FEHD releases sixth batch of gravidtrap indexes for Aedes albopictus in November
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| 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#).
Ends/Friday, November 28, 2025
Issued at HKT 17:00
Issued at HKT 17:00
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