The Food and Environmental Hygiene Department (FEHD) today (December 24) released the fourth batch of gravidtrap indexes and density indexes for Aedes albopictus in December, covering 25 survey areas, as follows:
 

District	Survey Area	December 2025
		First Phase Gravidtrap Index	First Phase Density Index
Eastern	Shau Kei Wan and Sai Wan Ho	0.0%	N/A
Islands	Cheung Chau South	0.0%	N/A
Kowloon City	Lok Fu West	0.0%	N/A
North	Fanling	0.0%	N/A
Tsuen Wan	Tsuen Wan Town	0.0%	N/A

 

District	Survey Area	December 2025
		Area Gravidtrap Index	Area Density Index
Central and Western	Sheung Wan and Sai Ying Pun	0.0%	N/A
	Sai Wan	0.0%	N/A
Southern	Pok Fu Lam	0.0%	N/A
Islands	Cheung Chau North	0.0%	N/A
	Tung Chung	0.0%	N/A
Mong Kok	Mong Kok	0.0%	N/A
Sham Shui Po	Cheung Sha Wan	0.0%	N/A
	Lai Chi Kok	0.0%	N/A
Wong Tai Sin	Wong Tai Sin West	0.0%	N/A
	Ngau Chi Wan	0.0%	N/A
Sai Kung	Tseung Kwan O East	0.0%	N/A
	Tseung Kwan O North	1.1%	1.0
	Sai Kung Town	0.9%	1.0
	Ngau Liu and Muk Min Shan	0.0%	N/A
Tai Po	Tai Po West	0.0%	N/A
Yuen Long	Yuen Long Town	0.0%	N/A
Tuen Mun	Tuen Mun North	0.8%	1.0
Tsuen Wan	Sheung Kwai Chung	0.0%	N/A
Kwai Tsing	Kwai Chung	0.0%	N/A
	Lai King	0.0%	N/A

     Among the fourth batch of First Phase Gravidtrap Indexes covering five survey areas and Area Gravidtrap Indexes covering 20 survey areas in December, all were below 10 per cent, and most of the areas recorded zero per cent, indicating that the distribution of Aedes albopictus mosquitoes was not extensive.

     The FEHD has so far released four batches of gravidtrap indexes for Aedes albopictus in December 2025, covering 55 survey areas. Among these 55 survey areas, 52 recorded a decrease or remained unchanged in the individual gravidtrap index as compared to the Area Gravidtrap Index last month, i.e. November 2025, representing that the areas' mosquito infestation improved or maintained a low level. Three other areas recorded a slight increase, but the indexes were lower than 10 per cent.

     The eggs of Aedes albopictus can withstand long periods of desiccation and will hatch when the temperature becomes suitable and water is present. Members of the public should continue to take mosquito control measures during winter to eliminate mosquito eggs.

     Public participation is crucial to the effective control of mosquito problems. The FEHD appeals to members of the public to continue to work together in strengthening personal mosquito control measures, including:

• tidy up their premises and check for any accumulation of water inside their premises;
• remove all unnecessary water collections and eliminate the sources;
• check household items (those placed in outdoor and open areas in particular), such as refuse containers, vases, air conditioner drip trays, and laundry racks to prevent stagnant water;
• change the water in flower vases and clear the water in saucers of potted plants at least once every seven days;
• properly cover all containers that hold water to prevent mosquitoes from accessing the water;
• properly dispose of articles that can contain water, such as empty lunch boxes and cans; and
• scrub drains and surface sewers with alkaline detergent at least once a week to remove any mosquito eggs.

     Starting in August this year, following the completion of the surveillance of individual survey areas, and once the latest gravidtrap index and the density index are available, the FEHD has been disseminating relevant information through press releases, its website and social media. It aims to allow members of the public to quickly grasp the mosquito infestation situation and strengthen mosquito control efforts, thereby reducing the risk of chikungunya fever (CF) transmission.

     Following recommendations from the World Health Organization and taking into account the local situation in Hong Kong, the FEHD sets up gravidtraps in districts where mosquito-borne diseases have been recorded in the past, as well as in densely populated places such as housing estates, hospitals and schools to monitor the breeding and distribution of Aedes albopictus mosquitoes, which can transmit CF and dengue fever. At present, the FEHD has set up gravidtraps in 64 survey areas of the community. During the two weeks of surveillance, the FEHD will collect the gravidtraps once a week. After the first week of surveillance, the FEHD will immediately examine the glue boards inside the retrieved gravidtraps for the presence of adult Aedine mosquitoes to compile the Gravidtrap Index (First Phase) and Density Index (First Phase). At the end of the second week of surveillance, the FEHD will instantly check the glue boards for the presence of adult Aedine mosquitoes. Data from the two weeks of surveillance will be combined to obtain the Area Gravidtrap Index and the Area Density Index. The gravidtrap and density indexes for Aedes albopictus in different survey areas, as well as information on mosquito prevention and control measures, are available on the department's webpage (www.fehd.gov.hk/english/pestcontrol/dengue_fever/Dengue_Fever_Gravidtrap_Index_Update.html#).

Ends/Wednesday, December 24, 2025
Issued at HKT 17:00

NNNN