Q What can be done to prevent the spread of dengue fever?
Permanent Secretary for Health Welfare, and Food Carrie Yau Tsang Ka-lai was quoted in your paper ('Taskforces to focus on combating mosquito scourge', published on Tuesday) as saying: 'One less empty can on the roadside could stop the breeding of hundreds of mosquitoes.'
This might suggest one possible solution to Mrs Yau. Given that a part of the mosquito's life cycle involves the laying of eggs in stagnant water, which later hatch into aquatic larvae, a controlling intervention here should be very effective.
First, establish the key areas implicated in the mosquito's reproductive cycle. Second, having removed all cans, bottles, and other possible reservoirs, and sterilised or obliterated any small bodies of water, provide the mosquitoes with thousands of small containers, tagged and colour-coded to allow easy collection.
They should be filled with stagnant water, not chlorinated, and designed in such a way that rainfall need not compromise their effectiveness.
Third, every five days, tour the collection of containers; empty and destroy the contents and replace the water. A team of two people, rotating areas, could cover five hot spots in this way. The cost would be minimal.
