The monthly ovitrap index, which reflects the distribution of the mosquito vector for Dengue fever transmission, fell to 2.7% in October from 4.4% in September.

At the district level, of the 38 locations surveyed, 22 areas recorded positive area ovitrap indices ranging from 1.8% to 13.7%. The index at Fanling was 13.7%, the only one that was above 10%. In port areas it dropped from 1.5% in September to 1.3% in October.

The Food & Environmental Hygiene Department's Consultant Dr Ho Yuk-yin said although the monthly average ovitrap index stayed at a low level, preventive measures should not be relaxed at all as the current weather is still favourable for mosquito breeding.

Concerning the department's year-long Japanese encephalitis vectors survey, adult Culex tritaeniorhynchus were recently collected in Tsim Sha Tsui, Sham Shui Po, Tung Chung, Tso Kung Tam and Tai O. Larvae were found in an illegal cultivation site in Tsing Lung Tau of Tsuen Wan. However, no virus was detected in them.

The ovitrap indices and information on anti-mosquito measures are available on the department's website and through its hotline 2868 0000. Information and advice is also available from the Centre for Health Protection website and its hotline 2833 0111.