Advisory Council on Food and Environmental Hygiene

 

Anti-mosquito Campaign 2004 and

Dengue Vector Surveillance in Hong Kong

 

 

PURPOSE

 

                   At the meeting held on 17 March 2003, Members were briefed on the Anti-mosquito Campaign 2003 and the dengue vector surveillance programme implemented by the Food and Environmental Hygiene Department (FEHD). This paper outlines the objectives and implementation plan of the Anti-mosquito Campaign 2004, reports the findings of the dengue vector surveillance programme in 2003 and describes how the programme will be further enhanced in 2004.

 

Anti-mosquito Campaign 2004

 

2.                                         To heighten public awareness of the potential risk of mosquito-borne diseases notably dengue fever and to forge partnership of the community and government departments concerned in anti-mosquito work, territory-wide anti-mosquito campaigns have been organised under the stewardship of FEHD annually. The Anti-mosquito Campaign 2004 will be implemented in three phases as follows:

 

Phase 1:   Phase 1: from 23.2.2004 to 3.4.2004, lasting for a period of six weeks

 

Phase 2:   Phase 2: from 24.5.2004 to 3.7.2004, lasting for a period of six weeks

 

Phase 3:   Phase 3: from 30.8.2004 to 23.10.2004, lasting for a period of eight weeks

 

3.                                         Control measures and publicity efforts will be stepped up during the campaign period, supplementing the regular inspection and enforcement works carried out by district pest control staff. The third phase of the Campaign will be extended to 8 weeks as this period follows the summer break, during which a large number of local residents will travel to dengue endemic areas and may bring the dengue virus with them back to the territory.

 

4.                                         Under the slogan of ��Beware of Dengue Fever Act Now�� ���p�ߵn���� ��ӧ�A����, the message of the campaign will be promulgated through different channels including Announcement of Public Interests on radio and television, VCD, exhibitions, talks, and publicity materials e.g. posters, leaflets, banners, etc. Relevant government departments including the Department of Health, Lands Department, Housing Department, Education and Manpower Bureau, Leisure and Cultural Services Department, Agriculture, Fisheries and Conservation Department, Marine Department, Architectural Services Department, Highways Department, Social Welfare Department, Labour Department, Environmental Protection Department, Home Affairs Department, Correctional Services Department, Immigration Department and Water Supplies Department will also play an active role in the campaign through eliminating mosquito problems in places under their charge and solicit community support for the campaign through their networks.

 

Findings of the Dengue Vector Surveillance Programme in 2003

 

5.                                         Since 2000, FEHD has put in place a dengue vector surveillance programme to monitor the distribution of Aedes albopictus at selected locations, evaluate the effectiveness of mosquito prevention and control work carried out by various parties, and provide surveillance information for making timely adjustments to our mosquito control strategies and measures. Following the finding of the first local dengue fever cases in Hong Kong in 2002, the programme has been enhanced in 2003 with a more comprehensive ovitrap survey introduced. 38 selected areas were covered by the ovitrap survey each month. Two different indices, namely, Area Ovitrap Index (AOI) and Monthly Ovitrap Index (MOI), are recorded. AOI indicates the extensiveness of the distribution of Aedine mosquitoes in a surveyed area while the MOI is the average of all AOIs of the same month, which reflects the distribution and activity of Aedes albopictus in the whole territory. The AOIs, once available, are provided to the relevant government departments so that mosquito control actions can be taken promptly according to the value of the ovitrap index recorded. The indices are also announced each month through FEHD��s website and press release to arouse public awareness of the situation of mosquito breeding in respective districts and to enlist community participation in mosquito control work.

 

6.                                         The MOIs and AOIs recorded in 2003 are shown in Appendix 1.  It can be seen that the MOIs were much lower than that of 2000-2002 (Appendix 2).  MOI increased gradually from 1.4% in March to 20.3% in July, which followed the seasonal pattern observed in the last three years although the peak appeared in July instead of June.  AOIs of individual surveyed areas also followed the seasonal changes.  Higher indices were generally observed during the warmer months in June, July and August.  Highest AOI of 48.0% was recorded in Cheung Chau and Tai Po North during June and July respectively.  Tin Shui Wai, on the other hand, had an AOI over 40% in June and July consecutively.

