August's monthly ovitrap index for Aedes albopictus continues to fall

     The Food and Environmental Hygiene Department (FEHD) today (September 26) announced that the monthly ovitrap index for Aedes albopictus for August dropped to 6.9 per cent from 10.2 per cent in July. After months of enhanced collaborative efforts of various departments in mosquito prevention and control work, the number of areas with the Area Ovitrap Index (AOI) exceeding the alert level of 20 per cent has decreased sharply from 17 in June to two in July, and none in August. 

     As of August, a total of four areas were recorded, with the AOI exceeding the alert level for two months or above this year, fewer than the six areas recorded in the same period last year. The number of times that the AOI has exceeded 40 per cent has decreased from three last year to one this year, while that between 20 and 40 per cent has also dropped from 32 last year to 25 this year. 
     A spokesman for the FEHD said, "Aedes albopictus is a kind of mosquito that can transmit dengue fever (DF) as well as the 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 World Health Organization also issued warnings that the number of DF cases recorded in Asia this year was exceptionally high when compared with last year. As at September 19, 151 imported DF cases were recorded in Hong Kong. Although there are outbreaks of DF cases in nearby areas, and that 29 local DF cases were recorded last year, there have been no confirmed local cases so far this year, indicating that the anti-mosquito efforts taken by the Government have achieved positive results." 
     Among the 57 areas surveyed last month, positive ovitrap indices, ranging from one per cent to 19.5 per cent, were recorded in 54 areas. As for the port areas, the monthly ovitrap index for Aedes albopictus for August also dropped to 1.2 per cent from 2.2 per cent in July. Although no individual area has recorded an AOI exceeding the alert level, the temperature of autumn in Hong Kong was still high, which is favourable for the breeding of mosquitoes. The public must stay alert and work with the Government to continue to carry out effective mosquito prevention and control measures.
     The FEHD launched the third phase of the territory-wide Anti-mosquito Campaign on August 19, to last for 12 weeks. During this period, the district offices of the FEHD are targeting areas that have drawn particular concerns, such as public markets, cooked food centres and hawker bazaars, single-block buildings, streets and back lanes, common parts of buildings, village houses, construction sites, vacant sites and road works sites, and have stepped up publicity at those places as well as mosquito prevention and control work at relevant public places. 
     In addition, the FEHD has also handled mosquito complaints promptly and taken out prosecutions under the relevant ordinance against mosquito breeding. Pest control inspection teams have stepped up inspections and enforcement actions at construction sites against mosquito breeding. This year (as at September 15), the FEHD instituted 136 prosecutions for mosquito breeding found on relevant premises under the Public Health and Municipal Services Ordinance (Cap 132), comprising 127 cases involving construction sites and nine cases involving other premises. 
     In order to keep the public abreast of the latest situation of mosquito infestation and assist them to take timely mosquito prevention and control measures, the FEHD is releasing two additional phased AOIs for Aedes albopictus before the announcement of the monthly AOI and the Monthly Ovitrap Index for Aedes albopictus. The FEHD will follow the established practice of notifying relevant government departments of the aforementioned indices so that they can carry out targeted mosquito prevention and control work promptly. 
     The spokesman added that as Aedes albopictus breeds in small water bodies, members of the public should carry out effective mosquito prevention and control measures, including inspecting their homes and surroundings to remove potential breeding grounds, changing the water in vases and scrubbing the inner surface as well as 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. He also advised public and estate management bodies to keep drains free of blockage and level all defective ground surfaces to prevent 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. 
     In addition, rural areas and the vicinity of shrubby areas are natural habitats for mosquitoes, other insects and animals. Members of the public living in rural areas may install mosquito screens on windows and doors if necessary. Those staying in the natural environment should take appropriate personal protective measures against mosquitoes, such as avoiding staying in the vicinity of shrubby areas for a long time, wearing light-coloured long-sleeved clothes and trousers, and applying DEET-containing insect repellent. Members of the public are reminded to make reports to relevant government departments via 1823 if mosquito problems are detected. 
     The spokesman reiterated that effective mosquito prevention and control requires the sustained effort of all parties concerned. The community must work together with the Government to carry out effective anti-mosquito measures. 

     The ovitrap indices for Aedes albopictus in different areas and information on mosquito prevention and control measures are available on the department website at     

Ends/Thursday, September 26, 2019
Issued at HKT 17:30