Replies to LegCo questions

LCQ18: Monitoring mosquito problem

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Following is a question by the Hon James To Kun-sun and a written reply by the Secretary for Health, Welfare and Food, Dr York Chow, in the Legislative Council today (October 18):

Question:

Regarding the placement of ovitraps for mosquito surveillance, will the Government inform this Council:

(a) in view of the Government's remarks that ovitraps should be placed at locations with heavy pedestrian flow, whether the authorities have reviewed if the ovitraps in Kowloon City are placed at locations which meet this criterion, and if the relevant ovitrap indices can fully reflect the situation of mosquito problem in that district;

(b) how the Government ensures that the ovitrap indices can reflect the mosquito problem in all districts of Hong Kong;

(c) whether the Government will consider moving the ovitraps which have consistently recorded low level of readings to new locations for optimum use of resources; if it will, when the measure will be implemented; if not, the reasons for that;

(d) whether the Government will review the locations of ovitraps more frequently, which are currently reviewed once a year;

(e) whether the Government will inject additional resources so that ovitraps may be placed at more locations in order to extend the coverage of mosquito surveillance; and

(f) in view of the dual roles of Food and Environmental Hygiene Department in monitoring mosquito problem and carrying out anti-mosquito work, which may give rise to conflict of interests, whether the Government has considered assigning the relevant duties to different government departments?

Reply:

Madam President,

(a) & (b) In selecting locations for placing ovitraps, the Food and Environmental Hygiene Department (FEHD) makes reference to the recommendations of the World Health Organisation (WHO) for dengue vector surveillance. As such, ovitraps are mainly set up in areas and hospitals where local dengue fever cases were reported, as well as densely populated housing estates and schools, etc. The ovitraps in Kowloon City are placed in accordance with this principle.

To ensure that the ovitrap indices can reflect the monitoring work of the dengue fever situation in all districts of Hong Kong, FEHD will, apart from strengthening its management, continue to draw reference from the recommendations of the WHO in adopting a scientific approach for the placement of ovitraps and handling of data collected. On the other hand, in monitoring and assessing the extent of mosquito problem, the Administration will also take into consideration the ovitrap indices as well as a basket of factors, namely, information obtained from the WHO and health authorities of neighbouring areas, the number of imported and local cases of mosquito-borne diseases, reports and number of mosquito complaints received and feedback from district councils and local personalities. All the information is useful to the Administration for making an overall assessment of the prevalence of mosquitoes in Hong Kong.

(c) & (d) The locations of ovitraps are fixed throughout the calendar year to enable FEHD to make meaningful comparison and monitor monthly trends. These locations are reviewed annually, taking into consideration past experience, new development (including the levels of ovitrap indices recorded) and emerging public health needs. The department considers the existing annual review to be appropriate, and there is no plan to move ovitraps to other locations when the index recorded is below a certain level.

(e) FEHD regularly reviews and improves the surveillance programme. The frequency of survey was increased from once every three months to once a month in 2003, and the number of localities under surveillance also increased from 34 to 38. In 2004, the surveillance programme was further extended to cover 30 port areas in the territory. Currently, about 2 000 ovitraps are placed by FEHD in the 38 localities covering all the District Board areas, to reflect the prevalence of dengue fever vector at both district and territorial levels. While the current surveillance programme has achieved its objectives, we will conduct annual review and adjust the scope of surveillance to respond to actual needs.

(f) District staff of FEHD are responsible for mosquito preventive and control operation, whereas the Pest Control Advisory Section (PCAS) of FEHD provides professional advice and technical support on pest control matters for FEHD's district operational staff as well as for other government departments. The PCAS also monitors territory-wide dengue vector through the ovitrap surveillance programme. Since anti-mosquito operations and monitoring work are carried out by two different and independent units, there is no question of overlapping roles. The Government has no plan to assign the relevant duties to different government departments.


Ends/Wednesday, October 18, 2006
Issued at HKT 14:18

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12 Apr 2019