not worry about keeping their kids from going to school. Instead, the country should be planning a dengue mosquito elimination campaign. Good for the public, good for tourism.

Prof. Dr. Bart G.J Knols of the University of Amsterdam is a medical entomologist and CEO of the private firm Soper Strategies, which aims to provide comprehensive mosquito-borne disease elimination programmes.


All comment pieces are the sole view of the author and do not reflect the editorial policy of Minivan News. If you would like to write an opinion piece, please send proposals to [email protected]