Public abuzz with ideas on fighting dengue

Suggestions for NEA include using GM mozzies, installing screen doors

THE rising dengue figures have led concerned members of the public to write in offering tips and suggestions they fear the National Environment Agency (NEA) may have overlooked.

The measures range from the sophisticated - the use of high- tech genetically modified mosquitoes - to the simple: installing mosquito screens on doors and windows.

The NEA said it welcomes any input the public has to offer on how the battle against dengue could be better fought.

The Straits Times forwarded some readers' suggestions to the NEA and pest experts to find out how feasible they are:

  • Releasing male Aedes mosquitoes which have been genetically modified so that they cannot reproduce. They would still mate with the female, but without producing young.

The population of disease-carriers locally would be reduced.

The NEA says it has been aware of this method since 2011 and that research is still ongoing.

However, this method comes with some risks. About 4 per cent of these mosquitoes are still capable of producing young.

The impact of the genetic modifications on the second-generation mosquitoes may be unpredictable.

  • Introducing guppies - a natural predator of mosquito larvae - into sewage drains and other bodies of water where they can prey on the larvae of the insects.

This has been carried out with some success in India. But this approach is not foolproof, as drains are designed to channel water quickly - a feature which makes it difficult to maintain fish life, says the NEA.

  • Installing mosquito screens on the doors and windows in homes

The NEA recommends that people sleep under mosquito nets instead.

  • Drilling holes in bamboo pole holders to let water drain out.

These holders can be found at most Housing Board flats and holes would prevent any excess rainwater from collecting inside.

However, the NEA says this approach is unsafe as it could undermine the integrity of the pole holders.

The agency is working to phase out bamboo pole holders in newer residential estates to eliminate potential breeding sites.

  • Drinking papaya leaf juice.

This is touted as a remedy for dengue, but dengue expert Ng Lee Ching, director of the Environmental Health Institute, says: "There is no evidence this works. The best advice is to go to the doctor."

Meanwhile, a quick street poll of 50 people aged from 18 to 65, shows that many could benefit from a lesson on mosquito behaviour. More than half of those polled thought they were safe from mosquitoes if they lived on higher floors, while less than half knew that mosquitoes tend to stay within a 150m radius of their breeding ground.

One of the respondents was sure people would take more care not to let mosquitoes breed if they knew this.

Civil servant Mohd Isamudin, 29, said he would for sure. "My family is important to me, especially my young son who is only two."

Ms Lisa Liew, 60, was another who thought that if people had more knowledge about facts like these, the mosquito situation could improve. Said the teacher: "The older folk or kids might still not be aware."

chanhj@sph.com.sg

Additional reporting by Fabian Koh, Natalie Kuan, Farah Ismail and Lim Min Zhang

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