Public urged to keep up anti-mosquito efforts

     The Food and Environmental Hygiene Department (FEHD) today (May 20) announced that the monthly gravidtrap index for Aedes albopictus for April was 2.2 per cent and remained at Level 1 at its lowest, indicating that mosquito infestation in the areas surveyed was not extensive.

     Among the 64 survey areas, no area recorded a gravidtrap index exceeding the alert level of 20 per cent. Moreover, the monthly density index for Aedes albopictus in April was 1.1, which represented that an average of 1.1 Aedes albopictus adults were found in the Aedes-positive gravidtraps, indicating that the number of adult Aedes albopictus was not high in the areas surveyed.

     Since March this year, the FEHD has classified the density index for Aedes albopictus into three levels to make it easier for members of the public to grasp the number of adult Aedes albopictus collected in gravidtraps of survey areas. The lowest level is Level 1 (with an index of 1 to 1.5), indicating that the number of Aedes albopictus is not abundant in the locations with positive gravidtraps. Level 2 (with an index of 1.6 to 2.4) indicates that the number of Aedes albopictus is slightly abundant in the locations with positive gravidtraps. The highest level is Level 3 (with an index of 2.5 or above), indicating that the number of Aedes albopictus is abundant in the locations with positive gravidtraps. Specific mosquito prevention and control measures will be initiated in the locations concerned accordingly. The gravidtrap and density indices for Aedes albopictus in different survey areas as well as information on mosquito prevention and control measures are available on the department's website at www.fehd.gov.hk.

     The department reminded members of the public to carry out effective preventive and control measures against mosquitoes early because mosquitoes breed quickly in the hot and rainy summer weather.

     A spokesman for the FEHD said, "Effective mosquito control requires the sustained effort of all parties concerned. The FEHD and relevant government departments will continue to intensify their mosquito prevention and control work covering areas under their purview and strengthen publicity and education. The FEHD is conducting a three-phase Anti-mosquito Campaign this year. The second phase of the territory-wide campaign, lasting nine weeks, has been launched on April 18 and will run until June 17. During the period, the district offices of the FEHD will target areas that have drawn particular concern to remove accumulated water and to carry out mosquito prevention and control work. After the second phase of the campaign, the FEHD will conduct territory-wide thematic mosquito prevention and control special operations, such as strengthening mosquito control measures at individual construction sites. To further enhance the effectiveness of mosquito control, the FEHD and relevant government departments have already launched the All-out Anti-mosquito Operations since March 10 to focus on eliminating potential breeding places of mosquitoes. The FEHD has called on property management bodies to arrange necessary repairs to their premises so that the chance of mosquito larvae hatching is reduced, and has conducted intense adult control by regular fogging operations."

     The FEHD appeals to members of the public to work together to carry out mosquito prevention and control measures early, including inspecting their homes and surroundings to remove potential breeding grounds, changing the water in vases and scrubbing the inner surfaces, removing the water in saucers under potted plants at least once a week, properly disposing of containers such as soft drink cans and lunch boxes, and drilling large holes in unused tyres. The FEHD also advises members of the public and estate management bodies to keep drains free of blockage and level all defective ground surfaces to prevent the accumulation of water. They should also scrub all drains and surface sewers with an alkaline detergent at least once a week to remove any mosquito eggs.

     Aedes albopictus is a kind of mosquito that can transmit dengue fever (DF) as well as Zika virus infection. DF is commonly found in tropical and subtropical regions of the world, and has become endemic in many countries in Southeast Asia. The dengue activity in neighbouring areas has remained high.