Hong Kong’s disease prevention authority reported no new confirmed cases of Chikungunya fever as of December 4, 2025, maintaining the year-to-date total at 77. However, the Centre for Health Protection (CHP) reclassified one recent infection from imported to local based on genetic analysis, highlighting the ongoing effort to track and contain the mosquito-borne virus within the community.
The revised total now includes ten locally acquired cases following the genomic sequencing of a virus sample from a 63-year-old man residing in Kwai Tsing. Originally categorized as an imported case, the man’s viral sequence was found to be identical to two preceding local cases—a 63-year-old man and a 49-year-old woman, both from Tsing Yi. Investigations revealed that the three individuals shared movement history in Tsing Yi North, specifically around the town center and the Tsing Yi Nature Trails. Crucially, this unique strain differs from all other local and imported infections detected in 2025, strongly suggesting a distinct local transmission chain.
Intensified Response Follows Local Clusters
While authorities indicated that this reclassification does not substantially alter the overall disease risk assessment, it underscores the persistent threat of local transmission originating from imported cases. Since late November, targeted public health measures have been ramped up in affected areas, including active contact tracing, enhanced anti-mosquito operations, and public awareness campaigns.
A separate investigation is ongoing concerning a local infection identified on December 3, involving a 23-year-old woman living in Sheung Wan. The CHP is urgently appealing to residents and workers located near Queen’s Road West (around Morrison Street and Hollywood Road) who have experienced common Chikungunya symptoms—fever, rash, or joint pain—since November 15, to immediately seek medical consultation or contact the CHP hotline at 2125 2373.
Outreach teams are actively engaging the Sheung Wan community to bolster awareness of symptoms and reinforce crucial household hygiene practices. To date, over 1,100 individuals from locations deemed higher-risk have undergone assessment through a dedicated health consultation booth at the Sheung Wan Civic Centre entrance, the CHP hotline, and administered surveys. One individual with mild symptoms has been referred for comprehensive blood testing, with results pending confirmation.
Battling Vectors in High-Risk Hiking Spots
A critical focus of vector control efforts remains the Tsing Yi Nature Trails, which have been designated a high-risk area after reports indicated that several confirmed patients were bitten by mosquitoes while hiking. The CHP advises anyone who recently visited Tsing Yi North or utilized the trails to seek prompt medical attention if symptoms develop.
The Food and Environmental Hygiene Department (FEHD) is spearheading intensified anti-mosquito measures across the district:
- Targeted Adult Mosquito Control: Fogging operations, including the deployment of large ultra-low-volume foggers, have been intensified along the trails to kill adult mosquitoes.
- Innovation in Operations: Authorities are piloting the use of a robot dog to enhance inspection and treatment efficiency in challenging terrain.
- Breeding Site Elimination: Efforts are focused on clearing refuse and containers prone to holding water. Larvicides and larvicidal oil are being applied to unavoidable stagnant water sources.
The FEHD has also initiated interdepartmental anti-mosquito task force meetings across various districts to ensure coordinated, strengthened prevention strategies. Hikers are receiving educational pamphlets to heighten vigilance and encourage personal preventive measures while enjoying outdoor pursuits. Protecting against mosquito bites, especially during peak vector season, remains the most effective defense against Chikungunya infection.