The monthly ovitrap index, which reflects the distribution of the mosquito vector for Dengue fever transmission, continued to fall in the past three months.

The Food & Environmental Hygiene Department said the figure for September was 15.9%, compared to 17.7% in August.

At the district level, the area ovitrap index recorded in 11 locations exceeded 20%, of which one was higher than 30%. In August, there were 12 locations with an index exceeding 20% and six over 30%.

Tung Chung, Wong Tai Sin and Kwai Chung, where the index exceeded 30% in August, all saw falls. But Lai King remained high at 33.3%.

As for port areas, the ovitrap index rose slightly from 5.4% in August to 5.5% in September. The department will closely monitor the situation there and continue to take effective measures to prevent mosquito breeding.

Releasing the figures today, the department's consultant Dr Ho Yuk-yin said although the overall situation is improving, there is no room for complacency.

"Concerted efforts by Government departments and the participation of the public are essential in resolving the mosquito problem and further bringing down the ovitrap indices."

Most Dengue cases imported

Dr Ho said Dengue is endemic in Southeast Asian countries. There have been 4,671 confirmed cases in Singapore, 59,321 cases in Indonesia and 45,830 cases in Vietnam this year.

"The 25 cases reported this year in Hong Kong originated mostly from Southeast Asia," he said.

"Although we fare well when compared with these countries, we should stay alert and keep up anti-mosquito efforts as local Dengue fever could still strike around this time of year."

Dr Ho called for full community support for the third phase of this year's anti-mosquito campaign, which runs until October 23.

He said the department conducted an ovitrap study between April and June in residential units. Although it showed mosquito breeding in residential flats was not serious, mosquitoes will still breed if there is stagnant water.

He urged people to take prevention measures, such as scrubbing vases and pot plant saucers at least once a week, proper disposal of containers like drink cans or lunch boxes, clearing air conditioner drip trays regularly, and drilling large holes in unused tyres to ensure they are all free of stagnant water.

People should play their part by eliminating potential mosquito breeding grounds in and around their homes and reporting mosquito problems to the department's hotline at 2868 0000.