FEHD releases seventh batch of gravidtrap indexes for Aedes albopictus in June
The Food and Environmental Hygiene Department (FEHD) today (July 7) released the seventh batch of gravidtrap indexes and density indexes for Aedes albopictus in June, covering 13 survey areas, as follows:
| District | Survey Area | June 2026 | |
| Area Gravidtrap Index | Area Density Index | ||
| Central and Western | Kennedy Town and Shek Tong Tsui | 7.4% | 1.3 |
| Eastern | North Point and Quarry Bay | 9.9% | 1.2 |
| Southern | Aberdeen and Ap Lei Chau | 9.2% | 1.9 |
| Wan Chai | Tin Hau and Causeway Bay | 8.3% | 2.0 |
| Kowloon City | Kowloon City | 5.6% | 1.7 |
| Kwun Tong | Kwun Tong Central | 14.1% | 1.2 |
| Wong Tai Sin | Wong Tai Sin West | 6.5% | 1.0 |
| Yau Tsim | Tsim Sha Tsui and Yau Ma Tei | 0.0% | N/A |
| Sha Tin | Tai Wai | 4.8% | 1.2 |
| Kwai Tsing | Tsing Yi South | 7.9% | 1.4 |
| Tsuen Wan | Tsuen Wan Town | 8.5% | 1.3 |
| Tuen Mun | Tuen Mun North | 6.3% | 1.0 |
| Yuen Long | Tin Shui Wai | 17.2% | 1.0 |
With reference to the data from the past few years, the gravidtrap indexes start to rise from April every year. The indexes are higher from May to June. The actual timing and extent of the rise are affected by factors like weather conditions and rainfall. As compared with last year, the temperature began to climb earlier this year and the rainfall in June increased substantially, creating favourable conditions for mosquito growth and breeding. Overall, the trend of gravidtrap indexes this year is similar to those of previous years.
The FEHD has also carried out a series of actions, including:
- conducting risk assessments to identify locations with more serious mosquito infestation, so as to carry out intensive and targeted mosquito control work, including stepping up inspections, eliminating mosquito breeding and potential breeding grounds, applying larvicides, conducting fogging operations to eradicate adult mosquitoes, and placing mosquito trapping devices at appropriate locations;
- convening special meetings of the interdepartmental task forces on anti-mosquito work to co-ordinate relevant departments and stakeholders, such as construction site contractors, schools and property management companies, in strengthening venues'mosquito control work;
- organising exhibitions with the relevant departments and stakeholders, and distributing leaflets and posters; and
- notifying residential estates that have subscribed to the gravidtrap Rapid Alert System, advising property management companies and residents to stay vigilant and work together in taking mosquito prevention and elimination measures.
During the follow-up actions and following the discovery of stagnant water or stagnant water containers at a construction site, a park, a public housing estate and a private housing estate in Kwun Tong District and Yuen Long District, the FEHD has issued four statutory notices to the responsible persons-in-charge, requiring the clearance of such items within a specified timeframe.
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 the 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.
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#).
FEHD releases seventh batch of gravidtrap indexes for Aedes albopictus in June Source: HKSAR Government Press Releases
FEHD releases seventh batch of gravidtrap indexes for Aedes albopictus in June Source: HKSAR Government Press Releases
