May 2014

The Nation Reviewed

Mosquito diplomacy

By Ashley Hay
A plan to stop dengue fever sets off invasion fears in Indonesia

Scientific experiments are designed around all sorts of conditions, but it would be fairly rare that volcanoes, the vagaries of international relations and the cultural weight of dissent all come into play. Thanks to a new collaboration in the Yogyakarta Special Region of Indonesia, the Australian-led Eliminate Dengue (ED) program has experience of all three.

Globally, there are about 390 million cases of dengue (a mosquito-borne disease) each year, with up to 25,000 deaths. ED releases mosquitoes that carry Wolbachia, a naturally occurring bacteria that prevents them transmitting the disease. It took thousands of attempts to micro-inject the bacteria from a fruit fly into the eggs of Aedes aegypti mosquitoes, but when insects reared from these eggs bred, the “inoculation” was passed on to their offspring. When these mosquitoes were released to breed with mosquitoes in the wild, the Wolbachia was passed on again.

Initial trials in far north Queensland released approximately 300,000 inoculated mosquitoes. Three years later, 100% of mosquitoes test positive for the bacteria at these sites. And while Cairns has logged more than 100 cases of dengue since December, no local transmission has occurred in the seven sites where the mosquitoes were released and now breed. In a country like Indonesia, with annual reports of about 100,000 dengue cases (roughly 3% of which are fatal), a successful release could make a big difference.

Public thinking about new interventions and biocontrol can be a bit like “the story of the Little Red Hen”, says Professor Scott O’Neill, ED’s team leader and the dean of science at Melbourne’s Monash University. “Everyone wants to eat the bread the hen bakes, but no one wants to help grow the wheat or mill the flour or make the loaf.”

Wolbachia exists naturally in about 60% of all insect species, and ED’s approach requires no genetic modifications. But communities may still worry about extra bites from the numbers of mosquitoes released: in Queensland, the average was around 15 mosquitoes per household – although half were males, which don’t bite. In Cairns, there’s a high level of community support, and the team feels this has enhanced the work’s success.

The Australian trials obtained consent from individual households – not because of any regulatory requirement but because the team wanted to take people’s views into account. In Indonesia, where the work was funded by a local non-profit organisation and managed by a local team at Gadjah Mada University (UGM), consent was obtained via a community-based approach. “This is very Indonesian,” O’Neill explains. “The leaders of the community decide for the community.” In preparation, more than 300 meetings were held across two years.

But as the January date for the first release of the mosquitoes edged closer, UGM’s Institutional Review Board (IRB) recommended a change of plan. “The IRB was concerned about the potential risk of coercion and – unusually for Indonesia – they wanted individual consent to be obtained.” The team surveyed households in the two release sites of Kronggahan and Nogotirto, and more than 90% consented.

The UGM team was given clear local ownership of the process. “We wanted to take what had been successful in Australia and apply it to Indonesia. But obviously we were stepping into a different culture, a different language, and we were working with local partners. We moved from a situation of having control to a situation of having influence, and not ever completely knowing what was going on.”

On top of this, O’Neill says, there were always local suspicions that Australian mosquitoes would be released in Indonesia. “We’ve always been careful to explain that this isn’t the case.” The mosquitoes were bred in Indonesia from Indonesian mosquitoes.

“Then with the publicly destabilising relationship between Indonesia and Australia, and Indonesia approaching elections, well, Australia wasn’t the flavour of the month.”

Still, community support was high, and the mosquitoes were ready to go, when the team began hearing reports of dissent and of one Nogotirto resident who was voicing concerns in local media. On 22 January, a letter in the man’s name, posted on the Ministry of Health website, questioned the project’s support and the “increase of mosquitoes” and championed “the rights of citizens to live in peace”. The local Twittersphere started to buzz and more than 150 Nogotirto residents withdrew their consent.

In Javanese culture, says O’Neill, there is a strong emphasis on community harmony. “Having a situation where the community is divided is abhorrent, and a lot of tension and stress were being generated by both [sides] as we kept trying to push forward.”

But mosquito releases need to occur during a particular season, so the team decided to proceed – although not in the now-contested areas. “As we’d always explained, even though we still had more than 90% informed consent, this very vocal opposition meant we chose not to proceed in this area. We didn’t release in about 30% of that village to respect those concerns.”

But what might this mean for the experiments? “Scientifically it’s a problem,” says O’Neill. The experiment might have to run longer; the team might need to release more mosquitoes in different places.

And then came the volcano: on 13 February, Mount Kelud blew its top. The eruption was more than 200 kilometres from ED’s Yogyakarta sites, but it coated them with 5 centimetres of fine volcanic ash. “It got into everything and it didn’t rain for a week afterwards … We gave out dust masks and information about how to deal with its possible respiratory complications.” Mosquito releases were suspended for a week.

Beyond the ash, what worries O’Neill is the permanence of some of the material published electronically during the period of loudest dissent. “It’s particularly difficult when it’s just plain wrong.” The best defence, as he sees it, is “to be as open and transparent as possible. Then it’s harder for misinformation to get traction.” When the releases finish, in late autumn, results will be delivered to the study villages and their neighbours via a formal structure of community leaders, reference groups and public meetings. In the long term, O’Neill has hopes of “re-engaging” with the missing 30% of Nogotirto.

“Our field teams are still out talking to people,” he adds, “particularly if they feel they’re being bitten more. We’re giving insecticide and repellents to those people so they can control mosquitoes around their houses.”

Do these interventions interfere with the experiment, too? “Not unless someone’s following us with a can of insecticide and spraying as we release.” O’Neill laughs. “Insecticides and repellents might achieve some local protection for people who use them carefully – but if they were so good, we wouldn’t have a dengue problem in the first place.”

Ashley Hay

Ashley Hay won last year’s Bragg UNSW Prize for Science Writing. Her last novel, The Railwayman’s Wife, won the Foundation for Australian Literary Studies’ Colin Roderick Award and the People’s Choice category in the NSW Premier’s Literary Awards. Her new novel, A Hundred Small Lessons, will be published this April. She lives in Brisbane.

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