The Food and Environmental Hygiene Department (FEHD) announced today (November 19) that the monthly territory-wide ovitrap index for Aedes albopictus dropped further, from 6 per cent in September to 2.2 per cent in October, indicating that the infestation of Aedes albopictus in the areas surveyed was not extensive. The FEHD reminded the public to keep on implementing effective measures against mosquitoes even winter is approaching.
        
     "Aedes albopictus is a kind of mosquito that can transmit dengue fever (DF) and Zika virus. In view of the 29 local DF cases recorded in Hong Kong so far this year, and that DF is also highly prevalent in neighbouring areas, as well as the relatively high temperature of autumn and winter in Hong Kong which is favourable for mosquito breeding, the public must remain vigilant and work with the Government to continue to carry out effective mosquito prevention and control measures," an FEHD spokesman said.
      
     Among the 57 areas surveyed last month, positive ovitrap indices were recorded in 38 areas, ranging from 0.9 per cent to 8.8 per cent, with the highest in Ma On Shan. As for the port areas, the monthly ovitrap index for Aedes albopictus for October fell to 0.2 per cent from 1.4 per cent in September.
      
     "The FEHD and relevant government departments will continue to intensify their mosquito preventive and control work covering areas under their purview and strengthen publicity and education campaigns. The FEHD has launched a special territory-wide thematic mosquito prevention and control operation on October 29, which will continue in the winter season and last till January 11, 2019. Relevant departments have also participated in the operation. The district offices of the FEHD will target areas which have drawn particular concern, such as single-block buildings, village houses, construction sites, areas previously detected with local DF cases and container terminals and cargo working areas in port areas, to intensify mosquito prevention and control work throughout winter. Closely following the thematic operation, the year-end clean-up operation will commence on January 11, 2019, during which mosquito control work will also be enhanced."
      
     In addition, the FEHD 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 of November 18, the FEHD has instituted 191 prosecutions for mosquito breeding found in relevant premises under the Public Health and Municipal Services Ordinance (Cap 132), comprising 182 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 additional results of the Area Ovitrap Index (AOI) for Aedes albopictus at two more stages every month, 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 to strengthen the anti-mosquito efforts.
      
     The spokesman added that as Aedes albopictus breeds in small water bodies, members of the public should continue to carry out effective mosquito prevention and control measures, including inspecting their homes and surroundings to remove potential breeding grounds, scrubbing vases and pot plant saucers 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 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 57 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 57 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.

     The effective exchange rate index for the Hong Kong dollar on Monday, November 19, 2018 is 105.6 (up 0.1 against last Saturday's index).

     The effective exchange rate index for the Hong Kong dollar on Saturday, November 17, 2018 was 105.5 (down 0.2 against last Friday's index).

     The Leisure and Cultural Services Department (LCSD) announced today (November 19) that Kwu Tung Grass Soccer Pitch in North District will be temporarily closed from November 21 to December 4 for turf maintenance works. During the closure period, the public may use the similar facility at Fanling Recreation Ground in the same district.
 
     For the most up-to-date closure schedules of the above leisure and sports facility, the public may refer to the notices at the venue or contact venue staff directly.

     The Buildings Department approved 13 building plans in September, with five on Hong Kong Island, two in Kowloon and six in the New Territories.
 
     Of the approved plans, seven were for apartment and apartment/commercial developments, four were for commercial developments, and two were for community services developments.
 
     In the same month, consent was given for works to start on 11 building projects which, when completed, will provide 20 799 square metres of gross floor area for domestic use involving 692 units, and 12 912 sq m of gross floor area for non-domestic use. The department has received notification of commencement of works for five building projects.
 
     The department also issued 18 occupation permits, with eight on Hong Kong Island, two in Kowloon and eight in the New Territories.
 
     Of the buildings certified for occupation, the gross floor area for domestic use was 112 010 sq m involving 1 095 units, and 145 284 sq m was for non-domestic use.
 
     The declared cost of new buildings completed in September totalled about $8.6 billion.
 
     In addition, one demolition consent involving a building structure was issued.
 
     The department received 2 285 reports about unauthorised building works (UBWs) in September and issued 1 079 removal orders on UBWs.
 
     The full version of the Monthly Digest for September can be viewed on the Buildings Department's homepage (www.bd.gov.hk).

