FEHD releases fifth batch of gravidtrap indexes for Aedes albopictus in June
Source: Hong Kong Government special administrative region
FEHD releases fifth batch of gravidtrap indexes for Aedes albopictus in June
District
District 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. Depending on factors like rainfall, the indexes may rise further, but the overall trend of gravidtrap indexes this year is similar to those of previous years.
The FEHD has also carried out a series of actions, including: During the follow-up actions and following the discovery of stagnant water or stagnant water containers at a construction site, a park, four public housing estates, four private housing estates and two private premises in Southern District, Kwun Tong District, Sham Shui Po District, North District, Sai Kung District and Yuen Long District, the FEHD has issued 12 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: 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#Issued at HKT 18:30