FEHD releases first batch of gravidtrap indexes for Aedes albopictus in March
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| District | Survey Area | March 2026 | |
| First Phase Gravidtrap Index | First Phase Density Index | ||
| Kowloon City | Kowloon City | 0.0% | N/A |
| Kwun Tong | Kwun Tong Central | 0.0% | N/A |
| Mong Kok | Mong Kok and Tai Kok Tsui | 0.0% | N/A |
| Sham Shui Po | Lai Chi Kok | 0.0% | N/A |
| Wong Tai Sin | Ngau Chi Wan and San Po Kong | 0.0% | N/A |
| Yau Tsim | Tsim Sha Tsui East and King's Park | 0.0% | N/A |
| North | Sheung Shui | 0.0% | N/A |
| Sai Kung | Tseung Kwan O East | 0.0% | N/A |
| Tseung Kwan O North | 2.3% | 1.0 | |
| Tseung Kwan O West | 0.0% | N/A | |
| Kwai Tsing | Tsing Yi South | 0.0% | N/A |
| Tsuen Wan | Ma Wan and Sham Tseng | 1.9% | 1.0 |
| Tuen Mun | So Kwun Wat | 0.0% | N/A |
| Tuen Mun North | 0.0% | N/A | |
Among the first batch of First Phase Gravidtrap Indexes covering 14 survey areas in March, most of the areas recorded 0 per cent, indicating that the distribution of Aedes albopictus mosquitoes was not extensive.
Among these 14 survey areas, 12 recorded a decrease or remained unchanged as compared to the Area Gravidtrap Index last month (i.e. February 2026), representing that the areas' mosquito infestation improved or maintained a low level. Two other areas recorded a slight increase, but the indexes were lower than 10 per cent.
The warm and humid weather of spring is favourable for mosquito breeding. Members of the public should strengthen prevention work against mosquito breeding before the rainy season, and eliminate potential mosquito breeding sites in advance, with a view to avoiding the nuisances caused by rapid mosquito breeding during the rainy season and reducing the risk of transmitting mosquito-borne diseases.
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 water in flower vases and scrubbing their inner surfaces thoroughly, and remove water in saucers under potted plants at least once a week;
- properly cover all containers that hold water to prevent mosquitoes from accessing the water;
- properly dispose of articles that can contain water, such as disposable meal boxes and empty cans; and
- scrub drains and surface sewers with alkaline detergent at least once a week to remove any mosquito eggs.
Starting in August 2025, 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 62 survey areas of the community, with a surveillance period of two weeks. During the surveillance period, 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/Tuesday, March 10, 2026
Issued at HKT 17:00
Issued at HKT 17:00
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