A greener vision for vector control: The example of the Singapore dengue control programme

Abstract

Vector-borne diseases are a major cause of morbidity and mortality worldwide. Aedes-borne diseases, in particular, including dengue, chikungunya, yellow fever, and Zika, are increasing at an alarming rate due to urbanisation, population movement, weak vector control programmes, and climate change. The World Health Organization calls for strengthening of vector control programmes in line with the Global Vector Control Response (GVCR) strategy, and many vector control programmes are transitioning to this new approach. The Singapore dengue control programme, situated within the country's larger vision of a clean, green, and sustainable environment for the health and well-being of its citizens, provides an excellent example of the GVCR approach in action. Since establishing vector control operations in the 1960s, the Singapore dengue control programme succeeded in reducing the dengue force of infection 10-fold by the 1990s and has maintained it at low levels ever since. Key to this success is consideration of dengue as an environmental disease, with a strong focus on source reduction and other environmental management methods as the dominant vector control strategy. The programme collaborates closely with other government ministries, as well as town councils, communities, the private sector, and academic and research institutions. Community engagement programmes encourage source reduction, and house-to-house inspections accompanied by a strong legislative framework with monetary penalties help to support compliance. Strong vector and epidemiological surveillance means that routine control activities can be heightened to specifically target dengue clusters. Despite its success, the programme continues to innovate to tackle challenges such as climate change, low herd immunity, and manpower constraints. Initiatives include development of novel vector controls such as Wolbachia-infected males and spatiotemporal models for dengue risk assessment. Lessons learnt from the Singapore programme can be applied to other settings, even those less well-resourced than Singapore, for more effective vector control.

Fig 1. Global Vector Control Response Framework [9].

Fig 2. Collaboration between National Environment Agency and other sectoral stakeholders.

NGO, nongovernmental organisation.

Fig 3. Redesign of washing line construction from bamboo pole holders with caps (A) to novel rack system (B).

Fig 4. Banners at construction sites to encourage good housekeeping to reduce Aedes habitats.

Fig 5. Vector control measures in Bishan-Ang Mo Kio Park.

(A) Stream treated monthly with Bti by the Public Utilities Board. (B) Papyrus beds treated with Bti and dried intermittently to reduce biting midges and A. sinensis. Bti, Bacillus thuringiensis israelensis.

Fig 6. ‘5-Step Mozzie Wipeout’ behaviour change communication materials.

Fig 7. Colour-coded community dengue alert system.

Fig 8. House inspections by NEA officers to identify Aedes habitats.

NEA, National Environment Agency.