New facility will integrate innovative automated technologies to achieve scalability, to enable the National Environment Agency (NEA) to expand male mosquito releases for Project Wolbachia – Singapore to more neighbourhoods over the next few years

Singapore, 2 December 2019 – Climate change is anticipated to worsen the spread of mosquito-borne diseases like dengue. It facilitates the spread of mosquito vectors, viruses and epidemics. There is thus a need to continually innovate and design sustainable solutions to deal with these environmental public health challenges. Singapore’s National Environment Agency (NEA) has established a new, highly automated facility that will allow researchers to eventually increase their production capacity of Wolbachia-carrying Aedes aegypti mosquitoes by more than 10-fold, compared to its previous production facility. This boost in capacity is critical for NEA’s plans to scale up Project Wolbachia – Singapore, in preparation for future deployment of the novel vector control technology. The new facility, located at Techplace II in Ang Mo Kio, was officially opened on 2 December 2019 by Dr. Amy Khor, Senior Minister of State, Ministry of the Environment and Water Resources (MEWR).

Expanding Project Wolbachia ­– Singapore

2.         NEA’s Project Wolbachia – Singapore involves the release of male Wolbachia-Aedes aegypti mosquitoes to suppress the urban Aedes aegypti mosquito population. Aedes aegypti is the primary vector of dengue, chikungunya and Zika in Singapore. When the released male Wolbachia-Aedes aegypti mosquitoes mate with urban female Aedes aegypti mosquitoes that do not carry Wolbachia, the resulting eggs do not hatch. Over time, continued releases of male Wolbachia-Aedes aegypti mosquitoes are expected to bring about a gradual reduction in the urban Aedes aegypti mosquito population, and hence lower the risk of dengue transmission.

3.         Phase 3 of Project Wolbachia – Singapore, carried out from February to November 2019, achieved more than 90 per cent suppression of the urban Aedes aegypti mosquito population at the study sites, comprising 144 residential blocks at Tampines West and Nee Soon East. This is an improvement on the 70 to 80 per cent suppression achieved at the conclusion of the Phase 2 field study in January 2019, and demonstrates the effectiveness of Wolbachia-Aedes technology in Singapore’s high-rise and high-density urban landscape. Importantly, continued releases have kept the urban Aedes aegypti mosquito populations at both study sites at low levels, which thus pose low dengue risk.

4.         With the success of the Phase 3 field study, Project Wolbachia – Singapore progressed to a Phase 4 field study in November 2019, to determine if the Aedes aegypti mosquito population suppression can be sustained over larger areas. The Phase 4 field study covers 284 residential blocks at Tampines West and Nee Soon East. This is a seven-fold expansion compared to Phase 1 in 2016. The current Phase 4 field study will further expand in early 2020.

5.         NEA’s new facility will provide the scalability in production and release of Wolbachia-Aedes aegypti mosquitoes needed for the expansion and future field deployment for Project Wolbachia – Singapore. Associate Professor Ng Lee Ching, Director of NEA’s Environmental Health Institute, said, “The new facility has a target capacity of five million male Wolbachia-Aedes aegypti mosquitoes per week—a 10-fold increase over the previous facility. It is also equipped with a water recycling system, allowing the efficient and improved use of water.”

Incorporation of innovative technologies for scalability

6.         Together with partners such as Orinno Technology Pte. Ltd., Verily, and the Joint Food and Agricultural Origanization of the United Nations (FAO)/International Atomic Energy Agency (IAEA), NEA researchers have developed innovative solutions to implement Wolbachia-Aedes technology and scale up the Project. This entails the effective integration of multiple technical disciplines, including biotechnology, engineering, and data analytics.

7.         At the new facility, these solutions boost production capacity and increase productivity. Besides the automated larvae counter and pupae counter previously developed, new systems include a male-female pupae sorter. Many of these have been co-developed by NEA and Orinno Technology Pte. Ltd. Another automated sorting technology developed by Verily, with improved efficiency, will also be used. More devices, such as a high-throughput larvae rearing system designed by FAO/IAEA and Orinno, are in the pipeline to further improve scalability in the near future.

8.         NEA has also worked closely with FAO/IAEA to incorporate low-dose X-ray irradiation in the production workflow. This step serves to render infertile any small number female Wolbachia-Aedes aegypti mosquitoes that may be inadvertently released alongside the males. This additional step provides additional safeguard to prevent any build-up of female Wolbachia-Aedes mosquitoes, which would hamper the effectiveness of Wolbachia-Aedes mosquito releases for suppressing urban Aedes aegypti mosquitoes.

