Mosquito index rises sharply in April, dengue risk increases: SSM

Macau’s mosquito ovitrap index for April was higher than in previous years, the Health Bureau (SSM) warned, indicating a significant increase in mosquito breeding and a continued rise in the risk of dengue fever and chikungunya transmission.

Macau’s mosquito breeding container index reached 38% in April, far exceeding the 15% recorded during the same period last year and the five-year average of 30%, according to Dr. Leong Iek Hou from the bureau’s Centre for Disease Control. The increase is believed to be due to high temperatures and heavy rainfall, which have accelerated the reproduction rate of Aedes albopictus mosquitoes.

Leong reminded the public that local cases of dengue fever have already been reported in Guangdong and Hong Kong. As a tourist destination with frequent travel between Macau and other regions, the risk of transmission of dengue fever and chikungunya continues to rise. She predicted that the risk will persist this year and urged residents to take proactive measures to prevent mosquito bites.

Notably, Macau recorded a total of 46 cases of chikungunya last year – 38 imported and eight locally transmitted – and 36 cases of dengue fever, of which 35 were imported and one was locally transmitted. Between January and April this year, meanwhile, Macau recorded five imported cases of dengue fever and two imported cases of chikungunya fever.

Authorities have announced the high-alert period for the Aedes albopictus mosquito in Macau, with countermeasures including 5,570 community patrols and 741 chemical mosquito-control operations targeting 130 sanitation hotspots. The Health Bureau has set up “Public Mosquito Repellent Stations” in 12 public parks and recreational areas across the city and will gradually expand coverage this month to include border quarantine points, health centers, government public service points, and facilities under the jurisdiction of the Secretary for Social Affairs and Culture.

After evaluating the pilot program’s effectiveness and making improvements, authorities plan to further extend the service to other government department service points and community organization premises.

The authorities also stated that they will continue to monitor the effectiveness of relevant measures in Hong Kong, draw on the experience of regions with similar environmental conditions, and then conduct a comprehensive and prudent assessment of the feasibility of piloting “mosquito-based mosquito control” prevention technology in Macau. Leong Iek Hou explained that the technology involves releasing sterilized male mosquitoes to suppress mosquito reproduction and is generally more suitable for implementation in rural and open areas.