 

7.                                         7.                   For areas with high indices over 30%, inter-departmental anti-mosquito response mechanism led by FEHD was activated with the setting up of Task Force at district level in a bid to contain the rise in ovitrap index. Apart from the government departments concerned, relevant non-governmental organizations including housing estate management companies and schools were also invited to participate in the special control operations.  In the fourth quarter of 2003, the control measures were further strengthened and the response mechanism would be activated in areas recording ovitrap indices over 20%. Intensive on-the-spot inspections would be conducted in those areas, followed by elimination of breeding sources and application of larvicides to potential breeding grounds that were non-removable. These measures have proved to be effective in lowering the ovitrap indices.

 

 

FURTHER ENHANCEMENT OF DENGUE VECTOR SURVEILLANCE PROGRAMME IN 2004

 

Port Surveillance

 

8.                                         Under the current vector surveillance programme, airport has always been under stringent monitoring using ovitraps. The existing 38 strategic locations also cover port areas. In view of the high number of imported cases of dengue fever last year and the fact that port areas are important strategic locations vulnerable to the introduction of dengue virus from neighbouring areas, there will be an enhancement of the dengue vector surveillance programme in 2004 through extending the coverage of the programme to all major port areas. These include airport, cross boundary sea ports, land ports, cargo working areas and container terminals (Appendix 3). The Port Ovitrap Index (POI) will be categorized into seven groups, namely, Airport, Public Cargo Working Areas (PCWA), Private Cargo Handling Areas (PCHA), Cross Boundary Ferry Piers (CBFP), Cross Boundary Check Points on Land (CBCP), Container Terminals (CT) and Rail Cargo Handling Areas (RCHA).  A Monthly Port Ovitrap Index (PMOI) will be enumerated to indicate the overall situation of mosquito breeding in port areas and will be released monthly together with the MOI and AOIs.

 

Community Surveillance

 

9.                                         After reviewing the 38 selected locations covered by the ovitrap survey in 2003, we decide to retain 36 old locations with some adjustments of their boundaries while two new locations will be added in 2004.  Lo Wu and Sai Ying Pun will no longer be covered by the community surveillance programme. Lo Wu as a cross boundary land port will be covered by the port surveillance programme, while most areas of Sai Ying Pun previously covered will remain to be covered by expanding the surveillance areas of the neighbouring Sheung Wan and Kennedy Town.

 

10.                                    The new areas to be included in the surveillance progarmme will be Yuen Long and North Point. The only one local dengue fever case in 2003 was found in Yuen Long, Pat Heung. Dengue vector surveillance will be carried out in the area to monitor the vectorial situation aiming to prevent a recurrence of the problem.  In addition, North Point will be included in the dengue vector surveillance programme in 2004 as it is a densely populated area with schools.      A total of 38 AOIs and a MOI will be recorded monthly to represent the vectorial situation in the community.

 

 

ADVICE SOUGHT

 

11.                                    Members are invited to note the Anti-mosquito Campaign 2004, the findings of the dengue vector surveillance programme in 2003, and the further enhanced dengue vector surveillance programme in 2004.

 

 

 

Food and Environmental Hygiene Department

January 2004

�@                                  

Ops Area

Locations

JAN�@

FEB�@

MAR�@

APR�@

MAY�@

JUN�@

JUL�@

AUG�@

SEP�@

OCT�@

 

NOV�@

 

DEC�@

 

Hong Kong Island &Outside Islands

Chai Wan West

0.0%

5.8%

0.0%�@

7.3%

30.8%

25.5%

20.8%

12.8%

14.6%

8.0%

10.9%

0.0%

 

Wan Chai North

0.0%

0.0%�@

6.0%

1.9%

10.4%

8.2%

8.0%

8.0%

2.0%

7.7%

2.0%

0.0%

 

Happy Valley

0.0%

0.0%�@

13.2%

3.7%

21.8%

20.8%

18.2%

17.6%

11.5%

5.8%

7.4%

7.7%

 