9.         “The impact of Project Wolbachia – Singapore goes beyond the realm of public health. The innovative solutions developed and collaborations formed through this important scientific initiative, have also advanced research and provided economic opportunities in Singapore”, said Dr. Amy Khor, Senior Minister of State, Ministry of the Environment and Water Resources, at the opening ceremony.

Building regional capacity to fight dengue

10.       The opening of the new facility coincided with the first day of the IAEA Regional Training Course (RTC) on Methods for the Mass Rearing, Irradiation and Release of Sterile Male Aedes Species. Co-organised and hosted by NEA’s Environmental Health Institute (EHI) at the new facility from 2 to 6 December 2019, the RTC involves 22 participants from 12 countries, who will be trained in the use of sterility-based approaches to suppress mosquito vector populations.

11.       “The Sterile Insect Technique and the Incompatible Insect Technique share many common components and challenges, and their combination has several advantages,” said Dr. Jérémy Bouyer, Medical Entomologist, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. He added, “This RTC is therefore an opportunity for the mutual exchange of ideas and knowledge sharing, which will help facilitate further collaboration, and will accelerate the development of novel technologies to tackle dengue, Zika, and other Aedes-borne diseases.”

12.       Mr. Tan Meng Dui, CEO of NEA, added, “This facility serves multiple functions. Besides providing us with the scalability we need to expand male Wolbachia-Aedes mosquito releases, it also serves as an incubator and test bed for innovative solutions, and provides a space for learning and mutual exchange of ideas”. 

 

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ANNEX A

NEW NEA MOSQUITO PRODUCTION FACILITY AND PHASE 4 FIELD STUDY

• The National Environment Agency (NEA) has established a new Wolbachia-Aedes mosquito production facility at Techplace II, Ang Mo Kio. The new facility, which replaces the former facility at Neythal Road, has been fully operational since September 2019.

• About 50 researchers from NEA’s Environmental Health Institute (EHI) are working at the facility and field study sites, to prepare for and carry out the Phase 4 field study. The Phase 4 field study entails a nearly two-fold expansion in release area size compared to in Phase 3, and an about seven-fold expansion compared to in Phase 1. It aims to determine how to sustain suppression of the dengue-transmitting Aedes aegypti mosquito population at the release sites.
  

Community engagement and Project Wolbachia Learning Journey

• Since 2012, NEA has consulted with and engaged local academia, medical and healthcare professionals, teachers and students, Non-Governmental Organisations (NGOs), Grassroots Leaders (GRLs) and members of the public, on the potential of Wolbachia technology in Singapore, through more than 100 seminars and outreach events.
• NEA continues to actively engage the community, and the public is welcome to visit our mosquito production facility.
• To-date more than 1,000 visitors, including residents from the study sites as well as other stakeholder groups (e.g. teachers and students, residents and GRLs from the study sites, Dengue Prevention Volunteers, media personnel, scientists and researchers, staff of private companies, and international visitors and experts) have visited NEA’s mosquito production facility at Neythal Road, as part of the Project Wolbachia Learning Journey. Learning Journeys will continue to be held at the new Techplace Facility.
• The Project Wolbachia Learning Journey brings visitors through the various processes involved in the production of Wolbachia-Aedes aegypti mosquitoes, and the behind-the-scenes scientific work carried out by EHI researchers. Visitors have the opportunity to see how fit and competitive mosquitoes are reared; how male and female mosquitoes are separated; and how innovative engineering solutions are developed to increase productivity and ensure quality of mosquitoes.

• For members of the public who would like to visit NEA’s mosquito production facility, please contact us at Project_Wolbachia@nea.gov.sg. Please note that scheduled slots are limited.

Information on Project Wolbachia Learning Journey

How are Wolbachia-Aedes aegypti mosquitoes produced?

• Visitors will learn how NEA researchers rear the Wolbachia-Aedes aegypti mosquitoes from eggs to adults. Optimal conditions, including temperature, space, and food, are necessary for laboratory-bred mosquitoes to be as fit and competitive as urban Aedes aegypti mosquitoes. 

