Update on mosquito-borne diseases, dengue fever and chikungunya fever
The Centre for Health Protection (CHP) of the Department of Health (DH) today (January 23) reported the latest situation of dengue fever (DF) and chikungunya fever (CF). The Controller of the CHP, Dr Edwin Tsui, reminds the public that temperatures in subtropical and some temperate regions (including neighbouring Southeast Asian countries) remain favourable for mosquito breeding. When travelling to areas affected by mosquito-borne diseases, the public should take measures to prevent mosquito bites, including wearing loose, light-coloured, long-sleeved tops and trousers and applying insect repellent containing DEET to clothing or exposed parts of the body.
Dengue fever
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From January 16 to yesterday (January 22), the CHP recorded two imported DF cases. The patients had travelled to the Philippines and United Arab Emirates respectively during the incubation period.
As of yesterday, five imported DF cases have been recorded so far this year. A total of 59 DF cases were recorded last year (2025), all of which were imported cases.
According to the World Health Organization (WHO), the global incidence of DF has markedly increased over the past two decades, posing a substantial public health challenge. In 2024, the WHO recorded over 14 million cases, which was a record number. From January to July 2025, over 4 million cases and over 3 000 DF-related deaths were reported in 97 countries/territories.
DF is prevalent in many neighbouring tourist destinations. In 2025, Indonesia, India and Vietnam each recorded over 120 000 cases; Malaysia and Thailand each recorded over 50 000 cases; and Singapore also recorded over 4 000 cases.Meanwhile, the Guangdong Provincial Center for Disease Control and Prevention recorded over 3 500 locally infected cases in Guangdong Province in 2025.
Detailed information on the latest DF situation in Hong Kong, as well as neighbouring and overseas countries and areas, has been uploaded to the CHP's website.
Chikungunya fever
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As of 5pm today, no new cases of CF had been recorded. Hong Kong has recorded a total of 82 confirmed CF cases last year. Among them, 11 were local cases, and the rest were imported cases.
Since the beginning of 2025, and as of December 10, 2025, a total of 502 264 CF cases and 186 CF-related deaths have been reported in over 40 countries/territories. Cases have been reported in the Americas, Africa, Asia, and Europe. Although the northern hemisphere has entered the winter season, temperatures in subtropical and some temperate regions remain elevated due to climate change, creating favourable conditions for mosquito breeding. In addition, CF outbreaks continue to occur in many countries worldwide. The risk of imported cases persists. Members of the public should check the situation of the destinations before travelling abroad, especially when travelling to Southeast Asian countries.
Continuously strengthening prevention and control
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Given that some local cases of CF have visited the Tsing Yi Nature Trails or the surrounding area in November last year, the trails are currently closed until further notice. Relevant government departments (including the Food and Environmental Hygiene Department (FEHD), Kwai Tsing District Office, Lands Department, Drainage Services Department, and Civil Engineering and Development Department) have been continuously conducting comprehensive mosquito control and environmental remediation work along the trails. Since the confirmation on December 10, 2025, of a case involving a person who had visited the Tsing Yi Nature Trails on November 30, 2025, no further local cases have been recorded to date.
The FEHD and relevant departments have comprehensively enhanced the mosquito control operations in Hong Kong since July last year, and this has continued. Among these, the FEHD has conducted vector investigations and targeted mosquito control operations against the imported and local cases. In light of the local case, the FEHD has immediately conducted follow-up actions, including:
- carrying out intensive fogging in scrubby areas within a 250-metre radius of the relevant locations to kill adult mosquitoes;
- carrying out inspections of the locations, removing stagnant water, applying insecticides and disposing of abandoned water containers every week with a view to preventing mosquito breeding; and
- enhancing public education efforts through organising health talks, setting up mobile education stations, and distributing publicity leaflets.
The abovementioned measures will be continued. Furthermore, the Government will further enhance the mosquito control efforts in addition to the existing measures.
Preventive measures to be taken by the public
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Members of the public should use DEET-containing insect repellents or other effective active ingredients properly to prevent mosquito bites, but the following precautions should be taken when using them:
- read the label instructions carefully first;
- apply right before entering an area with a risk of mosquito bites;
- apply on exposed skin and clothing;
- use DEET of up to 30 per cent for pregnant women and up to 10 per cent for children (for children who travel to countries or areas where mosquito-borne diseases are endemic or epidemic and where exposure is likely, those aged 2 months or above can use DEET-containing insect repellents with a DEET concentration of up to 30 per cent);
- apply sunscreen first, then insect repellent;
- reapply only when needed and follow the instructions; and
- in addition to DEET, there are other insect repellents available on the market containing different active ingredients, such as IR3535 and picaridin. When using any insect repellent, the public should follow the usage instructions and precautions on the product label.
The FEHD also appeals to members of the public to continue to stay alert and work together to carry out mosquito prevention and control measures early, including inspecting their homes and surroundings to remove potential breeding grounds, changing water in vases and scrubbing their inner surfaces, removing water in saucers under potted plants at least once a week, and properly disposing of containers such as empty cans and lunch boxes. The FEHD also advises members of the public and property management agencies to keep drains free of blockage and level all defective ground surfaces to prevent the accumulation of water. They should also scrub all drains and surface sewers with an alkaline detergent at least once a week to remove any mosquito eggs.
The public should call 1823 in case of mosquito problems, and may visit the following pages for more information: the CF page of the CHP and the Travel Health Service, the latest Travel Health News, tips for using insect repellents, and the CHP Facebook Page, Instagram Account and YouTube Channel, and also the Mosquito Prevention and Control dedicated page of the FEHD.
Source: AI-created image
