8th Singapore International Dengue Workshop - Ms Grace Fu

Speech by Ms Grace Fu, Minister For Sustainability and the Environment and Minister-in-charge of Trade Relations, at the 8th Singapore International Dengue Workshop on 25 November 2024

Dr Rabindra Abeyasinghe, WHO Representative and Head of the WHO Country Office to Malaysia, Brunei Darussalam and Singapore,

Dr Raman Velayudhan, Unit Head, Veterinary Public Health, Vector Control and Environment Unit, Department of Control of Neglected Tropical Diseases, WHO Geneva,

Distinguished Guests,

Ladies and Gentlemen,

1 A very warm welcome to Singapore. I would like to thank the World Health Organization (WHO) for your continued partnership in delivering this important capacity-building initiative.

2 Since its inception in 2009, this workshop has trained over 500 public health practitioners from 53 countries in various aspects of dengue control, including surveillance, vector control and clinical management. This year, we have 55 participants from 24 countries, representing the WHO regions of the Western Pacific, South-East Asia, and the Eastern Mediterranean.

Introduction

3 Dengue and other mosquito-borne diseases have challenged many countries along the tropical and subtropical belt. Climate change, increasing urbanisation and global connectivity will cause the burden of these diseases to rise in the coming decades. The world needs to get ahead of the curve in fighting the diseases. And building capacity through international cooperation is vital. We are privileged to have this opportunity to contribute to such efforts through this workshop.

Bridging sectors for a dengue-free city

4 This year’s workshop is themed “Bridging Sectors for a Dengue-Free City,” and brings together clinicians, public health practitioners, city programme managers and municipal officials. Cities bear the brunt of dengue, due to their high-density living conditions. The risk is further driven by the availability of stagnant water in man-made infrastructure and containers, which the major dengue vector, Aedes aegypti, thrives in. Dengue control thus requires collective efforts from all stakeholders of cities at risk to reduce mosquito breeding opportunities. Even as we build capacity in public health and clinical management, we recognise that planning and maintenance of infrastructure for drainage, sanitation and waste management could go a long way towards reducing mosquito breeding in urban environment. The experiences of city programme managers and municipal officials in our midst will certainly enrich the intersectoral discussion at the workshop, and we look forward to exploring more ideas to “design out” dengue.

Successful cross-sector collaboration in Singapore

5 Preventing and controlling dengue is not new for Singapore. Since the 1960s, environmental management has played a role in controlling mosquito vectors and dengue in Singapore. This includes promoting cleanliness, improving waste management infrastructure and drainage systems, and provision of piped water. Close collaboration among the public sector, private sector and the community forms the backbone of the programme.

6 Our Inter-Agency Dengue Task Force, comprising multiple government agencies and private sector partners, has been instrumental in mounting a multisectoral response to dengue outbreaks. I would like to express my thanks to Task Force members, some of whom are here today. In addition to active management of your respective premises, your efforts to share best practices and address cross-sector issues has helped in our fight against dengue.

7 After six decades of continued efforts to prevent and control dengue, a person living in Singapore today is ten times less likely to acquire a first-time dengue infection compared to the 1960s. However, this also means that a large proportion of our population is dengue-naïve. This low population immunity, together with climatic conditions that are conducive for mosquito breeding and the continued presence of dengue viruses, leaves us still vulnerable to large outbreaks.

8 To enhance Singapore’s resilience against dengue, we continue to monitor developments on the dengue vaccine front, and to find innovative approaches to suppress the Aedes mosquito populations in the community.

Integration of Wolbachia suppression technology

9 The National Environment Agency (NEA) has been implementing Project Wolbachia, which involves the release of male Wolbachia-carrying Aedes aegypti mosquitoes to suppress urban dengue mosquito populations for ten years now.

10 The latest data available from our recently concluded multi-site field study indicates that residents of Wolbachia-Aedes release sites are about 75 percent less likely to be infected with dengue, thanks to an 80 to 90 percent reduction in the Aedes aegypti mosquito population. These findings are consistent with results from NEA’s earlier, smaller trials. We have also found that residents living in non-release sites adjacent to release sites were 45 percent less likely to contract dengue compared to those living in sectors with no releases. This spillover effects suggest that neighbouring communities stand to benefit from releases as well.

11 We could not have done these important studies without the support of residents and community partners. In community surveys, we have consistently found strong public support for the Wolbachia technology, with 96 percent of respondents agreeing with or remaining neutral towards releases in their area. We are grateful for the community’s continued support, without which Project Wolbachia could not have come this far.

12 The completion of the multi-site field study is a major milestone in the Wolbachia suppression technology. Insights from studies of mosquito behaviour now guide our deployment strategies, and the integration of automation into production and release operations has boosted our in-house capacity 40-fold compared to the manual processes we started with. This decade-long investment in R&D has been essential for NEA to learn how to deploy the technology effectively and efficiently, and forms a strong foundation for further scaling.

13 Currently, Project Wolbachia covers more than 520,000 households, with recent expansions to Hougang, Serangoon Central, and Serangoon North. The coverage will increase to 580,000 households in the first quarter of 2025 as we move into Jurong East and Jurong West.

14 In 2023 and 2024, the mid-year surge in dengue cases we were bracing for was largely subdued. This was despite a high baseline of dengue cases, low population immunity, and high mosquito numbers in some non-release areas. Wolbachia coverage, together with strong and sustained community vigilance against breeding, has likely helped to avert large outbreaks.

Wolbachia coverage of 50% of all households by 2026

15 Project Wolbachia represents a new chapter in Singapore’s fight against dengue. Moving forward, we will step up capacity at the two existing Wolbachia mosquito production facilities managed by NEA and Verily Life Sciences, and establish a third facility to ensure operational resilience. By 2026, Wolbachia releases will reach 800,000 households, or 50% of all households in Singapore, providing coverage to areas at risk of large dengue outbreaks.

16 NEA will go one step further and pilot the technology in areas with active, intense dengue transmission, to understand its utility in interrupting the development of large and long-lived clusters. Thus far, Wolbachia suppression technology has been used in Singapore to suppress and sustain low dengue mosquito populations to prevent dengue outbreaks. If effective, this new application of Wolbachia as a cluster management tool could complement traditional outbreak response operations.

17 Other programmes have had similar successes with other technologies such as the Wolbachia replacement approach and the sterile insect technique. We are very encouraged by the potential for such novel tools to complement the existing suite of dengue control measures. This workshop will thus feature experts who will share their experiences with these novel approaches.

18 Nonetheless, we remain acutely aware of the rising challenges posed by the growing burden of mosquito-borne diseases. Continued vigilance by all stakeholders against mosquito breeding must remain a key component of any dengue control programme.

Multisectoral, holistic approach

19 As dengue continues to test health systems and communities, the need for a multisectoral, holistic approach to dengue prevention and control has never been more critical. The wealth of experience and array of disciplines among our participants and experts offer all of us an invaluable opportunity to learn from one another and build connections, thus strengthening our collective resilience and shared commitment against dengue.

20 Thank you all for your attention and for the important work you do in your respective countries. Together, we can work towards healthier communities across borders. I wish you all a productive and inspiring workshop.

21 Thank you very much.