November Gravidtrap Indexes Show Low Aedes albopictus Levels Across Hong Kong, Public Urged to Maintain Mosquito Control Efforts

FEHD releases sixth batch of gravidtrap indexes for Aedes albopictus in November

​The Food and Environmental Hygiene Department (FEHD) today (November 28) released the sixth batch of gravidtrap indexes and density indexes for Aedes albopictus in November, covering 14 survey areas, as follows:

District

Survey Area

November 2025

First Phase Gravidtrap Index

First Phase Density Index

Central and Western

Central and Admiralty

0.0%

N/A

Southern

Aberdeen and Ap Lei Chau

0.0%

N/A

Yau Tsim

Tsim Sha Tsui

0.0%

N/A

Tsim Sha Tsui East

1.9%

1.0

Kowloon City

Hung Hom

5.5%

1.0

Kai Tak North

0.0%

N/A

Wong Tai Sin

Wong Tai Sin Central

0.0%

N/A

Kwun Tong

Lam Tin and Sau Mau Ping

0.0%

N/A

Sha Tin

Tai Wai

1.7%

1.0

Sha Tin East

0.0%

N/A

Tsuen Wan

Ma Wan

8.3%

1.0

District

Survey Area

November 2025

Area Gravidtrap Index

Area Density Index

Wan Chai

Tin Hau

0.0%

N/A

Kwun Tong

Kowloon Bay

0.0%

N/A

Yuen Long

Tin Shui Wai

0.0%

N/A

Among the sixth batch of First Phase Gravidtrap Indexes covering 11 survey areas and Area Gravidtrap Indexes covering three survey areas in November, all were below 10 per cent.

The FEHD has so far released six batches of gravidtrap indexes for Aedes albopictus in November 2025, covering 59 survey areas. Among these 59 survey areas, 46 recorded a decrease or remained unchanged in the individual gravidtrap index as compared to the Area Gravidtrap Index last month, i.e. October 2025, representing that the areas' mosquito infestation improved or maintained a low level. Thirteen 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 the 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#).

Public Urged to Maintain Mosquito Control Efforts.

DSD deeply saddened by passing of contractor staff member

The Director of Drainage Services, Mr Ringo Mok, was deeply saddened by the passing of a staff member of its contractor in an accident that occurred at a construction site for upgrading works of existing sewerage system at Yen Chow Street in Sham Shui Po yesterday (May 27). He expressed his deepest condolences to the family of the deceased and requested the contractor to provide them with appropriate assistance.

At about 8.30am yesterday, the worker was injured during a lifting operation at the construction site. He was sent to Princess Margaret Hospital for treatment and was certified dead at about 11.30pm.

The Drainage Services Department (DSD) has requested the contractor to suspend the related works and conduct a safety check. The contractor was also instructed to carry out a thorough investigation into the cause of the accident. The DSD will also render full assistance to relevant departments in their investigations.

Source: AI-found images