Dengue Alert

But it is possible to make Singapore essentially mosquito-free.

To illustrate the problem, I would like to describe the situation in my estate at Cluny Park, where two recent cases of chikungunya prompted me to write this letter.

Leaves falling on the road are the responsibility of the National Environment Agency (NEA). But trees on the strip of land next to the road are the concern of the National Parks Board.

The strip of land is traversed by many side drains, which direct water on the road surface into monsoon drains. The monsoon drains are under the purview of the PUB, but the side drains are 'no man's land'.

The trees shed leaves constantly and the narrow side drains are usually choked with fallen leaves. They harbour stagnant water during wet weather and so produce mosquito larvae.

Private contractors, outsourced by the NEA, remove the leaves from the road surface, but they say clearing the side drains is not their job.

As a result, my estate is seldom free of mosquitoes during the wet season. My neighbours resort to frequent chemical fogging of their compounds - a futile measure that does not affect mosquito breeding, but adds harmful pollutants to the environment.

Once, I managed to persuade the NEA contractors to clear the side drains, and we were able to enjoy a mosquito-free period until the drains became blocked again.

As felling of trees is banned, a permanent solution to these problematic side drains is to cover them and their inlets with metal grilles to keep out fallen leaves.

The authorities respond promptly to complaints. But they solve only the immediate problem, not the fundamental factors that allow mosquito breeding.

There should be a systematic and holistic approach, as disjointed ad hoc measures of mosquito control have got us nowhere.

The NEA should divide the island into districts and assign an officer to each - like a Member of Parliament (MP) looking after a constituency. Residents in each district should have access to him. He would become familiar with his district and once mosquito breeding grounds are detected, he should take effective measures to ensure no recurrence.

His primary task is to pre-empt any situation that may lead to accumulation of stagnant water, such as drains obstructed by trash and leaves, littering of containers and plastic bags, untidy construction sites, unoccupied houses with ill-maintained gardens and swimming pools.

Dr Ong Siew Chey