Process	Highlights
Mass rearing and egg production	Matings between male Wolbachia-Aedes aegypti mosquitoes and female urban Aedes aegypti mosquitoes (which do not carry Wolbachia) result in eggs that do not hatch. Matings between male Wolbachia-Aedes aegypti mosquitoes and female Wolbachia-Aedes aegypti mosquitoes result in offspring with Wolbachia that will hatch. Blood feeding and egg production. Fig. 1 Mass rearing of adult mosquitoes in cages
Larvae rearing	Optimal number of larvae (4,000) is introduced into a tray of water using an in-house developed Larvae Counter. The latest version is 40 times faster than manual counting. Larvae are fed fish food. A Multi-layer Automated Feeding System is being tested, which will automatically deliver a fixed amount of feed into multiple rearing trays simultaneously. Use of High-density Rearing Racks saves space and time for water dispensing (20 times faster) and pupae harvesting (40 times faster). Water Recycling System enables wastewater recovery rate of 50 to 70%. Fig. 2 Aedes aegypti mosquito eggs and larvae
Pupae sorting	Male Wolbachia-Aedes aegypti mosquitoes that do not bite are released. A Male-Female Pupae Sorter that is 10 to 20 times faster than the Fay-Morlan method has been developed, to sort male Wolbachia-Aedes aegypti pupae (which are smaller in size) from female pupae. After sorting, a Pupae Counting and Dispensing Moduleaccurately counts and dispenses a fixed number of male Wolbachia-Aedes aegypti pupae into each release container.
X-ray treatment	This step serves to render infertile any Wolbachia-Aedes aegypti females that may be inadvertently released alongside the males. This additional step will prevent any build-up of female Wolbachia-Aedes mosquitoes that would hamper the effectiveness of Wolbachia-Aedes mosquito releases for suppressing urban Aedes aegypti mosquitoes.
Adult emergence and release	The irradiated pupae are packed into containers for release in the field. Each container holds about 150 male Wolbachia-Aedes aegypti mosquitoes. The in-house-developed Mosquito Launcher is a lightweight and portable device that allows field officers to carry and release more mosquitoes in a single trip.
Competitiveness and longevity tests	Large cages in the Field Cage Room are used to simulate field conditions, for studies of mosquito mating competitiveness and longevity.
Quality control	Audit checks are conducted, to ensure that male Wolbachia-Aedes aegypti mosquitoes to be released carry Wolbachia.

 

ANNEX B

INNOVATIVE SOLUTIONS FOR MOSQUITO PRODUCTION

Despite advances in engineering and artificial intelligence, few technological solutions exist for mosquito rearing, a laborious and time-consuming process. The National Environment Agency’s (NEA’s) Environmental Health Institute (EHI) is thus collaborating with Orinno Technology Pte. Ltd. (OTPL, a local start-up company) and the International Atomic Energy Agency (IAEA) to develop process modules and novel devices that will improve production efficiency and quality of Wolbachia-Aedes aegypti mosquitoes.

The male-female pupae sorter, which is 10 to 20 times faster than the current Fay-Morlan method, has recently been incorporated into the workflow. This new sorter has a specially designed sieve, lighting and water-flow control, to achieve high accuracy and high-efficiency separation of male pupae, female pupae and larvae. 

The larvae counter has shortened the time required to fill a tray with 4,000 larvae, from two hours to less than three minutes. The pupae counting and dispensing module—an automated device which accurately counts and dispenses the desired number of male Wolbachia-Aedes aegypti pupae into each release container—uses a similar engineering concept.

Field officers use the mosquito launcher, a lightweight and portable release device, to efficiently and systematically store, transfer and release male Wolbachia-Aedes aegypti mosquitoes at Singapore’s high-rise residential blocks.

Other devices under development include an automated feeding system and high-density rearing racks, which will help save on manpower and costs. The newly acquired high density-rearing racks from our collaborators OTPL and IAEA, will be fully operational by 2021. The racks save space and time for water dispensing (20 times faster) and pupae harvesting (40 times faster). 

As a result of these creative solutions, five intellectual property patents have been filed for these novel devices. These devices are also of interest to other international programmes that mass produce mosquitoes.             

Devices developed/ being developed

S/N	Innovation	Brief Description
1	Larvae counter	Larvae purification and counting system based on light and micro-fluid control 40 times faster than manual counting methods
2	Pupae counting and dispensing module [1]	Pupaecounting and concentration system based on light and fluid control 15 times faster than manual counting methods
3	Automated feeding system	Multi-layer larvae feeder, designed to automatically deliver a fixed amount of feed into multiple rearing trays simultaneously
4	Pupae male-female sorter	Incorporates specially designed sieve and automated separation of male pupae, female pupae and larvae
5	Mosquito launcher	Mosquito release mechanism, which combines knowledge of mosquito behaviour with microelectronics and mechanical engineering Lightweight and portable, allowing field operators to carry more mosquitoes in a single trip
6	High density rearing rack	40- and 60-tray compact rearing racks, from collaborators OTPL and IAEA Saves space and time for water dispensing (20 times faster) and pupae harvesting (40 times faster)
7	Water recycling system	Enables wastewater recovery rate of 50 to 70%