Dengue fever alert still vital, says expert
Dengue fever remains a threat if precautions against mosquito breeding are not taken - despite the risk of transmission falling by a third since May, a government expert said yesterday.
Risks were highest for rural villages, followed by public housing estates and private housing estates, said Ho Yuk-yin, a consultant for community medicine, risk assessment and communication with the Food and Environmental Hygiene Department.
Last month's ovitrap index, which measures the spread of mosquitoes and indicates the risk of dengue fever, dropped to about 21 per cent from 22 per cent in June and the 31.6 per cent peak in May.
But the department warned that allowing stagnant water to accumulate in the family home could send the risk soaring again. Even flower vases and pot plants are a threat.
Dr Ho presented results of a survey showing that provided no stagnant water is kept in a household, the likelihood of larvae from the dengue-transmitting Aedes albopictus mosquito being found there was negligible - 0 per cent in private housing estates, 0.7 per cent in public housing estates and 1.9 per cent in village houses. These percentages were far below the 5 per cent benchmark set by the World Health Organisation, he said.
But careless retention of stagnant water could drastically push the area ovitrap index to about 26 per cent for village housing, 17 per cent for public housing and 9 per cent for private housing, the survey found.
For village housing, Wong Nai Tau village in Sha Tin registered the highest risk in these circumstances at 34 per cent, followed by Wu Kai Sha village in Ma On Shan, at 22 per cent.
The public housing estate of Ap Lei Chau Estate recorded a risk level of 22 per cent, and Sha Tin Centre was the highest-risk private housing estate, at 13 per cent.
Dr Ho said the results showed that families had to get rid of stagnant water inside their homes at least once a week.
The results were announced at a news conference yesterday to mark the start of the third phase of the government's anti-mosquito campaign this year.
