FEHD releases fourth batch of gravidtrap indexes for Aedes albopictus in March
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     The Food and Environmental Hygiene Department (FEHD) today (March 24) released the fourth batch of gravidtrap indexes and density indexes for Aedes albopictus in March, covering 21 survey areas, as follows:
 
District Survey Area March 2026
First Phase Gravidtrap Index First Phase Density Index
Wan Chai Happy Valley and Tai Hang 0.0% N/A
Islands Tung Chung 0.0% N/A
Kowloon City Ho Man Tin 0.0% N/A
Kwun Tong Kowloon Bay 0.0% N/A
Lam Tin and Sau Mau Ping 1.6% 1.0 
Sham Shui Po Cheung Sha Wan 0.0% N/A
Sham Shui Po and Shek Kip Mei 0.0% N/A
Tai Po Tai Po West 0.0% N/A
Yuen Long Yuen Long Town 0.0% N/A
 
District Survey Area March 2026
Area Gravidtrap Index Area Density Index
Central and Western Sheung Wan and Sai Ying Pun 1.8% 1.0 
Southern Aberdeen and Ap Lei Chau 0.9% 1.0 
Deep Water Bay and Repulse Bay 0.0% N/A
Pok Fu Lam 0.0% N/A
Wan Chai Tin Hau and Causeway Bay 0.0% N/A
Wan Chai 0.0% N/A
Kowloon City Kai Tak 1.0% 1.0 
Sha Tin Sha Tin Town Centre and Fo Tan 0.0% N/A
Tai Wai 0.0% N/A
Kwai Tsing Kwai Chung East 0.0% N/A
Kwai Chung West 0.0% N/A
Tuen Mun Tuen Mun West 0.0% N/A

     Among the fourth batch of First Phase Gravidtrap Indexes covering nine survey areas and Area Gravidtrap Indexes covering 12 survey areas in March, most of the areas recorded 0 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 March 2026, covering 41 survey areas. Among these 41 survey areas, 32 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. Nine 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 scrub 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.

     â€‹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 24, 2026
Issued at HKT 17:00

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