Sheung Wan

0.0%

0.0%�@

0.0%�@

7.8%

8.0%

10.4%

12.2%

9.8%

8.2%

8.2%

4.2%

0.0%

 

Kennedy Town

2.1%

2.0%

2.2%

22.0%

14.0%

27.5%

18.0%

13.7%

11.5%

7.8%

2.0%

0.0%

 

Sai Ying Pun

0.0%�@

2.2%

6.8%

8.9%

13.3%

23.9%

12.2%

12.0%

12.0%

6.0%

2.0%

0.0%

 

Aberdeen

0.0%�@

0.0%�@

0.0%�@

7.8%

12.2%

17.4%

19.1%

14.6%

10.4%

6.1%

10.2%

0.0%

 

Pokfulam

0.0%�@

0.0%�@

1.9%

9.6%

10.9%

14.8%

12.0%

27.8%

14.6%

9.3%

5.8%

0.0%

 

Cheung Chau

0.0%�@

0.0%�@

0.0%�@

36.4%

29.2%

48.0%

21.2%

12.5%

15.2%

12.1%

5.9%

0.0%

 

Tung Chung

0.0%�@

0.0%�@

0.0%�@

22.2%

16.1%

13.3%

29.0%

23.5%

12.5%

12.5%

3.0%

0.0%

 

Kowloon

Tsim Sha Tsui

0.0%�@

0.0%�@

0.0%�@

13.0%

13.0%

9.4%

13.5%

16.0%

14.0%

12.0%

10.4%

0.0%

 

Yau Ma Tei

0.0%�@

0.0%�@

0.0%�@

4.2%

4.2%

5.8%

13.2%

11.5%

7.7%

9.8%

1.9%

0.0%

 

Lai Chi Kok

0.0%�@

0.0%�@

0.0%�@

1.9%

12.7%

7.8%

17.3%

11.3%

14.3%

7.5%

5.7%

0.0%

 

Kln Tong

0.0%�@

0.0%�@

0.0%�@

13.5%

24.5%

20.4%

18.4%

19.1%

22.0%

7.7%

4.7%

5.9%

 

Cheung Sha Wan

0.0%�@

0.0%�@

0.0%�@

7.5%

7.7%

11.8%

17.6%

15.7%

13.7%

14.3%

11.8%

0.0%

 

Kln City North

0.0%�@

0.0%�@

0.0%�@

7.8%

3.9%

12.5%

20.8%

16.3%

4.0%

12.0%

4.2%

0.0%

 

Ho Man Tin

0.0%�@

0.0%�@

0.0%�@

6.4%

4.7%

6.5%

14.8%

17.3%

22.4%

20.4%

3.9%

0.0%

 

Wong Tai Sin Central

0.0%�@

4.3%

0.0%�@

37.5%

35.6%

16.3%

36.5%

22.2%

18.5%

11.8%

4.0%

0.0%

 

Diamond Hill

2.4%

0.0%�@

0.0%�@

12.0%

20.8%

9.6%

19.6%

34.7%

15.4%

7.8%

9.3%

0.0%

 

Kwun Tong Central

2.2%

0.0%�@

0.0%�@

11.5%

11.3%

10.4%

20.8%

20.0%

13.7%

12.5%

10.0%

0.0%

 

Lam Tin

0.0%�@

0.0%�@

4.4%

4.4%

17.6%

14.3%

27.1%

18.9%

15.1%

5.9%

2.0%

0.0%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

New Territory East

Tseung Kwan O

0.0%�@

0.0%�@

0.0%�@

1.6%

9.2%

15.4%

17.5%

14.5%

17.7%

6.7%

3.2%

0.0%

 

Ma On Shan

0.0%�@

0.0%�@

0.0%�@

4.0%

25.5%

26.7%

16.7%

17.0%

14.3%

8.3%

6.3%

0.0%

 

Lek Yuen

0.0%�@

0.0%�@

0.0%�@

9.8%

21.8%

16.4%

16.3%

25.0%

13.7%

13.7%

3.7%

0.0%

 

