Bug brigade: The Food & Environmental Hygiene Department's Dr Ho Yuk-yin explains the anti-mosquito campaign.

An ovitrap study will be conducted in residential blocks to monitor mosquito breeding in individual families.

Starting this month, the Food & Environmental Hygiene Department pilot study will last two months covering residential flats on different floors of high-rise buildings.

Department Consultant Dr Ho Yuk-yin said the study was part of the Government's efforts in the second phase of this year's Anti-mosquito Campaign from May 26 to July 5.

"The findings of the study will be treated as a good reference for implementation of anti-mosquito measures inside homes," Dr Ho said.

"About 75 residential buildings in both public and private housing estates from 18 districts have been selected for the study. Ovitraps will be set inside 864 randomly selected flats at ground, middle and top floors of these buildings for one week to detect the presence of Aedes albopictus, a mosquito vector for dengue fever transmission."

The study will also give an early signal as to whether Aedes aegypti, the most important vector for the transmission of dengue fever worldwide that prefers to breed in indoor containers, has been introduced into Hong Kong.

The findings will be made public during the third phase of the 2003 campaign.

With the approach of the high-risk rainy season, Dr Ho appealed to the public to strictly observe environmental hygiene, reminding of the importance of eliminating stagnant water to halt mosquito breeding.

He said that both the monthly ovitrap index and area ovitrap indices were on the rise last month, following the seasonal pattern observed in the last three years.

The index in May was 17.1%, compared with 34.2% in the same month last year.

"Although the percentage for this year is substantially lower than that of last year, the area ovitrap indices at 15 locations were higher than 20%. This should be taken as a warning signal for the entire community to guard against the threat of dengue fever," Dr Ho said.

"All of us should stay alert and follow the mosquito prevention measures recommended in the Weekly Mosquito Inspection Programme prepared by the department.

"These measures include scrubbing vases and pot plant saucers at least once a week, disposal of containers such as soft drink cans or lunch boxes properly, clearing air conditioner drip trays regularly to ensure they are free of stagnant water and drilling large holes in tyres before discarding.

"The department will spare no efforts in implementing its anti-mosquito measures, including stepped-up inspection and enforcement action."

During the first five months of this year, the department treated 16,963 mosquito-breeding places, took out 111 prosecutions and issued 253 warnings.

Ovitrap indices and advice on anti-mosquito measures are available on the department's website  www.fehd.gov.hk  or the hotline 2868 0000.