     The Centre for Health Protection (CHP) of the Department of Health today (November 19) reported the latest number of cases of Legionnaires' disease (LD), and stressed the importance of using and maintaining properly designed man-made water systems, and that susceptible groups should strictly observe relevant precautions.

     From November 11 to 17, four community-acquired LD cases were reported. They are:
 

1. A female patient, aged 60 with good past health, who lives in Tower 2, Newton Harbour View, 2 Shau Kei Wan Main Street East;
2. A male patient, aged 83 with underlying illnesses, who lives in Block 19, Baguio Villa (Upper) , 555 Victoria Road, Southern District;
3. A male patient, aged 86 with underlying illnesses, who lives in Block B, Park View Court, 1 Lyttelton Road, Central and Western District; and
4. A male patient, aged 83 with underlying illnesses, who lives in Yuen Long Plaza, 249-251 Castle Peak Road, Yuen Long.

     "Epidemiological investigations are ongoing to identify potential sources of infection, high-risk exposure and clusters, if any," a spokesman for the CHP said.

     As of November 17, 96 LD cases had been reported in 2018. In 2017 and 2016, there were 72 and 75 cases respectively.

     "Men, people aged over 50, smokers, alcoholics and persons with weakened immunity are more susceptible to LD. Some situations may also increase the risk of infection, including poor maintenance of water systems leading to stagnant water; living in areas with old water systems, cooling towers or fountains; using electric water heaters, whirlpools and spas or hot water spring spas; and recent stays in hotels or vessels," the spokesman said.

     Legionellae are found in various environmental settings and grow well in warm water (20 to 45 degrees Celsius). They can be found in aqueous environments such as water tanks, hot and cold water systems, cooling towers, whirlpools and spas, water fountains and home apparatus which support breathing. People may get infected when they breathe in contaminated droplets (aerosols) and mist generated by artificial water systems, or when handling garden soil, compost and potting mixes.

     Immunocompromised persons should:
 

1. Use sterile or boiled water for drinking, tooth brushing and mouth rinsing;
2. Avoid using humidifiers, or other mist- or aerosol-generating devices. A shower may also generate small aerosols; and
3. If using humidifiers, or other mist- or aerosol-generating devices, fill the water tank with only sterile or cooled freshly boiled water, and not water directly from the tap. Also, clean and maintain humidifiers/devices regularly according to manufacturers' instructions. Never leave stagnant water in a humidifier/device. Empty the water tank, wipe all surfaces dry, and change the water daily.

     The public should observe the health advice below:
 

• Observe personal hygiene;
• Do not smoke and avoid alcohol consumption;
• Strainers in water taps and shower heads should be inspected, cleaned, descaled and disinfected regularly or at a frequency recommended by the manufacturer;
• If a fresh water plumbing system is properly maintained, it is not necessary to install domestic water filters. Use of water filters is not encouraged as clogging occurs easily, which can promote growth of micro-organisms. In case water filters are used, the pore size should be 0.2 micrometres (µm) and the filter needs to be changed periodically according to the manufacturer's recommendations;
• Drain and clean water tanks of buildings at least quarterly;
• Drain or purge for at least one minute the infrequently used water outlets (e.g. water taps, shower heads and hot water outlets) and stagnant points of the pipework weekly or before use;
• Seek and follow doctors' professional advice regarding the use and maintenance of home respiratory devices and use only sterile water (not distilled or tap water) to clean and fill the reservoir. Clean and maintain the device regularly according to the manufacturer's instructions. After cleaning/disinfection, rinse the device with sterile water, cooled freshly boiled water or water filtered with 0.2 µm filters. Never leave stagnant water in the device. Empty the water tank, keep all surfaces dry, and change the water daily; and
• When handling garden soil, compost and potting mixes:

     1. Wear gloves and a face mask;
     2. Water gardens and compost gently using low pressure;
     3. Open composted potting mixes slowly and make sure the opening is directed away from the face;
     4. Wet the soil to reduce dust when potting plants; and
     5. Avoid working in poorly ventilated places such as enclosed greenhouses.

     The public may visit the CHP's LD page, the Code of Practice for Prevention of LD and the Housekeeping Guidelines for Cold and Hot Water Systems for Building Management of the Prevention of LD Committee, and the CHP's risk-based strategy for prevention and control of LD.