Tai Wai

0.0%�@

5.8%

2.0%

10.0%

19.6%

22.0%

16.4%

18.9%

17.6%

13.7%

4.0%

0.0%

 

Tai Po North

0.0%�@

0.0%�@

8.5%

21.7%

17.3%

18.8%

48.0%

29.2%

28.0%

11.8%

8.0%

0.0%

 

Fanling

0.0%�@

0.0%�@

0.0%�@

15.2%

31.1%

17.0%

24.5%

18.9%

18.0%

6.1%

9.8%

3.9%

 

Lo Wu

0.0%�@

0.0%�@

4.6%

26.1%

33.3%

29.2%

10.0%

18.8%

8.8%

0.0%

3.1%

0.0%

 

Sheung Shui

0.0%�@

0.0%�@

0.0%�@

11.3%

20.0%

13.5%

21.2%

26.0%

14.3%

11.5%

11.5%

2.0%

 

New Territory West

Tin Shui Wai

2.3%

0.0%�@

4.6%

13.5%

25.0%

40.7%

46.0%

34.7%

27.7%

14.6%

4.3%

0.0%

 

Yuen Long Town

0.0%�@

0.0%�@

0.0%�@

18.8%

17.3%

18.0%

19.2%

17.0%

17.6%

3.9%

2.0%

0.0%

 

Tuen Mun (S)

0.0%�@

0.0%�@

0.0%�@

5.9%

5.7%

18.0%

18.8%

18.4%

18.4%

11.9%

4.0%

0.0%

 

Tuen Mun (N)

0.0%�@

0.0%�@

1.8%

12.7%

10.9%

12.7%

20.4%

23.1%

17.0%

5.7%

5.8%

0.0%

 

Tsuen Wan Town

0.0%�@

0.0%�@

0.0%�@

0.0%

3.7%

13.5%

13.2%

14.0%

7.5%

3.9%

3.8%

0.0%

 

Ma Wan

0.0%�@

0.0%�@

0.0%�@

39.3%

14.3%

11.5%

13.3%

17.2%

17.9%

6.9%

6.7%

0.0%

 

Kwai Chung

0.0%�@

0.0%�@

0.0%�@

22.6%

24.5%

10.6%

20.4%

35.4%

23.1%

17.0%

5.9%

1.9%

 

Lai King

0.0%�@

0.0%�@

0.0%�@

10.9%

28.3%

21.6%

27.5%

19.2%

17.3%

16.0%

10.0%

0.0%

 

Tsing Yi

0.0%�@

1.9%

0.0%�@

8.8%

21.1%

15.8%

28.6%

23.5%

17.0%

14.8%

11.5%

1.8%

 

Monthly Ovitrap Index

0.2%

0.6%

1.4%

11.4%

17.1%

16.8%

20.3%

19.7%

15.0%

9.8%

5.9%

0.6%

 

�@

�@

�@

�@

 

Cross Boundary Check Points on Land

Cross Boundary Ferry Piers

Public Cargo Working Areas

Private Cargo Handling Areas

Container Terminals

Rail Cargo Handling Areas

Airport

1.

Lok Ma Chau

Macau Ferry Terminal

Tuen Mun

China Merchant Wharf, Kennedy Town

No.1

Hung Hom Cargo Handling Area

Chek Lap Kok Island

2.

Lo Wu

China Ferry Terminal and Ocean Terminal

Rambler Channel

Yun Fat Pier, Shum Shui Po

No.2

Fo Tan Railway Siding

 

3.

Sha Tau Kok

 

Stonecutters Island

River Trade Terminal, Tuen Mun

No.3

Sheung Shui Railway Siding

 

4.

Man Kam To

 

New Yau Ma Tei

 

No.4

 

 

5.

 

 

Kwun Tong

 

No.5

 

 

6.

 

 

Cha Kwo Ling

 

No.6

 

 

7.

 

 

Western District

 

No.7

 

 

8.

 

 

Chai Wan

 

No.8

 

 

9.

 

 

 

 

No.9

 

 

�@

 

Back