April’s monthly ovitrap index for Aedes albopictus rises

     The Food and Environmental Hygiene Department (FEHD) today (May 29) announced that the monthly ovitrap index for Aedes albopictus for April rose to 1 per cent from 0.1 per cent in March, indicating that the infestation of Aedes albopictus in the areas surveyed was not extensive. Nevertheless, the FEHD reminded the public to carry out effective prevention and control measures against mosquitoes as the summer weather is favourable for mosquito breeding within a short period of time.
      
     Among the 52 areas surveyed, positive ovitrap indices were recorded in 15 areas, ranging from 1.5 per cent to 9.8 per cent, with the highest in Tseung Kwan O North. As for the port areas, the monthly ovitrap index for Aedes albopictus for April rose to 0.1 per cent from zero in March.
      
     "Aedes albopictus is a kind of mosquito that can transmit dengue fever (DF) and Zika virus. In view of the fact that Hong Kong recorded a confirmed local DF case, five local Japanese encephalitis (JE) cases and one imported case of Zika Virus Infection last year and DF is still highly prevalent in neighbouring areas, and that with the advent of summer, the hot and rainy weather is favourable for proliferation of mosquitoes, the community must work with the Government to continue to carry out effective mosquito control measures," an FEHD spokesman said.
      
     "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 campaigns. The FEHD will conduct a three-phase Anti-mosquito Campaign this year. The second phase of the territory-wide campaign, lasting for 10 weeks, was launched on April 23 and will end on June 29. During this period, mosquito prevention and control work is being enhanced by the FEHD and relevant government departments. The district offices of the FEHD have targeted areas which have drawn particular concern, 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 intensified mosquito prevention and control work at those places. The FEHD will, immediately after each phase of the campaign, conduct special territory-wide thematic mosquito prevention and control operations so as to enhance the effectiveness of the campaign," he added.
      
     The spokesman said that the FEHD had set up four Pest Control Inspection Teams in May last year to step up inspection of construction sites and enforcement action against mosquito breeding. This year (as at May 11), the FEHD had instituted 34 prosecutions for mosquito breeding found in relevant premises under the Public Health and Municipal Services Ordinance (Cap 132), with all cases involving construction sites.
      
     As Aedes albopictus breeds in small water bodies, the spokesman reminded members of the public to inspect their homes and surroundings to remove potential breeding grounds, scrub vases and pot plant saucers at least once a week, properly dispose of containers such as soft drink cans and lunch boxes, and drill large holes in unused tyres. He also advised the public and estate management bodies to keep drains free of blockage and fill up all depressions to prevent puddles from forming. They should also scrub all drains and surface sewers with an alkaline detergent compound at least once a week to remove any mosquito eggs.
      
     In addition, rural areas and the vicinity of shrubby areas are the 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 follow 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 the government departments via 1823 if mosquito problems are detected.
      
     The spokesman reiterated that effective mosquito control requires the sustained effort of all parties concerned. The community must work together with the Government to carry out effective mosquito control measures.
      
     The ovitrap index is divided into four levels, reflecting the infestation level of Aedes albopictus. Level 1 (< 5 per cent) indicates that infestation of the mosquito is not extensive in the area surveyed. Level 2 (5 per cent – < 20 per cent) indicates that infestation of the mosquito is slightly more extensive in the area surveyed. Level 3 (20 per cent – < 40 per cent) indicates that infestation of the mosquito exceeds one-fifth of the area surveyed. Level 4 (>/= 40 per cent) indicates that almost half of the surveyed area is infested with the mosquito. The Government will step up the scale of anti-mosquito operations according to the level of infestation as well as reports from front-line staff and the public.
      
     As Aedes albopictus can transmit DF and Zika virus, oviposition traps are set in 52 areas in Hong Kong for monitoring the breeding of Aedes albopictus, which is only one of the mosquito species commonly found in Hong Kong and is active only in the daytime. The index does not capture the activity of Aedes albopictus outside the 52 areas and it also does not measure the prevalence of other kinds of mosquitoes.
      
     The ovitrap indices for Aedes albopictus in different areas and information on mosquito prevention and control measures are available on the department website at www.fehd.gov.hk.